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1
Ivy, Joshua F. "Optoelectronically Active Metal-Inorganic Frameworks and Supramolecular Extended Solids." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1248495/.
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Metal-organic frameworks (MOFs) have been intensely researched over the past 20 years. In this dissertation, metal-inorganic frameworks (MIFs), a new class of porous and nonporous materials using inorganic complexes as linkers, in lieu of traditional organic linkers in MOFs is reported. Besides novel MIF regimes, the previously described fluorous MOF "FMOF-1", is re-categorized herein as "F-MIF1". F-MIF-1 is comprised of [Ag4Tz6]2- (Tz = 3,5-bis-trifluoromethyl-1,2,4-triazolate) inorganic clusters connected by 3-coordinate Ag+ metal centers. Chapter 2 describes isosteric heat of adsorption studies of F-MIF1 for CO2 at near ambient temperatures, suggesting promise for carbon capture and storage. We then successfully exchanged some of these Ag(I) centers with Au(I) to form an isostructural Au/F-MIF1. Other, nonporous MIFs have been synthesized using Ag2Tz2 clusters with bridging diamine linkers 4,4'-bipyridine, pyrazine, and a Pt(II) complex containing two oppositely-situated non-coordinating pyridines. This strategy attained luminescent products better-positioned for photonic devices than porous materials due to greater exciton density.
Chapter 3 overviews work using an entirely inorganic luminescent complex, [Pt2(P2O5)4]4- (a.k.a. "PtPOP") to form new carbon-free MIFs. PtPOP is highly luminescent in solution, but as a solid shows poor quantum yield (QY ~0.02) and poor stability under ambient conditions. By complexing PtPOP to various metals, we have shown a dramatic enhancement in its solid-state luminescence (by an order of magnitude) and stability (from day to year scale). One embodiment (MIF-1) demonstrates microporous character.
Chapter 4 overviews the design and application of new MIF linkers. Pt complexes based upon (pyridyl)azolates, functionalized with carboxylic acid groups, have been synthesized. These complexes, and their esterized precursors, show strong luminescence on their own. They have been used to generate new luminescent MIFs. Such new MIFs may be useful toward future inorganic (LEDs) or organic (OLEDs) light-emitting diodes, respectively. The electronic communication along their infinite coordination structures is desirable for color tuning and enhanced conductivity functions, compared to the small molecules used in such technologies, which rely on intermolecular interactions for these functions.
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Carson, Cantwell G. "Noble and transition metal aromatic frameworks synthesis, properties, and stability /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29657.
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Thesis (Ph. D.)--Materials Science and Engineering, Georgia Institute of Technology, 2009.Committee Chair: Rina Tannenbaum; Committee Co-Chair: Rosario A. Gerhardt; Committee Member: E. Kent Barefield; Committee Member: Karl I. Jacob; Committee Member: Preet Singh; Committee Member: R. Bruce King. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Planchais, Arnaud. "Etude des performances de matériaux hybrides MOFs pour le captage de COVs." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20228.
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Ce travail est une contribution à la compréhension des performances de matériaux hybrides poreux de type MOFs pour le captage de benzène, dans le cadre de la lutte contre les émissions de Composés Organiques Volatils (COVs) à partir de procédés basés sur l'adsorption d'effluents gazeux. Dans ce but, nous avons couplé diverses techniques expérimentales (spectroscopie d'impédance complexe, diffraction des rayons X, manométrie d'adsorption, …) à des simulations moléculaires (calculs basés sur la Théorie de la Fonctionnelle de la Densité, Monte Carlo ou Dynamique Moléculaire) pour étudier ces matériaux en termes de capacité et de mécanisme d'adsorption. Différentes familles de MOFs ont été sélectionnées afin d'analyser l'impact de diverses caractéristiques de ces matériaux, comme la flexibilité du réseau, la présence de cations extra-réseau et la nature chimique des ligands organiques, sur leurs propriétés d'adsorption de benzène. Par ailleurs, l'eau étant souvent considérée comme un facteur limitant lors de l'adsorption sélective d'une espèce à partir d'effluents gazeux chargés d'humidité, nous avons également envisagé l'étude de cet adsorbat seul, avant d'explorer la co-adsorption de mélanges benzène/eau dans des proportions différentes. Une rationalisation des données nous a permis de conclure que certains des matériaux explorés présentent une sélectivité benzène/eau intéressante pour envisager leur utilisation potentielle dans le cadre du captage de tracesThe Metal Organic Frameworks (MOFs), a recent class of hybrid porous solids, appears as valuable candidates for various applications related to their sorption abilities. The optimization of their performances requires a control of the parameters that govern the adsorption process, including the confined species/MOF interactions and the synergic dynamics of the system. In this context, experimental tools (Complex Impedance Spectroscopy, X Ray Diffraction, volumetric adsorption…) were combined with molecular simulations (Density Functional Theory, Monte Carlo and Molecular Dynamics calculations) to explore the benzene adsorption of MOFs in terms of capacity and microscopic mechanism. Different series of MOFs were selected to address the impact of various features, including the lattice flexibility, the presence of extra-framework cations and the ligand functionalization, on their adsorption performances. Benzene and water were considered as adsorbents separately, before exploring the co-adsorption of various benzene/water mixtures. The rationalization of the data allowed us to understand why some of the selected solids, showing interesting benzene/water selectivity, are likely to be used for the capture of benzene traces in humid conditions
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Li, Dongfang. "Copper-based Metal-Organic-Framework for Electrochemical Carbon Dioxide Reduction." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29915.
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Copper has generated variable studies and applications in electrochemical CO2 reduction reaction (CO2RR) due to its difference in product diversity compared with other transition metals. Metal-Organic Frameworks (MOFs) as high-porosity structures have huge potential in many fields, such as energy storage and conversion, UiO-67 is widely used, especially in scenarios where thermal stability and alkaline environments are required. Here this project will induct Cu@UiO-67 and Cu@UiO-bpy could be electrochemical catalysts for CO2RR under alkaline conditions. It investigated the factor of reacting with different copper sources and their reaction durations, and the components of these two-catalyst ink were considered as variables to be studied. Post-synthesis method was employed to construct the guest-encapsulated MOF structure. At the optimum mass ratio of Cu@UiO-67/Cu@UiO-bpy: carbon black 4:1 the Faradaic efficiency of C2+ products were 53.35% and 65.12%, respectively, which was achieved under a large current density of 500 mA/cm2 in the flow cell.
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He, Xiang. "Metal-Organic Framework (MOF)-Based Materials: Aerosol Synthesis and Photocatalytic Applications." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/5736.
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Metal-organic frameworks (MOFs) have been attracting great attention in the past several decades mainly because of their amazing properties, including tunable surface chemistry, flexible structure, large surface area, and huge porosity. Endorsed by those merits, MOFs have been applied in a wide range of applications, such as catalysis, gas separation, drug delivery, and sensing. Typically, MOFs are synthesized via the hydrothermal method, which, however, is difficult to scale up and requires long reaction durations (e.g., from hours to days). To achieve the full potentials of MOFs, the exploration of a novel strategy is necessary for the facile and fast synthesis of MOFs. Here in this dissertation, the aerosol route was presented as a facile route to synthesize MOFs and MOF-based composites. The aerosol route not only enabled fast crystallization of MOFs (i.e., within seconds), but also allowed continuous tuning of MOF’s properties by simply adjusting the operating parameters (e.g., temperature, pressure, and precursor conditions). To map out the formation mechanism of MOFs inside the microdroplets, systematic experimental and simulation work were carried out, which demonstrated that the fast heat and mass transfer during the aerosol route played a vital role in the rapid synthesis of MOFs.
Beyond the synthesis of MOFs, the photocatalytic applications of MOF-based materials for energy and environmental sustainability were also studied in detail. More specifically, several efficient MOF-based composite photocatalysts were designed, including HKUST-1/TiO2, HKUST-1/TiO2/Cu2O, ZIF-8/ZnO, and MIL-100(Fe)/TiO2. The composite photocatalysts exhibited remarkable efficiencies towards either CO2 photoreduction or water remediation. In-depth exploration of the photocatalytic mechanism was carried out with the aid of several advanced techniques, such as in situ diffuse reflectance infrared Fourier spectroscopy (DRIFTS), photoluminescence spectroscopy, grazing-incidence wide-angle X-ray scattering, and ultrafast transient absorption spectroscopy. Meanwhile, the density functional theory (DFT) calculation was also applied to provide further mechanistic insights. The results demonstrated that MOFs acted as excellent co-catalysts, which not only facilitated molecule adsorption and activation, but also promoted the separation of the photo-induced charge carriers, leading to increased charge carrier densities in the photocatalytic systems for significantly enhanced efficiencies.
The work from this dissertation is expected to broaden the synthesis strategies for the synthesis of MOF-based materials and advance the fundamental understanding of MOFs’ roles in photocatalytic applications, which should have a great impact on the rational design of MOF-based composite photocatalysts for energy and environmental sustainability.
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Springer, Sarah E. "Halide Directed Synthesis of Indium Derived Metal-Organic Frameworks." Youngstown State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1534804224484578.
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Li, Fuping. "Metal-Organic Framework (MOF) derived Catalysts for Efficient Syngas Conversion to Oxygenates." Thesis, Curtin University, 2020. http://hdl.handle.net/20.500.11937/81972.
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The direct synthesis of organic oxygenates from syngas has been widely reported during the past decade. Metal-organic frameworks (MOFs) have been considered as promising materials for their applications in the catalysis fields owing to the tunable porous structures and good configuration of active sites. In this project, Cu-, Zr- and Co-based MOF were applied as the platform to update these conventional catalysts with better performance for dimethyl ether and higher alcohols synthesis from syngas.
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Schneemann, Andreas, Volodymyr Bon, Inke Schwedler, Irena Senkovska, Stefan Kaskel, and Roland A. Fischer. "Flexible metal–organic frameworks." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-149990.
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Advances in flexible and functional metal–organic frameworks (MOFs), also called soft porous crystals, are reviewed by covering the literature of the five years period 2009–2013 with reference to the early pertinent work since the late 1990s. Flexible MOFs combine the crystalline order of the underlying coordination network with cooperative structural transformability. These materials can respond to physical and chemical stimuli of various kinds in a tunable fashion by molecular design, which does not exist for other known solid-state materials. Among the fascinating properties are so-called breathing and swelling phenomena as a function of host–guest interactions. Phase transitions are triggered by guest adsorption/desorption, photochemical, thermal, and mechanical stimuli. Other important flexible properties of MOFs, such as linker rotation and sub-net sliding, which are not necessarily accompanied by crystallographic phase transitions, are briefly mentioned as well. Emphasis is given on reviewing the recent progress in application of in situ characterization techniques and the results of theoretical approaches to characterize and understand the breathing mechanisms and phase transitions. The flexible MOF systems, which are discussed, are categorized by the type of metal-nodes involved and how their coordination chemistry with the linker molecules controls the framework dynamics. Aspects of tailoring the flexible and responsive properties by the mixed component solid-solution concept are included, and as well examples of possible applications of flexible metal–organic frameworks for separation, catalysis, sensing, and biomedicine.
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Mohd, Kamal Azhari Nurul Khaliesah. "Development of metal-organic framework carbon composites for carbon dioxide and methane separation." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2020. http://www.theses.fr/2020IMTA0201.
