Relevant bibliographies by topics / Catalysis and Reaction Engineering

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Catalysis and Reaction Engineering'

Author: Grafiati
Published: 4 June 2021
Last updated: 26 January 2023

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Journal articles on the topic "Catalysis and Reaction Engineering"

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Tsotsis, Theodore T. "Reaction engineering and catalysis." Current Opinion in Chemical Engineering 1, no. 3 (August 2012): 269–71. http://dx.doi.org/10.1016/j.coche.2012.07.001.

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Bloh, Jonathan Z., and Roland Marschall. "Heterogeneous Photoredox Catalysis: Reactions, Materials, and Reaction Engineering." European Journal of Organic Chemistry 2017, no. 15 (March 10, 2017): 2085–94. http://dx.doi.org/10.1002/ejoc.201601591.

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Sial, Atif, Afzal Ahmed Dar, Yifan Li, and Chuanyi Wang. "Plasmon-Induced Semiconductor-Based Photo-Thermal Catalysis: Fundamentals, Critical Aspects, Design, and Applications." Photochem 2, no. 4 (October 2, 2022): 810–30. http://dx.doi.org/10.3390/photochem2040052.

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Photo-thermal catalysis is among the most effective alternative pathways used to perform chemical reactions under solar irradiation. The synergistic contributions of heat and light during photo-thermal catalytic processes can effectively improve reaction efficiency and alter design selectivity, even under operational instability. The present review focuses on the recent advances in photo-thermal-driven chemical reactions, basic physics behind the localized surface plasmon resonance (LSPR) formation and enhancement, pathways of charge carrier generation and transfer between plasmonic nanostructures and photo-thermal conversion, critical aspects influencing photo-thermal catalytic performance, tailored symmetry, and morphology engineering used to design efficient photo-thermal catalytic systems. By highlighting the multifield coupling benefits of plasmonic nanomaterials and semiconductor oxides, we summarized and discussed several recently developed photo-thermal catalysts and their catalytic performance in energy production (CO2 conversion and H2 dissociation), environmental protection (VOCs and dyes degradation), and organic compound synthesis (Olefins). Finally, the difficulties and future endeavors related to the design and engineering of photo-thermal catalysts were pointed out to draw the attention of researchers to this sustainable technology used for maximum solar energy utilization.
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Ball, Philip. "Catalysis: facing the future." National Science Review 2, no. 2 (April 24, 2015): 202–4. http://dx.doi.org/10.1093/nsr/nwv022.

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Abstract Most of the chemical reactions used to produce the molecules and materials that our societies need—for example, in the petrochemical and pharmaceutical industries, the synthesis of plastics and other materials, and the production of foods and drinks—make use of catalysts. These speed up the rate at which atoms and molecules rearrange themselves into new forms, and provide a degree of control over the shape and form of those rearrangements. Catalysts let us drive a chemical reaction in a selected direction, in preference to others that could occur. In this way they turn chemistry from crude cookery into a rational and precise form of molecular engineering. And always we can draw inspiration, and sometimes borrow tricks, from the delicate and precise catalytic processes that occur in nature, where enzymes carry out processes in aqueous solution and at mild temperatures and pressures that often we struggle to achieve with far more extreme conditions—such as the fixation of atmospheric nitrogen into useful forms. It is often claimed that this particular catalytic process—the Haber–Bosch process for converting nitrogen into ammonia, discovered just over a century ago—has, by making possible the synthesis of artificial fertilizers, had a greater effect on humankind than any other single chemical innovation. It is what allows us to feed the world. Yet while nature performs this reaction using soluble molecules (enzymes) as catalysts, the Haber–Bosch process uses powdered iron (plus some additives). The reactions between nitrogen and hydrogen take place on the surface of iron particles: this is so-called heterogeneous catalysis, involving surface chemistry, rather than the homogeneous catalysis of enzyme reactions, in which the catalysts are soluble molecules. Both homogeneous and heterogeneous catalysis are essential to the chemical industries. National Science Review spoke with two of the foremost practitioners of the latter field—Nobel laureate Gerhard Ertl of the Fritz Haber Institute in Berlin, Germany, and Avelino Corma of the Institute of Chemical Technology (ITQ) at the Polytechnic University of Valencia, Spain—about the current status of research in catalysis and prospects for the future.
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Mantilli, Luca, David Gérard, Sonya Torche, Céline Besnard, and Clément Mazet. "Highly enantioselective isomerization of primary allylic alcohols catalyzed by (P,N)-iridium complexes." Pure and Applied Chemistry 82, no. 7 (May 4, 2010): 1461–69. http://dx.doi.org/10.1351/pac-con-09-09-10.

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The catalytic asymmetric isomerization of allylic amines to enamines stands out as one of the most accomplished and well-studied reactions in asymmetric catalysis as illustrated by its industrial application. In contrast, the related asymmetric isomerization of primary allylic alcohols to the corresponding aldehydes still constitutes a significant challenge in organic synthesis. Herein, we show that under appropriate reaction conditions, iridium-hydride catalysts promote the isomerization of primary allylic alcohols under very mild reaction conditions. The best catalysts deliver the desired chiral aldehydes with unprecedented levels of enantioselectivity and good yields. Mechanistic hypotheses have been drawn based on preliminary investigations.
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Longwitz, Lars, and Thomas Werner. "Recent advances in catalytic Wittig-type reactions based on P(III)/P(V) redox cycling." Pure and Applied Chemistry 91, no. 1 (January 28, 2019): 95–102. http://dx.doi.org/10.1515/pac-2018-0920.

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Abstract Numerous organic transformations are based on the use of stoichiometric amounts of phosphorus reagents. The formation of phosphane oxides from phosphanes is usually the thermodynamic driving force for these reactions. The stoichiometric amounts of phosphane oxide which are formed as by-products often significantly hamper the product purification. Organophosphorus catalysis based on P(III)/P(V) redox cycling aims to address these problems. Herein we present our recent advances in developing catalytic Wittig-type reactions. More specifically, we reported our results on catalytic Wittig reactions based on readily available Bu3P=O as pre-catalyst as well as the first microwave-assisted version of this reaction and the first enantioselective catalytic Wittig reaction utilizing chiral phosphane catalysts. Further developments led to the implementation of catalytic base-free Wittig reactions yielding highly functionalized alkylidene and arylidene succinates.
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Dittmeyer, Roland, and Simon Kuhn. "Editorial overview: Reaction engineering and catalysis: Microreactor engineering." Current Opinion in Chemical Engineering 36 (June 2022): 100822. http://dx.doi.org/10.1016/j.coche.2022.100822.

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Keglevich, György, Nóra Zsuzsa Kiss, Réka Henyecz, and Zoltán Mucsi. "Microwave irradiation and catalysis in organophosphorus reactions." Pure and Applied Chemistry 91, no. 1 (January 28, 2019): 145–57. http://dx.doi.org/10.1515/pac-2018-0501.

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AbstractThe usual advantage of microwave (MW) assistance is making organic reactions faster and more efficient. In this article we present reaction types from organophosphorus chemistry, when MW-assisted transformations (e.g. the direct esterification and alkylating esterification of phosphinic acids) may be promoted by suitable catalysts, or vice versa, when a catalytic reaction is enhanced by MW irradiation (e.g. the Arbuzov reaction of aryl halides), and when catalysts may be omitted or simplified under MW irradiation as shown by the alkylation of active methylene containing P=O substrates/the Kabachnik–Fields reaction/deoxygenation of phosphine oxides, and the Hirao reaction, respectively.
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Lapkin, Alexei A. "Editorial overview- Reaction engineering and Catalysis: Green chemical engineering." Current Opinion in Chemical Engineering 26 (December 2019): A3. http://dx.doi.org/10.1016/j.coche.2019.12.002.

