Relevant bibliographies by topics / Catalyst

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
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Academic literature on the topic 'Catalyst'

Author: Grafiati
Published: 4 June 2021
Last updated: 16 November 2024

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Journal articles on the topic "Catalyst"

1

Kaplunenko, Volodymyr, and Mykola Kosinov. "Electric field - induced catalysis. Laws of field catalysis." InterConf, no. 26(129) (October 18, 2022): 332–51. http://dx.doi.org/10.51582/interconf.19-20.10.2022.037.

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Abstract.The article explores a new type of catalysis - electric field catalysis. The laws of field catalysis are given. The characteristics of the electric field are determined, which set the values of the characteristics of the field catalysis. Field catalysis and field catalyst do not fit into the traditional definition of catalysis and catalyst, which may require a revision of the terminology of catalysis. The field is a more versatile catalyst compared to material catalysts, both in terms of its application to a wider range of chemical reactions, and in the ability to control the rate and selectivity. It is shown that a common donor-acceptor mechanism of catalysis is realized in heterogeneous and field catalysis. Generalized formulas are obtained, from which, as partial results, the laws of heterogeneous and field catalysis follow. New definitions of catalyst and field catalysis are given. The class of material catalysts has been expanded and supplemented with field catalysts.
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Ortega-Caballero, Fernando, and Mikael Bols. "Cyclodextrin derivatives with cyanohydrin and carboxylate groups as artificial glycosidases." Canadian Journal of Chemistry 84, no. 4 (April 1, 2006): 650–58. http://dx.doi.org/10.1139/v06-039.

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Two cyclodextrin derivatives (1 and 2) were prepared in an attempt to create glycosidase mimics with a general acid catalyst and a nucleophilic carboxylate group. The catalysts 1 and 2 were found to catalyse the hydrolysis of 4-nitrophenyl β-D-glucopyranoside at pH 8.0, but rapidly underwent decomposition with loss of hydrogen cyanide to convert the cyanohydrin to the corresponding aldehyde. The initial rate of the catalysis shows that the cyanohydrin group in these molecules functions as a good catalyst, but that the carboxylate has no positive effect. The decomposition product aldehydes display little or no catalysis. A mechanism for the decomposition is suggested.Key words: biomimicry, enzyme model, kinetics, intramolecular reaction.
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Lomic, Gizela, Erne Kis, Goran Boskovic, and Radmila Marinkovic-Neducin. "Application of scanning electron microscopy in catalysis." Acta Periodica Technologica, no. 35 (2004): 67–77. http://dx.doi.org/10.2298/apt0435067l.

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A short survey of various information obtained by scanning electron microscopy (SEM) in the investigation of heterogeneous catalysts and nano-structured materials have been presented. The capabilities of SEM analysis and its application in testing catalysts in different fields of heterogeneous catalysis are illustrated. The results encompass the proper way of catalyst preparation, the mechanism of catalyst active sites formation catalysts changes and catalyst degradation during their application in different chemical processes. Presented SEM pictures have been taken on a SEM JOEL ISM 35 over 25 years of studies in the field of heterogeneous catalysis.
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Su, Shu Hua, Shi Ye Feng, Yuan Fang Zhao, Qiang Lu, Wei Liang Cheng, and Chang Qing Dong. "Comparison of Three Types of NH3-SCR Catalysts." Applied Mechanics and Materials 130-134 (October 2011): 418–21. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.418.

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The selective catalysis reduction (SCR) is one of the most promising technologies for NOx reduction at present. There are three types of NH3-SCR catalysts in the market, honeycomb catalyst, plate-types catalyst and corrugated catalyst. This paper firstly describes the preparation of the three types of catalysts, and then analyzes their performance. The analysis indicates the catalyst structure plays an important role on their performance. The honeycomb catalyst and plate-type catalyst are widely utilized in world’s coal power station, which should be due to their excellent capabilities of ash prevention, wear resistance and anti-poisoning.
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Ma, Yubo, Zhixian Gao, Tao Yuan, and Tianfu Wang. "Kinetics of Dicyclopentadiene Hydroformylation over Rh–SiO2 Catalysts." Progress in Reaction Kinetics and Mechanism 42, no. 2 (May 2017): 191–99. http://dx.doi.org/10.3184/146867817x14821527549013.

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The hydroformylation of dicyclopentadiene (DCPD) to monoformyltricyclodecenes (MFTD) represents a key intermediate step in the conversion of the C5 fraction derived from the petrochemical process to value-added fine chemicals, for example, diformyltricyclodecanes and tricyclodecanedimethylol. Although both heterogeneous and homogeneous catalysts can catalyse this reaction, the heterogeneously catalysed pathway has received significantly less attention due to its lower catalytic activities. We demonstrate in this work that a low Rh loaded heterogeneous 0.1% Rh–SiO2 catalyst can present a similar performance relative to the homogeneous Rh(PPh3)Cl, a reference catalyst for this reaction. Furthermore, an extensive kinetic study of DCPD hydroformylation to MFTD using heterogeneous 0.1% Rh–SiO2 catalysts has been performed. A series of kinetic experiments was carried out over a broad range of conditions (temperature: 100–120 °C; pressure: 1.5–5 MPa; catalyst-to-reactant mass ratio: 0.02–0.05; PPh3 concentration: 5–12.5 g L−1). A kinetic analysis was carried out, indicating the activation energy for the reaction to be 84.7 kJ mol−1. DCPD conversion and MFTD yield could be optimised to be as high as 99% at 0.1% Rh loading, a DCPD/catalyst mass ratio of 25, a PPh3 concentration of 10 g L−1, a reaction time of 4 h and a reaction pressure of 4 MPa.
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Jakab-Nácsa, Alexandra, Attila Garami, Béla Fiser, László Farkas, and Béla Viskolcz. "Towards Machine Learning in Heterogeneous Catalysis—A Case Study of 2,4-Dinitrotoluene Hydrogenation." International Journal of Molecular Sciences 24, no. 14 (July 14, 2023): 11461. http://dx.doi.org/10.3390/ijms241411461.

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Utilization of multivariate data analysis in catalysis research has extraordinary importance. The aim of the MIRA21 (MIskolc RAnking 21) model is to characterize heterogeneous catalysts with bias-free quantifiable data from 15 different variables to standardize catalyst characterization and provide an easy tool to compare, rank, and classify catalysts. The present work introduces and mathematically validates the MIRA21 model by identifying fundamentals affecting catalyst comparison and provides support for catalyst design. Literature data of 2,4-dinitrotoluene hydrogenation catalysts for toluene diamine synthesis were analyzed by using the descriptor system of MIRA21. In this study, exploratory data analysis (EDA) has been used to understand the relationships between individual variables such as catalyst performance, reaction conditions, catalyst compositions, and sustainable parameters. The results will be applicable in catalyst design, and using machine learning tools will also be possible.
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Donatus Setyawan Purwo Handoko and Triyono. "Characterization of NI/Zeolite Catalyst Including Specific Surface Area, Acidity, Si/Al Ratio, Cation Content in Zeolite." Formosa Journal of Sustainable Research 2, no. 6 (June 30, 2023): 1457–70. http://dx.doi.org/10.55927/fjsr.v2i6.4396.

