Academic literature on the topic 'Cu-Ni catalysts'
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Journal articles on the topic "Cu-Ni catalysts"
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Yang, Haobo, Jichao Li, Hao Yu, Feng Peng, and Hongjuan Wang. "Metal-Foam-Supported Pd/Al2O3 Catalysts for Catalytic Combustion of Methane: Effect of Interaction between Support and Catalyst." International Journal of Chemical Reactor Engineering 13, no. 1 (2015): 83–93. http://dx.doi.org/10.1515/ijcre-2014-0009.
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Abstract Structured Pd/Al2O3 catalysts were fabricated by impregnating Pd onto Ni and Cu foams coated with Al2O3 layers. By testing the adhesion stability and catalytic activity in the combustion of methane, the superior performance of Ni-foam-supported Pd/Al2O3 catalyst was demonstrated, to its counterpart powder catalysts. The resultant structured catalysts enable the fabrication of lamellar microreactor systems. It is found that the metal foams influence the activity of catalyst layer, due to the diffusive penetration of metallic atoms into catalysts from metal foams. The Ni foam is beneficial for enhancing the activity of Pd/Al2O3 catalyst, while the Cu foam plays a negative role. The investigation to the model powder catalysts doped with Ni and Cu verified the modification of Ni and Cu to the physicochemical properties of Pd/Al2O3 catalyst, thereby the catalytic performances. Thus, it can be expected that the performance of structured catalysts may be improved by rationally designing and selecting proper supports.
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Xiao, Yan, Nannan Zhan, Jie Li, Yuan Tan, and Yunjie Ding. "Highly Selective and Stable Cu Catalysts Based on Ni–Al Catalytic Systems for Bioethanol Upgrading to n-Butanol." Molecules 28, no. 15 (2023): 5683. http://dx.doi.org/10.3390/molecules28155683.
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The catalytic upgrading of ethanol into butanol through the Guerbet coupling reaction has received increasing attention recently due to the sufficient supply of bioethanol and the versatile applications of butanol. In this work, four different supported Cu catalysts, i.e., Cu/Al2O3, Cu/NiO, Cu/Ni3AlOx, and Cu/Ni1AlOx (Ni2+/Al3+ molar ratios of 3 and 1), were applied to investigate the catalytic performances for ethanol conversion. From the results, Ni-containing catalysts exhibit better reactivity; Al-containing catalysts exhibit better stability; but in terms of ethanol conversion, butanol selectivity, and catalyst stability, a corporative effect between Ni–Al catalytic systems can be clearly observed. Combined characterizations such as XRD, TEM, XPS, H2-TPR, and CO2/NH3-TPD were applied to analyze the properties of different catalysts. Based on the results, Cu species provide the active sites for ethanol dehydrogenation/hydrogenation, and the support derived from Ni–Al–LDH supplies appropriate acid–base sites for the aldol condensation, contributing to the high butanol selectivity. In addition, catalysts with strong reducibility (i.e., Cu/NiO) may be easily deconstructed during catalysis, leading to fast deactivation of the catalysts in the Guerbet coupling process.
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Han, Dongmei, Yong Chen, Shuanjin Wang, Min Xiao, Yixin Lu, and Yuezhong Meng. "Effect of Alkali-Doping on the Performance of Diatomite Supported Cu-Ni Bimetal Catalysts for Direct Synthesis of Dimethyl Carbonate." Catalysts 8, no. 8 (2018): 302. http://dx.doi.org/10.3390/catal8080302.
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Alkali-adopted Cu-Ni/diatomite catalysts were designed and used for the direct synthesis of dimethyl carbonate (DMC) from carbon dioxide and methanol. Alkali additives were introduced into Cu-Ni/diatomite catalyst as a promoter because of its lower work function (Ni > Cu > Li > Na > K > Cs) and stronger electron-donating ability. A series of alkali-promoted Cu-Ni/diatomite catalysts were prepared by wetness impregnation method with different kind and different loading of alkali. The synthesized catalysts were fully characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), temperature-programmed reduction (TPR), and NH3/CO2-TPD. The experimental results demonstrated that alkali adoption can significantly promote the catalytic activity of Cu–Ni bimetallic catalysts. Under the catalytic reaction conditions of 120 °C and 1.0 MPa; the highest CH3OH conversion of 9.22% with DMC selectivity of 85.9% has been achieved when using 15%(2Cu-Ni) 2%Cs2O/diatomite catalyst (CuO + NiO = 15 wt. %, atomic ratio of Cu/Ni = 2/1, Cs2O = 2 wt. %).
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Pudi, Satyanarayana Murty, Tarak Mondal, Prakash Biswas, Shalini Biswas та Shishir Sinha. "Conversion of Glycerol into Value-Added Products Over Cu–Ni Catalyst Supported on γ-Al2O3 and Activated Carbon". International Journal of Chemical Reactor Engineering 12, № 1 (2014): 151–62. http://dx.doi.org/10.1515/ijcre-2013-0102.
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Abstract A series of Cu, Ni monometallic and bimetallic catalysts supported on γ-Al2O3 and activated carbon were synthesized by incipient wetness impregnation method and examined for hydrogenolysis and esterification of glycerol. Hydrogenolysis reaction was carried out in a 250 ml Teflon-coated stainless steel batch reactor at 250°C and 10 bar H2 pressure, whereas esterification of glycerol with acetic acid was carried out at 120°C at atmospheric pressure. The physiochemical properties of the catalysts were investigated by various techniques such as surface area, X-ray diffraction (XRD), NH3-temperature-programmed desorption (TPD). Characterization results dictated that the reduction behavior, acidic nature and the metal support interactions were varied with the support as well as Cu/Ni weight ratio. The XRD results confirmed the formation of mixed oxide Cu0.75Ni0.25 Al2O4 phase in Cu–Ni (3:1)/γ-Al2O3 catalyst. Among the catalysts tested, Cu–Ni bimetallic catalysts showed superior performance as compared to monometallic catalysts in both the reactions. The glycerol hydrogenolysis activity of γ-Al2O3 supported Cu–Ni catalysts was higher than the activated carbon-supported catalysts. 1,2-PDO was obtained as the main hydrogenolysis product independent of the support as well as Cu/Ni weight ratio and its selectivity was in the range of 92.8–98.5%. The acidic nature of γ-Al2O3 and the mixed oxide (Cu0.75Ni0.25Al2O4) phase played an important role for hydrogenolysis activity. Cu–Ni (3:1)/γ-Al2O3 catalyst showed the maximum 1,2-PDO selectivity to 97% with 27% glycerol conversion after a reaction time of 5 h. On the other hand, Cu–Ni(1:3)/C catalyst showed the highest glycerol conversion of 97.4% for esterification and obtained selectivity to monoacetin, diacetin and triacetin were 26.1%, 67.2% and 6.5%, respectively.