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Chen, Siyu, Zhanwei Xu, Jiayin Li, Jun Yang, Xuetao Shen, Ziwei Zhang, Hongkui Li, Wenyang Li, and Zhi Li. "Nanostructured transition-metal phthalocyanine complexes for catalytic oxygen reduction reaction." Nanotechnology 33, no. 18 (February 7, 2022): 182001. http://dx.doi.org/10.1088/1361-6528/ac4cef.

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Abstract Oxygen reduction reaction (ORR) plays a key role in the field of fuel cells. Efficient electrocatalysts for the ORR are important for fuel cells commercialization. Pt and its alloys are main active materials for ORR. However, their high cost and susceptibility to time-dependent drift hinders their applicability. Satisfactory catalytic activity of nanostructured transition metal phthalocyanine complexes (MPc) in ORR through the occurrence of molecular catalysis on the surface of MPc indicates their potential as a replacement material for precious-metal catalysts. Problems of MPc are analyzed on the basis of chemical structure and microstructure characteristics used in oxygen reduction catalysis, and the strategy for controlling the structure of MPc is proposed to improve the catalytic performance of ORR in this review.
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Dissertations / Theses on the topic "Catalysis and Reaction Engineering"

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Nancarrow, P. D. "Reaction engineering and separation studies on Friedel-Crafts catalysis in ionic liquids." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426655.

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Winchester, Charles Michael. "Generation and Kinetic Studies of Porphyrin-Manganese(IV)-Oxo Intermediates." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3074.

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High-valent metal-oxo complexes are vital as active oxidants in enzymatic and synthetic catalytic oxidations. Inspired by the ubiquitous cytochrome P450 enzyme, researchers have explored the power of metalloporphyrins to mimic one of Nature’s premier catalytic entities. In this work, four manganese(III)porphyrin systems, including three electronwithdrawing ligands and one electron-donating ligand, were investigated with regard to their ability to form high-valent manganese(IV)-oxo porphyrin systems. The porphyrin ligands studied were 5,10,15,20-tetra(2,6-difluorophenyl)porphyrin [H2(2,6-F2TPP)], 5,10,15,20-tetra(4-trifluoromethylphenyl)porphyrin [H2(4-CF3TPP)], 5,10,15,20-tetra(4- fluorophenyl)porphyrin [H2(4-FTPP)], and 5,10,15,20-tetra(2,6- dimethoxyphenyl)porphyrin [H2(TDMPP)]. All were synthesized purified and characterized spectroscopically. Using the mild oxidant iodobenzene diacetate, manganese(IV)-oxo porphyrins [MnIV(Por)O] were successfully generated in all systems as confirmed through spectroscopic methods. Meanwhile, a new photochemical approach was explored for its efficacy in producing the MnIV-oxo complexes by visible light irradiation of manganese(III) precursors containing the photolabile chlorate as the axial ligand. More importantly, the MnIV-oxo complexes obtained by chemical generation were tested for their abilities as oxygen atom transfer agents (OATs) with aryl alkenes, alkenes and thioanisoles in CH3CN. The apparent second-order rate constants for sulfoxidation ranged between (2.29 ± 0.08) and (12.9 ± 2.0) M-1s-1 x 10-2 which were, on average, a magnitude larger than the rates for epoxidation of the aryl alkenes. Most notably in reactions with substrate, the order of reactivity of [MnIV(Por)O] was [(4-F)TPP] > [(4- CF3)TPP] > [(2,6-F2)TPP], which is inverted from the expected result based on the electron-demands of the porphyrin ligands. The apparent rate constants for reaction with cyclohexene was found to be 1 to 2 orders of magnitude larger than those with sulfide substrates. The kinetic results are consistent with a reaction model involving disproportionation of MnIV(Por)O to give MnIII(Por) and MnV(Por)O species, the latter of the two being the active oxidant. Alternatively, the results from the sulfoxidations are consistent in part with a direct oxygen atom transfer by [MnIV(Por)O]
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Sharma, Amit. "Catalytic Reaction Engineering using Ionic liquids : Hydroformylation of 1-Octene." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT015G/document.

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Une démarche de type génie de la réaction chimique est appliquée à l'hydroformylation modèle d'oct-1-ène par des complexes lipophobes du rhodium préparés à partir de Rh(CO)2(acac) en phase liquide ionique ([Bmim][PF6]) ou en phase liquide ionique supportée sur silice. La réaction étant contrôlée par la concentration des réactifs dans la phase liquide ionique catalytique, une première étape a consisté à mesurer ces concentrations tant pour les deux gaz (H2 et CO) que pour l'oct-1-ène à différentes températures et pressions. Diverses méthodes de mesures sont utilisées pour la solubilité de l'oléfine : thermogravimétrie et chromatographie gazeuse après extraction multiple d’espace de tête, en présence de solvant (décane) et du produit de la réaction (nonanal). Le transfert gaz-liquide, qui peut conditionner la vitesse de réaction dans ces milieux visqueux, est également mesuré par une technique dynamique de variation de pression, en liquide ionique pur et en mélange biphasique liquide ionique-phase organique, dans un réacteur autoclave à autoaspiration de gaz par arbre creux. Une corrélation générale est proposée montrant une forte influence de la vitesse d'agitation.Une étude cinétique est réalisée en conditions de transferts non limitants en gaz-liquide organique-liquide ionique avec la TPPTS comme ligand. Les comportements habituels de l’hydroformylation en phase organique ou en phase aqueuse sont retrouvés : ordre voisin de 1 pour H2, inhibition par CO à forte concentration, énergie d'activation élevée. Si le turnover est convenable (70 h-1), le rapport n/iso est par contre très bas ce qui n'est pas en faveur de ce système catalytique. Quelques résultats permettent aussi une première analyse de la catalyse biphasique avec le ligand sulfoxantphos et de la catalyse en phase liquide ionique supportée sur silice avec la TPPTS
A chemical reaction engineering approach is applied to the hydroformylation of 1-octene using lipophobic complexes of rhodium prepared from Rh(CO)2(acac) in ionic liquid phase ([Bmim] [PF6]) or in the ionic liquid phase supported on silica. As the reaction is controlled by the concentration of the reagents in the catalytic ionic liquid phase, the concentrations of both gases (H2 and CO) and also of 1-octene are measured at various temperatures and pressures as an initial step. Different methods are used for the measurement of the olefin solubility inside the ionic liquid: thermogravimetry and multiple headspace chromatography, in the presence of solvent (decane) and reaction product (nonanal). The gas-liquid mass transfer, which can be a rate controlling step in these viscous media, is also measured by a dynamic technique of pressure variation, both in case of pure ionic liquid and biphasic mixture of ionic liquid and organic phase, in an autoclave reactor with self induced stirrer. A general correlation is proposed showing the strong influence of the agitation speed. A kinetic study is realized in no gas–liquid nor organic–ionic liquid mass transfer limiting conditions (chemical regime) with TPPTS as ligand. The usual hydroformylation behaviour is observed, as already found in organic phase or in aqueous phase: order close to 1 for H2, inhibition by CO at large concentration, and high activation energy. If the turnover frequency is suitable (70 h-1), the n/iso ratio is very low which is not favourable to this catalytic system. Some experimental results also allow a first analysis of biphasic catalysis with sulfoxantphos ligand and of ionic liquid phase supported catalysis with TPPTS ligand
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Brown, Darryl Edward. "Kinetic models for the Pt/CeO₂ catalysed water-gas shift reaction." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/27914.