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Specific Surface Area, acidity, Si/Al ratio, and cation concentration in zeolite catalysts have all been studied in relation to Ni/zeolite catalysts. The zeolite was submerged in water for 24 hours, dried, and then calcined for 3 hours at 400 oC before being incubated for 2 hours to create the Ni/zeolite catalyst. then 24 hours of stirring soaking in 6 M HCl, followed by 3 hours of refluxing with 1 M NH4Cl and 2 hours of oxygen gas oxidation. The zeolite will subsequently be impregnated with Ni, oxidized for three hours, and reduced with hydrogen gas for two hours. Additionally, a Ni/zeolite catalyst was acquired. The catalyst's metal concentration was then determined by characterizing the Ni/zeolite mixture, Si/Al ratio, specific surface area, and acidity of the catalyst. The outcomes of the characterisation are as follows: Ca and Fe are the main metals present in the Ni/zeolite catalyst, with only trace amounts of Na, Mg, and other metals (5 mg/gram of catalyst) present. In the meantime, the catalyst's acidity was 0.24 mmol/gram catalyst acidity, its surface area was 2.18 m2/gram catalyst surface area, and its Si/Al catalyst ratio was 10.21
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Jin, Jia Min. "Catalysis Mechanism and Application of Carbon Gasification Reaction-A Comparison of Two Heterogeneous Catalysis Mechanisms." International Journal of Chemistry 14, no. 1 (April 14, 2022): 23. http://dx.doi.org/10.5539/ijc.v14n1p23.

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This article is a brief summary article of research. The results of the three times experiments are reviewed. two heterogeneous catalysis mechanisms are introduced, namely: Chemical Reaction Mode Cyclic Catalysis Mechanism-CRM and Electron Cyclic Donate-Accept Catalysis Mechanism-ECDAM or Electron Orbital Deformation-Recovery Cyclic Catalysis Mechanism -EODRM. Some difficulties encountered by CRM are listed. The author clearly points out that the CRM is not credible. This false theory has misled us for more than 100 years. About ECDAM, the article also gives a brief description. The main point of ECDAM is that the catalysis phenomenon are physical rather than chemical phenomenon. The catalysts do not participate in chemical reactions. It's just contact, electron cyclic donate-accept or electron orbital deformation-recovery cycle. The theory contains three viewpoints: 1. There is a boundary between the catalyst and the poison. 2. The active of the catalyst or the degree of toxicity of the poison is closely related to ihe electronegative value of the catalyst or poison. 3. The active of catalyst is closely related to the chemical state of the catalyst The selectivity of catalyst is also related to electronegative or energy level According to ECDAM, the author considers that there are several problems worth studying in production and scientific research. such as: alumina is a poison in the Fe ammonia synthesis catalyst. The Cordierite (2MgO·2Al2O3·5SiO2) ceramic honeycomb support is also a poison in automotive exhaust purification catalyst. The Cordierite ceramic honeycomb is retardant in wall flow filter for diesel vehicles. Activated carbon is a poison in the Ruthenium catalyst for ammonia synthesis. Alumina and activated carbon all are a poison to noble metal catalysts, and so on.
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Shi, Chunjie, Xiaofeng Yu, Wei Wang, Haibing Wu, Ai Zhang, and Shengjin Liu. "The Activity and Cyclic Catalysis of Synthesized Iron-Supported Zr/Ti Solid Acid Catalysts in Methyl Benzoate Compounds." Catalysts 13, no. 6 (June 2, 2023): 971. http://dx.doi.org/10.3390/catal13060971.

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The catalytic activity and cyclic catalysis of different methyl benzoates were studied by using a series of Lewis solid acid catalysts. The iron-supported zirconium/titanium solid acid catalysts were characterized using FTIR, SEM, XRD, and BET. The details of catalytic activity and cyclic catalysis verified that the catalyst catalyzed the reactions of 31 benzoic acids with different substituents and methanol. In addition, the mechanism was revealed according to the microstructure, acid strength, and specific surface area of the catalysts, and the yields of methyl benzoates by the GC-MS. Zr ions had significant effects on the catalytic activity of the catalyst. A certain proportion of Fe and Ti ions additionally enhanced the catalytic activity of the catalyst, with the catalyst-specific composition of Fe:Zr: Ti = 2:1: 1 showing optimal catalytic activity. A variety of substituents in the benzene ring, such as the electron-withdrawing group, the electron-donating group, large steric hindrance, and the position of the group on the benzene ring, had regular effects on the catalytic activity of the methyl benzoates. An increase in the catalyst activity occurred owing to the increases in the catalyst surface and the number of acid sites after the Fe ion was added. The catalytic activity remained unchanged after the facile recycling method was performed.
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Jankovič, Ľuboš, and Peter Komadel. "Catalytic Properties of a Heated Ammonium-Saturated Dioctahedral Smectite." Collection of Czechoslovak Chemical Communications 65, no. 9 (2000): 1527–36. http://dx.doi.org/10.1135/cccc20001527.

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A series of acid catalysts was prepared by heating of NH4-saturated montmorillonite at 200-600 °C for 24 h. Their catalytic activity was tested in acetylation of 3,4,5-trimethoxybenzaldehyde with acetic anhydride. This reaction is sufficiently sensitive to modification of the catalyst and thus suitable for testing catalytic activity of modified montmorillonites. Most of the prepared catalysts were able to catalyse the test reaction and produce diacetate in higher than 50% yields. The most active catalyst was obtained after heating at 300 °C. It was slightly less effective than commercially available acid-activated K10 catalyst.
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Dissertations / Theses on the topic "Catalyst"

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Gill, Christopher Stephen. "Novel hybrid organic/inorganic single-sited catalysts and supports for fine chemical and pharmaceutical intermediate synthesis." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28218.

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Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Jones, Christopher; Committee Member: Agrawal, Pradeep; Committee Member: Teja, Amyn; Committee Member: Weck, Marcus; Committee Member: Zhang, John.
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Johnston, Eric. "New Tools for Green Catalysis : Studies on a Biomimetic Hybrid Catalyst and a Novel Nanopalladium Catalyst." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-65079.