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Hasnan, Nur Shamimie Nadzwin, Manoj Pudukudy, Zahira Yaakob, Nur Hidayatul Nazirah Kamarudin, Kean Long Lim, and Sharifah Najiha Timmiati. "Promoting Effects of Copper and Iron on Ni/MSN Catalysts for Methane Decomposition." Catalysts 13, no. 7 (2023): 1067. http://dx.doi.org/10.3390/catal13071067.
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Copper and iron-based bimetallic nickel catalysts supported on Mesostructured Silica Nanoparticles (MSNs) with compositions of 50% Ni–5% Cu/MSN and 50% Ni–5% Fe/MSN were prepared using an impregnation method, and they were compared with a monometallic 50% Ni–MSN catalyst for their activity and stability in methane decomposition reaction. The influence of promoters, such as Cu and Fe, at different reaction temperatures (700 °C, 800 °C and 900 °C) was investigated. The results revealed that the Cu and Fe-promoted catalysts significantly increased the hydrogen yield in methane decomposition compared with the unpromoted catalyst. This could be attributed to the formation of Ni–Cu and Ni–Fe bimetallic alloys in the catalysts, respectively, and this favored the stability of the catalysts. With increasing reaction temperature, the hydrogen yield also increased. However, the hydrogen yield and the lifetime of the nickel catalyst were enhanced upon the addition of iron compared to copper at all the reaction temperatures. The analysis conducted over the spent catalysts validated the formation of multi-walled carbon nanotubes with a bamboo-like internal channel over the catalysts along with a high crystallinity and graphitization degree of the carbon produced.
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Gai, Pratibha L. "In Situ Electron Microscopy in catalysis research and related surface reactions." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 614–15. http://dx.doi.org/10.1017/s0424820100155049.
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Catalysis plays a major role in the modern oil and chemical industries. Solid state catalysts are most common, whilst the reactants are commodity gases and liquids. The performance of the catalysts depends strongly on their microstructure, chemistry and surface structures on a fine (nanometer) scale and electron microscopy (EM) plays an increasingly important role in the characterization. In-situ EM with an environmental cell permits direct observations of chemical reactions under near operating conditions and in conjunction with HREM and AEM can provide in favorable cases, significant atomic level information about the surface/microstructural changes and about possible reaction with substrates. In this paper, examples of catalyst materials in chemical technology and the nature of catalysis in alloy steels with applications in nuclear reactors are shown to elucidate this.A variety of supported metallic catalysts were examined: Ni/carbon, Cu/alumina and bimetallic Cu-Pd/C (both of interest in methanol synthesis), Cu-Ru/C (incyclohexane conversions) and Cu-Ni/alumina.
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Yang, Wen, Yanyan Feng, and Wei Chu. "Catalytic Chemical Vapor Deposition of Methane to Carbon Nanotubes: Copper Promoted Effect of Ni/MgO Catalysts." Journal of Nanotechnology 2014 (2014): 1–5. http://dx.doi.org/10.1155/2014/547030.
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The Ni/MgO and Ni-Cu/MgO catalysts were prepared by sol-gel method and used as the catalysts for synthesis of carbon nanotubes by thermal chemical vapor deposition. The effect of Cu on the carbon yield and structure was investigated, and the effects of calcination temperature and reaction temperature were also investigated. The catalysts and synthesized carbon materials were characterized by temperature programmed reduction (TPR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Results showed that the addition of Cu promoted the reduction of nickel species, subsequently improving the growth and yield of CNTs. Meanwhile, CNTs were synthesized by the Ni/MgO and Ni-Cu/MgO catalysts with various calcination temperatures and reaction temperatures, and results suggested that the obtained CNTs on Ni-Cu/MgO catalyst with the calcination temperature of 500°C and the reaction temperature of 650°C were of the greatest yield and quantity of 927%.
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Zhu, Tianhan, Hua Song, Feng Li та Yanguang Chen. "Hydrodeoxygenation of Benzofuran over Bimetallic Ni-Cu/γ-Al2O3 Catalysts". Catalysts 10, № 3 (2020): 274. http://dx.doi.org/10.3390/catal10030274.
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Bimetallic NixCu(10−x)/γ-Al2O3 catalysts (where x is the mass fraction of Ni) with different Ni/Cu mass ratios were prepared. The catalysts were characterized by X-ray diffractometry, N2 adsorption–desorption, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, H2-temperature programmed reduction, and transmission electron microscopy. The effect of Ni/Cu mass ratio on benzofuran hydrodeoxygenation was investigated in a fixed-flow reactor. Cu addition improved the NiO reducibility. The strong interaction of Ni and Cu led to the formation of smaller and highly dispersed CuO and NiO species over γ-Al2O3, which favors an improvement in catalytic activity. Among the as-prepared catalysts, the Ni5Cu5/γ-Al2O3 showed the highest deoxygenated product yield (79.9%) with an acceptable benzofuran conversion of 95.2%, which increased by 18.3% and 16.9% compared with that of the monometallic Ni/γ-Al2O3 catalyst. A possible reaction network was proposed, which would provide insight into benzofuran hydrodeoxygenation over the Ni5Cu5/γ-Al2O3 catalyst.
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Jun, Uidam, Bon-Jun Ku, Yeji Gwon, et al. "Influence of Metal Composition and Support Material on Carbon Yield and Quality in the Direct Decomposition of Methane." Molecules 30, no. 9 (2025): 1903. https://doi.org/10.3390/molecules30091903.
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A series of catalysts were synthesized via a combination of evaporation-induced self-assembly and spray pyrolysis; they were then applied to the direct decomposition of methane. Among them, Ni-Cu/MgO catalysts exhibited the smallest Ni particle size (~9 nm), attributed to the Cu-induced suppression of Ni crystal growth during synthesis. These catalysts achieved the highest carbon yield, primarily due to the enhanced dispersion and nanoscale size of Ni particles. The interaction between methane and the catalysts, as well as the structural and electrical properties of the resulting carbon nanotubes, such as crystallinity and conductivity, were investigated with respect to the support material (MgO vs. Al2O3) and metal composition (Ni vs. Ni-Cu). The findings provide valuable insights for designing advanced catalyst systems for the efficient conversion of methane into high-value carbon-based materials.
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Gousi, Mantha, Eleana Kordouli, Kyriakos Bourikas, et al. "Green Diesel Production over Nickel-Alumina Nanostructured Catalysts Promoted by Copper." Energies 13, no. 14 (2020): 3707. http://dx.doi.org/10.3390/en13143707.