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Le dioxyde de carbone (CO2), principal contaminant des gaz naturels bruts et du biogaz doit être extrait en vue d’un enrichissement en méthane (CH4) compatible avec les spécifications d’injection en réseaux de gaz naturel. Au cours des dernières années, une famille de matériaux poreux de type réseaux organométalliques à base de magnésium (Mg-MOF-74) a ouvert une nouvelle perspective à cet effet en raison d’une excellente affinité des sites métalliques exposés au sein de la structure cristalline pour l’adsorption du CO2. Ce matériau est un adsorbant potentiellement bon candidat pour l’enrichissement en CH4 de gaz naturel et de biogaz par des procédés opérant en modulation de pression. La présente étude propose d’examiner l’amélioration des performances d'adsorption du CO2 en mélange avec le CH4 par dopage du matériau Mg-MOF-74 avec des nanotubes de carbone et de l'oxyde de graphène. L'objectif est d'améliorer les propriétés texturales pour favoriser la diffusion des molécules des gaz dans les micropores et leur accessibilité aux sites d'adsorption. Les matériaux ont été synthétisés sous réaction solvothermique et caractérisés par DRX, IRTF, MEB, ATG et physisorption d’azote à 77K. Les équilibres et énergies d'adsorption ont été mesurées suivant une méthode manométrique dans une gamme de pression allant jusqu'à 35 bar et à 25°C, 50°C et 75°C. La cinétique de sorption a été étudiée à partir d’expériences de manométrie et de la méthode dite « Zero Length Column » à 25°C, 50°C et 75°C. A une teneur optimisée à 0,3% en masse d’agent dopant, le modèle de Brunauer–Emmett–Teller montre que la surface spécifique des matériaux dopés est augmentée de plus de 21% par rapport à celle du matériau non-dopé. Les données d'équilibre indiquent que la capacité d’adsorption en CO2 est sensiblement améliorée pour les matériaux dopés dans toute la gamme opératoire étudiée, tandis qu’ils démontrent une sélectivité comparable ou améliorée, dépendante de la températureCarbon dioxide (CO2), which is the major contaminant present in raw natural gas and biogas need to be extracted to increase their methane (CH4) content and match the standards of pipeline injection. In recent years, a family of porous materials, magnesium-based Metal Organic Framework (Mg-MOF-74), has opened new perspectives for this purpose thanks to strong adsorption affinity of CO2 with exposed metallic sites in the crystalline network. This material is a potential good adsorbent candidate for the enrichment in CH4 of natural gas and biogas by Pressure Swing Adsorption processes. The present study proposes to examine the CO2 adsorption performances and separation ability from CH4 of Mg-MOF-74 materials doped with carbon nanotubes and graphene oxide. The objective is to improve the texture of the materials to promote the diffusion of gas molecules into micropores and their accessibility to adsorption sites. The materials were synthesized under solvothermal reaction and characterized by PXRD, FTIR, FESEM, TGA and physisorption of nitrogen at 77K. The adsorption equilibria and energies were measured using manometric method in a pressure range up to 35 bar and at 25°C, 50°C and 75°C. The sorption kinetics of CO2 and CH4 on the materials were studied from manometric experiments and using the Zero Length Column method at 25°C, 50°C and 75°C. At an optimized content of the doping agents of 0.3 wt%, Brunauer–Emmett–Teller model shows that the specific surface area is increased for both composites, by more than 21% compared to the pristine material. The equilibrium data indicates that the CO2 adsorption capacity is significantly improved in the whole range of operating conditions for both composites compared to the pristine material, whereas the CO2/CH4 adsorption selectivity appears either comparable or better as a function of temperature
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Taksande, Kiran. "Exploration of the Ionic Conduction Properties of Porous MOF Materials." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONS010.
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Ce travail a pour objectif l’étude de matériaux hybrides poreux de type Metal-Organic Frameworks (MOFs) et d’un cristal moléculaire en tant que conducteurs ioniques solides pour des applications dans le domaine de l’énergie et de l’environnement. Dans le premier cas, nous avons développé diverses stratégies pour optimiser et contrôler la teneur en sites acides de Lewis et en porteurs de charges de deux séries de MOFs afin de concevoir des matériaux aux propriétés de conduction protonique très prometteuses. A partir d’une approche basée sur la substitution progressive des ligands par des entités fonctionnalisées présentant des sources de protons acides, nous avons créé une série de MOFs, MIP-207-(SO3H-IPA)x-(BTC)1–x, dont la teneur en groupements sulfoniques, par l’intermédiaire du ligand SO3H-IPA, est contrôlée à façon. Le meilleur matériau qui combine stabilité structurale et conduction protonique élevée présente des performances sous humidité parmi les plus intéressantes au sein de la famille des MOFs conducteurs protoniques (e.g., σ = 2.6 × 10–2 S cm–1 à 363 K/95% d’humidité relative (RH)). Selon une autre approche, nous avons étudié un MOF mésoporeux connu (MIL-101(Cr)-SO3H) dont les parois des pores sont tapissées de sites protoniques et qui contient dans ses pores un liquide ionique, le chlorure chlorure de 1-Ethyl-3-methylimidazolium (EMIMCl) capable d’assurer le transfert de proton. L’encapsulation du liquide ionique, caractérisée par une série d’outils expérimentaux (sorption de diazote, DRX sur poudre, TGA/MS, DSC et analyse élémentaire), s’avère particulièrement efficace pour exalter les propriétés de conduction protonique des composites à la fois à l’état anhydre (σ473 K = 1.5 × 10-3 S cm-1) mais également à l’état hydraté (σ(343 K/60%-80%RH) ≥ 0.10 S cm-1). Enfin, ce travail a été étendu à une autre famille de solides poreux, à travers l’étude des propriétés de conduction ionique d’un cristal moléculaire à base de zirconium (Zr-3) qui contient des paires ioniques KCl. Nous avons démontré que ZF-3 transite d’un comportement isolant à l’état anhydre (σ = 5.1 x 10-10 S cm-1 à 363 K/0% RH) vers un comportement super-conducteur ionique en présence d’eau (σ = 5.2 x 10-2 S cm-1 à 363 K/95 % RH), suite à l’augmentation de la dynamique de ions Cl- sous hydratation. Par ailleurs, des simulations moléculaires ont permis de décrire les mécanismes microscopiques à l’origine des propriétés de conduction des matériaux étudiés. Ces avancées devraient permettre de développer dans le futur de nouveaux matériaux performants dans le domaine de la conduction protonique et ioniqueThe conductivity performance of a new series of chemically stable proton conducting Metal Organic Frameworks (MOFs) as well as a superionic molecular crystal was explored. The contribution of this PhD was to (i) select a variety of architectures and functionalities of robust MOFs/superionic molecular solids and (ii) characterize and rationalize their conducting performance over various temperature/humidity conditions. We designed two series of MOFs to achieve promising proton-conducting performance, using distinct approaches to modulate the concentration of Brønsted acidic sites and charge carriers and further boost the conductivity properties. First, a multicomponent ligand replacement strategy was successfully employed to elaborate a series of multivariate sulfonic-based solids MIP-207-(SO3H-IPA)x-(BTC)1–x which combine structural integrity with high proton conductivity values (e.g., σ = 2.6 × 10–2 S cm–1 at 363 K/95% Relative Humidity -RH-). Secondly, a proton conducting composite was prepared through the impregnation of an ionic liquid (1-Ethyl-3-methylimidazolium chloride, EMIMCl) in the mesoporous MIL-101(Cr)-SO3H. The resulting composite displaying high thermal and chemical stability, exhibits outstanding proton conductivity not only at the anhydrous state (σ473 K = 1.5 × 10-3 S cm-1) but also under humidity (σ(343 K/60%-80%RH) ≥ 0.10 S cm-1) conditions. Finally, the ionic conducting properties of another class of porous solids, considering a zirconium-formate molecular solid containing KCl ion pairs (ZF-3) were explored. ZF-3 switches from an insulator (σ = 5.1 x 10-10 S cm-1 at 363 K/0% RH) to a superionic conductor upon hydration (σ = 5.2 x 10-2 S cm-1 at 363 K/95 % RH), in relation with the boost of Cl- dynamics upon water adsorption. Noteworthy, quantum- and force-field based simulations were combined with the experimental approach to elucidate the microscopic mechanisms at the origin of the ionic conducting properties of the studied materials. This fundamental knowledge will serve to create novel robust superionic conductors with outstanding performances that will pave the way towards appealing societal applications for clean energy production
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Renouf, Catherine Louise. "Coordinatively unsaturated metal organic frameworks for olefin separations." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3686.
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The research presented in this thesis aims to assess the capacity of metal organic frameworks with open metal sites for the separation of olefin mixtures. Chapter 1 provides a background to the field, including industrial separation techniques, metal organic frameworks and their applications and the current state-of-the- art for olefin separation. Chapter 3 describes the experimental techniques used in this research. Ethylene and propylene adsorption and desorption isotherms on Ni-CPO-27 and HKUST-1 at a range of temperatures are presented and compared in Chapter 4, and used to calculate isosteric heats of adsorption at varying coverages using the virial method. These pure component isotherms are used in Chapter 5 to predict selectivities for the separation of binary mixtures using ideal adsorbed solution theory. Temperature programmed desorption is used in Chapter 5 to calculate the enthalpy of desorption using Redhead's method and the heating rate variation method, and the two results are compared. The results presented in Chapters 4 and 5 conclude that propylene/ethylene separation is possible using adsorption onto metal organic frameworks with open metal sites. A new in situ environmental gas cell for single crystal X-ray diffraction is developed in Chapter 6, and the challenges encountered during this development process are discussed. The dehydration of one framework, Co-CPO-27, is studied in detail using the environmental gas cell. A dehydrated structure of HKUST-1, obtained using the gas cell, is presented for the first time. Crystal structures for the complete dehydration-adsorption-delivery cycle for biologically active NO on Co-CPO-27 are presented in Chapter 7, showing the utility of the in situ gas cell for prolonged experiments in multiple different gaseous environments. The crystal structure of NO-loaded Co-CPO-27 improves upon the models suggested in the literature, and the treatment of the dual occupancy of the open metal sites by water and NO is discussed in depth. A crystal structure of CO-loaded Co-CPO-27 is obtained for the first time, and crystal structures of Co-CPO-27 in ethylene and propylene environments are presented.
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Stults, Katrina A. "Metal-organic framework-metal oxide composites for toxic gas adsorption and sensing." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51836.
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Metal organic frameworks (MOFs) and metal oxide-MOF composites were investigated for adsorption and oxidation of carbon monoxide. Metal oxides were successfully included in MOFs via both impregnation and encapsulation. UiO-66, a zirconium-based MOF, was impregnated with magnesium or cobalt oxide. Cobalt oxide in UiO-66 increases the room temperature CO capacity and shows increased adsorption at 65°C due to strong cobalt-CO interactions. Titania and magnetic nanoparticles were encapsulated in HKUST-1, a copper-based MOF. Including titania in HKUST-1 lowers the CO oxidation onset temperature by over 100°C compared with HKUST-1, and the composite reaches complete conversion by 250°C. HKUST-1 with magnetic nanoparticles shows enhanced structural stability and increased room temperature adsorption of CO and hexane. MOF-74, an isostructural family with coordinatively unsaturated metal centers of cobalt, magnesium, nickel, or zinc, was investigated for the metal center’s impact on stability and adsorption. Pre-treatment conditions to optimize accessibility were found that maximize solvent removal while retaining structural integrity. The impact of air exposure on equilibrium CO capacity was investigated, and these predictions were compared to dynamic conditions, separating CO from nitrogen or air at room temperature. The cobalt analog loses only 25% of its CO capacity with air exposure, retaining higher capacity than the other analogs under ideal conditions. Unlike cobalt, the magnesium analog does not follow the predicted trends with air exposure, having higher dynamic capacities with pre-exposed samples. Under all dynamic conditions, the nickel analog oxidized a portion of the carbon monoxide feed.
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Bhaskar, A. "Design and synthesis of metal organic framework (MOF) - polymer composite membranes for gas separation." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2015. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2063.
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Beltrán-Suito, Rodrigo, Angela Pinedo-Flores, Fabiola Bravo-Hualpa, Jorge Ramos-Muñoz, and María del Rosario Sun-Kou. "Adsorption of N,N-dimethylamine from aqueous solutions by a metal organic framework, MOF – 235." Taylor and Francis Inc, 2018. http://hdl.handle.net/10757/624712.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.Water-resistant MOF-235 was used to adsorb N,N-dimethylamine (DMA) from aqueous solutions. It was synthesized from terephthalic acid and FeCl3.6H2O under air-free conditions and characterized by its crystalline structure, functional groups and temperature resistance. The kinetic data results were best adjusted to the pseudo-second order model (R2>0.963). The best-fit isotherm, Langmuir model, suggested the adsorption of DMA is localized on homogenously distributed active sites on the surface. This fit was confirmed by the value of β = 1 on the Redlich-Peterson model. Our study suggests that the manipulation of novel materials such as MOF-235 promises new avenues for water treatment solutions. Schematic structure of MOF-235 and its application as adsorbent.
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Combelles, Cécil. "Modélisation ab-initio Appliquée à la Conception de Nouvelles Batteries Li-Ion." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2009. http://tel.archives-ouvertes.fr/tel-00421182.