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As the global population grows, so does the world's demand for energy. Consequently, there exists an increased interest in the development of fuel cells for power generation due to their low greenhouse gas emissions. For fuel cells to be a successful power source, a reliable hydrogen source is required. Ultimately, the goal is for hydrogen to be supplied from renewable energy technology however, this type of technology is currently not mature enough to meet the continuous demand of the world's energy systems. Producing hydrogen from fossil fuels can be seen as a temporary solution while further advances are made in developing renewable hydrogen infrastructure. A fuel processing train, therefore, remains an important alternative to producing hydrogen. A fuel processing train converts fossil fuels into hydrogen for use in fuel cells and eliminates the need for hydrogen storage as hydrogen is produced on demand. Currently, the water-gas shift (WGS) reactor is one of the largest components in a fuel processing train and thus opportunity exists to reduce the size of this reactor. To design future WGS catalysts and an optimised fuel processor, the reaction kinetics taking place must be understood and quantified. In this study, kinetic measurements were conducted at 2 bar(a) and across a temperature range of 270 - 300 °C using 16 parallel fixed bed reactors (high throughput experimentation) over a 0.5 wt% Pt/CeO₂ catalyst. The feed composition was varied over the ranges 2 - 12 mol% CO, 20 - 45 mol% H₂O, 4 - 15 mol% CO₂ and 25 - 55 mol% H₂. An online micro gas chromatograph (μGC) was used to analyse the dry gas composition. Fitting of experimental data to various kinetic models was accomplished with the gPROMS software package. An initial evaluation of several Langmuir-Hinshelwood (LH) type mechanisms to two data sets obtained from literature was undertaken to evaluate the strengths and weaknesses of different kinetic expressions. The results of the initial evaluation indicate that a dual-site mechanism with an intermediate species results in the best fit for reducible supports, while a single site mechanism offers a better fit for non-reducible supports. For both kinetic models, the formation of the intermediate species is most likely to be the rate determining step. A power-rate law empirical rate expression and a LH type rate expression were both found to predict the WGS outlet composition well within 10 % error at 2bar(a). The apparent activation energy of the reaction was determined to be 110 kJ/mol. This value was confirmed to be constant, throughout the range of conditions evaluated, by means of a classical Arrhenius analysis. Simulations of increasing total system pressure, using both the empirical and "best fitting" LH model, indicate a significant pressure effect for the LH type equation, whereas the power-rate law empirical equation predicts a small, negative effect on the reaction rate with increaseing pressure. Consequently, further experiments were conducted to determine the true effect of pressure. It was found that increasing system pressure increased the WGS reaction rate, which has also been reported by Twigg (1989:288). Only the LH type rate expression was able to predict this. It is therefore recommended that either the power-rate law empirical rate expression or the LH type rate expression be used to predict the WGS outlet composition when operating below 2 bar(a). Furthermore, when predicting reaction rates outside of the window in which the rate equations were derived, it is recommended that the LH model be used as it is expected to give a better prediction as it is based on fundamental steps.
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Khasu, Motlokoa. "In situ study of Co₃O₄ morphology in the CO-PROX reaction." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/24905.

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The preferential oxidation (PROX) reaction is an effective process for the removal of trace amounts of carbon monoxide from a reformate stream. Tricobalt tetraoxide (Co₃O₄) is the candidate for CO-PROX in a H₂ rich gas and could be an alternative to the rare and expensive PGMs. This study investigates the effect of different Co₃O₄ morphologies in the preferential oxidation of carbon monoxide in H₂ rich gas. Reports have shown morphology dependency in CO oxidation in the absence of hydrogen, no study has investigated the morphology dependency in H₂ rich atmospheres. Different morphologies of nanocubes, nanosheets and nanobelts were prepared using hydrothermal mn and precipitation. Conventional spherical nanoparticles from our group were included to compare the activity of conventional nanoparticles with nanoparticles of different morphology. The model catalysts were supported on silica spheres which were also prepared. The CO-PROX experiments were conducted in the in situ UCT-developed magnetometer and PXRD capillary cell instruments by induced reduction at temperatures between 50 and 450°C. Catalyst tests showed two distinct temperature regions with maximum activity. In the range of 150 – 175ᵒC, activity decreased from nanoparticles > amine nanosheets > nanobelts. However, the surface area specific rate of CO₂ formation displayed an inverse trend. In the region of 225 – 250ᵒC, nanocubes > NaOH nanosheet > HCl nanocubes showed maximum activity. The surface area specific rate was the same for amine nanocubes and NaOH nanosheets. None of the model catalysts retained their morphology after the temperature was ramped from 50ᵒC to 450ᵒC, and back to 50ᵒC. The catalysts were partially reduced to metallic Coo (other phase being CoO). Figure 1: In situ PXRD analysis and kinetics of CH4, CO and CO₂ showing the behaviour of Co₃O₄/SiO₂ (amine nanocubes) under CO-PROX conditions
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Matsutsu, Molefi. "DFT insight into the oxygen reduction reaction (ORR) on the Pt₃Co(111) surface." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/22066.