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A series of nickel–alumina catalysts promoted by copper containing 1, 2, and 5 wt. % Cu and 59, 58, and 55 wt. % Ni, respectively, (symbols: 59Ni1CuAl, 58Ni2CuAl, 55Ni5CuAl) and a non-promoted catalyst containing 60 wt. % Ni (symbol: 60NiAl) were prepared following a one-step co-precipitation method. They were characterized using various techniques (N2 sorption isotherms, XRD, SEM-EDX, XPS, H2-TPR, NH3-TPD) and evaluated in the selective deoxygenation of sunflower oil using a semi-batch reactor (310 °C, 40 bar of hydrogen, 96 mL/min hydrogen flow rate, and 100 mL/1 g reactant to catalyst ratio). The severe control of the co-precipitation procedure and the direct reduction (without previous calcination) of precursor samples resulted in mesoporous nano-structured catalysts (most of the pores in the range 3–5 nm) exhibiting a high surface area (192–285 m2 g−1). The promoting action of copper is demonstrated for the first time for catalysts with a very small Cu/Ni weight ratio (0.02–0.09). The effect is more pronounced in the catalyst with the medium copper content (58Ni2CuAl) where a 17.2% increase of green diesel content in the liquid products has been achieved with respect to the non-promoted catalyst. The copper promoting action was attributed to the increase in the nickel dispersion as well as to the formation of a Ni-Cu alloy being very rich in nickel. A portion of the Ni-Cu alloy nanoparticles is covered by Ni0 and Cu0 nanoparticles in the 59Ni1CuAl and 55Ni5CuAl catalysts, respectively. The maximum promoting action observed in the 58Ni2CuAl catalyst was attributed to the finding that, in this catalyst, there is no considerable masking of the Ni-Cu alloy by Ni0 or Cu0. The relatively low performance of the 55Ni5CuAl catalyst with respect to the other promoted catalysts was attributed, in addition to the partial coverage of Ni-Cu alloy by Cu0, to the remarkably low weak/moderate acidity and relatively high strong acidity exhibited by this catalyst. The former favors selective deoxygenation whereas the latter favors coke formation. Copper addition does not affect the selective-deoxygenation reactions network, which proceeds predominantly via the dehydration-decarbonylation route over all the catalysts studied.
Dissertations / Theses on the topic "Cu-Ni catalysts"
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Lortie, Maxime. "Reverse Water Gas Shift Reaction over Supported Cu-Ni Nanoparticle Catalysts." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31733.
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CuNi nanoparticles were synthesized using a new polyol synthesis method. Three
different CuxNi1-x catalysts were synthesized where x = 20, 50 and 80. The nanoparticles were deposited on carbon, C, gamma-alumina, γ-Al2O3, yttria-stabilized zirconia, YSZ, and samariumdoped ceria, SDC. Each set of catalysts was tested using the Reverse Water Gas Shift, RWGS, reaction under atmospheric pressure and at temperatures ranging from 400°C-700°C. The experiments were repeated 3 times to ensure stability and reproducibility. Platinum nanoparticles
were also deposited on the same supports and tested for the RWGS reaction at the same conditions. The CuNi nanoparticles were characterized using a variety of different techniques. Xray diffraction, XRD, measurements demonstrate the resence of two CuNi solid solutions: one Cu rich solid solution, and the other a Ni rich solid solution. X-ray photo electron spectroscopy, XPS, measurements show Cu enrichment on all catalytic surfaces. Scanning electron microscopy, SEM, measurements show CuNi nanoparticles ranging in size from 4 nm to 100 nm.
Some agglomeration was observed. SDC showed the best yield with all catalysts. Furthermore, high oxygen vacancy content was shown to increase yield of CO for the RWGS reaction. Cu50Ni50/SDC shows the combination of highest yield of CO and the best stability among CuNi catalysts. It also has similar yields (39.8%) as Pt/SDC at 700°C, which achieved the equilibrium yield at that temperature (43.9%). The catalyst was stable for 48 hours when exposed to high temperatures (600-700°C). There was no CH4 observed during any of the experiments when the
partial pressure of the reactant gases was fed stoichiometrically. Partial pressure variation experiments demonstrated the presence of CH4 when the partial pressure of hydrogen was increased to twice the value of the partial pressure of CO2.
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Lin, Jiann-Horng. "Supported Copper, Nickel and Copper-Nickel Nanoparticle Catalysts for Low Temperature Water-Gas-Shift Reaction." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1327068565.
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Yu, Zhiqiang. "Transient Studies of Ni-, Cu-Based Electrocatalysts in CH4 Solid Oxide Fuel Cell." Akron, OH : University of Akron, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1194625466.
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Dissertation (Ph. D.)--University of Akron, Dept. of Chemical Engineering, 2007.<br>"December, 2007." Title from electronic dissertation title page (viewed 03/12/2008) Advisor, Steven S. C. Chuang; Committee members, Lu-Kwang Ju, Edward Evans, W. B. Arbuckle, Stephen Z. D. Cheng; Department Chair, Lu-Kwang Ju; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
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Wang, Zhao. "Selective Hydrogenation of Butadiene over Non-noble Bimetallic Catalysts." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066102/document.
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Ce travail porte sur la préparation et la caractérisation de catalyseurs bimétalliques Cu-Zn, Ni-Zn et Fe-Zn supportés sur TiO2 avec des rapports atomiques variables et sur l'étude de leurs propriétés catalytiques pour l'hydrogénation sélective d'hydrocarbures polyinsaturés. Les méthodes de co-dépôt-précipitation à l'urée (DPu) et co-dépôt-précipitation à pH fixe (DP8) ont été utilisées pour la préparation des matériaux. Les ions métalliques se déposent séquentiellement sur la surface de TiO2 (selon la séquence CuII < ZnII ?FeII <br>This work investigates the preparation and characterization of titania-supported non-noble bimetallic Cu-Zn, Ni-Zn and Fe-Zn catalysts with various atomic ratios and their catalytic properties for the selective hydrogenation of polyunsaturated hydrocarbons. Co-deposition-precipitation with urea (DPu) and co-deposition-precipitation at fixed pH (DP8) methods were employed for the samples preparation. The metal ions were sequentially deposited onto the TiO2 surface (the sequence of pH for ions deposition being CuII < ZnII ≈FeII < NiII) during the DPu, while they were simultaneously deposited using DP8 method. After sample reduction at proper temperature (350 °C for Cu-Zn, 450 °C for Ni-Zn and 500 °C for Fe-Zn), XRD and STEM-HAADF coupled with EDS showed that bimetallic nanoparticles were formed in Cu-Zn/TiO2 (Cu3Zn1 or Cu0.9Zn0.1 alloy) and Ni-Zn systems (Ni1Zn1 or Ni4Zn1 alloy) with average particle size smaller than 5 nm. Only metallic Fe was detected by XRD in Fe-Zn/TiO2. Zn is inactive for butadiene selective hydrogenation, and acts as a modifier of the monometallic catalysts whose activity follows the sequence: Cu < Fe < Ni. The addition of Zn slightly decreases the activity and influences the selectivity to butenes, but provides much more stable catalysts. The higher stability of the bimetallic catalysts was ascribed to the formation of lower amount of carbonaceous species during the reaction, resulting from the change in the size of the active metal surface ensembles by alloying with Zn
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Chen, Shuo. "Effect of metal dispersion on the catalytic performance of monometallic Ni/SBA-15 and Cu/SBA-15 catalysts in the hydroconversion of HMF." Thesis, Lille, 2019. http://www.theses.fr/2019LIL1R008.