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Pour améliorer les performances des batteries au lithium, des ruptures technologiques sont nécessaires. Ceci impose que les aspects fondamentaux liés au fonctionnement de ces dispositifs électroniques soient reconsidérés. Dans cette optique, les méthodes de la chimie quantique peuvent apporter une aide précieuse, notamment pour comprendre les phénomènes électroniques microscopiques, à l'origine du stockage de l'énergie. Établir une relation directe entre la nature de la liaison chimique (microscopique) et les propriétés physico-chimiques (macroscopiques) des matériaux d'électrode pour batteries Li-Ion est donc l'objectif dans lequel s'inscrivent les travaux exposés dans cette thèse. Ce travail explore à la fois des aspects méthodologiques et des applications. Il vise à proposer des méthodologies d'analyse simples permettant de traiter les réactions électrochimiques d'un point de vue théorique et de déterminer les mécanismes microscopiques mis en jeu au cours des cycles de charge et de décharge des batteries. Les systèmes étudiés sont les composés d'insertion du graphite (Li-GICs) et un matériau hybride de type MOFs (« Metal Organic Framework ») basé sur l'ion ferrique (MIL-53(Fe)). Pour les Li-GICs, une nouvelle méthode couplant des calculs premiers principes DFT à un modèle statistique dérivé du modèle de Bethe-Peierls a été développée pour rendre compte des effets d'entropie (de configuration) dans leur diagramme de phase. Les résultats obtenus apportent un nouveau regard sur les processus électrochimiques induits par le lithium, ouvrant des perspectives technologiques intéressantes pour remédier aux problèmes de sécurité posés par ce type d'électrode. Pour le MIL-53(Fe), la méthode DFT+U a été utilisée pour rendre compte des effets de corrélation électronique et pour reproduire l'état fondamental complexe de ce système. Les résultats obtenus ont permis de comprendre l'origine de la faible capacité de ce matériau vis-`a-vis du lithium.
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Grünker, Ronny, Volodymyr Bon, Philipp Müller, Ulrich Stoeck, Simon Krause, Uwe Mueller, Irena Senkovska, and Stefan Kaskel. "A new metal–organic framework with ultra-high surface area." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-149154.
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A new mesoporous MOF, Zn4O(bpdc)(btctb)4/3 (DUT-32), containing linear ditopic (bpdc2−; 4,4′-biphenylenedicarboxylic acid) and tritopic (btctb3−; 4,4′,4′′-[benzene-1,3,5-triyltris(carbonylimino)]tris-benzoate) linkers, was synthesised. The highly porous solid has a total pore volume of 3.16 cm3 g−1 and a specific BET surface area of 6411 m2 g−1, adding this compound to the top ten porous materials with the highest BET surface area.
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Boulhout, Mohammed. "Etude de l'adsorption de composés organiques sur des matériaux poreux de type Metal Organic Framework (MOF)." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4824/document.
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Afin de répondre aux demandes des industriels de nouveaux matériaux poreux sont testés pour de nouvelles applications ou pour améliorer les procédés existants. Les adsorbants de types Metal Organic Frameworks(MOFs) ont des structures construites à partir d'unités inorganiques reliées entre elles par des ligands organiques. La possibilité de varier ces deux entités, offre une grande diversité de structures avec des cavités de tailles contrôlées. L'objectif de cette thèse a été d'évaluer les performances des MOFs pour l'adsorption de composés organiques et de comprendre les mécanismes d'adsorption. Les deux problématiques sélectionnées sont d'intérêt pour l'industrie pétrochimique. La séparation du para-xylène des autres isomères du xylène et de l'éthylbenzene, permets de répondre à la demande de matière première pour la synthèse du polytéréphtalate d'éthylène. L'adsorption des composés azotés et soufrés (teneur fixée par des législations), permets la purification de carburants. Notre étude thermodynamique est basée sur la réalisation d'isothermes d'adsorption et la détermination d'enthalpies d'adsorption par microcalorimétrie en phase liquide. L'adsorption des vapeurs des xylènes purs a été étudiée pour comprendre l'effet du solvant. Une grande variété de comportement a été observée selon les structures des MOFs. Nous avons par exemple mis en évidence l'effet de l'empilement moléculaire des isomères du xylène sur la sélectivité des MOFs. Nous avons démontré que la flexibilité des MOFs intervient sur les interactions au cours de l'adsorption des xylènes. Nous avons mis en évidence une sélectivité des MOFs possédant un centre métallique insaturé en faveur des composés azotésIn order to meet the industrials requirements, new porous materials are tested for new applications or to improve existing processes. The Metal Organic Frameworks (MOFs) are hybrids crystalline compounds made up of clusters (or chains) of metal ions coordinated by organic linkers to form three dimensional structures. The ability to vary these two entities offers to MOFs a wide variety of organized structure with pore sizes controlled. The aim of this thesis was to evaluate the MOF performances for the adsorption of organic compounds and also understand the related adsorption mechanism. The two selected issues are of interest for the petrochemical industry. The para-xylène separation from the other xylene isomers (ortho, meta) and ethylbenzene, allows to meet the demand for raw materials in the polyethylene terephthalate (PET) synthesis. The nitrogen and sulphur compounds adsorption allows the purification of fuels (sulphur content set by legislation). We present a thermodynamic study of adsorption from solution based on the determination of adsorption isotherms by depletion method and adsorption enthalpies by microcalorimetry. The pure xylenes vapour adsorption was also studied to understand the solvent effect. A wide variety of behaviour has been observed depending on MOF structures. For example we demonstrated the effect of xylene isomers molecular packing on MOF selectivity. Furthermore we have shown that the MOF structure flexibility influence the interactions involved during xylene isomers adsorption. We also demonstrated that MOF with unsaturated metallic centres present selectivity for nitrogen compounds (Lewis acid/base)
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Larabi, Cherif. "Surface organometallic chemistry on Metal Organic Frameworks (MOF) : synthesis, characterization and their application in catalysis." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10008/document.
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Les structures organométalliques poreuses (Metal Organic Framework, MOF) sont une nouvelle classe de matériaux, composées d'ions métalliques ou de clusters liés à des ligands organiques ou des complexes organométalliques dans des réseaux cristallins 1D, 2D ou 3D. Au cours de cette thèse la possibilité de construire de nouveaux MOF a été illustrée par le développement de matériaux MOF à base d’imidazolium, précurseur important pour la synthèse de catalyseurs. En outre, ce travail démontre l’utilité de la modification post-synthèse des MOFs par chimie organométallique de surface à visée catalytique : i) un MOF connu, UiO-66, avec des pores relativement petits a été fonctionnalisé avec un groupement amino et ses capacités d'adsorption de gaz ont été étudiées. ii) la synthèse de MOF a structure poreuse, CPO-27, MOF a été optimisée et utilisée comme précurseur pour produire un catalyseur d'hydrodésulfuration après l'introduction d'espèces actives, via la chimie organométallique de surface, dont les performances catalytiques ont été évaluéesMetal organic frameworks (MOF) are a new class of material, which consist of metal ions or clusters coordinated to organic ligands or metal-organic complexes and result in 1D, 2D or 3D crystalline networks. The possibility of constructing new MOF has been exemplified in this thesis by development of imidazolium based MOF, a highly important ligand system in catalysis. Moreover, this work has performed post synthesis modification via surface organometallic chemistry on existing MOF: i) a known MOF, UiO-66, with relatively small pores has been functionalized with amino group and its gas adsorption capacity has been investigated, ii) the syntheses of a 3D open structure MOF, CPO-27, MOFs have been optimized and used as a precursor to produce a hydrodesulfurization catalyst after introducing active species via surface organometallic chemistry approach, whose catalytic performances have been measured
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Taksande, Kiran. "Exploration of the Ionic Conduction Properties of Porous MOF Materials." Thesis, Montpellier, 2022. https://ged.scdi-montpellier.fr/florabium/jsp/nnt.jsp?nnt=2022UMONS010.
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Ce travail a pour objectif l’étude de matériaux hybrides poreux de type Metal-Organic Frameworks (MOFs) et d’un cristal moléculaire en tant que conducteurs ioniques solides pour des applications dans le domaine de l’énergie et de l’environnement. Dans le premier cas, nous avons développé diverses stratégies pour optimiser et contrôler la teneur en sites acides de Lewis et en porteurs de charges de deux séries de MOFs afin de concevoir des matériaux aux propriétés de conduction protonique très prometteuses. A partir d’une approche basée sur la substitution progressive des ligands par des entités fonctionnalisées présentant des sources de protons acides, nous avons créé une série de MOFs, MIP-207-(SO3H-IPA)x-(BTC)1–x, dont la teneur en groupements sulfoniques, par l’intermédiaire du ligand SO3H-IPA, est contrôlée à façon. Le meilleur matériau qui combine stabilité structurale et conduction protonique élevée présente des performances sous humidité parmi les plus intéressantes au sein de la famille des MOFs conducteurs protoniques (e.g., σ = 2.6 × 10–2 S cm–1 à 363 K/95% d’humidité relative (RH)). Selon une autre approche, nous avons étudié un MOF mésoporeux connu (MIL-101(Cr)-SO3H) dont les parois des pores sont tapissées de sites protoniques et qui contient dans ses pores un liquide ionique, le chlorure chlorure de 1-Ethyl-3-methylimidazolium (EMIMCl) capable d’assurer le transfert de proton. L’encapsulation du liquide ionique, caractérisée par une série d’outils expérimentaux (sorption de diazote, DRX sur poudre, TGA/MS, DSC et analyse élémentaire), s’avère particulièrement efficace pour exalter les propriétés de conduction protonique des composites à la fois à l’état anhydre (σ473 K = 1.5 × 10-3 S cm-1) mais également à l’état hydraté (σ(343 K/60%-80%RH) ≥ 0.10 S cm-1). Enfin, ce travail a été étendu à une autre famille de solides poreux, à travers l’étude des propriétés de conduction ionique d’un cristal moléculaire à base de zirconium (Zr-3) qui contient des paires ioniques KCl. Nous avons démontré que ZF-3 transite d’un comportement isolant à l’état anhydre (σ = 5.1 x 10-10 S cm-1 à 363 K/0% RH) vers un comportement super-conducteur ionique en présence d’eau (σ = 5.2 x 10-2 S cm-1 à 363 K/95 % RH), suite à l’augmentation de la dynamique de ions Cl- sous hydratation. Par ailleurs, des simulations moléculaires ont permis de décrire les mécanismes microscopiques à l’origine des propriétés de conduction des matériaux étudiés. Ces avancées devraient permettre de développer dans le futur de nouveaux matériaux performants dans le domaine de la conduction protonique et ioniqueThe conductivity performance of a new series of chemically stable proton conducting Metal Organic Frameworks (MOFs) as well as a superionic molecular crystal was explored. The contribution of this PhD was to (i) select a variety of architectures and functionalities of robust MOFs/superionic molecular solids and (ii) characterize and rationalize their conducting performance over various temperature/humidity conditions. We designed two series of MOFs to achieve promising proton-conducting performance, using distinct approaches to modulate the concentration of Brønsted acidic sites and charge carriers and further boost the conductivity properties. First, a multicomponent ligand replacement strategy was successfully employed to elaborate a series of multivariate sulfonic-based solids MIP-207-(SO3H-IPA)x-(BTC)1–x which combine structural integrity with high proton conductivity values (e.g., σ = 2.6 × 10–2 S cm–1 at 363 K/95% Relative Humidity -RH-). Secondly, a proton conducting composite was prepared through the impregnation of an ionic liquid (1-Ethyl-3-methylimidazolium chloride, EMIMCl) in the mesoporous MIL-101(Cr)-SO3H. The resulting composite displaying high thermal and chemical stability, exhibits outstanding proton conductivity not only at the anhydrous state (σ473 K = 1.5 × 10-3 S cm-1) but also under humidity (σ(343 K/60%-80%RH) ≥ 0.10 S cm-1) conditions. Finally, the ionic conducting properties of another class of porous solids, considering a zirconium-formate molecular solid containing KCl ion pairs (ZF-3) were explored. ZF-3 switches from an insulator (σ = 5.1 x 10-10 S cm-1 at 363 K/0% RH) to a superionic conductor upon hydration (σ = 5.2 x 10-2 S cm-1 at 363 K/95 % RH), in relation with the boost of Cl- dynamics upon water adsorption. Noteworthy, quantum- and force-field based simulations were combined with the experimental approach to elucidate the microscopic mechanisms at the origin of the ionic conducting properties of the studied materials. This fundamental knowledge will serve to create novel robust superionic conductors with outstanding performances that will pave the way towards appealing societal applications for clean energy production
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Eubank, Jarrod F. "Rational synthesis toward the design of functional metal-organic materials." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002408.
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Padmanaban, Mohan, Philipp Müller, Christian Lieder, Kristina Gedrich, Ronny Grünker, Volodymyr Bon, Irena Senkovska, et al. "Application of a chiral metal–organic framework in enantioselective separation." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138682.