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The first part of this thesis describes an improved synthetic route to hybrid (hydroquinone-Schiff base)cobalt catalysts. Preparation of the 5-(2,5-hydroxyphenyl)salicylaldehyde building block was improved by altering the protective groups of the hydroquinone (HQ) starting material. Both protection and deprotection could be carried out under mild conditions, resulting in high yields. By optimizing the reaction conditions of the Suzuki cross-coupling, an efficient and inexpensive synthetic route with a good overall yield was developed. The second part describes the use of the hybrid catalyst as an electron transfer mediator (ETM) in the palladium-catalyzed aerobic carbocyclization of enallenes. By covalently linking the HQ to the cobalt Schiff-base complex the reaction proceeded at lower temperatures with a five-fold increase of the reaction rate compared to the previously reported system. The third part describes the application of the hybrid catalyst in the biomimetic aerobic oxidation of secondary alcohols. Due to the effi­ciency of the intramolecular electron transfer, the hybrid catalyst allowed for a lower catalytic loading and milder reaction conditions compared to the previous separate-component system. Benzylic alcohols as well as aliphatic alcohols were oxidized to the corresponding ketones in excellent yield and selectivity using this methodology. The fourth part describes the synthesis and characterization of highly dispersed palladium nanoparticles supported on aminopropyl-modified siliceous mesocellular foam. The Pd nanocatalyst showed excellent activity for the aerobic oxidation of a wide variety of alcohols under air atmosphere. Moreover, the catalyst can be recycled several times without any decrease in activity or leaching of the metal into solution. Finally, the fifth part describes the application of the Pd nanocatalyst in transfer hydrogenations and Suzuki coupling reactions. The catalyst was found to be highly efficient for both transformations, resulting in chemoselective reduction of various alkenes as well as coupling of a variety of aryl halides with various boronic acids in excellent yields. Performing the latter reaction under microwave irradiation significantly increased the reaction rate, compared to conventional heating. However, no significant increase in reaction rate was observed for the transfer hydrogenations, under microwave heating.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Manuscript.

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Guo, Chris. "Alkane Oxidation Catalysis by Homogeneous and Heterogeneous Catalyst." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/622.

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Abstract Cobalt-based complexes are widely used in industry and organic synthesis as catalysts for the oxidation of hydrocarbons. The Co/Mn/Br (known as "CAB system") catalyst system is effective for the oxidation of toluene. The Co/Mn/Br/Zr catalyst system is powerful for the oxidation of p-xylene, but not for the oxidation of toluene. [Co3O(OAc)5(OH)(py)3][PF6] (Co 3+ trimer 5) is more effective than [Co3O(OAc)6(py)3][PF6] (Co 3+ trimer 6) as a catalyst in the CAB catalyst system. Higher temperatures favour the oxidation of toluene. Zr 4+ does not enhance the oxidation of toluene. Zr 4+ could inhibit the oxidation of toluene in the combination of Co/Br/Zr, Co/Mn/Zr or Co/Zr. NHPI enhances the formation of benzyl alcohol, but the formation of other by-products is a problem for industrial processes. Complex(es) between cobalt, manganese and zirconium might be formed during the catalytic reaction. However, attempts at the preparation of complexes consisting of Co/Zr or Mn/Zr or Co3ZrP or Co8Zr4 clusters failed. The oxidation of cyclohexane to cyclohexanone and cyclohexanol is of great industrial significance. For the homogeneous catalysis at 50 o C and 3 bar N2 pressure, the activity order is: Mn(OAc)3 �2H2O > Mn12O12 cluster > Co 3+ trimer 6 > [Co3O(OAc)3(OH)2(py)5][PF6]2 (Co 3+ trimer 3) > Co 3+ trimer 5 > Co(OAc)2 �4H2O > [Co2(OAc)3(OH)2(py)4][PF6]-asym (Co dimerasym) > [Co2(OAc)3(OH)2(py)4][PF6]-sym (Co dimersym); whereas [Mn2CoO(OAc)6(py)3]�HOAc (Mn2Co complex) and zirconium(IV) acetate hydroxide showed almost no activity under these conditions. But at 120 o C and 3 bar N2 pressure, the activity order is changed to: Co dimerasym > Co(OAc)2 �4H2O > Co trimer 3 and Mn(OAc)3 �2H2O > Co 3+ trimer 6 > Mn2Co complex > Co 3+ trimer 5 > Co dimersym > Mn12O12 cluster. The molar ratio of the products was close to cyclohexanol/cyclohexanone=2/1. Mn(II) acetate and zirconium(IV) acetate hydroxide showed almost no activity under these conditions. Among those cobalt dimers and trimers, only the cobalt dimerasym survived after the stability tests, this means that [Co2(OAc)3(OH)2(py)4][PF6]-asym might be the active form for cobalt(II) acetate in the CAB system. Metal-substituted (silico)aluminophosphate-5 molecular sieves (MeAPO-5 and MeSAPO-5) are important heterogeneous catalysts for the oxidation of cyclohexane. The preparation of MeAPO-5 and MeSAPO-5 and their catalytic activities were studied. Pure MeAPO-5 and MeSAPO-5 are obtained and characterised. Four new pairs of bimetal-substituted MeAPO-5 and MeSAPO-5(CoZr, MnZr, CrZr and MnCo) were prepared successfully. Two novel trimetal-subtituted MeAPO-5 and MeSAPO-5 (MnCoZr) are reported here. Improved methods for the preparation of four monometal-substituted MeAPO-5 (Cr, Co, Mn and Zr) and for CoCe(S)APO-5 and CrCe(S)APO-5 are reported. Novel combinational mixing conditions for the formation of gel mixtures for Me(S)APO-5 syntheses have been developed. For the oxidation of cyclohexane by TBHP catalysed by MeAPO-5 and MeSAPO-5 materials, CrZrSAPO-5 is the only active MeSAPO-5 catalyst among those materials tested under conditions of refluxing in cyclohexane. Of the MeAPO-5 materials tested, whereas CrCeSAPO-5 has very little activity, CrZrAPO-5 and CrCeAPO-5 are very active catalysts under conditions of refluxing in cyclohexane. MnCoAPO-5, MnZrAPO-5 and CrAPO-5 are also active. When Cr is in the catalyst system, the product distribution is always cyclohexanone/cyclohexanol equals 2-3)/1, compared with 1/2 for other catalysts. For MeAPO-5, the activity at 150 o C and 10 bar N2 pressure is: CrZrAPO-5 > CrCeAPO-5 > CoZrAPO-5. For MeAPO-5 and MeSAPO-5, at 150 o C and 13 bar N2 pressure, the selectivity towards cyclohexanone is: CrZrAPO-5 > CrZrSAPO-5 > CrCeAPO-5 > CrAPO-5 > MnCoAPO-5 > MnZrAPO-5; and the selectivity towards cyclohexanol is: MnZrAPO-5 > CrZrAPO-5 > MnCoAPO-5 > CrZrSAPO-5 > CrCeAPO-5 > CrAPO-5. Overall the selectivity towards the oxidation of cyclohexane is: CrZrAPO-5 > CrZrSAPO-5 > CrCeAPO-5 > CrAPO-5 > MnCoAPO-5 > MnZrAPO-5. The amount of water in the system can affect the performance of CrCeAPO-5, but has almost no effect on CrZrAPO-5. Metal leaching is another concern in potential industrial applications of MeAPO-5 and MeSAPO-5 catalysts. The heterogeneous catalysts prepared in the present work showed very little metal leaching. This feature, coupled with the good selectivities and effectivities, makes them potentially very useful.
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Guo, Chris. "Alkane Oxidation Catalysis by Homogeneous and Heterogeneous Catalyst." University of Sydney. Chemistry, 2005. http://hdl.handle.net/2123/622.