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La production d'additifs pour les carburants, d’indices d'octane élevés, à partir des molécules biosourcées telles que le 5-hydroxyméthylfurfural (HMF) est le sujet de nombreuses études. Les catalyseurs à base de Pt, de Pd et de Ru sont décrits comme particulièrement actifs dans la réaction de conversion du HMF en 2,5-diméthylfurane (DMF) et en 2,5-diméthyltétrahydrofurane (DMTHF). Cependant leur substitution dans les formulations catalytiques est souhaitable compte tenu de leur coût élevé et de leur faible disponibilité. Les éléments de substitution peuvent être certains métaux de transition (par exemple Cu ou Ni), plus abondants, mais généralement moins actifs. Mes travaux de recherche ont donc portés sur la préparation de catalyseurs, à base de métaux de transition, actifs et sélectifs pour l'hydrogénation du HMF en des molécules pouvant être incorporées dans les carburants. Les phases actives étudiées au cours de mon doctorat reposent sur les métaux de transition Ni et Cu. Ces phases actives ont été supportées sur des silices mésoporeuses de type SBA-15. L'étude est divisée en deux parties distinctes, en fonction du métal étudié. La première partie du doctorat présente les résultats obtenus avec des catalyseurs monométalliques Ni supportés. Dans un premier temps, l'optimisation des paramètres de réaction pour l'hydroconversion sélective du HMF en DMF et en DMTHF a été réalisée en utilisant un catalyseur préparé par la méthode d'imprégnation à humidité naissante d’une solution du précurseur nitrate (Chapitre 3). Les paramètres de réaction optimisés incluent la température de réaction, la pression de dihydrogène, le rapport molaire HMF/Ni et le temps de réaction. Une étude cinétique préliminaire a également été réalisée. L’effet de la dispersion et de la taille des particules métalliques de Ni sur les performances catalytiques des catalyseurs Ni/SBA-15 a été étudié sur des matériaux préparés par la méthode d’infiltration à l'état fondu des précurseurs nitrates (Chapitre 4). Le niveau de dispersion du nickel a été modifié en utilisant des supports SBA-15 contenant des porosités d’interconnexion différentes et obtenues à différentes températures de synthèse. Les résultats montent que le catalyseur Ni/SBA-15, préparé par la méthode simple IWI, permet d’atteindre des rendements élevés en DMF et DMTHF dans des conditions réactionnelles optimales. Le niveau de dispersion du Ni, tel qu’observé à partir des matériaux obtenus par infiltration des sels fondus, a quant à lui un effet significatif sur l'activité catalytique du catalyseur. La deuxième partie de mes travaux de recherche porte sur les propriétés catalytiques des catalyseurs monométalliques à base de Cu/SBA-15 préparés par différentes méthodes, et présentant des états de division de la phase Cu différents (Chapitre 5). Les modes de synthèse appliqués incluent la méthode d’imprégnation à humidité naissante (IWI), la méthode d'autocombustion in situ (ISAC) et la méthode de déposition par précipitation (DP). La première partie de l’étude a donc portée sur l'optimisation des conditions de réaction pour l'hydroconversion sélective du HMF en DMF (avec le catalyseur Cu/SBA-15 préparé par la méthode ISAC). Les paramètres de réaction optimisés, comme dans le cadre de l’étude avec Ni/SBA-15, ont été la température de réaction, la pression de dihydrogène, le rapport molaire HMF/Cu et le temps de réaction. La réutilisation du catalyseur a également été étudiée, et une étude cinétique de la transformation du HMF sur Cu menée. Cette partie démontre que l’activité du Cu pour la conversion sélective du HMF en DMF dépend principalement de l’état de dispersion du Cu. L'utilisation de la méthode DP a conduit à un catalyseur Cu/SBA-15 hautement divisé, ce qui a permis d’atteindre des rendements élevs en DMF<br>The production of fuel additives, having high octane numbers, from biosourced molecules such as 5-hydroxymethylfurfural (HMF), is the subject of many studies. The Pt, Pd and Ru-based catalysts are described as particularly active in the conversion reaction of HMF to 2,5-dimethylfuran (DMF) and to 2,5-dimethyltetrahydrofuran (DMTHF). However, their substitutions in the catalytic formulations are desirable in view of their high cost and low availability. The substitution elements can be transition metals (for example Cu or Ni), which are more abundant, but generally less active. My research has focused on the preparation of catalysts, based on transition metals, active and selective for the hydrogenation of HMF into molecules that can be incorporated into fuels. The active phases studied during my Ph.D. are based on Ni and Cu transition metals. These active phases were supported on mesoporous silica of SBA-15 type. The study is divided into two distinct parts, depending on the metal studied.The first part of the Ph.D. presents the results obtained with Ni supported monometallic catalysts. In a first step, the optimization of the reaction parameters for the selective hydroconversion of HMF to DMF and DMTHF was carried out using a catalyst prepared by the incipient wetness impregnation (IWI) of the nitrate precursor solution (Chapter 3). Optimized reaction parameters include reaction temperature, dihydrogen pressure, HMF/Ni molar ratio, and reaction time. A preliminary kinetic study was also performed. The effect of the dispersion and size of Ni metal particles on the catalytic performance of Ni/SBA-15 catalysts was studied on materials prepared by the melt infiltration (MI) method of nitrate precursors (Chapter 4). The level of dispersion of the nickel was modified using SBA-15 supports containing different interconnection porosities, obtained at different synthesis temperatures. The results show that the Ni/SBA-15 catalyst, prepared by the simple IWI method, achieves high yields of DMF and DMTHF under optimal reaction conditions. The level of Ni dispersion, as observed from the materials obtained by infiltration of molten salts, has a significant effect on the catalytic activity of the catalyst.The second part of my research focuses on the catalytic properties of Cu/SBA-15 monometallic catalysts prepared by different methods, and having different Cu phase division degree (Chapter 5). The methods of preparation applied include the IWI method, the in situ autocombustion method (ISAC) and the deposition-precipitation method (DP). The first part of the study therefore focused on the optimization of the reaction conditions for the selective hydroconversion of HMF to DMF (over the Cu/SBA-15 catalyst prepared by the ISAC method). Optimized reaction parameters, as for Ni/SBA-15, were reaction temperature, hydrogen pressure, HMF/Cu molar ratio, and reaction time. The reuse of the catalyst was also studied, and a kinetic study of the transformation of HMF on Cu/SBA-15 conducted. This part demonstrates that the activity of Cu for the selective conversion of HMF to DMF depends mainly on the state of dispersion of Cu. The use of the DP method led to a highly divided Cu/SBA-15 catalyst, which made it possible to achieve high yields of DMF
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Wang, Zhao. "Selective Hydrogenation of Butadiene over Non-noble Bimetallic Catalysts." Electronic Thesis or Diss., Paris 6, 2017. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2017PA066102.pdf.