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Proton exchange membrane fuel cells (PEMFC) are identified as future energy conversion devices, for application in portable and transportation devices. The preferred catalyst for the PEMFC is a Pt-catalyst. However, due to the slow oxygen reduction reaction (ORR) kinetics, high Pt loadings have to be used. The high Pt loadings lead to high costs of the PEMFC. Pt-Co alloys have been identified as catalysts having higher ORR activity higher than of a Pt-catalyst. Therefore, in the present study, the Density Functional Theory (DFT) technique is used to gain fundamental insight into the ORR on the Pt₃Co(111) surface. The calculations have been performed using the plane wave based code, the Vienna ab-initio Simulation Package (VASP). DFT spin-polarized calculations, utilizing the GGA-PW91 functional, have been used to study the adsorption of the ORR intermediates, viz. O₂, O, OOH, OH, H₂O and HOOH on the Pt₃Co(111) surface. The results obtained on the Pt₃Co(111) surface are compared to the results obtained on the Pt(111) surface. The adsorption strength of the ORR intermediates has been shown to be affected by the presence of Co to varying extents on the Pt₃Co(111) surface relative to adsorption on the Pt(111) surface. The most strongly stabilised ORR intermediate on the Pt₃Co(111) surface relative to adsorption on the Pt(111) surface is O: on the Pt₃Co(111) surface O is 0.45 eV more strongly adsorbed than on the Pt(111) surface. The least affected ORR intermediate is H₂O: H₂O adsorption on the Pt₃Co(111) surface is 0.20 eV more stable than on the Pt(111) surface. The energetically favorable, i.e. most strongly bound adsorption configurations for all the ORR intermediates involves a configuration in which the ORR intermediate is bonded to a surface Co atom. Therefore, the surface Co atom stabilizes the adsorption of the ORR intermediates, relative to adsorption on the Pt(111) surface. Coadsorbed configurations have been used to study the formation and dissociation of the ORR intermediates. From the coadsorption studies, it is shown that there is an energy cost associated with moving the adsorbates from their lowest energy sites, while separately adsorbed, to the higher energy coadsorbed state, prior to reaction. Hence, adsorbate-adsorbate interactions are expected to destabilize the coadsorbed state at the coverages considered in the present study. The Climbing Image Nudged Elastic Band (CI-NEB) method has been used to locate the transition states and to calculate the activation energies of the different elementary reaction steps. The calculated dissociation reaction activation energies for the Pt₃Co(111) surface are found to be lower than the dissociation activation energies calculated on the Pt(111) surface. The most lowered dissociation activation energy is for the dissociation of O₂: on the Pt₃Co(111) surface the activation energy is 0.08 eV, whilst on the Pt(111) surface the activation energy is 0.59 eV. For the hydrogenation reaction steps, only the hydrogenation of O to form OH occurs with a lower activation energy of 0.86 eV on the Pt₃Co(111) surface, compared to 0.95 eV on the Pt(111) surface. For other hydrogenation reaction steps, the activation energies on the Pt₃Co(111) surface are higher than those on the Pt(111) surface. Based on the calculated activation energies of the elementary ORR reaction steps, the dissociative and the O-assisted H₂O dissociation mechanisms are identified as the mechanisms most likely to be dominant on the Pt₃Co(111) surface, due to having lower activation energies relative to the associative mechanisms. For both mechanisms, the reaction step with the highest activation energy is the step involving O, i.e. O hydrogenation to form OH for the dissociative mechanism, and the O* + H₂O* --> 2OH* reaction for the O-assisted H₂O dissociation mechanism. Thus, the reaction step involving the reaction of the strongly adsorbed O species, is identified as the potential rate limiting step of the ORR. Both the dissociative and the O-assisted H₂O dissociation mechanisms are expected to be in competition on the Pt₃Co(111) surface, since the potential rate limiting step for both mechanisms have similar activation energies. Hence, the preferred mechanism will depend on the relative abundances of the H species and H₂O on the Pt₃Co(111) surface. A microkinetic analysis would be need needed to fully account for concentration and entropic contributions to the rate of reaction for the different ORR elementary reaction steps.
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Hlabangana, Ntandoyenkosi. "Influence of particle size and morphology of Pt₃Co/C on the oxygen reduction reaction." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/24324.

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Polymer electrolyte fuel cells have shown great potential in providing clean energy with no emissions. The kinetics of the cathode reaction, i.e. the oxygen reduction reaction (ORR) are sluggish necessitating high loadings of the catalyst metal, i.e. platinum. Platinum is a limited resource and expensive. Its price has been one of the major drawbacks in wide scale commercialisation of fuel cells. In an effort to improve the activity of the catalyst and therefore reduce Pt loadings on the catalyst, Pt can be alloyed with transition metal elements (e.g. Ni, Co and Fe) to form bimetallic catalysts. Alloying has been known to improve the activity and stability of a catalyst for the ORR. The enhanced activity of the alloys originates from the modified electronic structures of the Pt in these alloy catalysts which reduces the adsorption of spectator species therefore increasing the number of active sites for the ORR (Wang et al., 2012 (2)). The aim of this study was to gain a better understanding of the influence of Pt alloy particle size and active surface morphology on the ORR activity. The Pt alloy that was investigated was Pt₃Co/C. The surface morphology was modified by varying the Pt/Pt₃Co loading on a carbon support. The catalysts were prepared using thermally induced chemical deposition. The support used was Vulcan-XC-72R. The effects of varying the metal loadings on the ORR was investigated. The loadings that were investigated were 20, 40, 60 and 80 wt. % Pt and Pt₃Co. The alloy catalysts were subjected to annealing at 900 °C and acid leaching. The catalysts were analysed using electrochemical characterisation techniques such as cyclic voltammetry, CO stripping voltammetry, rotating disk electrode and rotating ring disk electrode. Physical characterisation of the catalysts was also implemented. The techniques used were x-ray diffraction, thermogravimetric analysis and transmission electron microscopy. The Pt particles on the carbon support were found not to agglomerate significantly despite the loading being increased. This trend was also observed for the Pt₃Co/C catalysts even after heat treatment and leaching. The lack of agglomeration was credited to a new reactor system developed in this work. The particle growth increased from low loadings to high loadings for both the Pt/C and Pt₃Co/C catalysts. Particle growth was more significant for the Pt₃Co/C catalysts at high loadings. At lower loadings (20 and 40 wt. %) the particle sizes between the Pt/C and Pt₃Co/C catalysts were comparable despite the Pt₃Co/C catalysts undergoing annealing and leaching. The mass specific activity of the Pt/C catalysts was not improved by alloying with the exception of the 20 wt. % catalyst which saw an enhancement factor of 1.66. The surface specific activity of the Pt/C catalysts was improved significantly with factors of 2.40 and 3.11 being recorded for the 20 and 80 wt. % Pt₃Co/C catalysts respectively. The enhancement factors of the intermediate loadings (40 and 60 wt. %) were lower and fairly similar at 1.30 and 1.35 respectively.
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Brinkley, Kendra W. "The Synthesis of Solid Supported Palladium Nanoparticles: Effective Catalysts for Batch and Continuous Cross Coupling Reactions." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3959.

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Catalysis is one of the pillars of the chemical industry. While the use of catalyst is typically recognized in the automobile industry, their impact is more widespread as; catalysts are used in the synthesis of 80% of the US commercial chemicals. Despite the improved selectivity provided by catalyst, process inefficiencies still threaten the sustainability of a number of synthesis methods, especially in the pharmaceutical industry. Recyclable solid supported catalysts offer a unique opportunity to address these inefficiencies. Such systems coupled with continuous synthesis techniques, have the potential to significantly reduce the waste to desired product ratio (E-factor) of the production techniques. This research focuses developing sustainable processes to synthesize organic molecules by using continuous synthesis methods. In doing so, solid supported metal catalyst systems were identified, developed, and implemented to assist in the formation of carbon-carbon bonds. Newly developed systems, which utilized metal nanoparticles, showed reactivity and recyclability, comparable to commercially available catalyst. Nanoparticles are emerging as useful materials in a wide variety of applications including catalysis. These applications include pharmaceutical processes by which complex and useful organic molecules can be prepared. As such, an effective and scalable synthesis method is required for the preparation of nanoparticle catalysts with significant control of the particle size, uniform dispersion, and even distribution of nanoparticles when deposited on the surface of a solid support. This project describes the production of palladium nanoparticles on a variety of solid supports and the evaluation of these nanoparticles for cross coupling reactions. This report highlights novel synthesis techniques used in the formation of palladium nanoparticles using traditional batch reactions. The procedures developed for the batch formation of palladium nanoparticles on different solid supports, such as graphene and carbon nanotubes, are initially described. The major drawbacks of these methods are discussed, including limited scalability, variation of nanoparticle characteristics from batch to batch, and technical challenges associated with efficient heating of samples. Furthermore, the necessary conditions and critical parameters to convert the batch synthesis of solid supported palladium nanoparticles to a continuous flow process are presented. This strategy not only alleviates the challenges associated with the robust preparation of the material and the limitations of scalability, but also showcases a new continuous reactor capable of efficient and direct heating of the reaction mixture under microwave irradiation. This strategy was further used in the synthesis of zinc oxide nanoparticles. Particles synthesized using this strategy as well as traditional synthesis methods, were evaluated in the context industrially relevant applications.
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Jayatissa, Kuruppu Lilanthi. "A Metal-Free Approach to Biaryl Compounds: Carbon-Carbon Bond Formation from Diaryliodonium Salts and Aryl Triolborates." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2229.