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Abstract Cobalt-based complexes are widely used in industry and organic synthesis as catalysts for the oxidation of hydrocarbons. The Co/Mn/Br (known as "CAB system") catalyst system is effective for the oxidation of toluene. The Co/Mn/Br/Zr catalyst system is powerful for the oxidation of p-xylene, but not for the oxidation of toluene. [Co3O(OAc)5(OH)(py)3][PF6] (Co 3+ trimer 5) is more effective than [Co3O(OAc)6(py)3][PF6] (Co 3+ trimer 6) as a catalyst in the CAB catalyst system. Higher temperatures favour the oxidation of toluene. Zr 4+ does not enhance the oxidation of toluene. Zr 4+ could inhibit the oxidation of toluene in the combination of Co/Br/Zr, Co/Mn/Zr or Co/Zr. NHPI enhances the formation of benzyl alcohol, but the formation of other by-products is a problem for industrial processes. Complex(es) between cobalt, manganese and zirconium might be formed during the catalytic reaction. However, attempts at the preparation of complexes consisting of Co/Zr or Mn/Zr or Co3ZrP or Co8Zr4 clusters failed. The oxidation of cyclohexane to cyclohexanone and cyclohexanol is of great industrial significance. For the homogeneous catalysis at 50 o C and 3 bar N2 pressure, the activity order is: Mn(OAc)3 �2H2O > Mn12O12 cluster > Co 3+ trimer 6 > [Co3O(OAc)3(OH)2(py)5][PF6]2 (Co 3+ trimer 3) > Co 3+ trimer 5 > Co(OAc)2 �4H2O > [Co2(OAc)3(OH)2(py)4][PF6]-asym (Co dimerasym) > [Co2(OAc)3(OH)2(py)4][PF6]-sym (Co dimersym); whereas [Mn2CoO(OAc)6(py)3]�HOAc (Mn2Co complex) and zirconium(IV) acetate hydroxide showed almost no activity under these conditions. But at 120 o C and 3 bar N2 pressure, the activity order is changed to: Co dimerasym > Co(OAc)2 �4H2O > Co trimer 3 and Mn(OAc)3 �2H2O > Co 3+ trimer 6 > Mn2Co complex > Co 3+ trimer 5 > Co dimersym > Mn12O12 cluster. The molar ratio of the products was close to cyclohexanol/cyclohexanone=2/1. Mn(II) acetate and zirconium(IV) acetate hydroxide showed almost no activity under these conditions. Among those cobalt dimers and trimers, only the cobalt dimerasym survived after the stability tests, this means that [Co2(OAc)3(OH)2(py)4][PF6]-asym might be the active form for cobalt(II) acetate in the CAB system. Metal-substituted (silico)aluminophosphate-5 molecular sieves (MeAPO-5 and MeSAPO-5) are important heterogeneous catalysts for the oxidation of cyclohexane. The preparation of MeAPO-5 and MeSAPO-5 and their catalytic activities were studied. Pure MeAPO-5 and MeSAPO-5 are obtained and characterised. Four new pairs of bimetal-substituted MeAPO-5 and MeSAPO-5(CoZr, MnZr, CrZr and MnCo) were prepared successfully. Two novel trimetal-subtituted MeAPO-5 and MeSAPO-5 (MnCoZr) are reported here. Improved methods for the preparation of four monometal-substituted MeAPO-5 (Cr, Co, Mn and Zr) and for CoCe(S)APO-5 and CrCe(S)APO-5 are reported. Novel combinational mixing conditions for the formation of gel mixtures for Me(S)APO-5 syntheses have been developed. For the oxidation of cyclohexane by TBHP catalysed by MeAPO-5 and MeSAPO-5 materials, CrZrSAPO-5 is the only active MeSAPO-5 catalyst among those materials tested under conditions of refluxing in cyclohexane. Of the MeAPO-5 materials tested, whereas CrCeSAPO-5 has very little activity, CrZrAPO-5 and CrCeAPO-5 are very active catalysts under conditions of refluxing in cyclohexane. MnCoAPO-5, MnZrAPO-5 and CrAPO-5 are also active. When Cr is in the catalyst system, the product distribution is always cyclohexanone/cyclohexanol equals 2-3)/1, compared with 1/2 for other catalysts. For MeAPO-5, the activity at 150 o C and 10 bar N2 pressure is: CrZrAPO-5 > CrCeAPO-5 > CoZrAPO-5. For MeAPO-5 and MeSAPO-5, at 150 o C and 13 bar N2 pressure, the selectivity towards cyclohexanone is: CrZrAPO-5 > CrZrSAPO-5 > CrCeAPO-5 > CrAPO-5 > MnCoAPO-5 > MnZrAPO-5; and the selectivity towards cyclohexanol is: MnZrAPO-5 > CrZrAPO-5 > MnCoAPO-5 > CrZrSAPO-5 > CrCeAPO-5 > CrAPO-5. Overall the selectivity towards the oxidation of cyclohexane is: CrZrAPO-5 > CrZrSAPO-5 > CrCeAPO-5 > CrAPO-5 > MnCoAPO-5 > MnZrAPO-5. The amount of water in the system can affect the performance of CrCeAPO-5, but has almost no effect on CrZrAPO-5. Metal leaching is another concern in potential industrial applications of MeAPO-5 and MeSAPO-5 catalysts. The heterogeneous catalysts prepared in the present work showed very little metal leaching. This feature, coupled with the good selectivities and effectivities, makes them potentially very useful.
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5

Baumgart, Jerry William. "Characterization of a CoMo/Al[subscript]2O[subscript]3 catalyst exposed to a coke inducing environment." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/11714.

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Ford, David Dearborn. "The Role of Catalyst-Catalyst Interactions in Asymmetric Catalysis with (salen)Co(III) Complexes and H-Bond Donors." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11154.