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Ce travail porte sur la préparation et la caractérisation de catalyseurs bimétalliques Cu-Zn, Ni-Zn et Fe-Zn supportés sur TiO2 avec des rapports atomiques variables et sur l'étude de leurs propriétés catalytiques pour l'hydrogénation sélective d'hydrocarbures polyinsaturés. Les méthodes de co-dépôt-précipitation à l'urée (DPu) et co-dépôt-précipitation à pH fixe (DP8) ont été utilisées pour la préparation des matériaux. Les ions métalliques se déposent séquentiellement sur la surface de TiO2 (selon la séquence CuII < ZnII ?FeII <br>This work investigates the preparation and characterization of titania-supported non-noble bimetallic Cu-Zn, Ni-Zn and Fe-Zn catalysts with various atomic ratios and their catalytic properties for the selective hydrogenation of polyunsaturated hydrocarbons. Co-deposition-precipitation with urea (DPu) and co-deposition-precipitation at fixed pH (DP8) methods were employed for the samples preparation. The metal ions were sequentially deposited onto the TiO2 surface (the sequence of pH for ions deposition being CuII < ZnII ≈FeII < NiII) during the DPu, while they were simultaneously deposited using DP8 method. After sample reduction at proper temperature (350 °C for Cu-Zn, 450 °C for Ni-Zn and 500 °C for Fe-Zn), XRD and STEM-HAADF coupled with EDS showed that bimetallic nanoparticles were formed in Cu-Zn/TiO2 (Cu3Zn1 or Cu0.9Zn0.1 alloy) and Ni-Zn systems (Ni1Zn1 or Ni4Zn1 alloy) with average particle size smaller than 5 nm. Only metallic Fe was detected by XRD in Fe-Zn/TiO2. Zn is inactive for butadiene selective hydrogenation, and acts as a modifier of the monometallic catalysts whose activity follows the sequence: Cu < Fe < Ni. The addition of Zn slightly decreases the activity and influences the selectivity to butenes, but provides much more stable catalysts. The higher stability of the bimetallic catalysts was ascribed to the formation of lower amount of carbonaceous species during the reaction, resulting from the change in the size of the active metal surface ensembles by alloying with Zn
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Galhardo, Thalita Soares. "Oxidação de glicerol utilizando catalisadores mono e bimetálicos à base de nanopartículas de Pt, Cu ou Ni suportadas em carvão ativado." reponame:Repositório Institucional da UFABC, 2017.
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Melo, Jarbas Almeida de. "Catalisadores a base de Cu, Ni e Mg suportados em Al2O3 aplicados à gaseificação de etanol em meio contendo água em condições supercríticas." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8981.
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Previous issue date: 2018-09-28<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>In this work the synthesis of catalysts was carried
out with the objective of H2 production from gasification of ethanol in medium containing
water under supercritical conditions. Based on reports from the literature, Cu, Ni and Mg
were selected as components for the active phase, alumina (Al2O3) as catalysts support.
The catalysts were prepared from aqueous solutions of nitrate salts precursors of Cu, Ni
and Mg. The catalysts were characterized by X-ray fluorescence (FRX), scanning electron
microscopy, thermogravimetric and thermal differential analysis (TG/ATD), X-ray
diffraction (DRX) and textural analysis by N2 adsorption / desorption isotherms at -196 °
C. The TG/ATD analysis indicated that the calcination of the catalytic precursors was
sufficient for the removal of water and decomposition of the nitrates of the metal salts
precursors of the active phase. In the FRX analysis, the increase in the concentration of
the metals in relation to the nominal values after the synthesis of the catalysts was
characterized, with an increase of 20 to 40% depending on the metal due to the loss of
water from the alumina support. The FRX analysis of the catalysts used in the catalytic
tests shows that there was no significant leaching during the gasification process. DRX
analysis have characteristic results that the metals are in amorphous form or dispersed in
the form of small crystallites. Textural analysis of N2 adsorption / desorption isotherms
indicated a reduction of approximately 60% in the specific surface area between the
alumina and the calcined alumina and the specific area values between the alumina and
the metal catalysts were kept close. The catalytic tests were performed at a pressure of
25 MPa and at temperatures of 400 to 650 ° C. A 10/1 molar water / ethanol solution was
fed. In the catalytic tests H2, CH4, CO, CO2, C2H4, C2H6, C2H4O were obtained. The
highest ethanol conversions were obtained at the temperature of 650 ° C for the catalysts
NiO/Al2O3 and NiO-MgO/Al2O3, both 81%. The highest yield was 0.41 mol H2 / mol
ethanol fed to the NiO / Al2O3 catalyst, at a temperature of 600 ° C. The highest selectivity
at the temperature of 600 ° C was 39%, obtained by the NiO/Al2O3 catalyst.<br>Neste trabalho foi realizada a síntese de catalisadores com o objetivo da
produção de H2 a partir da gaseificação de etanol em meio contendo água em condições
supercríticas. A partir de relatos da literatura, foram selecionados Cu, Ni e Mg como
componentes para a fase ativa e a alumina (Al2O3) como suporte dos catalisadores. Os
catalisadores foram preparados a partir de soluções aquosas de sais de nitrato
precursores de Cu, Ni e Mg. Os catalisadores foram caracterizados por fluorescência de
raios X (FRX), microscopia eletrônica de varredura (MEV), análises termogravimétrica e
térmica diferencial simultânea (TG/ATD), difração de raios X (DRX) e análise textural por
isotermas de adsorção/dessorção de N2 a -196°C. As análises de TG/ATD indicaram que
a calcinação dos precursores catalíticos foi suficiente para a remoção da água e
decomposição dos nitratos dos sais metálicos precursores da fase ativa. Nas análises de
FRX ficou caracterizado o aumento da concentração dos metais em relação aos valores
nominais, após a síntese dos catalisadores, com acréscimo de 20 a 40 % dependendo do
metal, devido à perda de água do suporte de alumina. As análises FRX dos catalisadores
utiilzados nos testes catalíticos mostraram que não houve lixiviação considerável durante
o processo de gaseificação. Análises de DRX apresentaram resultados característicos de
que os metais se encontram na forma amorfa ou dispersos na forma de pequenos
cristalitos. Os resultados foram coerentes com as imagens de microscopia eletrônica de
varredura. Análises textural por isotermas de adsorção/dessorção de N2 indicaram uma
redução de aproximadamente 60% na área superficial específica entre a alumina e a
alumina calcinada e mantiveram-se próximos os valores de área específica entre a
alumina e os catalisadores metálicos. Os testes catalíticos foram realizados a uma
pressão de 25 MPa e nas temperaturas de 400 a 650 °C. Foi alimentada uma solução de
água/etanol na razão de 10/1 molar. Nos testes catalíticos foram obtidos H2, CH4, CO,
CO2, C2H4, C2H6, C2H4O. As maiores conversões de etanol foram obtidas na temperatura
de 650 °C para os catalisadores de NiO/Al2O3 e NiO-MgO/Al2O3, ambas 81 %. O maior
rendimento obtido foi de 0,41 mol H2/mol etanol alimentado para o catalisador de NiO/
Al2O3, na temperatura de 600 °C. A maior seletividade na temperatura de 600 °C foi de
39 %, obtida pelo catalisador de NiO/Al2O3.