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Biaryl moieties are important structural motifs in many industries, including pharmaceutical, agrochemical, energy and technology. The development of novel and efficient methods to synthesize these carbon-carbon bonds is at the forefront of synthetic methodology. Since Ullmann’s first report of stoichiometric Cu-mediated homo-coupling of aryl halides, there has been a dramatic evolution in transition metal catalyzed biaryl cross-coupling reactions. Our work focuses on the discovery and development of an unprecedented reagent combination for metal-free cross-coupling. It is hypothesized that direct carbon-carbon bond formation occurs via a triaryl-λ3-iodane and that electrophile/nucleophile pairing is critical for success in the reaction. Proof-of-concept for this approach focused on the reaction between bromo 4-trifluoromethylphenyl (trimethoxybenzene)-λ3-iodane and potassium 3-fluorophenyltriolborate. The spectator ligand and counter ions are important parameters for both reactivity and selectivity of the aryl group transfer in this reaction. Moderate to good yields of biaryl products are obtained by this method. Experimental evidence supports the assertion of a metal-free cross-coupling reaction.
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Houlding, T. K. "Application of radiofrequency heating in catalytic reaction engineering." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.676521.

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Radiofrequency (RF) heating of composite magnetic materials enables direct and efficient transfer of energy to the sites of catalytic reactions within a chemical reactor. The materials consist of an RF heated magnetic component and a catalytic component. The two components can be optimised separately according to the demands of the application. This approach was applied to continuous direct amide formation from amines and carboxylic acids under flow conditions, a reaction of great interest and potential to the pharmaceutical industry. The RF heat generation of NiFe2 04-TiO2 magnetic materials were optimised. Catalyst screening showed sulfated commercial P 25 Ti02 to give good catalytic activity in the reaction of 4-phenylbutyric acid with aniline in xylene. The composite material was prepared mechanochemically from a mixture of the optimised magnetic and catalytic components. A continuous RF heated reactor was developed, consisting of a 6 mm diameter insulated micro packed-bed reactor placed within an RF induction coil. The reactor was operated at 7 bar and up to 200°C for up to 10 hours. The sulfated composite achieved t he highest activity of up to 50% conversion in a single pass and the least deactivation. Temperature profiles obtained from the analytical solutions were combined with a catalyst kinetic model to form a reactor model, which was validated by the experimental results. The concentration profiles obtained from the reactor model gave an insight into the mechanism of the observed process intensification - the temperature rise along the RF heated reactor axis helped to offset the reduction in the reaction rate as a result of depletion of the reactants. This novel type of process is therefore most suited to reactions with high reaction rate orders and it would therefore be of great interest to investigate other processes where this effect could be demonstrated.
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Books on the topic "Catalysis and Reaction Engineering"

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Berty, J. M. Experiments in catalytic reaction engineering. Amsterdam: Elsevier, 1999.

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Chemical and catalytic reaction engineering. Mineola, N.Y: Dover Publications, 2001.

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Asia-Pacific Chemical Reaction Engineering Symposium (4th 2005 Kyŏngju-si, Korea). New developments and application in chemical reaction engineering: Proceedings of the 4th Asia-Pacific Chemical Reaction Engineering Symposium (APCRE '05), Gyeongju, Korea, June 12-15, 2005. Amsterdam: Elsevier, 2006.

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Asia-Pacific Chemical Reaction Engineering Symposium (4th 2005 Kyŏngju-si, Korea). New developments and application in chemical reaction engineering: Proceedings of the 4th Asia-Pacific Chemical Reaction Engineering Symposium (APCRE '05), Gyeongju, Korea, June 12-15, 2005. Amsterdam: Elsevier, 2006.

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service), Wiley InterScience (Online, ed. Modern heterogeneous oxidation catalysis: Design, reactions and characterization. Weinheim: Wiley-VCH, 2009.

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Catalytic reactors. Berlin: Walter de Gruyter GmbH & Co., KG, 2016.

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Chemical reactor design, optimization, and scaleup. New York: McGraw-Hill, 2002.

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Nauman, E. B. Chemical reactor design, optimization, and scaleup. 2nd ed. Hoboken, N.J: Wiley, 2008.

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Lister, Ted. Reaction rates, catalysis and enzymes. Cambridge: Pearson Publishing, 1992.

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Molnár, Árpád. Palladium-catalyzed coupling reactions: Practical aspects and future developments. Weinheim, Germany: Wiley-VCH, 2013.

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Book chapters on the topic "Catalysis and Reaction Engineering"

1

Kapteijn, Freek, Jorge Gascon, and T. Alexander Nijhuis. "Catalytic Reaction Engineering." In Catalysis, 221–69. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2017. http://dx.doi.org/10.1002/9783527810932.ch6.

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Schmal, Martin, and José Carlos Pinto. "Catalysis: Analyzing variables influencing the catalytic properties." In Chemical Reaction Engineering, 689–718. 2nd ed. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003046608-24.

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Marin, G. B., F. Kapteijn, A. E. Diepen, and J. A. Moulijn. "Catalytic Reaction and Reactor Engineering." In Combinatorial Catalysis and High Throughput Catalyst Design and Testing, 239–81. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-011-4329-5_8.

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Woodley, John M. "Reaction and Process Engineering." In Enzyme Catalysis in Organic Synthesis, 217–47. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527639861.ch7.

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Marchetti, Jorge M. "Catalysis Preparation and Characterization." In Reaction Engineering, Catalyst Preparation, and Kinetics, 1–41. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429466847-1.

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Vedrine, Rapporteur J. C. "Session Five, Chemical Kinetics and Chemical Engineering." In Elementary Reaction Steps in Heterogeneous Catalysis, 461–63. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1693-0_29.

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Schmal, Martin, and José Carlos Pinto. "Catalyst deactivation." In Chemical Reaction Engineering, 511–32. 2nd ed. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003046608-19.

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Tapio, Salmi, Mikkola Jyri-Pekka, and Wärnå Johan. "Catalytic Two-Phase Reactors." In Chemical Reaction Engineering and Reactor Technology, 150–221. Boca Raton, FL : CRC Press, Taylor & Francis Group, 2019.: Chapman and Hall/CRC, 2019. http://dx.doi.org/10.1201/9781315200118-5.

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Tapio, Salmi, Mikkola Jyri-Pekka, and Wärnå Johan. "Catalytic Three-Phase Reactors." In Chemical Reaction Engineering and Reactor Technology, 222–48. Boca Raton, FL : CRC Press, Taylor & Francis Group, 2019.: Chapman and Hall/CRC, 2019. http://dx.doi.org/10.1201/9781315200118-6.

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Levec, Janez. "Opportunities in Catalytic Reaction Engineering. Examples of Heterogeneous Catalysis in Water Remediation and Preferential CO Oxidation." In Chemical Engineering, 103–24. Chichester, UK: John Wiley & Sons, Ltd, 2005. http://dx.doi.org/10.1002/0470025018.ch5.

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Conference papers on the topic "Catalysis and Reaction Engineering"

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Zhang, Bo, Pengfei He, and Chao Zhu. "Modeling on Hydrodynamic Coupled FCC Reaction in Gas-Solid Riser Reactor." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21368.