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In asymmetric catalysis, interactions between multiple molecules of catalyst can be important for achieving high catalyst activity and stereoselectivity. In Chapter 1 of this thesis, we introduce catalyst-catalyst interactions in the context of the classic Kagan nonlinear effect (NLE) experiment, and present examples of the strengths and drawbacks of the NLE experiment. For the remainder of the thesis, we explore catalyst-catalyst interactions in the context of two different reactions. First, in Chapter 2, we apply a combination of reaction kinetics and computational chemistry to a reaction that is well known to require the cooperative action of two molecules of catalyst: the (salen)Co(III)-catalyzed hydrolytic kinetic resolution (HKR) of terminal epoxides. In our investigation, we demonstrate that stereoselectivity in the HKR is achieved through catalyst-catalyst interactions and provide a model for how high selectivity and broad substrate scope are achieved in this reaction. In Chapter 3, we focus our attention on the thiourea-catalyzed enantioselective alkylation of alpha-chloroethers with silyl ketene acetal nucleophiles, a reaction that was not known to require the cooperative action of two molecules of catalyst at the outset of our investigation. By using a wide range of physical organic chemistry tools, we established that the resting state of the optimal thiourea catalyst is dimeric under typical reaction conditions, and that two molecules of catalyst work cooperatively to activate the alpha-chloroether electrophile. The implications of this mechanism for catalyst design are discussed.
Chemistry and Chemical Biology
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Nguyen, Joseph Vu. "Design, synthesis, and optimization of recoverable and recyclable silica-immobilized atom transfer radical polymerization catalysts." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6860.

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Despite the growing interest in heterogeneous polymerization catalysis, the majority of the polymerization catalysts used industrially are single-use entities that are left in the polymer product. Recoverable and recyclable polymerization catalysts have not reached the industrial utility of single-use catalysts because the catalyst and product separation have not become economical. The successful development of recyclable transition metal polymerization catalysts must take a rational design approach, hence academic and industrial researchers need to further expand the fundamental science and engineering of recyclable polymerization catalysis to gain an understanding of critical parameters that allow for the design of economically viable, recoverable solid polymerization catalysts. Unfortunately, the rapid development of Atom Transfer Radical Polymerization over the past 10 years has not resulted in its wide spread industrial practice. Numerous reports regarding the immobilization of transition metal ATRP catalysts, in attempts to increase its applicability, have extended the fundamentals of recyclable polymerization catalysis. However, for industrial viability, more research is required in the area of how the catalyst complex immobilization methodology and support structure affect the catalyst polymerization performance, regeneration, and recyclability. A comprehensive rational catalyst design approach of silica-immobilized ATRP catalyst was undertaken to answer these questions and are discussed here.
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Meyer, Simon [Verfasser]. "Carbide Materials as Catalysts and Catalyst Supports for Applications in Water Electrolysis and in Heterogeneous Catalysis / Simon Meyer." München : Verlag Dr. Hut, 2014. http://d-nb.info/1058284967/34.

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Craig, Kim Meyer. "New concepts in catalyst design: homogeneous organometallic catalysts with tunable architectures." Thesis, University of Auckland, 2010. http://hdl.handle.net/2292/6114.

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This theses describes the development of homogeneous catalysts containing receptor elements which are capable of participating in reversible bonding interactions with groups bearing complementary functionality. This approach is amenable to combinatorial chemistry, and could facilitate catalyst development processes which are conventionally expensive and time-intensive. To date, the implication of reversible supra molecular interactions in anthropogenic organometallic catalysis are not widely understood.
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Mansor, N. B. "Development of catalysts and catalyst supports for polymer electrolyte fuel cells." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1460064/.

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Polymer Electrolyte Membrane fuel cells (PEMFC) are clean and efficient electrochemical energy converters that can be adapted to a wide range of domestic and automotive applications. However, large-scale commercialisation is hindered by issues of cost and durability relating to the catalyst layer. This work aims to address the need for cheaper and durable catalysts through the development of novel catalyst and catalyst support. The initial aim of this work is to investigate the potential application of Pd-based alloy catalyst in PEMFC. Pd is about 42% cheaper than Pt and 50 times more abundant on earth. Previous studies have shown that there is a correlation between electronic structure and catalytic activity of Pd binary alloys, and therefore it is possible to design a highly efficient Pd-based alloy catalyst. In this work, Pd-based catalyst was synthesised and characterized electrochemically in ex-situ and in-situ configurations to determine their activity and durability. It was found that Pd-based catalyst could potentially replace Pt as a low-cost anode catalyst. The second part of this work investigated the potential application of graphitic carbon nitride materials as catalyst support. Carbon black is the most widely used catalyst support for state-of-the-art PEMFCs even though it is known to undergo carbon corrosion during operation. Graphitic carbon nitride could offer enhanced durability and activity due to their graphitic structure and intrinsic catalytic properties. In addition, graphitic carbon nitride is low-cost, fairly simple to synthesise and highly tunable. In this work, various graphitic carbon nitride materials were prepared and characterised using accelerated carbon corrosion protocol. They were found to be more electrochemically stable compared to conventional carbon black. Superior methanol oxidation activity is also observed for graphitic carbon nitride supported Pt catalysts on the basis of the catalyst electrochemical surface area. However further work is needed to optimise the deposition and utilisation of metal catalyst on graphitic carbon nitride materials.
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Books on the topic "Catalyst"

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International Symposium on Catalyst Deactivation (8th 1999 Brugge, Belgium). Catalyst deactivation 1999: Proceedings of the 8th International Symposium, Brugge, Belgium, October 10-13, 1999. Amsterdam: Elsevier, 1999.

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1937-, Anderson James A., and Fernández Garcia Marcos, eds. Supported metals in catalysis. London: Imperial College Press, 2005.

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1924-, Petersen Eugene E., Bell Alexis T. 1942-, and International Symposium on Catalysis Deactivation and Poisoning (3rd : 1985 : Lawrence Berkeley Laboratory), eds. Catalyst deactivation. New York: M. Dekker, 1987.

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1959-, Regalbuto John R., ed. Handbook of catalyst preparation. Boca Raton: Taylor & Francis, 2007.

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Chapman, Carol. Catalyst. Oxford: Heinemann Educational, 2003.

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Chapman, Carol. Catalyst. Oxford: Heinemann Educational, 2003.

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Hoffman, Nina Kiriki. Catalyst. San Francisco: Tachyon Publications, 2006.

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Carol, Chapman, ed. Catalyst. Oxford: Heinemann Educational, 2004.

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Anne, McCaffrey. Catalyst. New York: Random House Publishing Group, 2010.

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Carol, Chapman, ed. Catalyst. Oxford: Heinemann Educational, 2004.

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Book chapters on the topic "Catalyst"

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Gao, Yuanfeng, Hong Lv, Yongwen Sun, Han Yao, Ding Hu, and Cunman Zhang. "Enhancement of Acidic HER by Fe Doped CoP with Bimetallic Synergy." In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 465–74. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_45.