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Seah, Choon-Ming. "Synthesis of monolayer graphene on polycrystalline Ni and Ni-Cu bimetallic catalyst and study toward reuse of catalyst." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0281/document.
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Le graphène est une couche de carbone d’une épaisseur atomique pour laquelle les atomes de carbone sont hybridés sp². Il possède diverses propriétés remarquables supérieures à celles des autres matériaux connus. Le dépôt chimique en phase vapeur (CVD) est une méthode prometteuse pour produire du graphène monocouche. Dans cette étude, du graphène monocouche a pu être synthétisé directement sur une feuille de Ni polycristallin par CVD sous pression atmosphérique à l'aide d'un refroidissement rapide. Par ailleurs, nous proposons une technique simple pour préparer du graphène monocouche homogène dont la croissance est réalisée simultanément sur deux feuilles de Cu et de Ni assemblés en bicouche métallique. L’application du refroidissement rapide induit la formation de Ni3C, qui permet de réutiliser la feuille de Ni jusqu'à 6 fois sans causer d’écart significatif de la qualité et l'uniformité du graphène produit. Ce travail a donc démontré avec succès que le coût moyen pour synthétiser une monocouche de graphène de haute qualité pouvait être réduit avec des procédés simples à mettre en œuvre<br>Graphene is a layer of sp2 hybridized carbon atoms with a thickness of only one atom. It possesses various magnificent properties that are not shared by other materials. To date, Chemical Vapor Deposition (CVD) is a promising method to produce wafer-scale graphene. From our study, monolayer graphene was grown directly on polycrystalline Ni foil under simple atmospheric pressure CVD with the assist of fast cooling. On the other hand, another facile technique was successful to grow uniform monolayer graphene simultaneously on both polycrystalline Ni and Cu foils using a Ni-Cu bilayer catalyst. The application of post-CVD fast cooling encourages the formation of Ni3C within the Ni foil, which subsequently enables the Ni foil to be reused again up to 6 cycles without causing a huge deviation. This work has successfully demonstrated a simple, novel and cost effective route to synthesize monolayer graphene with high quality
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Obrecht, Lorenz. "Artificial metalloenzymes in catalysis." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7248.
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This thesis describes the synthesis, characterisation and application of artificial metalloenzymes as catalysts. The focus was on two mutants of SCP-2L (SCP-2L A100C and SCP-2L V83C) both of which possess a hydrophobic tunnel in which apolar substrates can accumulate. The crystal structure of SCP-2L A100C was determined and discussed with a special emphasis on its hydrophobic tunnel. The SCP-2L mutants were covalently modified at their unique cysteine with two different N-ligands (phenanthroline or dipicolylamine based) or three different phosphine ligands (all based on triphenylphosphine) in order to increase their binding capabilities towards metals. The metal binding capabilities of these artificial proteins towards different transition metals was determined. Phenanthroline modified SCP-2L was found to be a promising scaffold for Pd(II)-, Cu(II)-, Ni(II)- and Co(II)-enzymes while dipicolylamine-modified SCP-2L was found to be a promising scaffold for Pd(II)-enzymes. The rhodium binding capacity of two additional phosphine modified protein scaffolds was also investigated. Promising scaffolds for Rh(I)- and Ir(I)-enzymes were identified. Rh-enzymes of the phosphine modified proteins were tested in the aqueous-organic biphasic hydroformylation of linear long chain 1-alkenes and compared to the Rh/TPPTS reference system. Some Rh-enzymes were found to be several orders of magnitude more active than the model system while yielding comparable selectivities. The reason for this remarkable reactivity increase could not be fully elucidated but several potential modes of action could be excluded. Cu-, Co-, and Ni-enzymes of N-ligand modified SCP-2L A100C were tested in the asymmetric Diels-Alder reaction between cyclopentadiene and trans-azachalcone. A promising 29% ee for the exo-product was found for the phenanthroline modified protein in the presence of nickel. Further improvement of these catalyst systems by chemical means (e.g. optimisation of ligand structure) and bio-molecular tools (e.g. optimisation of protein environment) can lead to even more active and (enantio)selective catalysts in the future.
Books on the topic "Cu-Ni catalysts"
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Lukašēvics, Tomass. Kobalta katalizēta C‒H saites funkcionalizēšana/Cobalt Catalyzed C‒H Bond Functionalization. RTU Press, 2022. http://dx.doi.org/10.7250/9789934227806.
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Over the past few decades, transition metal catalyzed C–H activation has been immensely investigated due to the ability to functionalize relatively unreactive C-H bonds whilst simplifying synthetic schemes and making the synthetic pathway more economical. Nowadays, a great emphasis has been placed on substitution of noble metal catalysts (Pd, Rh, Ru, etc.) with more abundant and cheaper alternatives (Cu, Co, Ni). The aim of the Doctoral Thesis is the development of novel cobalt catalyzed C-H bond functionalization methodology. The Doctoral Thesis is prepared as a collection of publications. The main results of the Thesis were summarized in 4 scientific publications, 3 review articles and 2 book chapters.
Book chapters on the topic "Cu-Ni catalysts"
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Wang, Chengrui, Yanhong Fang, Guangfen Liang, Huamei Duan, Dengfu Chen, and Mujun Long. "Synthesis and Characterization of Cu-Ni Bimetallic Catalysts Support on GO, rGO, and NGO." In The Minerals, Metals & Materials Series. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92563-5_80.
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Yang, Tianzu, Wei Chen, Lin Chen, Liu Weifeng, and Zhang Duchao. "CH4reforming by CO2and O2using Ni-M (M= Cu, Fe, Co, Mn, Zn, Cr) Bimetallic Aerogel Catalysts." In Energy Technology 2016: Carbon Dioxide Management and Other Technologies. John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119274704.ch20.