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The fluid catalytic cracking (FCC) riser reactor consists of a bottom section of liquid feed injection and vaporization and an upward straight riser of vapor-catalysts transport and reaction. The product yield, obtained at the top of riser, is an accumulative result of liquid feed injection, vaporization by liquid contacting with hot catalysts, and subsequent catalytic cracking of feed vapor while being transported concurrently with catalysts through the riser. The FCC process involves not only these sequential sub-processes but also complicated coupling among multiphase fluid hydrodynamics, heat and mass transfer between phases, and catalytic kinetic reactions of vapor components in each sub-process. It is essential to build up a model covering all sub-processes/mechanisms mentioned above through riser reactor and giving prompt results, especially for real-time online optimization of industrial operation. This paper aims to develop a parametric model, integrated from bottom feed nozzle to top exit of riser, that can quickly predict both hydrodynamic and kinetic characteristics throughout the riser as well as various parametric effects on production yield and selectivity. Highlights of modeling contributions in this integrated model include a mechanistic and spatial-structural model of multiple-nozzle feeding with strong interactions not only among sprays themselves but also with cross-flowing steam and catalysts, a heat transfer model between gaseous and catalyst phases, and a more-rigorously derived model of reactant conservation in the multiphase flow transport. The convective nature dominating the nozzle feeding, riser transport and kinetic reactions allows us to simplify the governing equations in this integrated model to a set of coupled first-order ordinary differential equations whose solutions can be obtained quickly via Runge-Kutta algorithm. Compared to the published plant data, the predicted VGO conversion and gasoline yield from the proposed model shows a much better agreement to those from previous parametric models, which suggests the newly-added sub-models of previously overlooked mechanisms can be quite important. Some parametric effects, such as the effect of catalyst-to-oil ratio and catalyst inlet temperature, on production yield and selectivity are further predicted. The results show that a higher CTO or catalyst temperature normally leads to higher cracking conversion, higher gasoline production and lower coke content. However, a very high inlet temperature of catalysts does cause over-cracking and lower the gasoline selectivity.
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Hasmady, Saiful, Manuel Philipp Wacker, Kazuyoshi Fushinobu, and Ken Okazaki. "Treatment of Heterogeneous Electrocatalysis in Modeling Transport-Reaction Phenomena in PEFCs." In ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference collocated with the ASME 2007 InterPACK Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ht2007-32581.

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Thermal and water management is a critical issue in PEFCs. In this research, the thermal behavior of PEFC is focused. The objective is to understand the influence of heat on cell performance both by experiment and theoretical analysis, as well as improving cell performance and reliability. In order to investigate the theoretical behavior, especially in the catalyst layer where the electrochemical reactions occur, a detailed modeling of heterogeneous surface reaction coupled with reactant transport is needed. In this paper, a theoretical model that improves the dependency of the exchange current density with reactant concentrations by applying data from a known surface reaction steps found in catalysis is developed. It served as a preliminary step before the thermal-electrochemical behavior of a PEFC can be fully understood.
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Sharma, Poonam, and Rakesh Kumar Sharma. "Comparative study of Pt loaded carbon support catalysis in hydrogenation reaction." In Annual International Conference on Chemistry, Chemical Engineering and Chemical Process. Global Science & Technology Forum (GSTF), 2015. http://dx.doi.org/10.5176/2301-3761_ccecp15.65.

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Hyland, Patrick, Jungmin Lee, Chien Shung Lin, Jeongmin Ahn, and Paul D. Ronney. "Effect of Ammonia Treatment on Pt Catalyst Used for Low-Temperature Reaction." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42040.

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Platinum based catalysts are well known as the most active ones among noble metals for oxidation of hydrocarbons as well as hydrogen. Microcombustion experiments using bare Pt foil catalyst have shown that hydrocarbon fuels (e.g. propane) can be oxidized at low-temperature (< 60 °C) and ignited (< 90 °C) by treating the catalyst surface by burning propane-air mixtures with ∼ 5% of the propane replaced by ammonia for half an hour. This NH3 pre-treatment etches the catalyst surface and creates surface structures on the scale of few μms, completely unlike those without NH3 treatment. This change in structure with NH3 treatment is noteworthy in that it increases the performance of the catalyst by a factor of 3, but only for low Re, corresponding to conditions with low maximum reaction temperatures characteristic of microcombustors. However, no similar such low-temperatures were found without NH3 pre-treatment, even for catalytic reactions. This is not merely a surface area effect, since increasing bulk catalyst area had almost no effect on combustion performance. Nevertheless, it may be possible to further extend reaction and ignition to even lower temperatures by examining alternative hydrocarbon fuels and catalysts. Self-starting fuels and catalysts are highly desirable, especially for the micro-combustors used for MEMS (Micro Electro-Mechanical Systems) power generators, because it would eliminate the need for glow plugs, supplemental battery, electronics, etc. associated with active ignition systems.
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Raoufi, Arman, Sagar Kapadia, and James C. Newman. "Sensitivity Analysis and Computational Optimization of Fuel Reformer." In ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2016 Power Conference and the ASME 2016 10th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/fuelcell2016-59110.

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In this study, the catalytic combustion of methane is numerically investigated using an unstructured, implicit, fully coupled finite volume approach. Nonlinear system of equations is solved by Newton’s method. The catalytic partial oxidation of methane over both platinum and rhodium catalysts are studied three-dimensionally. Eight gas-phase species (CH4, CO2, H2O, N2, O2, CO, OH and H2) are considered for the simulation. Surface chemistry is modeled by detailed reaction mechanisms including 24 heterogeneous reactions with 11 surface-adsorbed species for Pt catalyst and 38 heterogeneous reactions with 20 surface-adsorbed species for Rh catalyst. The numerical results are compared with the experimental data and good agreement is observed. The performance of the fuel reformer is analyzed for two different catalysts. The sensitivity analysis for the reactor is performed using three different approaches: finite difference, direct differentiation and adjoint method. The design cycle is performed using two gradient-based optimization algorithms to improve the value of the implemented cost function and optimize the reactor performance.
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Murugan, Eagambaram, J. Nimita Jebaranjitham, and S. Govindaraju. "Heterogeneous nanoparticle catalyst: PPI(G2) dendrimer grafted poly(styrene) beads stabilized with AuNPs for catalysis to knovenegal reaction." In International Conference on Nanoscience, Engineering and Technology (ICONSET 2011). IEEE, 2011. http://dx.doi.org/10.1109/iconset.2011.6167966.

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Depcik, Christopher, Sudarshan Loya, and Anand Srinivasan. "Adaptive Carbon Monoxide Kinetics for Exhaust Aftertreatment Modeling." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11173.