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AbstractCompared to single metal site catalysis, the bimetallic synergistic strategy can exploit the complementary ability of different active sites for active species uptake and desorption to develop excellent catalysts. Pure phase metal phosphides are a disadvantage as a promising electrocatalyst for platinum-free hydrogen precipitation with either too strong or too weak adsorption of hydrogen. Here, synthetic Fe-doped CoP particles anchored with MWCNTs, which exhibited excellent catalytic performance for HER, required an overpotential of 123 mV to reach 10 mA cm−2, with a Tafel slope of 58.8 mV dec−1. It was found experimentally that Fe doping improved the conductivity of the catalyst regulated the electronic structure of CoP, and optimized the overall hydrogen adsorption energy of the catalyst. The difference in hydrogen adsorption strength of Fe, Co is used to break the symmetry constraint of single active center and improve the intrinsic activity of the catalyst, a strategy that can be used to guide the preparation of inexpensive and high performance catalysts.
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Zhang, Peng, Songzhe Chen, Laijun Wang, and Ping Zhang. "Study on the High-Performance Catalyst for Sulfuric Acid Decomposition in the IS Cycle." In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 370–82. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_36.

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AbstractThe iodine-sulfur cycle coupled with a high-temperature gas-cooled reactor is a clean and efficient hydrogen production technology. The sulfuric acid decomposition reaction is the highest temperature process in the iodine-sulfur cycle, which requires 850 °C high temperature and catalyst to carry out at a high conversion rate. This study prepared a series of loaded sulfuric acid decomposition catalysts using anatase TiO2 and Ta2O5 as catalyst carriers and precious metal Pt as the active component. XRD, BET, and ICP-MS characterization of the catalysts demonstrated that the high calcination temperature could increase the crystallinity and content of the active components and decrease the specific surface area of the catalysts. The Pt/TiO2-850 catalyst showed good performance under different feed concentrations, reaction temperatures, and particle sizes. In addition, the scale-up production does not affect the Pt/TiO2-850 catalyst reaction performance. The Pt/TiO2-850 catalyst was tested in a bayonet-tube SiC reactor with a 100-h high throughput lifetime, which proved that the Pt/TiO2-850 catalyst has good stability.
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Bährle-Rapp, Marina. "catalyst." In Springer Lexikon Kosmetik und Körperpflege, 93. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_1718.

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Gooch, Jan W. "Catalyst." In Encyclopedic Dictionary of Polymers, 124. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_2034.

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Cleaves, Henderson James. "Catalyst." In Encyclopedia of Astrobiology, 397–98. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_246.

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Peroulis, Dimitrios, Prashant R. Waghmare, Sushanta K. Mitra, Supone Manakasettharn, J. Ashley Taylor, Tom N. Krupenkin, Wenguang Zhu, et al. "Catalyst." In Encyclopedia of Nanotechnology, 403. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-90-481-9751-4_100108.

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Cleaves, Henderson James. "Catalyst." In Encyclopedia of Astrobiology, 262. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_246.

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Cleaves, Henderson James. "Catalyst." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_246-5.

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Cleaves, Henderson James. "Catalyst." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-642-27833-4_246-6.

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Cleaves, Henderson James. "Catalyst." In Encyclopedia of Astrobiology, 504–5. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_246.

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Conference papers on the topic "Catalyst"

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Zhang, Aihua. "EXPERIMENTAL STUDY ON THE APPLICATION OF MACHINE LEARNING METHOD IN CATALYTIC MATERIALS." In Topics In Chemical & Material Engineering (TCME). Volkson Press, 2023. http://dx.doi.org/10.26480/smmp.01.2023.24.27.

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Machine learning has emerged as a powerful tool for analyzing complex data sets and making predictions in a wide range of applications, including catalysis. Bycombining statistical methods, algorithms, and computational power, machine learning can help identify patterns and relationships in catalytic systems that are difficult or impossible to discern using traditional approaches. This can lead to more efficient and effective catalyst design, optimization, and prediction of catalytic activity. Machine learning has already been successfully applied to various aspects of catalysis, including catalyst discovery, reaction mechanism identification, and kinetic modeling. The continued integration of machine learning with catalysis research holds great promise for advancing our understanding of catalytic systems and developing new and improved catalysts for important industrial processes.
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Parks, James E., H. Douglas Ferguson, Aaron M. Williams, and John M. E. Storey. "Lean NOx Trap Catalysis for NOx Reduction in Natural Gas Engine Applications." In ASME 2004 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/icef2004-0871.

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Reliable power generation and distribution is a critical infrastructure for the public and industry. Large-bore spark-ignited natural gas reciprocating engines are a reliable source of power generation. Lean operation enables efficient operation, and engines can conveniently be placed wherever natural gas resources are located. However, stricter emission regulations may limit the installation and use of more natural gas reciprocating engines if emissions cannot be reduced. Natural gas engine emissions of concern are generally methane, carbon monoxide, and oxides of nitrogen (NOx). Methane and carbon monoxide can be controlled by oxidation catalysts; however NOx emissions are difficult to control in lean exhaust conditions. One method of reducing NOx in lean exhaust conditions is lean NOx trap catalysis. Lean NOx trap technologies (also known as NOx adsorber catalysts, NOx storage and reduction catalysts, etc.) have demonstrated >90% NOx reduction for diesel reciprocating engines and natural gas turbines. In the work presented here, the feasibility of a lean NOx trap catalyst for lean burn natural gas reciprocating engines will be studied. Tests were conducted on a Cummins 8.3-liter engine on a dynamometer. The lean Nox trap catalyst was controlled in a valved exhaust system that utilized natural gas as the catalyst reductant. Oxidation and reformer catalysts were used to enhance utilization of methane for catalyst regeneration. The feasibility of this approach will be discussed based on the observed NOx reduction and associated fuel penalties.
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Bond, Gary, A. Halman, H. Eccles, R. Mao, S. Pollington, P. Hinde, V. Demidyuk, and A. Gkelios. "A COMPARATIVE STUDY OF MICROWAVE AND BARRIER DISCHARGE PLASMA FOR THE REGENERATION OF SPENT ZEOLITE CATALYSTS." In Ampere 2019. Valencia: Universitat Politècnica de València, 2019. http://dx.doi.org/10.4995/ampere2019.2019.9936.