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Patel, Madhumita, K. K. Pant, and Pravakar Mohanty. "Renewable Hydrogen Generation by Steam Reforming of Acetic Acid over Cu-Zn-Ni Supported Calcium Aluminate Catalysts." In ACS Symposium Series. American Chemical Society, 2012. http://dx.doi.org/10.1021/bk-2012-1092.ch009.
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Bergamaschi, V. S., F. M. S. Carvalho, W. R. Santos, and C. Rodrigues. "Synthesis and Characterization of Ni-Cu/ZrO2 and Co-Cu/ ZrO2 Catalysts Used for Ethanol Steam Reforming." In Materials Science Forum. Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-423-5.619.
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Tuza, Pablo, Robinson L. Manfro, Nielson F. P. Ribeiro, and Mariana M. V. M. Souza. "Production of Renewable Hydrogen by Aqueous-Phase Reforming of Glycerol Over Ni-Cu Catalysts Derived from Hydrotalcite Precursors." In Progress in Sustainable Energy Technologies: Generating Renewable Energy. Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-07896-0_24.
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Yang, Tianzu, Wei Chen, Lin Chen, Weifeng Liu, and Duchao Zhang. "CH4 Reforming by CO2 and O2 Using Ni-M (M= Cu, Fe, Co, Mn, Zn, Cr) Bimetallic Aerogel Catalysts." In Energy Technology 2016. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-48182-1_20.
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The Luong, Nguyen, Tran Van Hoang, Pham Minh Tuan, and Le Anh Tuan. "Thermal Efficiency and Exhaust Emission of an SI Engine Using Hydrogen Enriched Gas from Exhaust Gas Fuel Reforming Based on Ni-Cu/Al2O3 Catalysts." In The AUN/SEED-Net Joint Regional Conference in Transportation, Energy, and Mechanical Manufacturing Engineering. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1968-8_79.
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Itsuno, S. "Catalytic and Separation Functions." In Functional Macromolecular Complexes. Royal Society of Chemistry, 2024. http://dx.doi.org/10.1039/9781837675142-00313.
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Polymers having various functionalities can form complexes with metals, which can be used as polymer complex catalysts. Organometallic catalysis is highly efficient and has been used in various industrial processes. Although the organometallic catalysts are very effective in many reactions, transition metals are expensive and toxic. In some cases, contamination of the product with metals could greatly impair the properties. The use of polymer complex catalysts can minimize this risk. This chapter describes the recent developments of polymer complex catalysts composed of Ti, Mn, Fe, Ru, Co, Ir, Ni, Pd, Cu, Au, and Zn. These polymer complex catalysts show high catalytic activity and are easily removed from the reaction mixture and reused. Application of polymer complex catalysts to continuous flow systems is also possible. They are used as a powerful tool in organic reactions.
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Sermon, P. A., M. A. M. Luengo (Yates), and Y. Wang. "Comparison of ZnO-Supported Cu, Cu-Mn, Cu-Fe, Cu-Co and Cu-Ni Catalysts in CO Hydrogenation." In Studies in Surface Science and Catalysis. Elsevier, 1993. http://dx.doi.org/10.1016/s0167-2991(08)64402-x.
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Mariño, F., M. Jobbagy, G. Baronetti, and M. Laborde. "Steam reforming of ethanol using Cu-Ni supported catalysts." In Studies in Surface Science and Catalysis. Elsevier, 2000. http://dx.doi.org/10.1016/s0167-2991(00)80786-7.
Full textConference papers on the topic "Cu-Ni catalysts"
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Agarwal, D. C., and Jutta Kloewer. "Nickel Base Alloys: Corrosion Challenges in the New Millennium." In CORROSION 2001. NACE International, 2001. https://doi.org/10.5006/c2001-01325.
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Abstract To fully appreciate the corrosion challenges of the new millenium, one has to learn from the innovations made in the nickel alloy metallurgy of the past century. In the 21st century, as was the case in the last century, within the various industries, after carbon steel, the 300 series stainless steels will continue to be the "most widely used tonnage" material. Other corrosion mitigation technologies such as electrochemical protection, non-metallics, coatings and paints and use of inhibitor technology will also play a major role. The materials of construction for these modern chemical process, petrochemical industries and other industries not only have to resist uniform corrosion caused by various corrodents, but must also have sufficient localized corrosion and stress corrosion cracking resistance as well. These industries have to cope with both the technical and commercial challenges of rigid environmental regulations, the need to increase production efficiency by utilizing higher temperatures and pressures, and more corrosive catalysts, and at the same time possess the necessary versatility to handle varied feed stock and upset conditions. Even though nickel as an element was discovered about 250 years ago, the first major nickel alloy introduced to the industry, about 100 years ago, was a Ni-Cu alloy 400. This alloy is still being widely used in a variety of industries and will continue to be used in this current century. Over the past 100 years, specially in the last 50 years, improvements in alloy metallurgy, melting technology, and thermo-mechanical processing, along with a better fundamental understanding of the role of various alloying elements has led to new nickel alloys. These have not only extended the range of usefulness of existing alloys by overcoming their limitations, but are reliable and cost-effective and have opened new areas of applications. This paper briefly describes the various nickel alloy systems developed and in use during the last 100 years with comments as to what the future holds for the newer alloys developed in the last 20 years and the competition faced by these alloys in the new millennium.
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Divi, Suresh, and Sri Krishna Chimbli. "Electrochemical Corrosion Behavior of Carbon Steel with and without High Residual Elements." In CORROSION 2020. NACE International, 2020. https://doi.org/10.5006/c2020-14245.
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Abstract Residual elements (RE) in carbon steel, not specifically included in the specified steel, appear to influence the corrosion rate under certain conditions, especially in services involving hydrofluoric acid (HF). The relative proportions of RE, specifically %C, %Ni, %Cu, and %Cr in carbon steel base and weld metals used in refineries, especially in alkylation processes with HF as the catalyst, significantly impact corrosion behavior. Studies described in the literature show corrosion damage with high RE (Cu + Ni + Cr &gt;0.20) components as compared to low RE (Cu + Ni + Cr &lt;0.20) components. In this study, electrochemical corrosion testing was performed on a 3-inch pipe elbow section with high REs that had developed a through-wall leak in service. Test results were compared to those obtained on a similar pipe elbow section with lower REs. The samples were exposed to 50% HF at room temperature and at 65°C. Linear polarization resistance (LPR) corrosion rates were measured at both temperatures. Potentiodynamic (PD) polarization scans were performed on samples of low and high RE steel exposed to 50% HF at room temperature. Test results indicated that LPR corrosion rates were higher for the high RE carbon steel samples than for low RE carbon steel samples at both temperatures. PD scans showed that the critical current densities were higher for high RE steel than for low RE steel.