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A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal–organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reportedDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Philippi, Mar?lia. "S?ntese e caracteriza??o de Metal-Organic Framework (MOF) para uso na adsor??o de CO2." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2017. http://tede2.pucrs.br/tede2/handle/tede/7727.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Growing concern about global warming and reducing greenhouse gas emissions in the atmosphere has driven the development of technological options to reduce the negative impacts of human activities, and CO2 capture and storage is one of them. Solid adsorbent materials are being used with the aim of adsorbing polluting gases. Metal-Organic Frameworks (MOFs) are a class of porous materials of great potential for adsorption of greenhouse gases, formed by the connection of metallic ions and organic binders. In this context, the objective of this work is to synthesize the MOF of type NH2-MIL-53(Al), to characterize and evaluate its use in the adsorption of carbon dioxide. For synthesis of the MOF, a hydrothermal process was used in a PFA closed reactor (155 ?C) with subsequent washes and resuspensions, obtaining an average mass yield of 90%. The obtained MOF was characterized with the use of the techniques such as SEM-FEG-EDS, elemental analysis, FAAS, XRF, FTIR, TGA, XRD/Refinement by the Rietveld Method and MAS-NMR, exhibiting characteristics of the structure NH2-MIL-53(Al). For the adsorption and desorption tests of CO2 the synthesized material was used as a powder in a fixed bed system. The synthesized MOF presented CO2 adsorption capacity of 0.13 mmol g-1 and SBET of 27 m2 g-1, lower than that reported in the literature, which were attributed to the presence of occluded binder in the pores of the material. The calculated average cost for the synthesis of the MOF in the laboratory was 34% of the value of the non-functionalized commercial standard available in the market. The residual solvent purification process from the MOF synthesis proved to be satisfactory, completely removing the DMF and with a residual contribution of methanol of only 0.00008%.
A crescente preocupa??o com o aquecimento global e com a redu??o das emiss?es de gases de efeito estufa na atmosfera tem impulsionado o desenvolvimento de op??es tecnol?gicas para redu??o dos impactos negativos das atividades humanas e, a captura e armazenamento de CO2 ? uma delas. Materiais s?lidos adsorventes est?o sendo utilizados com o objetivo de adsorver gases poluentes. Os Metal-Organic Frameworks (MOFs) s?o uma classe de materiais porosos de grande potencial para adsor??o de gases de efeito estufa, formados pela conex?o de ?ons met?licos e ligantes org?nicos. Neste contexto, o objetivo deste trabalho ? sintetizar o MOF do tipo NH2-MIL-53(Al), caracterizar e avaliar seu uso na adsor??o de di?xido de carbono. Para s?ntese do MOF foi utilizado processo hidrot?rmico em reator fechado de PFA (155 ?C) com posteriores lavagens e resuspens?es, obtendo um rendimento m?ssico m?dio de 90%. O MOF obtido foi caracterizado com o uso das t?cnicas como MEV-FEG-EDS, an?lise elementar, FAAS, FRX, FTIR, TGA, DRX/Refinamento pelo M?todo Rietveld e MAS-RMN, apresentando caracter?sticas da estrutura NH2-MIL-53(Al). Para os testes de adsor??o e dessor??o de CO2 o material sintetizado foi utilizado sob a forma de p? em sistema de leito fixo. O MOF sintetizado apresentou capacidade de adsor??o de CO2 de 0,13 mmol g-1 e SBET de 27 m2 g-1, inferiores ao reportado pela literatura, e que foram atribu?dos a presen?a de ligante oclu?do nos poros do material. O custo m?dio calculado para s?ntese do MOF em laborat?rio foi de 34% do valor do padr?o comercial n?o funcionalizado dispon?vel no mercado. O processo de purifica??o do solvente residual da s?ntese do MOF demonstrou ser satisfat?rio, removendo completamente o DMF e com uma contribui??o residual de metanol de apenas 0,00008%.
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Benzaqui, Marvin. "Synthesis of Metal-Organic Framework nanoparticles and mixed-matrix membrane preparation for gas separation and CO2 capture." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV075/document.
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La séparation CO2/N2 et H2/CO2 permet de limiter le rejet de CO2 dans l’atmosphère issu des gaz industriels et les membranes présentent de nombreux avantages tant sur le plan économique que pratique. Les membranes polymère sont faciles à mettre en forme mais un compromis entre perméabilité et sélectivité doit généralement être trouvé : pour améliorer les performances, des membranes à matrice mixte (MMM) incorporant des MOFs (matériaux hybrides poreux cristallisés) dispersés dans la phase polymère ont été proposées. A la différence des matériaux poreux inorganiques, les MOFs ont une meilleure compatibilité avec la matrice polymère du fait de leur caractère hybride organiqueinorganique. Dans le cadre de cette thèse, des polycarboxylates de Fe3+ et Al3+ poreux, stables à l’eau, et possédant de bonnes propriétés d’adsorption sélective du CO2 ont été synthétisés en milieu aqueux et mis à l’échelle de quelques grammes. Deux nouveaux polycarboxylates de Fe3+ poreux fonctionnalisés par des fonctions -COOH libres ont été obtenus à température ambiante. Pour l’un d’entre eux, la structure a été déterminée par diffraction des rayons X. Une deuxième partie de la thèse a été consacrée à la synthèse de nanoparticules de MOFs avec un bon rendement. Une partie importante de ce travail a porté sur le contrôle de la taille et la morphologie des nanoparticules de MIL-96(Al). Ce travail a conduit à la préparation de MMMs à base de MIL-96(Al) dont les performances sont supérieures à la membrane pure polymère pour la séparation CO2/N2. La dernière partie de ce travail de thèse a porté sur l’étude physico-chimique de la compatibilité entre le ZIF-8 et deux polymères (PVA et PIM-1). Ce travail a consisté à effectuer une caractérisation complète de solutions colloïdales MOFs/polymère en couplant plusieurs techniques (DLS, TEM, SAXS). Cette étude a montré que la compatibilité MOF/polymère est très dépendante de la chimie de surface des MOFs et des propriétés physico-chimiques du polymère (rigidité, caractère hydrophile/hydrophobe…)CO2 capture and storage (CCS) is of high economical and societal interest. CO2/N2 andH2/CO2 separations are able to limit atmospheric CO2 emissions produced by industrial exhausts andmembranes present numerous economical and practical advantages. Polymer membranes are easy toprocess and possess interesting mechanical properties. However, there is a trade-off to make betweenpermeability and selectivity. Mixed-matrix membranes (MMM) based on MOFs (porous crystallinehybrid materials) have been proposed to boost the performances of polymer membranes for CO2capture. In comparison to other inorganic porous materials, one may expect that the compatibilitybetween MOFs and polymers is enhanced due to the hybrid character of MOFs.In this work, porous water stable polycarboxylate MOFs based on Fe3+ and Al3+ with promisingproperties for CO2 adsorption were synthesized for large-scale production using water as the mainsolvent. Two new porous polycarboxylate Fe3+ MOF bearing free -COOH groups in the frameworkwere obtained at room temperature as nanoparticles. The crystallographic structure of one of thesematerials was determined by single crystal X-ray diffraction. A second part of the thesis was devotedto the synthesis of MOFs nanoparticles with good yield. We focused our attention on the control of thediameter and morphology of MIL-96(Al) nanoparticles. This study led to the preparation of MMMsbased on MIL-96(Al) with promising properties for CO2/N2 separation. Finally, the compatibilitybetween MOF particles and polymers was studied for two systems (ZIF-8/PIM-1 and ZIF-8/PVOH),showing the influence of the surface chemistry of MOFs and the physico-chemical properties ofpolymer on the matching between MOFs and polymers
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SANTOS, Guilherme de Coimbra. "Estudo da decodificação de aromático via luminescência de MOF, e de novos compósitos, em fase sólida, à base de MOFs e curcubiturila, na adsorção seletiva de corantes." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/25145.
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CNPQ
Este trabalho apresenta a síntese da já conhecida MOF [Zn2(BDC)2(dpNDI)]n (BDC = 1,4-benzenodicarboxilato, dpNDI = N’N’-di(4-piridil)-1,4,5,8-naftalenodiimida), mas, agora dopada em diferentes percentagens (0,1%, 0,5%, 1%, 2% e 5%) com o íon európio (íon sonda), por via solvotermica. Após suas caracterizações, observam-se respostas espectroscópicas, frente à monoaromático, favoráveis na identificação de moléculas hóspedes. A síntese e caracterização de redes de coordenação cristalinas, bem como de compósitos a base de carvão ativado, a partir de íons lantanídeos (Pr³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Dy³⁺, Er³⁺, Tm³⁺ e o Yb³⁺) com emprego do ligante flexível, succinato, utilizando-se a técnica hidrotermal para obtenção desses sistemas, foram realizadas, além de investigações de sistemas mixmetal nessa mesma matriz carbonácea. Novos compósitos porosos LnBDC@CA (CA = Carvão ativado, Ln = Pr³⁺; Nd³⁺; Sm³⁺; Eu³⁺; Gd³⁺; Er³⁺; Tm³⁺ e Yb³⁺ e BDC = 1,4benzenodicaboxilato) e CB[6]@CA (CB[6] = Cucurbit[6]uril) foram obtidos utilizando via hidrotermal. O LnBDC e o CB[6] estão localizados dentro dos poros do carvão, como foi observado em análise MEV-EDS, Raio X de pó e IV. A análise de porosimetria mostrou valores tipicamente entre o material CA e LnBDC, com tamanho de poro e área de superfície, respectivamente, 29,56 Å e 353,98 m²g⁻¹ para LnBDC@CA e 35,53 Å e 353,98 m²g⁻¹ para CB[6]@CA. Ambos os materiais mostraram boa capacidade de adsorção para o alaranjado de metila (MO) e o azul de metileno (MB) com seletividade em função do pH. Em meio ácido, ambos os materiais apresentam seletividade por MB e em pH alcalino para o MO, com desempenho perceptível para o CB[6]@CA. Adicionalmente, a luminescência do európio foi utilizada como sonda estrutural para investigar o ambiente de coordenação do íon Eu³⁺ no compósito EuBDC@CA após experimentos de adsorção.
This work presents the synthesis Already known of MOF [Zn2(BDC)2(dpNDI)] (BDC = 1,4-benzenedicarboxylate, dpNDI = N'N'-di (4-pyridyl) -1,4,5,8 - naphthalenediimide), but now doped in different percentages (0.1%, 0.5%, 1%, 2% and 5%) with the europium ion (probe ion) by Solvothermal synthesis. After their characterizations, spectroscopic responses are observed, in touch to monoaromatic, favorable in the identification of guest molecules. The synthesis and characterization of crystalline coordination networks, as well as activated carbon based composites, from lanthanide ions (Pr³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Dy³⁺, Er³⁺, Tm³⁺ e o Yb³⁺) with the use of flexible ligands, succinate, using the hydrothermal technique to obtain these systems, were performed, in addition to investigations of mixmetal systems in this same carbonaceous matrix. New porous composites LnBDC@AC (AC= Activated carbon, Ln= Pr3+; Nd³⁺; Sm³⁺; Eu³⁺; Gd³⁺; Er³⁺; Tm³⁺ e Yb³⁺ and BDC= 1,4benzenedicaboxylate) and CB[6]@AC (CB[6]= Cucurbit[6]uril) were obtained using hydrothermal route. The LnBDC and CB[B] are located inside the pore of the carbon materials as was observed in SEM-EDS, XRPD and FT-IR analysis. Porosimetry analysis showed values typically between AC and LnBDC material, with pore size and surface area, respectively, 29,56 Å and 353.98 m2g-1 for LnBDC@AC and 35,53 Å and 353.98 m²g⁻¹ for CB[6]@AC. Both materials showed good absorptive capacity of metil orange (MO) and methylene blue (MB) with selectivity as a function of pH. In acid medium, both materials present selectivity by MB and alkaline pH for MO, with notable performance for CB[6]@AC. Additionally, europium luminescence was used as structural probe to investigate the coordination environment of Eu³⁺ ions in the EuBDC@AC composite after adsorption experiment.
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Rayder, Thomas M. "Modulation of Catalyst@MOF Host-Guest Composites in Pursuit of Synthetic Artificial Enzymes:." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:108930.
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Thesis advisor: Jeffery A. ByersThesis advisor: Chia-Kuang (Frank) Tsung
Biological systems have evolved over time to favor structures beneficial for the efficient transformation of simple feedstocks to sophisticated products. In particular, enzymes have evolved such that cooperative and geometrically controlled interactions between active sites and substrates enhance catalytic activity and selectivity. Separation of these active sites from other incompatible catalytic components allows for chemical transformation in a stepwise fashion, circumventing the inherent limitations to performing reactions in a single step. This dissertation describes the use of porous crystalline materials called metal-organic frameworks (MOFs) as hosts to mimic the component separation and precise active site control observed in nature. The first phase of these efforts explores the use of dissociative “aperture-opening” linker exchange pathways in a MOF to encapsulate transition metal complexes for carbon dioxide hydrogenation to formate. This strategy is then used to separate two incompatible complexes and perform the cascade conversion of carbon dioxide to methanol, resulting in unique and previously unobserved network autocatalytic behavior. Finally, the modularity of the MOF host is leveraged to install beneficial functionality in close proximity to the encapsulated transition metal complex, leading to activity exceeding that of any reported homogeneous system for carbon dioxide reduction. The insights gained through these studies can inform the development of composites for other reactions, allowing for access to new and unique reaction manifolds
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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Padmanaban, Mohan, Philipp Müller, Christian Lieder, Kristina Gedrich, Ronny Grünker, Volodymyr Bon, Irena Senkovska, et al. "Application of a chiral metal–organic framework in enantioselective separation." Royal Society of Chemistry, 2011. https://tud.qucosa.de/id/qucosa%3A27771.