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Due to their acid characteristics and pore structure, which can induce high product selectivity; zeolite catalysts are used extensively in industry to catalyse reactions involving hydrocarbons. However, these catalysts can suffer from deactivation due to cracking reactions that result in the deposition of carbon leading to poisoning of the acid sites and blocking of the pores [1]. Depending upon the reaction and the particular catalyst involved this deactivation may take place over several months or even years but in some cases occurs in minutes. Therefore, zeolite catalysts are frequently reactivated / regenerated. This generally involves a thermal treatment involving air which results in oxidation of the carbon [2]. However, the oxidation of carbon is highly exothermic, and if not carefully controlled, results in the generation of exceedingly high localized temperatures which can destroy the zeolite structure and result in subsequent loss of catalyst activity. More conservative thermal treatments can result in incomplete regeneration and again a catalyst displaying inferior activity. This paper explores the use of non-thermal plasma which had been either generated using microwaves or via a barrier discharge to regenerate spent zeolite catalysts. The catalyst, H-mordenite, was tested for the disproportionation of toluene (Figure 1) using conventional heating. The spent catalyst was then regenerated using a plasma or conventional thermal treatment before having its activity re-evaluated for the toluene disproportionation reaction as previous. Fig. 1. Reaction Scheme for Toluene Disproportionation. Interestingly, not only is plasma regeneration highly effective but also catalysts can be regenerated in greatly reduced times. There is an additional advantage in that plasma regeneration can impart physical properties that result in a zeolite that is resistant to further deactivation. However, the results are highly dependent upon the experimental conditions involved for plasma regeneration. References Wu J, Leu L., Appl. Catal., 1983; 7:283-294. M. Guisnet and P. Magnoux, Deactivation of Zeolites by Coking. Prevention of Deactivation and Regeneration. In: Zeolite Microporous Solids: Synthesis, Structure, and Reactivity. E.G. Derouane, F Lemos, C. Naccache, F. Ramôa Ribeiro, Eds. Pages 437-456. Springer 1992.
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Maity, Pintu, Ajay Khande, Supriyo Majumder, Prabha Dasila, and Chiranjeevi Thota. "Enhancing the Efficiency of Refining Processes: A Desktop Solution for Predicting FCC Yield Profiles." In ADIPEC. SPE, 2024. http://dx.doi.org/10.2118/222584-ms.

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Abstract The current state of FCC technology has the potential to dictate the overall profitability of any complex oil refinery worldwide, where the catalyst plays a central role in maximizing fuel and olefin yields. Innovations in FCC catalysis have led to higher conversion rates, improved selectivity, and better tolerance to contaminants. Consequently, every FCC catalyst changeover presents an opportunity to enhance the refinery’s profit margin. However, this potential increment in margin necessitates thorough testing and selection of candidate optimum catalysts which is often a time-consuming process. While various computational models based on first principles, databases, linear programming, or artificial intelligence exist to expedite this process, they typically serve as intermediaries between laboratory experiments and commercial yield predictions. To streamline this process, the R&D team at Bharat Petroleum Corporation Limited (BPCL) has developed a proprietary Yield Prediction (Y-P) model. This model is designed to eliminate the need for experimental catalyst testing by estimating potential yield, selectivity, and conversion based on FCC feed and catalyst characteristics. The Y-P model employs a mathematical kinetic model using the tenlump scheme, integrating feed and catalyst properties into the prediction algorithm. By leveraging multivariate regression, lumped reaction mechanisms, and artificial neural networks, the model utilizes feedstock properties such as con-carbon, density, distillation, sulfur/nitrogen content, and catalyst properties like surface area, unit cell size, and acidity to predict commercial plant yields. The trial results of the Y-P model have shown strong alignment with conventional in-house catalyst evaluation methods, demonstrating its reliability and accuracy. This model not only facilitates the selection of FCC catalysts but also enables their reformulation to meet changing market demands. By bringing catalyst selection to the operator’s fingertips, the Y-P model significantly enhances the efficiency and profitability of refinery operations.
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THOMAS, JOHN MEURIG. "HETEROGENOUS CATALYSIS AND CHARACTERIZATION OF CATALYST SURFACES." In 24th International Solvay Conference on Chemistry. WORLD SCIENTIFIC, 2018. http://dx.doi.org/10.1142/9789813237179_0019.

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Wüthrich, Kurt, R. H. Grubbs, T. Visart de Bocarmé, and Anne De Wit. "Heterogeneous Catalysis and Characterization of Catalyst Surfaces." In 24th International Solvay Conference on Chemistry. WORLD SCIENTIFIC, 2018. http://dx.doi.org/10.1142/9789813237179_others02.

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Lee, C. H., C. H. Huang, C. T. Lin, Y. C. Liu, and Hsin-Sen Chu. "Development of Methanol Reformer for the Portable PEFC Power System by ITRI." In ASME 2004 2nd International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2004. http://dx.doi.org/10.1115/fuelcell2004-2519.

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In order to apply the PEFC power generation system in near future, ITRI is cooperating with Taiwanese local electrical company to develop a compact methanol reformer. This methanol reformer can simultaneously catalyze autothermal and steam reforming reactions, depending on the application. Except the catalyst for methanol steam reforming and low temperature water gas shift reactions, ITRI has developed several catalysts for autothermal reforming, high temperature water-gas shift, and CO preferential oxidation reactions. We have integrated these catalysts to assemble a methanol reformer prototype. The characteristics of this methanol reformer operated at steady state are the maximum flow rate of hydrogen being 39 L/min (corresponding to 2.4 kWe), H2 concentration being 45∼65%, CO concentration less than 50 ppm, and the cold startup time less than 35 minutes. In addition, we have been developing a catalyst for methanation reaction. We hope to shorten the start-up time to less than 20 minutes and the volume of the reformer being reduced in half by integrating a good methanation catalyst into my next generation methanol reformer.
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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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Gandhi, Rohan, Ori Rottenstreich, and Xin Jin. "Catalyst." In CoNEXT '17: The 13th International Conference on emerging Networking EXperiments and Technologies. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3143361.3143397.

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Garg, Anshuj, Debadatta Mishra, and Purushottam Kulkarni. "Catalyst." In VEE '17: 13th ACM SIGPLAN/SIGOPS International Conference on Virtual Execution Environments. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3050748.3050760.

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Reports on the topic "Catalyst"

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Olsen, Daniel, Bryan Hackleman, and Rodrigo Bauza Tellechaea. PR-179-16207-R01 Oxidation Catalyst Degradation on a 2-Stroke Lean-Burn NG Engine - Washing. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), May 2019. http://dx.doi.org/10.55274/r0011586.

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Oxidation catalysts are often utilized to reduce carbon monoxide, formaldehyde, and volatile organic compounds in order to meet emissions regulations for large bore natural gas engines. These catalysts degrade over time and need to be replaced or regenerated to maintain emissions compliance. This work evaluates the effectiveness of catalyst regeneration, or catalyst washing. The evaluation is performed by utilizing field and laboratory slip streams combined with catalyst module performance (reduction efficiency) measurements and catalyst material surface analysis to quantify catalyst poisons.
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Stevens and Olsen. PR-179-12214-R01 CO Sensor Experimental Evaluation for Catalyst Health Monitoring. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), September 2014. http://dx.doi.org/10.55274/r0010827.