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Future emission standards are driving the need for advanced control of both Spark (SI) and Compression Ignition (CI) engines. However, even with the implementation of cooled Exhaust Gas Recirculation and Low Temperature Combustion (LTC), it is unlikely that in-cylinder combustion strategies alone will reduce emissions to levels below the proposed standards. As a result, researchers are developing complex catalytic aftertreatment systems to meet these tailpipe regulations for both conventional and alternative combustion regimes. Simulating these exhaust systems requires fast and accurate models suitable for significant changes in inlet conditions. Most aftertreatment devices contain Platinum Group Metals because of their widely documented beneficial catalysis properties; examples include Diesel Oxidation Catalysts, Three-Way Catalysts and Lean NOx Traps. There are kinetic mechanisms available for each of these devices, but often they do not extrapolate well to other formulations. For example, Carbon Monoxide (CO) levels entering a catalyst are significantly different between an SI and CI engine. In addition, modifying engine control to utilize LTC operation can result in an increase in CO levels due to lower combustion efficiency. This adversely affects the conversion capabilities of a catalytic device through increased levels of CO inhibition. Finally, catalyst loading and metal dispersion differences between devices often prohibit a direct extension of kinetic constants. As a result, mechanisms often need recalibration for correct modeling capabilities. In order to begin creating a more predictive kinetic mechanism, this paper simulates CO oxidation as a function of different inlet concentration levels and metal loadings. While aftertreatment devices contain many reactions, modeling of one fundamental reaction is a first step to determine the feasibility of adaptive kinetics. In addition, research into the history of the CO oxidation mechanism over platinum illustrates a more accurate rate expression to utilize in deference to current modeling activities. The authors calibrate this expression to experimental data taking into account significant changes in inlet conditions, metal loading and dispersion values. Model fidelity is determined through the simulation of additional data not part of the initial calibration efforts. In addition, the paper discusses strengths and weaknesses of the model along with how other researchers can help foster adaptive kinetic development.
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Patel, Sanjay, and K. K. Pant. "Hydrogen Production for PEM Fuel Cells via Oxidative Steam Reforming of Methanol Using Cu-Al Catalysts Modified With Ce and Cr." In ASME 2006 4th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2006. http://dx.doi.org/10.1115/fuelcell2006-97209.

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The performance of Cu-Ce-Al-oxide and Cu-Cr-Al-oxide catalysts of varying compositions prepared by co-precipitation method was evaluated for the PEM fuel cell grade hydrogen production via oxidative steam reforming of methanol (OSRM). The limitations of partial oxidation and steam reforming of methanol for the hydrogen production for PEM fuel cell could be overcome using OSRM and can be performed auto-thermally with idealized reaction stoichiomatry. Catalysts surface area and pore volume were determined using N2 adsorption-desorption method. The final elemental compositions were determined using atomic absorption spectroscopy. Crystalline phases of catalyst samples were determined by X-ray diffraction (XRD) technique. Temperature programmed reduction (TPR) demonstrated that the incorporation of Ce improved the copper reducibility significantly compared to Cr promoter. The OSRM was carried out in a fixed bed catalytic reactor. Reaction temperature, contact-time (W/F) and oxygen to methanol (O/M) molar ratio varied from 200–300°C, 3–21 kgcat s mol−1 and 0–0.5 respectively. The steam to methanol (S/M) molar ratio = 1.4 and pressure = 1 atm were kept constant. Catalyst Cu-Ce-Al:30-10-60 exhibited 100% methanol conversion and 152 mmol s−1 kgcat−1 hydrogen production rate at 300°C with carbon monoxide formation as low as 1300 ppm, which reduces the load on preferential oxidation of CO to CO2 (PROX) significantly before feeding the hydrogen rich stream to the PEM fuel cell as a feed. The higher catalytic performance of Ce containing catalysts was attributed to the improved Cu reducibility, higher surface area, and better copper dispersion. Reaction parameters were optimized in order to maximize the hydrogen production and to keep the CO formation as low as possible. The time-on-stream stability test showed that the Cu-Ce-Al-oxide catalysts subjected to a moderate deactivation compared to Cu-Cr-Al-oxide catalysts. The amount of carbon deposited onto the catalysts was determined using TG/DTA thermogravimetric analyzer. C1s spectra were obtained by surface analysis of post reaction catalysts using X-ray photoelectron spectroscopy (XPS) to investigate the nature of coke deposited.
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Kulić Mandić, Aleksandra, Milena Bečelić-Tomin, Đurđa Kerkez, Gordana Pucar Milidrag, Vesna Pešić, and Miljana Prica. "A mini review: Optimal dye removal by fenton process catalysed with waste materials." In 10th International Symposium on Graphic Engineering and Design. University of Novi Sad, Faculty of technical sciences, Department of graphic engineering and design,, 2020. http://dx.doi.org/10.24867/grid-2020-p21.

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Large quantities of solid waste from different industries are commonly disposed in landfills, where can generate wide range of environmental problems. Therefore, the aim of this paper is to give insight on the usage of various waste materials as oxidation catalysts in different Fenton processes for dye removal. In that manner the circular value chain of these materials will be reinforced, obtaining disposal cost reduction and further value addition. Some of industrial wastes (fly ash, electric arc furnace dust, red mud, coal bottom ash, activated carbon from biomass, etc.) that have been used to catalyse Fenton reaction in various researches are reviewed from optimization point of view. Both types of optimization, one-factor-at-a-time (OFAT) and response surface methodology (RSM) are investigated. The study revealed that factors as catalyst concentration, pH value, hydrogen peroxide concentration, dye concentration and reaction time are main factors that influence final Fenton capacity as oxidation process catalysed with reviewed waste materials.
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Wang, Dawei, Rajesh Patel, Chao Zhu, and Teh C. Ho. "Coupling of Hydrodynamics, Vaporization and Reaction With Liquid Spray Injection Into a High-Temperature Gas-Solid Reactor." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44158.

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A mechanistic model that to provide a quantitative understanding of the interplay of hydrodynamics, heat/mass transfer, and cracking reactions in the feed injection zone of a fluid catalytic cracking (FCC) riser reactor with a single nozzle spray. With the injection of an oil spray into a gas-solid flow, the collision between cold oil droplets and hot catalyst particles results in a strong momentum transfer that affects the spray hydrodynamics in terms of penetration and scattering. It also causes a significant heat transfer giving rise to rapid droplet vaporization and the attendant cooling of the catalyst. The presence of cracking reactions introduces volume expansion, changes in gas composition and volume fraction, and a cooling effect due to endothermicity. Accordingly, we in this study present an analysis of chemically-induced “entrance effects” in an FCC riser with a single nozzle spray. The cracking reaction network is described by a four-lump reaction model, while the ambient gas-solid transport is represented by a dense-phase riser flow. A Lagrangian modeling approach is adopted to track the spray trajectory as cracking reactions proceed. It is shown that cracking reactions play an important role in dictating the spray behavior, reaction and heat/mass transfer characteristics in the feed injection zone of an FCC riser.
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Reports on the topic "Catalysis and Reaction Engineering"

1

Klipstein, David H., and Sharon Robinson. Vision 2020. Reaction Engineering Roadmap. Office of Scientific and Technical Information (OSTI), January 2001. http://dx.doi.org/10.2172/1218702.

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J. Thomas Mckinnon. Computational Chemistry and Reaction Engineering Workbench. Office of Scientific and Technical Information (OSTI), December 2003. http://dx.doi.org/10.2172/820562.

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Li, Xinle. Active sites engineering of metal-organic frameworks for heterogeneous catalysis. Office of Scientific and Technical Information (OSTI), December 2016. http://dx.doi.org/10.2172/1409199.

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Resasco, Daniel E. Final Technical Report- Center for Interfacial Reaction Engineering. Office of Scientific and Technical Information (OSTI), October 2017. http://dx.doi.org/10.2172/1408909.

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Wei Goh, Tian. Atomic-level engineering and in-situ spectroscopy studies of metal-organic frameworks in heterogeneous catalysis. Office of Scientific and Technical Information (OSTI), April 2019. http://dx.doi.org/10.2172/1593380.