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Dan, M., M. Mihet, V. Almasan, et al. "Modified Ni-Cu catalysts for ethanol steam reforming." In PROCESSES IN ISOTOPES AND MOLECULES (PIM 2013). AIP, 2013. http://dx.doi.org/10.1063/1.4833729.
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Das, Randip K., B. B. Ghosh, Souvik Bhattacharyya, and Maya DuttaGupta. "Catalytic Control of SI Engine Emissions Over Ion-Exchanged X-Zeolites." In ASME 1997 Turbo Asia Conference. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-aa-077.
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Three catalysts based on X-zeolite have been developed by exchanging its Na+ ion with Copper, Iron and Nickel metal ions and tested in a SI engine exhaust for a wide range of exhaust and operating conditions. Of the three catalysts, the Cu-X catalyst exhibits the best NOx and CO conversion performance while Ni-X shows slightly better performance compared to the Fe-X catalyst at any catalyst temperature. Unlike noble metals, the doped X-zeolite catalysts, studied here, exhibit significant NOx reduction for a wide λ range and exhibit a slow rate of decrease with increase in λ ratio. Back pressure developed across the catalyst bed is found to be well-afford able and power loss due to back pressure is only 0.216% at space velocity of 52500 /h. During 30 hours of testing of each catalyst, no significant deactivation of any catalyst is observed.
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Mesa, Camilo A., Roser Fernández-Climent, Felipe Garcés-Pineda, José R. Galán-Mascarós, and Sixto Gimenez. "Operando mechanistic characterisation of Cu- and Ni-based catalysts for water splitting." In MATSUS Fall 2023 Conference. FUNDACIO DE LA COMUNITAT VALENCIANA SCITO, 2023. http://dx.doi.org/10.29363/nanoge.matsus.2023.368.
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"INFLUENCE OF Cu AND Ni CATALYSTS ON ETHANOL GASIFICATION UNDER SUPERCRITICAL WATER CONDITIONS." In International Symposium on Energy: Energy Transition, Green Hydrogen and Sustainable Industry. Softaliza Tecnologias, 2024. https://doi.org/10.55592/ise.v2i1.11160.
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Hui, K. S., Christopher Y. H. Chao, C. W. Kwong, and M. P. Wan. "Performance of Transition Metal Ions Exchanged Zeolite 13X in Greenhouse Gas Reduction." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41360.
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This study investigated the performance of multi-transition metal (Cu, Cr, Ni and Co) ions exchanged zeolite 13X catalysts on methane emission abatement, especially at methane level of the exhaust from natural gas fueled vehicles. Catalytic activity of methane combustion using multi-ions exchanged catalyst was studied under different parameters: mole % of metal loading, inlet velocity and inlet methane concentration at atmospheric pressure and 500 °C. Performance of the catalysts was investigated and explained in terms of the apparent activation energy, number of active sites and BET surface area of the catalyst. This study showed that the multi-ions exchanged catalyst outperformed the single-ions exchanged and the acidified 13X catalysts. Lengthening the residence time could also lead to higher methane conversion %. Catalytic activity of the catalysts was influenced by the mole % of metal loading which played important roles in affecting the apparent activation energy of methane combustion, active sites and also the BET surface area of the catalyst. Increasing mole % of metal loading in the catalyst decreased the apparent activation energy for methane combustion and also the BET surface area of the catalyst. In view of these, there existed an optimized mole % of metal loading where the highest catalytic activity was observed.
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Yung, K. P., J. Wei, and B. K. Tay. "Effects of Catalysts Supporting Layer on Carbon Nanotubes Growth." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80555.
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Due to their extraordinary electrical, thermal and mechanical properties, carbon nanotubes have been foreseen as potential materials for electronics devices in the future. To integrate carbon nanotubes in electronic applications, carbon nanotubes would need to be grown on different metal layer. In this study, carbon nanotubes growth with Ni as catalyst on three different support layers, Cu, Al and Cr, by hot filament chemical vapor deposition (HFCVD) is reported. The nanotubes were grown using C2H2 acetylene as carbon feedstock, in a hydrogen and nitrogen atmosphere. The catalyst layers and their support layers were deposited by magnetron sputtering technique. Deposited films were annealed at 600 °C for 10 minutes before exposing to C2H2 for the growth of nanotubes at same temperature for another 10 minutes. The effects of the support layer have been investigated with reference to nanotubes formation. The morphology and microstructure of the films were measured and analyzed by scanning electron microscopy (SEM) and Raman spectrometer. It was found that reaction of the catalyst with its supporting layer has significant effects on the growth of nanotubes. For Cu or Cr as support layer, its effect on the nanotubes growth was minimal. However Al support layer prevented the growth of carbon nanotubes. The possible mechanisms for the observed results are proposed.
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Kosivtsov, Yury, Yury Lugovoy, Kirill Chalov, Alexander Sidorov, and Mikhail Sulman. "INFLUENCE OF ZEOLITE CATALYSTS IMPREGNATED WITH TRANSITION METALS ON THE PROCESS OF DEOXYGENATION OF VOLATILE PRODUCTS OF FAST PYROLYSIS OF FLAX SHIVES." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/4.1/s17.15.
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A study was made of the influence of ZSM-5 zeolite on the composition and properties of the products of fast pyrolysis of flax shives in the temperature range of 350-750 �C. Zeolite ZSM-5 increased the heat of combustion of gaseous products, as well as the content of methane, ethylene, hydrogen, and carbon dioxide, which is probably associated with the processes of cracking of volatile products passing through a layer of a catalyst heated to high temperatures. The synthesis and study of zeolite catalysts ZSM-5 containing transition metals (Fe, Co, Ti, V, Mn, Zn, Cu, Cr) with a 2% metal concentration in the process of deoxygenation of volatile products of fast pyrolysis of waste biomass of plant origin. According to the activity in the deoxygenation process, the metals studied during the work stage can be arranged in the following descending order: Pd > Pt > Co > Cu > Ni > Fe > Cr > Mn > V > Ti > Zn.The 2%Co-ZSM-5 catalyst showed high activity in the deoxygenation process, since its use led to an increase in the low volumetric calorific value of the fast pyrolysis gas by 1.3-1.5 times, as well as to a decrease in the tars content.
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Meng, Fanxu, Asanga Wijesinghe, John Colvin, Carolyn LaFleur, and Richard Haut. "Conversion of Exhaust Gases from Dual-Fuel (Natural Gas-Diesel) Engine under Ni-Co-Cu/ZSM-5 Catalysts." In WCX™ 17: SAE World Congress Experience. SAE International, 2017. http://dx.doi.org/10.4271/2017-01-0908.
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