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A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal–organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reported.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Bon, Volodymyr, Volodymyr Senkovskyy, Irena Senkovska, and Stefan Kaskel. "Zr(IV) and Hf(IV) based metal–organic frameworks with reo-topology." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138895.
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Zr and Hf based MOFs with enhanced pore accessibility for large molecules and good hydrothermal stability were obtained using a bent dithienothiophene dicarboxylate and Zr4+ or Hf4+ source. A modulator (benzoic acid) facilitates formation of an eight-connecting cluster leading to a new framework which adopts reo topologyDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Grünker, Ronny, Irena Senkovska, Ralf Biedermann, Nicole Klein, Martin R. Lohe, Philipp Müller, and Stefan Kaskel. "A highly porous flexible Metal–Organic Framework with corundum topology." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138599.
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A flexible Metal–Organic Framework Zn4O(BenzTB)3/2 (DUT-13) was obtained by combination of a tetratopic linker and Zn4O6+ as connector. The material has a corundum topology and shows the highest pore volume among flexible MOFsDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Perrot, Virginie. "Méthode innovante de croissance de couches minces de MOF par CVD pour la détection de gaz." Thesis, Lyon, 2021. http://www.theses.fr/2021LYSE1331.
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La mesure sur site et en temps réel des concentrations de gaz est cruciale pour la compréhension et la surveillance des processus industriels et environnementaux. Ces dernières années, il devient de plus en plus nécessaire de développer des outils d'analyse multigaz portatifs permettant la détection in situ de mélanges gazeux complexes, principalement pour des raisons de sécurité, de processus et d'environnement. Une approche prometteuse est basée sur l'intégration de différentes parties de systèmes analytiques de détection (par exemple pré-concentrateur, colonne de chromatographie en phase gazeuse ou encore capteurs gravimétriques) dans une puce en silicium en utilisant les technologies standards de microélectronique. Toutefois, chacun de ces dispositifs doit être fonctionnalisé avec une couche sensible appropriée. Les Metal-Organic-Framework (MOF), des matériaux hybrides cristallins microporeux aux propriétés modulables, sont intéressant pour ce type d'application en raison de leur surface spécifique élevée et de leur stabilité chimique. Cependant, ces matériaux sont généralement synthétisés par des procédés en solution (synthèse solvothermale), ce qui complique la croissance de couches minces continues et leur intégration dans des micro-dispositifs. Ce travail a pour objectif le développement d’un procédé de synthèse en phase vapeur pour produire des films minces de Zeolitic Imidazolate Framework 8 (ZIF-8), un MOF particulièrement intéressant. La méthode de croissance est basée sur le dépôt de couches de ZnO par Atomic Layer Deposition (ALD) sur un substrat, suivi de sa conversion et de la formation de ZIF-8 par exposition cyclique à la vapeur d'eau et au ligand organique en phase vapeur. Cette approche a permis la formation de films minces d'épaisseur comprise entre 5 et 200 nm, indépendamment de l'épaisseur de ZnO initiale. L'impact des paramètres du procédé (température du substrat, pression de vapeur d'eau...) sur la croissance du MOF a été étudié. La composition, la morphologie et la cristallinité ont été examinées à l'aide d'un large panel de techniques de caractérisation (AFM, DRX, MEB, FTIR). De plus, les mécanismes de croissance ont été étudiés par XPS et ToF-SIMS pour comprendre le rôle de l'eau pendant la réaction et plusieurs hypothèses ont été émises. Enfin, les films ont été activés thermiquement et la porosité a été évaluée par ellipsométrie-porosimétrie. Le volume des pores représente 30 % du volume des films dans certains cas. Les propriétés d'adsorption des films ont également été étudiées à l'aide de capteurs de gaz gravimétriques. En effet, des films de ZIF-8 ont été déposés sur des microbalances à cristal de quartz (QCM) pour étudier les interactions entre la couche et plusieurs gaz (méthanol, acétone et eau) afin de déterminer l'intérêt des films minces de ZIF-8 dans des capteurs de ce type. Ce travail montre que les capteurs fonctionnalisés avec du ZIF-8 permettent la détection de tous les gaz indépendamment dans les gammes de concentration testées. Cependant, la sensibilité de la détection du méthanol est fortement impactée par l'ajout d'humidité relativeOn-site and real-time measurement of gas concentrations are crucial for both the understanding and the monitoring of industrial and environmental processes. In recent years, there is an increasing need to develop portable multi-gas analysis tools allowing in situ detection of complex gas mixtures mainly due to safety, process and environmental considerations. A promising approach is based on the integration of the different parts of the analytical system (i.e. pre-concentrator, gas chromatography column, gravimetric sensors) in a silicon die by using standard microelectronic technologies. Each of these devices need to be coated by an appropriate functional layer. Metal Organic Frameworks (MOF), hybrid microporous crystalline materials with tuneable properties, are attractive for this type of application regarding their high specific surface area and chemical stability. However, these materials are usually synthetized via solvothermal techniques, which complicates the growth of continuous thin films and their integration in micro-devices. This work focuses on the development of a vapor phase-based route to produce Zeolitic Imidazolate Framework 8 (ZIF-8) thin films, a MOF of particular interest. The growth method is based on the deposition of ZnO layers by atomic layer deposition (ALD) on a substrate followed by ZIF-8 formation using cyclic exposure to water vapour and organic ligand in the gas phase. This approach allowed formation of thin films with tunable thickness between 5 and 200 nm, independently of the initial ZnO thickness. The impact of the process parameters (temperature of the substrate, water vapor pressure…) on the MOF growth was studied. The composition, morphology and crystallinity were examined using a wide range of characterization techniques (AFM, SEM, XRD and FTIR). Moreover, the growth mechanism was investigated by XPS and ToF-SIMS to understand the role of water during the reaction and several hypotheses were given. Finally, the as-synthesized films were thermally activated and the porosity was assessed using ellipsometric-porosimetry. Pore volume represents 30 % of the volume of the films in some cases. The adsorption properties of the films were also investigated using gravimetric gas sensors. Indeed, ZIF-8 films were grown on quartz crystal microbalance to study the interactions between the layer and several gases (methanol, acetone and water) in order to determine the benefit of ZIF-8 thin films in sensors. This work shows that the sensors coated with the ZIF-8 enable the detection of all the gases independently in the range of concentration tested. However, the sensitivity of the methanol detection is highly impacted by the addition of relative humidity
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Bon, Volodymyr, Volodymyr Senkovskyy, Irena Senkovska, and Stefan Kaskel. "Zr(IV) and Hf(IV) based metal–organic frameworks with reo-topology." Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27790.
Full textAbstract:
Zr and Hf based MOFs with enhanced pore accessibility for large molecules and good hydrothermal stability were obtained using a bent dithienothiophene dicarboxylate and Zr4+ or Hf4+ source. A modulator (benzoic acid) facilitates formation of an eight-connecting cluster leading to a new framework which adopts reo topology.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Grünker, Ronny, Irena Senkovska, Ralf Biedermann, Nicole Klein, Martin R. Lohe, Philipp Müller, and Stefan Kaskel. "A highly porous flexible Metal–Organic Framework with corundum topology." Royal Society of Chemistry, 2011. https://tud.qucosa.de/id/qucosa%3A27762.
Full textAbstract:
A flexible Metal–Organic Framework Zn4O(BenzTB)3/2 (DUT-13) was obtained by combination of a tetratopic linker and Zn4O6+ as connector. The material has a corundum topology and shows the highest pore volume among flexible MOFs.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Yu, Zhewei. "Equilibrium and kinetics studies of hydrogen storage onto hybrid activated carbon-metal organic framework adsorbents produced by mild syntheses." Thesis, Nantes, Ecole des Mines, 2016. http://www.theses.fr/2016EMNA0236/document.
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Depuis une quinzaine d’années, les matériaux poreux de type Metal Organic Frameworks (MOFs) offrent de nouvelles perspectives dans le cadre du stockage d’hydrogène par adsorption. Ces matériaux possèdent une structure et un réseau de pores particulièrement bien adaptés à l’adsorption des gaz. Ainsi, le téréphtalate de Chrome (III) (MIL-101(Cr)), composé chimiquement très stable, possède une grande capacité de stockage de l’hydrogène, du dioxyde de carbone et du méthane. Afin de renforcer sa capacité de stockage d’hydrogène, un dopage au charbon actif (AC) du matériau a été envisagé. Les synthèses des matériaux dopés et non-dopés ont été réalisées et, pour cela, différents agents minéralisants (acide fluorhydrique, acide acétique et acétate de sodium) ont été testés. Les matériaux synthétisés furent caractérisés par diffraction des rayons X (DRX), par microscopie électronique à balayage (MEB), par analyses thermogravimétriques (ATG) et par adsorption d’azote à 77K. Les capacités de stockage d’hydrogène de ces matériaux à 77 K et 100 bar ont été évaluées par mesures des isothermes d’adsorption d’hydrogène, réalisées par méthodes volumétrique et gravimétrique. Les résultats obtenus par ces deux méthodes sont en parfait accord et le matériau composite affiche une capacité d’adsorption de 13.5 wt%, qui est supérieure à celle du matériau non dopé (8.2 wt% dans les même conditions expérimentales). Les cinétiques d’adsorption ont été mesurées à 77 K par méthode volumétrique. Les résultats obtenus ont été comparés au modèle de la force motrice linéaire, Linear Driving Force (LDF). Un modèle de diffusion dépendant de la température a été développé afin de tenir compte des variations de températures qui se produisent durant le processus d’adsorptionSince the last 15 years, the porous solids such as Metal-Organic Frameworks (MOFs) have opened new perspectives for the development of adsorbents for hydrogen storage. The structure and the pore networks of these materials are especially adapted to the adsorption of gases. The chromium (III) terephthalate-based MIL-101(Cr) is a very stable material which exhibits good adsorption uptakes for hydrogen (H2), carbon dioxide (CO2) and methane (CH4).In this study, syntheses were carried out by different ways and several mineralizing agents such as hydrofluoric acid (HF), acetic acid (CH3COOH) and sodium acetate (CH3COONa) have been tested. Moreover, Activated Carbon (AC) has been introduced in the framework to create an AC incorporated composite material with an enhanced specific surface area. Conventional techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and nitrogen (N2) adsorption isotherms at 77 K were used for materials characterizations.In the aim to evaluate hydrogen storage capacities of these materials, hydrogen adsorption isotherms were measured at 77 K via both volumetric and gravimetric methods, and the obtained results are in good agreement. A hydrogen uptake value of 13.5 wt% has been measured at 77 K and 100 bar for the composite material which shows a great improvement of hydrogen capacity compared to the pristine MIL-101(Cr) (8.2 wt%).Finally, hydrogen adsorption kinetics has been measured at 77 K using volumetric method. The obtained results were compared to the Linear Driving Force (LDF) and a temperature dependent diffusion model was also considered to take into account the temperature variations which occur during the adsorption process
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Leclerc, Hervé. "Caractérisation par spectroscopie infrarouge de solides organiques inorganiques de type MOF (Metal Organic Framework) : Thèse soutenue sur un ensemble de travaux." Caen, 2011. http://www.theses.fr/2011CAEN2017.