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Fort, J. A. Reaction Engineering International and Pacific Northwest Laboratory staff exchange: Addressing computational fluid dynamics needs of the chemical process industry. Office of Scientific and Technical Information (OSTI), July 1995. http://dx.doi.org/10.2172/104431.

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Cowles, Bradford A., and Daniel G. Backman. Manufacturing Technology Support (MATES II) Task Order 0005: Manufacturing Integration and Technology Evaluation to Enable Technology Transition. Subtask Phase 0 Study Task: Manufacturing Technology (ManTech) and Systems Engineering For Quick Reaction Systems. Fort Belvoir, VA: Defense Technical Information Center, October 2014. http://dx.doi.org/10.21236/ada618195.

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Shmulevich, Itzhak, Shrini Upadhyaya, Dror Rubinstein, Zvika Asaf, and Jeffrey P. Mitchell. Developing Simulation Tool for the Prediction of Cohesive Behavior Agricultural Materials Using Discrete Element Modeling. United States Department of Agriculture, October 2011. http://dx.doi.org/10.32747/2011.7697108.bard.

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The underlying similarity between soils, grains, fertilizers, concentrated animal feed, pellets, and mixtures is that they are all granular materials used in agriculture. Modeling such materials is a complex process due to the spatial variability of such media, the origin of the material (natural or biological), the nonlinearity of these materials, the contact phenomenon and flow that occur at the interface zone and between these granular materials, as well as the dynamic effect of the interaction process. The lack of a tool for studying such materials has limited the understanding of the phenomena relevant to them, which in turn has led to energy loss and poor quality products. The objective of this study was to develop a reliable prediction simulation tool for cohesive agricultural particle materials using Discrete Element Modeling (DEM). The specific objectives of this study were (1) to develop and verify a 3D cohesionless agricultural soil-tillage tool interaction model that enables the prediction of displacement and flow in the soil media, as well as forces acting on various tillage tools, using the discrete element method; (2) to develop a micro model for the DEM formulation by creating a cohesive contact model based on liquid bridge forces for various agriculture materials; (3) to extend the model to include both plastic and cohesive behavior of various materials, such as grain and soil structures (e.g., compaction level), textures (e.g., clay, loam, several grains), and moisture contents; (4) to develop a method to obtain the parameters for the cohesion contact model to represent specific materials. A DEM model was developed that can represent both plastic and cohesive behavior of soil. Soil cohesive behavior was achieved by considering tensile force between elements. The developed DEM model well represented the effect of wedge shape on soil behavior and reaction force. Laboratory test results showed that wedge penetration resistance in highly compacted soil was two times greater than that in low compacted soil, whereas DEM simulation with parameters obtained from the test of low compacted soil could not simply be extended to that of high compacted soil. The modified model took into account soil failure strength that could be changed with soil compaction. A three dimensional representation composed of normal displacement, shear failure strength and tensile failure strength was proposed to design mechanical properties between elements. The model based on the liquid bridge theory. An inter particle tension force measurement tool was developed and calibrated A comprehensive study of the parameters of the contact model for the DEM taking into account the cohesive/water-bridge was performed on various agricultural grains using this measurement tool. The modified DEM model was compared and validated against the test results. With the newly developed model and procedure for determination of DEM parameters, we could reproduce the high compacted soil behavior and reaction forces both qualitatively and quantitatively for the soil conditions and wedge shapes used in this study. Moreover, the effect of wedge shape on soil behavior and reaction force was well represented with the same parameters. During the research we made use of the commercial PFC3D to analyze soil tillage implements. An investigation was made of three different head drillers. A comparison of three commonly used soil tillage systems was completed, such as moldboard plow, disc plow and chisel plow. It can be concluded that the soil condition after plowing by the specific implement can be predicted by the DEM model. The chisel plow is the most economic tool for increasing soil porosity. The moldboard is the best tool for soil manipulation. It can be concluded that the discrete element simulation can be used as a reliable engineering tool for soil-implement interaction quantitatively and qualitatively.
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Locy, Robert D., Hillel Fromm, Joe H. Cherry, and Narendra K. Singh. Regulation of Arabidopsis Glutamate Decarboxylase in Response to Heat Stress: Modulation of Enzyme Activity and Gene Expression. United States Department of Agriculture, January 2001. http://dx.doi.org/10.32747/2001.7575288.bard.

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Most plants accumulate the nonprotein amino acid, g-aminobutyric acid (GABA), in response to heat stress. GABA is made from glutamate in a reaction catalyzed by glutamate decarboxylase (GAD), an enzyme that has been shown by the Israeli PI to be a calmodulin (CaM) binding protein whose activity is regulated in vitro by calcium and CaM. In Arabidopsis there are at least 5 GAD genes, two isoforms of GAD, GAD1 and GAD2, are known to be expressed, both of which appear to be calmodulin-binding proteins. The role of GABA accumulation in stress tolerance remains unclear, and thus the objectives of the proposed work are intended to clarify the possible roles of GABA in stress tolerance by studying the factors which regulate the activity of GAD in vivo. Our intent was to demonstrate the factors that mediate the expression of GAD activity by analyzing the promoters of the GAD1 and GAD2 genes, to determine the role of stress induced calcium signaling in the regulation of GAD activity, to investigate the role of phosphorylation of the CaM-binding domain in the regulation of GAD activity, and to investigate whether ABA signaling could be involved in GAD regulation via the following set of original Project Objectives: 1. Construction of chimeric GAD1 and GAD2 promoter/reporter gene fusions and their utilization for determining cell-specific expression of GAD genes in Arabidopsis. 2. Utilizing transgenic plants harboring chimeric GAD1 promoter-luciferase constructs for isolating mutants in genes controlling GAD1 gene activation in response to heat shock. 3. Assess the role of Ca2+/CaM in the regulation of GAD activity in vivo in Arabidopsis. 4. Study the possible phosphorylation of GAD as a means of regulation of GAD activity. 5. Utilize ABA mutants of Arabidopsis to assess the involvement of this phytohormone in GAD activation by stress stimuli. The major conclusions of Objective 1 was that GAD1 was strongly expressed in the elongating region of the root, while GAD2 was mainly expressed along the phloem in both roots and shoots. In addition, GAD activity was found not to be transcriptionally regulated in response to heat stress. Subsequently, The Israeli side obtained a GAD1 knockout mutation, and in light of the objective 1 results it was determined that characterization of this knockout mutation would contribute more to the project than the proposed Objective 2. The major conclusion of Objective 3 is that heat-stress-induced changes in GAD activity can be explained by heat-stress-induced changes in cytosolic calcium levels. No evidence that GAD activity was transcriptionally or translationally regulated or that protein phosphorylation was involved in GAD regulation (objective 4) was obtained. Previously published data by others showing that in wheat roots ABA regulated GABA accumulation proved not to be the case in Arabidopsis (Objective 5). Consequently, we put the remaining effort in the project into the selection of mutants related to temperature adaptation and GABA utilization and attempting to characterize events resulting from GABA accumulation. A set of 3 heat sensitive mutants that appear to have GABA related mutations have been isolated and partially characterized, and a study linking GABA accumulation to growth stimulation and altered nitrate assimilation were conducted. By providing a better understanding of how GAD activity was and was not regulated in vivo, we have ruled out the use of certain genes for genetically engineering thermotolerance, and suggested other areas of endeavor related to the thrust of the project that may be more likely approaches to genetically engineering thermotolerance.
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