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Oxidation catalysts and three-way catalysts can be used to reduce the amount of CO present in engine exhaust. For 2-stroke lean-burn engines, the oxidation catalyst degrades over time be-cause of the buildup of poisons such as sulfur, zinc, phosphorous, and calcium. Three-way cata-lysts used with stoichiometric engines also degrade over time. Emissions analyzers are often used to evaluate the degradation of oxidation catalysts and three-way catalysts, but it can be very time consuming and expensive. Ideally, a simple sensor system would be beneficial for operating companies to determine if the catalyst were out of compliance according to normal operating standards. An ECM CO sensor and recording device was acquired for testing. The CO sensor system was evaluated for its ability to monitor post-catalyst CO concentration. The results show that this CO sensor system is ineffective at monitoring post-catalyst CO concentration.
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Olsen and Neuner. PR-179-12207-R01 Performance Measurements of Oxidation Catalyst on an Exhaust Slipstream. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2013. http://dx.doi.org/10.55274/r0010800.

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Oxidation catalysts are effective at reducing CO, formaldehyde, and VOCs as long as the catalyst temperature is above the light-off temperature for each species. It is important to understand the effects of temperature and space velocity on regulated species in order to effectively apply oxidation catalyst technology to lean burn engines, in particular 2-stroke engines that typically have lower exhaust temperatures. Various catalysts were tested on an exhaust slipstream coupled to a 4-stroke lean-burn engine which allows tests to be conducted at different temperatures and flow rates. The effect of the oxidation catalysts on NO2 and odor are also discussed.
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Badrinarayanan and Olsen. PR-179-11201-R01 Performance Evaluation of Multiple Oxidation Catalysts on a Lean Burn Natural Gas Engine. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2012. http://dx.doi.org/10.55274/r0010772.

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Two-way catalysts or oxidation catalysts are the common after-treatment systems used on lean burn natural gas engines to reduce CO, VOCs and formaldehyde emissions. The study evaluates the performance of oxidation catalysts from commercial vendors for varying catalyst temperature and space velocity. For this study, a part of the exhaust from a Waukesha VGF-18 GL lean burn natural gas engine was flowed through a catalyst slipstream system to assess the performance of the oxidation catalysts. The slipstream is used to reduce the size of the catalysts and to allow precise control of temperature and space velocity. Analyzers used include Rosemount 5-gas emissions bench, Nicolet Fourier Transform Infra-Red spectrometer and HP 5890 Series II Gas Chromatograph. The oxidation catalysts were degreened at 1200oF (650oC) for 24 hours prior to performance testing. The reduction efficencies for the emission species varied among the oxidation catalysts tested from different vendors. Most oxidation catalysts showed over 90% maximum reduction efficiencies on CO, VOCs and formaldehyde. VOC reduction efficiency was limited by poor propane emission reduction efficiency at the catalyst temperatures tested. Saturated hydrocarbons such as propane showed low reduction efficiencies on all oxidation catalysts due to high activation energy. Variation in space velocity showed very little effect on the conversion efficiencies. Most species showed over 90% conversion efficiency during the space velocity sweep. Adding more catalyst volume may not increase the reduction efficiency of emission species. Varying cell density showed very little effect on performance of the oxidation catalysts. The friction factor correlation showed the friction factor for flow through a single channel is inversely proportional to cell density.
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Defoort, Willson, and Olsen. L51849 Performance Evaluation of Exhaust Catalysts During the Initial Aging on Large Industrial Engines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), June 2001. http://dx.doi.org/10.55274/r0011213.

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An investigation of catalyst performance during the initial aging process, providing insight into the deactivation rate of the catalyst and assisting in predicting the operational lifetime of the catalyst was preformed. The information gained through the test program provides a mechanism to assist in developing new technologies geared at reducing engine emission while providing improvements in efficiency, reliability, and operability for the aging industrial reciprocating engine fleet. Two natural gas lean burn engines, a 2-stroke, large bore slow speed and a 4-stroke medium bore medium speed, were operated at pre-determined conditions in conjunction with an oxidation catalyst. The aging process of the catalysts was observed. The research concluded that the catalyst performance is much lower than anticipated,particularly in relation to the aging process. During the aging process for the large bore 2-stroke engine (about 200 hours) the catalyst efficiency drops from 95% to 80% for CO and from 75% to 45% for CH2O. Results for the medium bore 4-stroke engine are better as a result of nearly 200°F higher catalyst temperatures. During aging (approximately 150 hours) the catalyst efficiencies are reduced from 99.2 to 97.7% for CO and from undetectable post catalyst levels (essentially 100% removal) to 67% for CH2O.
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Swanson, Dr Larry, and Christopher Samuelson. PR-362-06208-R01 Evaluation of Byproduct Emissions from Gas Turbine SCR Catalyst. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), February 2009. http://dx.doi.org/10.55274/r0010978.

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The primary objective of the test program was to evaluate byproduct emissions at steady state and transient operating conditions for two commercially available SCR catalysts used in gas turbine applications. Both NOX removal efficiency and ammonia slip behavior were also examined to validate expected catalyst trends and activity. Even though the study replicated expected field catalyst process conditions as well as possible (e.g., flue gas temperatures, space velocities, and inlet species concentrations), the data and results are from pilot-scale testing only, and consequently may differ from actual gas turbine field tests.
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Bauza, Rodrigo, and Daniel Olsen. PR-179-20200-R01 Improved Catalyst Regeneration Process to Increase Poison Removal. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), June 2021. http://dx.doi.org/10.55274/r0012106.

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In this work, the details of catalyst poison deposition are studied, and new catalyst restoration methods are explored. Lubrication oil makes its way through the combustion chamber and into the exhaust system, depositing poisons onto the catalyst and degrading catalyst performance. To estimate the degradation rate of the units and to find the best restoration method, two identical alumina-platinum oxidation catalysts were used in a dual setting, combining a field degradation engine and a laboratory testing engine. In order to find the best restoration process, the combination of both baking and washing is tested with poison deposition and performance analysis, and a hydrogen reduction is tested for the restoration of the platinum crystallites. The units were aged, then restored with the industry-standard washing procedure, then aged again until reaching non-compliance with emissions standards, and then restored a second time with a modified version of the industry-standard washing process that combines baking and washing. There is a related webinar.
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Delgass, William Nicholas, Mahdi Abu-Omar, James Caruthers, Fabio Ribeiro, Kendall Thomson, and William Schneider. Catalysis Science Initiative: Catalyst Design by Discovery Informatics. Office of Scientific and Technical Information (OSTI), July 2016. http://dx.doi.org/10.2172/1260972.

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Watkins, Thomas R., Michael J. Lance, Lawrence Frederick Allard, Jr, Krishna Kamasamudram, and Aleksey Yezerets. Catalyst Characterization. Office of Scientific and Technical Information (OSTI), September 2014. http://dx.doi.org/10.2172/1157139.

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Davis, A., H. H. Schobert, G. D. Mitchell, and L. Artok. Catalyst dispersion and activity under conditions of temperature- staged liquefaction. [Catalyst precursors for molybdenum-based catalyst and iron-based catalyst]. Office of Scientific and Technical Information (OSTI), July 1992. http://dx.doi.org/10.2172/7233290.

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