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Ce travail rapporte la caractérisation par spectroscopie infrarouge in situ d’une famille iso-structurale de quatre solides poreux organiques-inorganiques de type MOF (MOF : Metal Organic Framework) dénommés MIL-100(X) (MIL pour Matériaux de l’Institut Lavoisier) avec X= Al3+, Fe3+, Al3+ et V3+. Les caractérisations des centres métalliques et des propriétés acido-basiques ont été réalisées pour différentes températures d’activation des matériaux par ajouts ou non de molécules sondes telles que CO, CO2, CD3CN, pyridine et propyne. La première partie, portant sur l’étude du MIL-100(Cr), révèle l’absence de sites basiques de force notable, mais la présence de centres acides de Lewis Cr3+ localisés sur les trimères. L’adsorption d’eau ou d’alcools transforme ces sites en sites acides Bronsted dont la force dépend de la nature de l’adsorbat et du complexe formé. La deuxième partie est consacrée à l’étude du MIL-100(Fe). Elle révèle d’abord l’existence de sites Fe3+ susceptibles de se réduire en sites Fe2+ par chauffage sous vide, puis démontre l’existence d’un phénomène de rétrodonation qui accroit les interactions entre les sites Fe2+ insaturés et des molécules telles que le CO, le propène et le propyne. L’étude spectroscopique du MIL-100(Al), présentée en troisième partie, rapporte pour la première fois une caractérisation fine de sites Al3+ insaturés en conformation pentaédrique et présents en grande quantité dans un environnement cristallographique bien défini. Le dernier chapitre présente une caractérisation du MIL-100(V) pour différentes température d’activation : nature des espèces extra réseaux et des centres métalliques insaturésThis study reports the characterization by in situ infrared spectroscopy of an isostructural family of four porous MOFs (MOF: Metal Organic Framework) denoted MIL-100(X) (MIL: Material from the Institute Lavoisier) with X: Al3+, Fe3+, Al3+ and V3+. The characterizations of the metallic centers and acido-basic properties have been performed at different temperature of activation by adsorption or not of probe molecules such as CO, CO2, CD3CN, pyridine and propyne. The first part devoted to the MIL-100(Cr), reveals the lack of any significant basic sites but the occurrence of Cr3+ Lewis acid sites located on the trimers. Adsorption of water or alcohols transforms the Lewis sites into Bronsted acid sites whose strength depends on the nature of the adsorbate and of the complex formed. The second part is dedicated to the study of the MIL-100(Fe) material. It reveals first the presence of Fe3+ sites able to be reduced into Fe2+ sites by thermal treatment under vacuum and secondly demonstrates the occurrence of a pi-back donation effect which increases the interactions between Fe2+ unsaturated sites and molecules such as CO, propene and propyne. The spectroscopic study of MIL-100(Al) presented in the third part reports for the first time a precise characterization of unsaturated pentahedral Al3+ sites present in a large amount and in a well defined crystallographic environment. The last chapter presents the characterization of MIL-100(V) activated at different temperatures: nature of the extra framework species and of unsaturated metallic sites
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McPherson, Matthew Joseph. "Control of water and toxic gas adsorption in metal-organic frameworks." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/16489.
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The research presented in this thesis aims to determine the effectiveness of the uptake of toxic gases by several MOFs for future use in gas-mask cartridges, and to attempt to compensate for any deficiencies they show in “real-world” conditions. The main findings of this thesis confirm that MOFs are suitable candidates for the use in respirator cartridge materials and provide high capacity for adsorption of toxic gases like ammonia and STAM-1 in particular showed an impressive improvement in humid conditions, which normally decrease the performance of MOFs made from the same materials, such as HKUST-1. STAM-1's improved performance in humid conditions is attributed to the structural shift it displays upon dehydration and rehydration and this was shown to be the case in a structural analogue, CuEtOip, which was synthesised in the author's research group. This analogue was analysed using a combination of single crystal XRD and solid state MAS-NMR, both of which showed the structural change occurring and displays similar gas sorption behaviours, suggesting that this mechanism is the source of STAM-1's improved performance in humid conditions. This thesis also examines the “Armoured MOF” process and investigates the transferability of the process of deposition of mesoporous silica onto MOFs with vastly different properties and synthetic methods compared to those published in the original publication. Alongside this, attempts to protect MOFs using mesoporous silicates were investigated for their viability.
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Esken, Daniel [Verfasser], Roland A. [Gutachter] Fischer, and Martin [Gutachter] Muhler. "Stabilization of cavity-size matching metal clusters and compound semiconductors inside metal-organic frameworks (MOFs) / Daniel Esken ; Gutachter: Roland A. Fischer, Martin Muhler ; Fakultät für Chemie und Biochemie." Bochum : Ruhr-Universität Bochum, 2011. http://d-nb.info/1209358271/34.
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Jee, Bettina. "Cw and pulsed EPR spectroscopy of Cu(II) and V(IV) in metal-organic framework compounds: metal ion coordination and adsorbate interactions." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-126200.
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Metal-organic framework (MOF) compounds as a new class of porous coordination polymers consists of metal ions or clusters linked by organic molecules. They have gained recent interest because of their large surface areas and huge variety of the porous network structures. They exhibit interesting adsorption properties and therefore are potential candidates for various technical applications.
In this work, continuous wave (cw) and pulsed electron paramagnetic resonance (EPR) methods such as pulsed electron-nuclear double resonance (ENDOR) and hyperfine sublevel correlation (HYSCORE) spectroscopy are applied to study metal-organic frameworks with respect to different aspects of their properties: The host-guest interactions between Cu2+ ions in [Cu3(btc)2]n (HKUST-1; btc: 1,3,5-benzenetricaboxylate) with adsorbed methanol (CH3OH), 13C enriched carbon monoxide and dioxide (13CO, 13CO2), hydrogen (H2), deuterium (D2) and mixed isotopic HD. In [Cu3(btc)2]n, the Cu2+ ions are connected to binuclear Cu/Cu paddle wheel units. Since the Cu2+ ions in the [Cu3(btc)2]n are antiferromagnetically coupled, the new compound [Cu2.97Zn0.03(btc)2]n is synthesized by isomorphous substitution containing about 1 % paramagnetic Cu/Zn paddle wheel units. The modified Cu/Zn paddle wheel units prove to be a very sensitive probe for the interactions with the adsorbed molecules.
Secondly, the exchange interactions of antiferromagnetically coupled Cu/Cu paddle wheel units as well as additional inter-paddle wheel exchange interactions between the Cu/Cu pairs are studied in [Cu2(bdc)2(dabco)]n, a layered MOF with 1,4-benzenedicaboxylate (bdc) as linker and 1,4-diazabicyclo[2.2.2]octane (dabco) acting as pillars between the layers. In comparison to [Cu3(btc)2]n, the additional inter-paddle wheel exchange interactions are much easier disturbed by incorporation of Zn2+ ions into the framework structure.
Third, the structural dynamics of the framework is investigated in the compound [Al(OH)(bdc)]n (MIL-53) which was isomorphously substituted by V(III)/V(IV) species. The 51V hyperfine structure revealed to be sensitive to the so-called breathing effect, a flexible structural behaviour upon guest adsorption/desorption or upon thermal treatment. It is shown that the aluminum ions can be substituted by vanadium but the octahedral coordination environment changes slightly to a pseudo-octahedral or a square-pyramidal coordination.
Based on the hyperfine interactions between the electron spin and the nuclear spins of the surrounding atoms, structural models can be derived from orientation-selective measurements. In such a way, structural information of materials like powder samples and adsorbate complexes can be obtained which are hardly or even not accessible by other methods.
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Zhao, Chao. "Synthesis and characterization of porous zinc carboxyethylphosphonates : a new class of ion-exchangeable metal-organic framework compounds." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4198/.
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Metal-organic framework materials have been the subject of great interest in recent years as their enormous chemical and structural diversity offers opportunities for potential applications. We have developed synthetic routes to a series of new zinc organophosphonate materials, exemplified by the zinc carboxyethylphosphonate (NH\(_4\))\(_2\)[Zn\(_2\)(O\(_3\)PCH\(_2\)CH\(_2\)COO)\(_2\)]·5H\(_2\)O, prepared under hydrothermal conditions in a Teflon-lined autoclave. In common with many other MOFs, it has a low molecular weight and three-dimensional porous framework structure, with pores of ca.7.6 Å diameter providing potential access to a high internal surface area, but unlike most has the advantage of containing exchangeable ammonium cations within the pores. The ability to undergo ion exchange is of interest in its own right, but also enables fine-turning of the properties of these materials. MOFs have already shown considerable promise for hydrogen storage owing to their high uptake capacity at low temperature and excellent kinetics and reversibility. In some MOFs and zeolites the hydrogen physisorption properties have been successfully improved by varying the exchangeable cations or adding exposed metal sites. Here we report the results of ion exchange experiments on (NH\(_4\))\(_2\)[Zn\(_2\)(O\(_3\)PCH\(_2\)CH\(_2\)COO)\(_2\)]·5H\(_2\)O with a view to producing MOF materials with enhanced hydrogen physisorption properties.
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Van, Heest Timothy Milner. "Identification of metal-organic framework materials for adsorptive separation of the rare gases: applicability of IAST and effects of inaccessible regions." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43715.
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A collection of >3000 MOFs with experimentally confirmed structures were screened for performance in three binary separations: Ar/Kr, Kr/Xe, and Xe/Rn. 70 materials were selected for further analysis, and calculations were performed to account for inaccessible regions. Single component GCMC calculations were performed to parameterize IAST calculations on these 70 materials, and the curve fitting problem in IAST was discussed. IAST calculations were confirmed with extensive binary GCMC calculations. For each binary separation, materials were identified with predicted performance that surpasses the state of the art. "Reverse selective" materials, for which a smaller gas species is preferably adsorbed over a larger species, were explained on the basis of surface fractal geometry, computed via a corrected surface area calculation. The effect of temperature on separation performance was also examined.
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Larabi, Cherif. "La chimie organométallique de surface appliquée aux structures organométalliques poreuses (MOF) : synthèses, caractérisations, et leurs applications en catalyse." Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00858896.
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Les structures organométalliques poreuses (Metal Organic Framework, MOF) sont une nouvelle classe de matériaux, composées d'ions métalliques ou de clusters liés à des ligands organiques ou des complexes organométalliques dans des réseaux cristallins 1D, 2D ou 3D. Au cours de cette thèse la possibilité de construire de nouveaux MOF a été illustrée par le développement de matériaux MOF à base d'imidazolium, précurseur important pour la synthèse de catalyseurs. En outre, ce travail démontre l'utilité de la modification post-synthèse des MOFs par chimie organométallique de surface à visée catalytique : i) un MOF connu, UiO-66, avec des pores relativement petits a été fonctionnalisé avec un groupement amino et ses capacités d'adsorption de gaz ont été étudiées. ii) la synthèse de MOF a structure poreuse, CPO-27, MOF a été optimisée et utilisée comme précurseur pour produire un catalyseur d'hydrodésulfuration après l'introduction d'espèces actives, via la chimie organométallique de surface, dont les performances catalytiques ont été évaluées.
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MacLeod, Michelle (Michelle Jeanette). "Development of N-heterocyclic carbene ligands for nanomaterials in aqueous media and expanding the interface of metal-organic framework (MOF) and polymer chemistry via polyMOFs." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115796.
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Thesis: Ph. D. in Inorganic Chemistry, Massachusetts Institute of Technology, Department of Chemistry, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references.
In the field of coordination chemistry, there are many standard organic ligand designs that are optimized for their ease of synthesis as well as established and favorable properties. Nevertheless, there is still room to add new ligand classes to the toolbox for specific applications. This thesis focuses on expansion of the types of ligands available for (1) metallic nanomaterial surface modification and (2) metal-ligand driven supramolecular assembly. (1) Surface ligands are typically used for surface passivation, imparting new properties such as solubility, or introducing a functional handle for further modification. The different demands in many diverse fields such as catalysis, electronics, and biomedicine necessitate that ligands interact strongly with surfaces and are structurally versatile. Herein, we advance N-heterocyclic carbenes (NHCs) as a new class of surface ligands to complement other established classes such as thiols, carboxylic acids, phosphines, ammonium salts, and phosphine oxides. Our studies have focused on ligand design for gold nanoparticles (NPs) and nanorods (NRs) in aqueous media. Using a polyethylene glycol (PEG)-conjugated NHC strategy, we demonstrate the first example of water-soluble NHC-stabilized Au-NPs. We then develop a bidendate NHC-thiol to modify gold NRs for photothermal therapy. (2) We examine the interface between amorphous polymers and crystalline metal organic frameworks (MOFs) in an emerging class of materials called polyMOFs. PolyMOFs use polymer ligands as their building blocks, opening the door to new material properties. In our work, we have developed a strategy for the synthesis of addressable, unimolecular polyMOF-forming oligomers using iterative-exponential growth, which has allowed us to study unique structure-property relationships of polyMOFs. Furthermore, we have developed pre- and post- synthetic modification strategies for polyMOF based materials.
by Michelle MacLeod.
Ph. D. in Inorganic Chemistry
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Stoeck, Ulrich, Simon Krause, Volodymyr Bon, Irena Senkovska, and Stefan Kaskel. "A highly porous metal–organic framework, constructed from a cuboctahedral super-molecular building block, with exceptionally high methane uptake." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138864.
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A highly porous metal–organic framework Cu2(BBCDC) (BBCDC = 9,9′-([1,1′-[b with combining low line]iphenyl]-4,4′-diyl)[b with combining low line]is(9H-[c with combining low line]arbazole-3,6-[d with combining low line]i[c with combining low line]arboxylate) (DUT-49) with a specific surface area of 5476 m2 g−1, a pore volume of 2.91 cm3 g−1, a H2 excess uptake of 80 mg g−1 (77 K, 50 bar), a CO2 excess uptake of 2.01 g g−1 (298 K, 50 bar) and an exceptionally high excess methane storage capacity of 308 mg g−1 (298 K, 110 bar) was obtained using an extended tetratopic linkerDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Stoeck, Ulrich, Simon Krause, Volodymyr Bon, Irena Senkovska, and Stefan Kaskel. "A highly porous metal–organic framework, constructed from a cuboctahedral super-molecular building block, with exceptionally high methane uptake." Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27787.
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A highly porous metal–organic framework Cu2(BBCDC) (BBCDC = 9,9′-([1,1′-[b with combining low line]iphenyl]-4,4′-diyl)[b with combining low line]is(9H-[c with combining low line]arbazole-3,6-[d with combining low line]i[c with combining low line]arboxylate) (DUT-49) with a specific surface area of 5476 m2 g−1, a pore volume of 2.91 cm3 g−1, a H2 excess uptake of 80 mg g−1 (77 K, 50 bar), a CO2 excess uptake of 2.01 g g−1 (298 K, 50 bar) and an exceptionally high excess methane storage capacity of 308 mg g−1 (298 K, 110 bar) was obtained using an extended tetratopic linker.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Batista, Poliane Karenine. "Desenvolvimento de metodologias em síntese orgânica: uso do catalisador Eu-MOF na síntese de cianoidrinas e obtenção de anéis tetraidropirânicos utilizando [BIMIM][PF6]." Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9193.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Currently several works have been developed in order to provide alternative routes for the synthesis of several organic compounds. These new protocols are generally aimed at obtaining softer and more eco-friendly reactive conditions, better yields and / or reactional times, and mechanistic studies, among others. This work consists of the study of synthesis routes of cyanohydrins and tetrahydropyrans, using lanthanide catalysts and ionic liquids, respectively. As cyanohydrins are products that can be transformed into important organic intermediates. They are obtained by the cyanosilylation of aldehydes reaction, which is synthetically viable only in the presence of a Lewis acid. In this work, the MOF [Eu2 (MELL)(H2O)6] was used as a heterogeneous catalyst in the cyanosilylation of aldehydes reaction. The catalytic assays were optimized using a thermally activated MOF in acetonitrile. Different aldehydes several structurally provided their respective cyanohydrins ranging from 1 to 6 hours and yields of 62 to 100%. The MOF was recycled in the addition reaction of TMSCN to 2-furfuraldehyde without loss of activity for five cycles. Tetrahydropyran rings (THP) are common in many natural products, so various strategies are being developed to synthesize them. In this work we also describe the study to obtain 2,4,6-trisubstituted tetrahydropyrans in a single step promoted by the ionic liquid (IL) BMIM][PF6] between the allyl bromide and aldehydes, through the Barbier-Prins reaction. The tests were performed under different conditions and optimized using 1: 4 benzaldehyde and allyl bromide. The use of IL [BMIM][PF6] provided THPs of various aldehydes in good yields ranging from 40% to 75% in 8 hours of reaction. In addition, IL [BMIM][PF6] was recovered and reused in the preparation of 4-bromo-2,6-diphenyl-tetrahydro-2H-pyran by up to 5 times without significant loss of yield of that product. The influence of the PF6- anion on the reaction between benzaldehyde and allyl bromide under the Barbier reaction conditions was investigated, as well as the influence of SnBr2 salt on the Prins cyclization reaction between homoallylic alcohol and benzaldehyde. The results show evidence that PF6- acts by accelerating the Barbier reaction and the excess of SnBr2 acts as Lewis acid in the Prins cyclization reaction. Subsequently, the use of KI in the reaction between benzaldehyde and allyl bromide was investigated, and it was found that depending on the ratio used between KI and SnBr2, the preferential formation of homoalyl alcohol or THP compound could occur.
Atualmente vários trabalhos têm sido desenvolvidos no intuito de possibilitar rotas alternativas para a síntese de diversos compostos orgânicos. Esses novos protocolos visam geralmente a obtenção de condições reacionais mais brandas e eco-amigáveis, melhores rendimentos e/ou tempos reacionais, estudos mecanísticos entre outros. Este trabalho consiste no estudo de rotas de síntese de cianoidrinas e tetraidropiranos, utilizando catalisadores de lantanídeos e líquidos iônicos, respectivamente. As cianoidrinas são substâncias que podem ser transformadas em intermediários orgânicos importantes. São geralmente obtidas através da reação de cianossililação de aldeídos, que é sinteticamente viável apenas na presença de um ácido de Lewis. Nesse trabalho, a MOF [Eu2(MELL)(H2O)6] foi utilizada como catalisador heterogêneo na reação de cianossililação de aldeídos. Os ensaios catalíticos foram otimizados utilizando a MOF ativada termicamente em acetonitrila. Diversos aldeídos estruturalmente diferentes forneceram suas respectivas cianoidrinas variando de 1 a 6 horas e com rendimentos de 62 a 100%. A MOF foi reciclada na reação de adição de TMSCN à 2-furfuraldeído sem perda de atividade durante cinco ciclos. Anéis tetraidropirânicos (THP) são comuns em vários produtos naturais, portanto várias estratégias estão sendo desenvolvidas para sintetizá-los. Nesse trabalho descrevemos também o estudo para a obtenção de tetraidropiranos 2,4,6-trissubstituídos meso em uma única etapa promovida pelo líquido iônico (LI) BMIM][PF6] entre o brometo de alila e aldeídos, através da reação Barbier-Prins. Os testes foram realizados sob diferentes condições e foi otimizado utilizando-se o benzaldeído e brometo de alila na proporção 1:4. A utilização LI [BMIM][PF6] forneceu produtos THPs de vários aldeídos com bons rendimentos variando-se de 40% a 75% em 8 horas de reação. Adicionalmente o LI [BMIM][PF6] foi recuperado e reutilizado na preparação do 4-bromo-2,6-difenil-tetraidro-2H-pirano em até 5 vezes sem perda significativa dos rendimentos desse produto. Foi investigado a influência isolada do ânion PF6- na reação entre o benzaldeído e o brometo de alila nas condições reacionais de Barbier, assim como a influência do sal SnBr2 na reação de ciclização de Prins entre o álcool homoalílico e o benzaldeído. Os resultados mostram evidências que o PF6- atua acelerando a reação de Barbier e o excesso de SnBr2 atua como ácido de Lewis na reação de ciclização de Prins. Posteriormente foi investigado a utilização do KI na reação entre o benzaldeído e o brometo de alila, e verificou-se que dependendo da proporção utilizada entre o KI e o SnBr2 pode ocorrer a formação preferencial do álcool homoalílico ou do composto THP.Atualmente vários trabalhos têm sido desenvolvidos no intuito de possibilitar rotas alternativas para a síntese de diversos compostos orgânicos. Esses novos protocolos visam geralmente a obtenção de condições reacionais mais brandas e eco-amigáveis, melhores rendimentos e/ou tempos reacionais, estudos mecanísticos entre outros. Este trabalho consiste no estudo de rotas de síntese de cianoidrinas e tetraidropiranos, utilizando catalisadores de lantanídeos e líquidos iônicos, respectivamente. As cianoidrinas são substâncias que podem ser transformadas em intermediários orgânicos importantes. São geralmente obtidas através da reação de cianossililação de aldeídos, que é sinteticamente viável apenas na presença de um ácido de Lewis. Nesse trabalho, a MOF [Eu2(MELL)(H2O)6] foi utilizada como catalisador heterogêneo na reação de cianossililação de aldeídos. Os ensaios catalíticos foram otimizados utilizando a MOF ativada termicamente em acetonitrila. Diversos aldeídos estruturalmente diferentes forneceram suas respectivas cianoidrinas variando de 1 a 6 horas e com rendimentos de 62 a 100%. A MOF foi reciclada na reação de adição de TMSCN à 2-furfuraldeído sem perda de atividade durante cinco ciclos. Anéis tetraidropirânicos (THP) são comuns em vários produtos naturais, portanto várias estratégias estão sendo desenvolvidas para sintetizá-los. Nesse trabalho descrevemos também o estudo para a obtenção de tetraidropiranos 2,4,6-trissubstituídos meso em uma única etapa promovida pelo líquido iônico (LI) BMIM][PF6] entre o brometo de alila e aldeídos, através da reação Barbier-Prins. Os testes foram realizados sob diferentes condições e foi otimizado utilizando-se o benzaldeído e brometo de alila na proporção 1:4. A utilização LI [BMIM][PF6] forneceu produtos THPs de vários aldeídos com bons rendimentos variando-se de 40% a 75% em 8 horas de reação. Adicionalmente o LI [BMIM][PF6] foi recuperado e reutilizado na preparação do 4-bromo-2,6-difenil-tetraidro-2H-pirano em até 5 vezes sem perda significativa dos rendimentos desse produto. Foi investigado a influência isolada do ânion PF6- na reação entre o benzaldeído e o brometo de alila nas condições reacionais de Barbier, assim como a influência do sal SnBr2 na reação de ciclização de Prins entre o álcool homoalílico e o benzaldeído. Os resultados mostram evidências que o PF6- atua acelerando a reação de Barbier e o excesso de SnBr2 atua como ácido de Lewis na reação de ciclização de Prins. Posteriormente foi investigado a utilização do KI na reação entre o benzaldeído e o brometo de alila, e verificou-se que dependendo da proporção utilizada entre o KI e o SnBr2 pode ocorrer a formação preferencial do álcool homoalílico ou do composto THP.
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Castagnoli, Riccardo. "Synthesis, Characterization, and Applications of a Novel Cu(II)-MOF Based on a Propargylcarbamate-Functionalized Isophthalate Ligand." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23112/.
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This work describes the synthesis of a propargylcarbamate-functionalized isophthalate ligand and its use in the solvothermal preparation of a new copper(II)-based metal organic framework named [Cu(1,3-YBDC)]ˑxH2O (also abbreviated as Cu-MOF. The characterization of this compound was performed using several complementary techniques such as infrared (ATR-FTIR) and Raman spectroscopy, X-ray powder diffraction spectroscopy (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS) as well as thermal and surface area measurements. Synchrotron X-ray diffraction analysis revealed that this MOF contains a complex network of 5-substituted isophthalate anions bound to Cu(II) centers, arranged in pairs within paddlewheel (or “Chinese lantern”) structure with a short Cu…Cu distance of 2.633 Å. Quite unexpectedly, the apical atom in the paddlewheel structure belongs to the carbamate carbonyl oxygen atom. Such extra coordination by the propargylcarbamate groups drastically reduces the MOF porosity, a feature that was also confirmed by BET measurements. Indeed, its surface area was determined to be low (14.5 ± 0.8 m2/g) as its total pore volume (46 mm3/g). Successively the Cu-MOF was treated with HAuCl4 with the aim of studying the ability of the propargylcarbamate functionality to capture the Au(III) ion and reduce it to Au(0) to give gold nanoparticles (AuNPs). The overall amount of gold retained by the Cu-MOF/Au was determined by AAS while the amount of gold and its oxidation state on the surface of the MOF was studied by XPS. A glassy carbon (GC) electrode was drop-casted with a Cu-MOF suspension to electrochemically characterize the material through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The performance of the modified electrodes towards nitrite oxidation was tested by CV and chronoamperometry.
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Müller, Tobias. "Untersuchungen zum „Controlled SBU Approach“ an metall-organischen Gerüstverbindungen und Syntheseversuche metallsubstituierter MOF-5- und MOF-177-Homologer." Master's thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2012. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-89799.
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Die potentiellen Precursor Magnesiumoxobromid bzw. Mangan(II,III)-oxopivalat für die noch unbekannten metallsubstituierten IRMOF-Homologen MOF-5(Mg) bzw.
MOF-5(Mn) konnten erfolgreich synthetisiert und Charakterisiert werden.
Deren experimenteller Einsatz zur Synthese der IRMOF-Homologen schlug jedoch fehl. Es konnte gezeigt werden, dass unter den klassischen CSA-Reaktionsbedingungen sowie unter modifizierten Parametern keine Synthese der IRMOF-Homologen möglich ist. Diese Feststellung wurde mit der Diskussion um die Eigenschaften der Komplexe, der Metallionen sowie mit einer Aufarbeitung der dazu zugänglichen Literatur begründet.
Es ist mit der Synthese der neuen MOF-177-Homologen MOF-177(Co) und
MOF-177(Be) gelungen, die bereits bei MOF-5-Homologen eingesetzten Precursor und Parameter auf ein System anzuwenden, das nicht zu den Yaghi\\\\\\\\\\\\\\\'schen IRMOFs gehört. Die Festkörper weisen mit ihren Oberflächenwerten SBET(MOF-177(Co)) = 3742 m²/g bzw. SBET(MOF-177(Be)) = 1816.4 m²/g klar mikroporöses Adsorptionsverhalten auf. Eine erste vereinfachte Anpassung der Kristallstrukturen an die experimentellen PXRDs konnte für beide MOFs vorgenommen werden. MOF-177(Co) zeigt wie auch MOF-5(Co) eine leicht vergrößerte Gitterkonstante. MOF-177(Be) konnte aufgrund der Verdrehung der Carboxylatgruppen am Berylliumoxocluster ausschließlich in röntgenamorpher Form hergestellt werden.
Die Untersuchung der auftretenden Co-Spezies in reinen und mit Zinkprecursor gemischten Lösungen an Cobaltoxopivalat in den Lösungsmitteln Toluol brachte folgende Erkenntnisse:
• Der im Feststoff dimere achtkernige Cobaltprecursor zerfällt während des Lösens in die vierkernige monomere Form und ist strukturanalog dem basischen Zinkcarboxylaten (Typ I).
• Der Komplex unterliegt einem solvensabhängigem Komplexstabilitäts-gleichgewicht. Dieses ist aufgrund der koordinierenden Eigenschaften des DEF, in den DEF-Lösungen weiter in Richtung der Zersetzungsprodukte verschoben. In beiden Lösungen ist der Komplex zu über 90% undissoziiert.
• Nur in DEF treten bei dem Zumischen verschiedener Zinkprecursor Metallaustauschreaktionen auf. Es ist somit die Existenz von vierkernigen
Zn-Co-Mischclustern der allg. Form [CoyZn(4-y)O] bewiesen worden.
• Es wurde nachgewiesen, dass beim Vorhandensein von Acetat und Pivalat Anionenaustauschreaktionen stattfinden und Komplexe der Form
[CoyZn(4-y)O(Piv)xAc(6-x)] auftreten. Die Bedeutung für das Stattfinden des CSAs unter Berücksichtigung der empirischen Erkenntnisse aus der Literatur wurde erörtert.
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Ngo, Thuhuong T. "Photocatalytic Reduction of CO2 with Tunable Bandgap and Bandedge Materials." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6551.
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Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.
Since the discovery of TiO2 photocatalysts for splitting water (4) and reducing CO2 (5) to form useful chemical feedstock such as H2, CO and CH4, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, 7). Issues being addressed include the wide bandgap and mismatched band edge for reactions (thermodynamic energy for reaction), poor quantum efficiency of the photon collector systems, high recombination of e-/h+ pairs and limitation in the rate of charge transfer from photocatalyst to reactants.
This work focuses on improving efficiency of photocatalysts for fuel production through several approaches: (1) engineering a metal-organic-framework (MOF) to have proper band gaps and band edges for targeted reactions and for enhancing photoadsorption in the visible light range, (2) tuning an ABO3-type perovskite for desired bandgaps and thermodynamically favored bandedges for CO2 reduction with water in visible light range.
A porphyrin-based Ti-MOF is studied for CO2 photoreduction to gaseous chemical fuels such as CH4 and CO. The porphyrin linkers allow porphyrin-based MOF-525 to achieve narrow bandgap (Eg = ~1.7eV) to absorb visible light, indicating its ability to harvest more solar energy than conventional TiO2. Ti/Zr-MOF-525 also exhibited the appropriate energy level alignment for CO2 and H2O redox reaction for CO and CH4 production. Its CO2 photoreactivity under visible light was demonstrated in a photoreaction, illuminated by 150W Xenon solar simulator. Interestingly, Ti/Zr-MOF-525 demonstrates a selectivity toward CH4, a more valuable fuels than CO. The gas phase reaction condition is an advance over liquid photoreaction. The catalyst stability was also studied and presented. After 3 cycles of reactions, Ti/Zr-MOF-525 is relatively stable for CO2 photoreduction and able to maintain its photoreactivity at about 60-65% of fresh catalyst. The reduction of reactivity is due to a less stable fresh catalyst.
When investigating LaCr1-xFexO3 perovskite oxides for photocatalyst, it was found that when replacing Cr ions at the B sites of LaCrO3 by Fe ions, the bandgap does not follow a linear trend in regards to metal ratio composition but rather reflects the smaller bandgap of LaFeO3. Bandedges were successfully measured for the new synthesized materials. At x = 0.25, the conduction band potential remains similar with x = 0. However, at x = 0.75, the conduction band potential was more negative than either perovskites at x = 0 or x = 1. Future simulation of density of state could address this interesting observation. CO2 reduction relativities of each perovskites were predicted well by their measured bandgaps and bandedges. Among five studied perovskites, synthesized LaCr0.25Fe0.75O3 (x = 0.75) is the most active for CO2 photoreduction under visible illumination at room temperature thanks to its small bandgap (2.0 eV) and its suitable bandedges for CO2 photoreduction.
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Abdulla, Beyar. "Nanocellulose surface functionalization for in-situ growth of zeolitic imidazolate framework 67 and 8." Thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-417650.
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This master’s thesis was conducted at the Department of Nanotechnology and Functional Materials at Ångström Laboratory as part of an on-going project to develop hybrid nanocomposites from Cladophora cellulose and a sub-type of metal-organic frameworks; zeolitic imidazolate frameworks (ZIFs). By utilizing a state-of-the-art interfacial synthesis approach, in-situ growth of ZIF particles on the cellulose could be achieved. TEMPO-mediated oxidation was diligently used to achieve cellulose nanofibers with carboxylate groups on their surfaces. These were ion-exchanged to promote growth of ZIF particles in a nanocellulose solution and lastly, metal ions and organic linkers which the ZIFs are composed of were added to the surface functionalized and ion-exchanged nanocellulose solution to promote ZIF growth. By vacuum filtration, mechanical pressing and furnace drying; freestanding nanopapers were obtained. A core-shell morphology between the nanocellulose and ZIF crystals was desired and by adjusting the metal ion concentration, a change in morphologies was expected. The nanocomposites were investigated with several relevant analytical tools to confirm presence, attachment and in-situ growth of ZIF crystal particles upon the surface of the fine nanocellulose fibers. Both the CNF@ZIF-67 and CNF@ZIF-8 nanocomposites were successfully prepared as nanopapers with superior surface areas and thermal properties compared to pure TEMPO-oxidized cellulose nanopapers. The CNF@ZIFs showcased hierarchical porosities, stemming from the micro- and mesoporous ZIFs and nanocellulose, respectively. Also, it was demonstrated that CNF@ZIF-8 selectively adsorbed CO2 over N2. Partial formation of core-shell structure could be obtained, although a relationship between increased metal ions and ZIF particle morphology could not wholly be observed.
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Bonnefoy, Jonathan. "Conception de nouveaux matériaux hybrides types MOFs bio-inspirés à fonctionnalités avancées pour la catalyse." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10195/document.
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Les MOFs sont des solides à la structure cristalline poreuse à base de clusters métalliques et de ligands organiques qui font l'objet de très nombreuses études, dans des champs d'applications très variés, qui vont de la catalyse au « drug delivery », en passant par le stockage de gaz et, plus récemment, en tant que senseurs biologiques. Les ligands organiques, qui les constituent, peuvent lorsqu'ils possèdent un point d'ancrage, comme des groupements amino, être fonctionnalisés grâce à des réactions chimiques. Les travaux présentés dans cette thèse reportent la fonctionnalisation de MOFs, via différentes stratégies, comme des greffages covalent et issues de la chimie de coordination, tel que le couplage peptidique ou encore la synthèse d'urée. Dans cette thèse, est notamment présentée une nouvelle méthode permettant de greffer très rapidement des peptides chiraux dans les nanopores des MOFs. Une large bibliothèque MOF-peptides a ainsi été obtenue et caractérisée. Ces nouveaux composés ont également été utilisés pour l'ancrage de complexes organométalliques dans les cavités des MOFs. Suivant un échange de ligands post-synthétique, il a aussi été possible d'intégrer un complexe organométallique photo-catalytique dans la structure d'un MOF, améliorant ainsi ses activités et sélectivités pour la photo-réduction de CO2. Enfin, les performances catalytiques de ces derniers matériaux MOFs se sont révélées supérieures aux versions homogènes des complexes, ce qui offre de nouvelles opportunités pour la catalyse fineMetal Organic Frameworks, MOFs, are porous crystalline solid based on metal clusters and organic ligands, investigated for numerous applications such as catalysis, drug delivery, gas storage and, more recently, biosensors. The work presented in this thesis focuses on functionalizing MOFs through different strategies, such as covalent grafting or surface coordination chemistry, through chemical reactions, such as peptide coupling or synthesis of urea. In particular, a new method to very quickly graft chiral peptides into the nanopores of MOFs is reported. A large library of MOF-peptides has thus been obtained and characterized. These novel compounds have also been used for grafting organometallics in the cavities of MOFs. Following a post-synthetic ligand exchange, it was also possible to integrate a photocatalytic complex in the structure of a MOF, improving its activities and selectivities for the photocatalytic CO2 reduction. In general, the catalytic performances of these materials were superior to those of their homogeneous counterparts, thus further expanding the potential of MOFs as well-defined heterogeneous catalysts for fine chemistry
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Genesio, Guillaume. "Développement de MOFs fonctionnels sur support solide : application à la photochimie." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS125/document.
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Les travaux présentés dans ce manuscrit s’inscrivent dans le cadre général de la conversion et du stockage de l’énergie lumineuse. Dans ce domaine, l’utilisation de MOFs (Metal-Organic Frameworks) polyfonctionnels n’en est qu’à ses débuts et ils sont principalement utilisés sous forme de poudre cristalline. Or le développement de ces MOFs sur un support solide est essentiel dans l’obtention d’un objet technologiquement avancé répondant à des critères industriels. Les travaux réalisés lors de ce projet ont donc porté sur la croissance contrôlée de matériaux hybrides polyfonctionnels de type MOF sur une surface conductrice transparente TCO (Transparent Conductive Oxide). Les différentes fonctionnalités ont été introduites au sein du MOF par intégration d’une partie photosensible et d’une unité catalytique.A partir de systèmes de MOFs modèles à base de zirconium, il a été possible de produire des systèmes polyfonctionnels par modifications directement pendant la synthèse et/ou post synthèse. Le contrôle de la croissance, en maîtrisant les conditions expérimentales lors de la synthèse solvothermale directe in situ, nous a permis d’obtenir une couche de cristaux monodisperses solidement attachés aux supports TCO. Des efforts importants ont également été dédiés à la compréhension des mécanismes de croissance des MOF sur support TCO. Des essais de photodégradation du bleu de méthylène (polluant organique) ont permis de valider le potentiel photochimique de nos dispositifs.La méthodologie développée pour le contrôle de la croissance des MOFs à base de zirconium a été transposée avec succès à des analogues à base de titane, démontrant la portabilité de la stratégie vers d’autres types de MOFs. Ces derniers ont été utilisés en photo-réduction du CO2 lors d’essais préliminaires (collaboration avec le Collège de France) conduisant sélectivement à l’obtention de formiateThis work is focused on the development of a functionalization method of TCO transparent conductive surfaces (Transparent Conductive Oxide) by hybrid multifunctional materials, Metal-Organic Frameworks (MOFs). Different properties are provided within the MOF by adding different photosensitive and catalytic units. The development of such materials is in its infancy and they have been mainly developed as crystalline powder. However the development of these MOFs onto a solid support is challenging but also essential toward obtaining a technologically advanced device.This project is focused on the growth controlled of MOFs crystals onto TCO support. From a Zirconium material, it was possible to obtain multifunctional systems by changing components directly during the synthesis or by post synthesis modifications. It has been possible to control the growth of materials on the support by direct in situ solvothermal synthesis and to obtain a monodisperse layer of crystals well anchored to the TCO supports. Photodegradation of methylene blue (organic pollutant) has been performed to validate their photoreactivity.The methodology developed with the Zirconium based MOF has been implemented successfully in a similar compound to include higher photosensitizer components and with titanium-based MOFs. It shows the portability of the strategy towards other types of MOFs. They were used in CO2 photo-reduction (in collaboration of the College de France) where selectively of formate production was observed
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Hoffmann, Herbert C., Silvia Paasch, Philipp Müller, Irena Senkovska, Mohan Padmanaban, Frank Glorius, Stefan Kaskel, and Eike Brunner. "Chiral recognition in metal–organic frameworks studied by solid-state NMR spectroscopy using chiral solvating agents." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138884.
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Recently, we have described the synthesis of chiral metal–organic frameworks iPr-ChirUMCM-1 and Bn-ChirUMCM-1 and their use in enantioselective separation. Here, we demonstrate for the first time the use of a chiral solvating agent (1-phenyl-2,2,2-trifluoroethanol, TFPE) for chiral recognition in iPr-ChirUMCM-1 and Bn-ChirUMCM-1 by means of solid-state13C NMR spectroscopyDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich