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ENGINEERING (1195 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Full-text available via subscription   (Followers: 5)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 216)
Acta Geotechnica     Hybrid Journal   (Followers: 6)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 1)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 10)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 4)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 5)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 6)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Artificial Neural Systems     Open Access   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 9)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 40)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 35)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 29)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 5)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 6)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 7)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 4)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 2)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 7)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 7)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 3)
Batteries     Open Access   (Followers: 3)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 23)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 3)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 9)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 16)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 1)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Full-text available via subscription   (Followers: 13)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 40)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
Case Studies in Thermal Engineering     Open Access   (Followers: 4)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 5)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 4)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 4)
Coatings     Open Access   (Followers: 2)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 23)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 252)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 177)
Composites Part B : Engineering     Hybrid Journal   (Followers: 223)
Composites Science and Technology     Hybrid Journal   (Followers: 164)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 12)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 25)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 8)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 25)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 7)
Control Engineering Practice     Hybrid Journal   (Followers: 40)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 24)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  
Current Applied Physics     Full-text available via subscription   (Followers: 4)

        1 2 3 4 5 6 | Last

Journal Cover Applied Catalysis A: General
  [SJR: 1.234]   [H-I: 159]   [5 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0926-860X
   Published by Elsevier Homepage  [3032 journals]
  • Study of butanol conversion to butenes over H-ZSM-5: Effect of chemical
           structure on activity, selectivity and reaction pathways
    • Authors: Dieter Gunst; Konstantinos Alexopoulos; Kristof Van Der Borght; Mathew John; Vladimir Galvita; Marie-Françoise Reyniers; An Verberckmoes
      Pages: 1 - 12
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Dieter Gunst, Konstantinos Alexopoulos, Kristof Van Der Borght, Mathew John, Vladimir Galvita, Marie-Françoise Reyniers, An Verberckmoes
      To evaluate the viability of the use of butanol as a green chemical key molecule, the effects of temperature and site time on the transformation of the three butanol isomers, 1-butanol, 2-butanol and iso-butanol, towards butenes over H-ZSM-5 have been studied in search of the most promising isomer. Under dehydration conditions, 2-butanol is by far the most active and intermediate ether formation is only observed for 1-butanol. On the other hand, only isobutanol allows the direct formation of isobutene, the most valuable of the butene isomers. Hence, it is especially interesting to further stimulate the biomass derived isobutanol production, e.g. via genetic modification of appropriate microorganisms, in order to allow thereafter the formation of green drop-in isobutene upon dehydration with H-ZSM-5 in existing refineries. Due to the large potential of isobutanol, a reaction path analysis via ab-initio based microkinetic simulations is conducted for this molecule. Comparing these results with simulations on 1-butanol indicates that the shift is occurring due to a shift of the dominant reaction pathway towards the direct dehydration via anti elimination. A Gibbs free energy analysis shows that the large distortion of the transition state for isobutanol etherification renders this path far less favorable, resulting in the lack of formation of the di-alkyl ether, whilst the increased degree of substitution of the alkyl chain in isobutanol is found to promote the direct dehydration path, leading to an increase of the overall activity of isobutanol as compared to 1-butanol.
      Graphical abstract image

      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.03.036
      Issue No: Vol. 539 (2017)
  • Micellar effect on the direct Fischer synthesis of alkyl glucosides
    • Authors: J. Nowicki; J. Woch; M. Mościpan; E. Nowakowska-Bogdan
      Pages: 13 - 18
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): J. Nowicki, J. Woch, M. Mościpan, E. Nowakowska-Bogdan
      This manuscript presents results from the investigation on the synthesis of alkyl glucosides by the novel, very efficient and environmentally friendly protocol of the Fischer-type synthesis from unprotected glucose and aliphatic alcohols. The use of the dual functionality catalysts (surfactant+acid catalyst) and micellar reaction system are the main novelty of described method. It has been found, that in developed method of synthesis the reaction of unprotected glucose with aliphatic alcohols carried out with significantly different route, than the normal (classical) route and leads to alkyl glucopyranoside derivatives with high yields. In progress analyses by DLS, HPLC and GC/MS confirm the general postulated pathway of developed method.
      Graphical abstract image

      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.04.002
      Issue No: Vol. 539 (2017)
  • Selective hydrogenation of 3-Hexyn-1-ol with Pd nanoparticles synthesized
           via microemulsions
    • Authors: Thomas Montsch; Moritz Heuchel; Yvonne Traa; Elias Klemm; Cosima Stubenrauch
      Pages: 19 - 28
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Thomas Montsch, Moritz Heuchel, Yvonne Traa, Elias Klemm, Cosima Stubenrauch
      In the study at hand we present a design strategy for novel catalysts which can be used for the selective hydrogenation of alkynes to alkenes. The design of the novel catalysts is based on two main ideas, namely (1) the synthesis of Pd nanoparticles via microemulsions and (2) the use of highly-ordered mesoporous silica with a 3-D pore network (FDU-12) serving as support. The nanoparticles are deposited on FDU-12 in two different ways. Firstly, we simply impregnated the support with a dispersion of the nanoparticles. The resulting catalyst was not selective at all; on the contrary, it fully hydrogenated our model alkyne, namely 3-hexyn-1-ol. Secondly, we synthesized the FDU-12 in the presence of the nanoparticles (in-situ synthesis). In this case, we obtained one catalyst which performed as well as the Lindlar catalyst although the metal content was slightly lower and our catalyst contained no Pb. Another catalyst of the same series, prepared in the presence of another stabilizer, performed as well as the NanoSelect™ catalyst but at a 7 times higher metal content. For the sake of comparison we also impregnated FDU-12 via classical incipient wetness impregnation and again obtained a completely nonselective catalyst. Our results demonstrate that the in-situ synthesis has great potential as regards the development of novel catalysts.
      Graphical abstract image

      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.03.038
      Issue No: Vol. 539 (2017)
  • Deactivation study of the hydrodeoxygenation of p-methylguaiacol over
           silica supported rhodium and platinum catalysts
    • Authors: F.P. Bouxin; X. Zhang; I.N. Kings; A.F. Lee; M.J.H. Simmons; K. Wilson; S.D. Jackson
      Pages: 29 - 37
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): F.P. Bouxin, X. Zhang, I.N. Kings, A.F. Lee, M.J.H. Simmons, K. Wilson, S.D. Jackson
      Hydrodeoxygenation of para-methylguaiacol using silica supported Rh or Pt catalysts was investigated using a fixed-bed reactor at 300°C, under 4 barg hydrogen and a WHSV of 2.5h−1. The activity, selectivity and deactivation of the catalysts were examined in relation to time on stream. Three catalysts were tested: 2.5% Rh/silica supplied by Johnson Matthey (JM), 2.5% Rh/silica and 1.55% Pt/silica both prepared in-house. The Rh/silica (JM) showed the best stability with steady-state reached after 6h on stream and a constant activity over 3days of reaction. In contrast the other two catalysts did not reach steady state within the timeframe of the tests, with continuous deactivation over the time on stream. Nevertheless higher coking was observed on the Rh/silica (JM) catalyst, while all three catalysts showed evidence of sintering. The Pt catalyst (A) showed higher selectivity for the production of 4-methylcatechol while the Rh catalysts were more selective toward the cresols. In all cases, complete hydrodeoxygenation of the methylguaiacol to methylcyclohexane was not observed.
      Graphical abstract image

      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.03.039
      Issue No: Vol. 539 (2017)
  • Polyoxometalate based mesoporous acidic catalyst from biogenic silica for
           vegetable oil methanolysis: Structure activity relationship study
    • Authors: Raju Dutta; Sunit Kumar Singh; Sachin A. Mandavgane; Jayant D. Ekhe
      Pages: 38 - 47
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Raju Dutta, Sunit Kumar Singh, Sachin A. Mandavgane, Jayant D. Ekhe
      A superacidic mesoporous catalyst WOX/RHS-MCM-41 was synthesized using high purity biogenic silica extracted from an agro-waste, rice husk ash. Catalyst acidity was enhanced by dispersion of surface WOX groups on mesoporous support and was used for methanolysis of soybean oil and free fatty acid. Catalyst activity was found to depend upon the structure of WOX species formed over catalyst surface. Characterization with XRD, SEM, TEM, UV–vis DRS, Raman spectroscopy and acidity determination revealed that formation of highly dispersed amorphous polyoxotungstate phase on the catalyst surface developed with a specific tungsten loading and originated strong acidic sites showing high activity. Kinetic analysis revealed that pseudo-first order kinetics was followed up to the optimum reaction time with an activation energy 42.7kJmol−1. Catalyst showed high activity giving ∼90% FAME yield and reusability for multiple cycles without regeneration. The high catalytic activity was retained even in presence of free fatty acid also.
      Graphical abstract image

      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.03.032
      Issue No: Vol. 539 (2017)
  • δ-Alumina supported cobalt catalysts promoted by ruthenium for
           Fischer-Tropsch synthesis
    • Authors: Olga A. Kungurova; Alexander A. Khassin; Svetlana V. Cherepanova; Andrey A. Saraev; Vasily V. Kaichev; Natalya V. Shtertser; Galina K. Chermashentseva; Еvgeny Yu. Gerasimov; Еvgeny A. Paukshtis; Оlga V. Vodyankina; Tatyana P. Minyukova; Georges Abou-Jaoudé
      Pages: 48 - 58
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Olga A. Kungurova, Alexander A. Khassin, Svetlana V. Cherepanova, Andrey A. Saraev, Vasily V. Kaichev, Natalya V. Shtertser, Galina K. Chermashentseva, Еvgeny Yu. Gerasimov, Еvgeny A. Paukshtis, Оlga V. Vodyankina, Tatyana P. Minyukova, Georges Abou-Jaoudé
      The paper presents the low-temperature nitrogen adsorption, TG, XRD, IR spectroscopy, XPS, TEM and SEM data for ruthenium promoted (0.2–1wt.%) Сo-δAl2O3 catalysts and characteristics of the catalysts in Fischer-Tropsch synthesis after their activation under the conditions ensuring the reduction of comparable fractions of metallic cobalt. It was shown that cobalt in oxide precursors is a component of the spinel-like Со3-xAlxO4 phase containing the impurity anions СО3 2−, NO3 −, ОН−, and NO in promoted samples, which belong to the thermolysis product of the Ru precursor. Average sizes of Со3-xAlxO4 crystallites are in a range of 5–10nm. As ruthenium content in the catalyst increases upon reduction, the temperature of metallic phase formation decreases substantially (by more than 150°C). After the reduction, selectivity of promoted catalysts for α-olefins and high-molecular hydrocarbons was higher in comparison with unpromoted catalysts, without a noticeable decrease in catalytic activity. Therewith, in 0.5–1.0wt.% catalysts, a part of ruthenium forms individual ultradispersed metallic particles ca. 1nm in size that are located on the surface of oxide support and are not active in Fischer-Tropsch synthesis. The oxide layer decorating the surface of metallic cobalt particles is also strongly enriched with ruthenium. In the 0.2wt.% catalyst, the major part of ruthenium resides in metallic cobalt particles. Although the ruthenium-cobalt alloy segregates with enrichment of the surface with cobalt, the presence of ruthenium in the metallic particles and probably in the decorating oxide layer exerts a considerable effect on selectivity of the catalysts.
      Graphical abstract image

      PubDate: 2017-04-18T14:02:15Z
      DOI: 10.1016/j.apcata.2017.04.003
      Issue No: Vol. 539 (2017)
  • Structure evolution of mesoporous silica supported copper catalyst for
           dimethyl oxalate hydrogenation
    • Authors: Yujun Zhao; Yaqing Zhang; Yue Wang; Jian Zhang; Yan Xu; Shengping Wang; Xinbin Ma
      Pages: 59 - 69
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Yujun Zhao, Yaqing Zhang, Yue Wang, Jian Zhang, Yan Xu, Shengping Wang, Xinbin Ma
      A modified ammonia evaporation method with an ordered mesoporous silica as the precursor of the support was applied to prepare the well dispersed copper-based catalysts. Appropriate amount of ammonia was used during the aging stage to prevent the destruction of the ordered mesoporous structure, which can ensure the homogeneous pre-distribution of the copper precursor ([Cu(NH3)4]2+) in the mesopores. Then the formation of copper phyllosilicate or surface Cu–O–Si species can be prompted during the ammonia evaporation stage, resulting in large surface areas of both Cu0 and Cu+ species in the final catalysts. It was also revealed that the formation of copper phyllosilicate led to the destruction of mesoporous silica structure in the ammonia evaporation stage especially at the higher copper loading. The catalysts with various copper loading were systematically characterized and applied in the hydrogenation of dimethyl oxalate to ethylene glycol (EG). An excellent low-temperature catalytic performance and stability were achieved on 20Cu/OMS with EG selectivity of 98.2% at 453K, due to the superior surface areas of both Cu0 and Cu+, as well as the highest ratio of Cu+/(Cu0 +Cu+).
      Graphical abstract image

      PubDate: 2017-04-18T14:02:15Z
      DOI: 10.1016/j.apcata.2017.04.001
      Issue No: Vol. 539 (2017)
  • Efficient green catalysis for the conversion of fructose to levulinic acid
    • Authors: Indira Thapa; Brian Mullen; Ammar Saleem; Cora Leibig; R. Tom Baker; Javier B. Giorgi
      Pages: 70 - 79
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Indira Thapa, Brian Mullen, Ammar Saleem, Cora Leibig, R. Tom Baker, Javier B. Giorgi
      Highly efficient and selective production of levulinic acid has been achieved from D-fructose in the presence of polystyrene-based sulphonic acid resin catalyst, Dowex 50×8-100, at mild reaction conditions of 120°C, over 24h in a 50:50 mixture of water/GVL resulting in 72mol% yield under optimized reaction conditions. Optimization of the effect of reaction temperature, time, pressure, catalyst to substrate ratio, fructose concentration and solvent was performed. Various polystyrene-based sulfonic acid resins were also investigated for quantitative production of LA from 5-hydroxymethylfurfural (5-HMF) in pure water. Catalyst recycling was carried out up to 6 cycles. Significant mechanistic information was obtained for the formation of “humins”, which are the primary cause of catalyst fouling, by the identification of soluble by-products and polymerization presursors using Q-Tof mass spectrometry based on accurate masses.
      Graphical abstract image

      PubDate: 2017-04-18T14:02:15Z
      DOI: 10.1016/j.apcata.2017.03.016
      Issue No: Vol. 539 (2017)
  • Sn and Zn modified HZSM-5 for one-step catalytic upgrading of glycerol to
           value-added aromatics: Synergistic combination of impregnated Sn
           particles, ALD introduced ZnO film and HZSM-5 zeolite
    • Authors: Fei Wang; Xuan Kang; Ma-xi Zhou; Xing-hui Yang; Li-jing Gao; Guo-min Xiao
      Pages: 80 - 89
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): Fei Wang, Xuan Kang, Ma-xi Zhou, Xing-hui Yang, Li-jing Gao, Guo-min Xiao
      The chemoselective catalytic conversion of glycerol into high value-added aromatics (GTA) can greatly enhance the economic profits in biodiesel and biomass industry chain. In order to enhance the aromatization activity, stability and conversion efficiency of carbon in glycerol into aromatics during the GTA process, Zn species, which could directly convert alkenes originated from deoxygenation of glycerol into aromatics through dehydrogenation reaction, was introduced into Sn/HZSM-5 zeolite via atomic layer deposition (ALD) and incipient wet impregnation (IWI) method. Compared with impregnated ZnO modified Sn/HZSM-5, ZnO introduced by 20 ALD cycles into Sn/HZSM-5 deposited in the form of thin film, which not only fully coated both HZSM-5 external and internal surface, but also partially covered impregnated Sn particles. This film stabilized the oxidation state of loaded SnOx species which acted as catalytically active materials and further healed HZSM-5 structural defects, leading to the better synergistic effect among HZSM-5 zeolite, impregnated Sn particles and ALD introduced ZnO films. Besides, the reusability of this catalyst could be tremendously improved due to the protective effect of introduced ALD ZnO film which could prevent irreversible dealumination of HZSM-5 from exposure of HZSM-5 framework to steam during GTA reaction and regeneration procedure. However, when the deposited ZnO ALD cycle number reached 40, Sn particles on HZSM-5 could be completely packaged by ZnO film, on which occasion Sn could not participate in the GTA process, thereby leading to the reduction in both aromatics yields and catalyst lifetime.
      Graphical abstract image

      PubDate: 2017-04-18T14:02:15Z
      DOI: 10.1016/j.apcata.2017.04.005
      Issue No: Vol. 539 (2017)
  • Synthesis of N,N-dimethylformamide from carbon dioxide in aqueous biphasic
           solvent systems
    • Authors: R. Kuhlmann; S. Schmitz; K. Haßmann; A. Prüllage; A. Behr
      Pages: 90 - 96
      Abstract: Publication date: 5 June 2017
      Source:Applied Catalysis A: General, Volume 539
      Author(s): R. Kuhlmann, S. Schmitz, K. Haßmann, A. Prüllage, A. Behr
      This paper presents the homogeneous catalyzed hydrogenation of carbon dioxide to N,N-dimethylformamide (DMF) with an in-situ generated ruthenium catalyst based on RuCl3 ×H2O and the phosphine ligand 2,2′-bis(diphenylphosphinomethyl)-1,1′-biphenyl (BISBI). Investigations showed that the complex formation of an active species requires the presence of an amine. The catalyst was recycled by immobilization in a nonpolar alcoholic solvent while the formed product was extracted in-situ into the aqueous phase. The self-assembling reaction system showed stability for 10 recycling runs without a significant loss of activity resulting in an average yield of 31% DMF at 40bar and 140°C without the occurrence of any byproducts. Furthermore, a combination of the developed reaction system with ternary amines enables the application of wash amine solutions as carbon dioxide carrier.
      Graphical abstract image

      PubDate: 2017-04-18T14:02:15Z
      DOI: 10.1016/j.apcata.2017.03.037
      Issue No: Vol. 539 (2017)
  • Enhanced electrocatalytic hydrogen evolution performance of MoS2 ultrathin
           nanosheets via Sn doping
    • Authors: Cuicui Du; Hao Huang; Juan Jian; Yue Wu; Mengxiang Shang; Wenbo Song
      Pages: 1 - 8
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Cuicui Du, Hao Huang, Juan Jian, Yue Wu, Mengxiang Shang, Wenbo Song
      Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have drawn much attention due to their unique physical and chemical properties. Molybdenum disulfide (MoS2) is particularly promising in hydrogen evolution reaction (HER) as a substitute for noble-metal catalysts. Although numerous attempts have been made to improve the HER activity of MoS2, engineering the MoS2-based electrocatalysts with activities similar to noble-metal catalysts remains challenging. Herein, we synthesize high-quality tin doped molybdenum disulfide (Sn-MoS2) ultrathin nanosheets by a g-C3N4 sacrificial template assisted thermolytic approach, and detailly investigate the role of Sn doping on the HER activity. The porous Sn-MoS2 nanosheets displays superior HER performance, exhibiting an overpotential of 28mV at 10mAcm−2 and a Tafel slope of 37.2mVdec−1 with an admirable stability. Compared to pristine MoS2 nanosheets, the significantly improved catalytic activity is ascribed to the increased active edge sites, enhanced intrinsic catalytic activity for each active site as well as accelerated electron transfer upon Sn doping. This work may provide guidelines for the design and synthesis of efficient non-precious HER catalysts.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.010
      Issue No: Vol. 538 (2017)
  • Amine-functionalized hyper-crosslinked polyphenanthrene as a metal-free
           catalyst for the synthesis of 2-amino-tetrahydro-4H-chromene and pyran
    • Authors: Reddi Mohan Naidu Kalla; Anuraj Varyambath; Mi Ri Kim; Il Kim
      Pages: 9 - 18
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Reddi Mohan Naidu Kalla, Anuraj Varyambath, Mi Ri Kim, Il Kim
      The hyper-crosslinked microporous polyphenanthrene spheres were fabricated simply by the polymerization of phenanthrene using bromomethyl methyl ether as a bridging agent in the absence of any templates. The organic spheres were subjected to amine-functionalizing on the periphery of them using unreacted bromomethyl groups. The amine-functionalized microporous polyphenthrene could be employed as a highly effective and stable solid basic catalyst for the syntheses of functionalized 2-amino-tetrahydro-4H-chromene and pyran derivatives. The significant features of these reactions are high product yields, environmental benignity, short reaction time, broad substrate scope, and non-requirement of toxic solvents. Furthermore, the catalyst can be reused up to four times without significant loss of activity.
      Graphical abstract image

      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.009
      Issue No: Vol. 538 (2017)
  • Heterogeneously catalyzed persulfate by CuMgFe layered double oxide for
           the degradation of phenol
    • Authors: Yun Chen; Jingchun Yan; Da Ouyang; Linbo Qian; Lu Han; Mengfang Chen
      Pages: 19 - 26
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Yun Chen, Jingchun Yan, Da Ouyang, Linbo Qian, Lu Han, Mengfang Chen
      CuMgFe layered double oxide (CuMgFe-LDO) was successfully obtained from CuMgFe layered double hydroxide (CuMgFe-LDH) and employed to degrade phenol in the heterogeneous catalysis of persulfate (PS). The effects of CuMgFe-LDO dosage, PS concentration, initial pH (pH0) and the presence of common inorganic anions on the removal of phenol were comprehensively evaluated in this study. It was revealed that CuMgFe-LDO performed excellently in activating PS to remove phenol with a great stability under a wide range of pH0 values ranging from 5.0 to 11.0. With 0.5g/L CuMgFe-LDO and 0.5mmol/L PS at pH0 6.4, 95.3% of 0.1mmol/L phenol was removed within 30min. Based on the results of electron paramagnetic resonance (EPR) and radical quenching experiments, it was inferred that free radicals bounded to the surface of CuMgFe-LDO was the dominant oxidant for the degradation of phenol. Furthermore, p-benzoquinone was considered to be the major intermediate in the oxidation process. Finally, the CuMgFe-LDO exhibited excellent stability after 3 times recycling with the concentration of the leached copper ion at 0.19mg/L, being lower than the drinking water standard of U.S Environmental Protection Agency (1.3mg/L). The findings of the work provided a new insight into the remediation of phenol polluted water within the system of CuMgFe-LDO/PS.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.020
      Issue No: Vol. 538 (2017)
  • Mechanistic insight into the facet-dependent selectivity of ethylene
           epoxidation on Ag nanocatalysts
    • Authors: Lin Zhu; Wei Zhang; Jiqin Zhu; Daojian Cheng
      Pages: 27 - 36
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Lin Zhu, Wei Zhang, Jiqin Zhu, Daojian Cheng
      Ethylene epoxidation reaction to selectively produce the ethylene oxide (EO) is a crucial heterogeneous catalytic chemical process in industry. However, the intrinsic catalytic selectivity depending on the facet of commonly used Ag catalysts is still far from understanding. In this work, we used the periodical density functional theory (DFT) calculations to gain an atomistic insight into the facet-dependent reaction selectivity of the ethylene epoxidation on Ag catalysts. We investigated the adsorption of atomic or molecular oxygen and oxametallacycle (OMC) intermediate, and further study the dissociation of molecular oxygen and the reaction mechanism of ethylene epoxidation on (111), (110), (100), and (211) surfaces of Ag catalysts. Our results indicate that the adsorption of the O atom is not facet-dependent under low oxygen coverage. Moreover, although the adsorption of molecular oxygen is facet-dependent, the dissociation of molecular oxygen would not have the essential influence on selectively producing EO in the ethylene epoxidation reaction. In addition, the catalytic selectivity of ethylene epoxidation reaction is facet-dependent, following the order of (110)>(100)>(111)>(211), which is consistent with the order of the adsorption strength of the OMC intermediate. Our results show that the stability of the OMC intermediate has an essential effect on the selectivity to EO in the ethylene epoxidation reaction. We have faith in that our results can provide useful information which would guide the intellectual design of the catalysts for ethylene epoxidation by controlling their morphologies.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.011
      Issue No: Vol. 538 (2017)
  • Highly dispersed CuyAlOx mixed oxides as superior low-temperature alkali
           metal and SO2 resistant NH3-SCR catalysts
    • Authors: Qinghua Yan; Yu Nie; Ruoyan Yang; Yuhan Cui; Dermot O’Hare; Qiang Wang
      Pages: 37 - 50
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Qinghua Yan, Yu Nie, Ruoyan Yang, Yuhan Cui, Dermot O’Hare, Qiang Wang
      For NO x removal from the exhaust gases of municipal solid waste (MSW) incinerators by selective catalytic reduction (SCR) technology, a suitable SCR catalyst which is active at low temperatures and robust to the presence of alkali metals and SO2 is highly desired. In this contribution, we report the successful fabrication of a highly dispersed CuyAlO x (y =2–4) mixed oxides for NH3-SCR catalyst using high surface area, flower-like highly dispersed AMO-Cu-Al-CO3 LDHs precursors. The influence of the Cu/Al ratio (2, 3, 4, and 5), calcination temperature (400, 500, 600, and 700°C), and testing temperature (150, 200, 250, and 300°C) on the activity of the CuyAlO x mixed oxide catalysts were systematically investigated. Among all samples, Cu4AlO x showed the highest NO x conversion of 91.1% at 200°C. After being thermally treated at 700°C, the NO x conversion of Cu4AlO x was still as high as 84.7%, which is much higher than that of the control catalyst 10wt% CuO/γ-Al2O3 (57.5%). XRD and HR-TEM analyses suggested that the highly dispersed CuO nanoparticles are the active species for the SCR reaction. The catalytic De-NO x performance of Cu4AlO x in the presence of alkali metals (K and Na) and SO2 was also studied. In the presence of 50ppm SO2, the NO x conversion of Cu4AlO x (78.4%) was much higher than that of CuO/γ-Al2O3 (48%). The selectivity of NO x conversion to N2 and resistance to H2O (and co-existence of H2O and SO2) for Cu4AlO x catalyst were also evaluated. In all, we have demonstrated that the newly obtained Cu4AlO x catalyst not only possesses higher thermal stability and higher low temperature (150–250°C) catalytic activity, but also has much better alkali metal (K and Na), SO2, and H2O resistance than a conventional CuO/γ-Al2O3 catalyst.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.021
      Issue No: Vol. 538 (2017)
  • β-Diimine nickel complexes in BMI·AlCl4 ionic liquid: a catalytic
           biphasic system for propylene oligomerization
    • Authors: Katiúscia Machado Nobre Borba; Michèle Oberson de Souza; Roberto Fernando de Souza; Katia Bernardo-Gusmão
      Pages: 51 - 58
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Katiúscia Machado Nobre Borba, Michèle Oberson de Souza, Roberto Fernando de Souza, Katia Bernardo-Gusmão
      β-Diimine nickel complexes have been synthesized using phenyl-amino-based ligands (NPh) substituted with none, two or three methyl groups. The resulting complexes, NiNPh, NiNPhMe2 and NiNPhMe3, which associated with ethylaluminum sesquichloride (EASC) as a co-catalyst, were tested for propylene oligomerization conducted under homogeneous and biphasic conditions using cyclohexane and the ionic liquid 1-methyl-3-butylimidazolium tetrachloroaluminate (BMI·AlCl4), respectively. The cocatalyst/nickel complex ratio was evaluated (Al/Ni=100 and 200) for both systems. Under homogeneous conditions, the highest activity was obtained with NiNPh and Al/Ni=100 (9s−1), and the highest selectivity in propylene dimers was attained with NiNPhMe3 (91%). Under biphasic conditions, all the catalysts showed activities similar or slightly superior to those obtained under homogeneous conditions; the highest activity was attained with NiNPh (10.8s−1), and the highest selectivity for propylene dimers was attained with NiNPhMe3 (98.3%). Under both reaction conditions, i.e., homogeneous and biphasic, 2-methyl-2-pentene was the major product. However, when reactions were conducted under biphasic conditions, less products were formed by isomerization in comparison with those formed using homogeneous systems. For the recycling reactions, no significant changes in the activity of the system were observed for each new cycle.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.014
      Issue No: Vol. 538 (2017)
  • Catalytic performance of metal azolate frameworks in the solventless
           synthesis of cyclic carbonates from CO2 and epoxides
    • Authors: Han-Ung Kim; Robin Babu; Roshith Roshan; Dae-Won Park
      Pages: 59 - 65
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Han-Ung Kim, Robin Babu, Roshith Roshan, Dae-Won Park
      Two types of metal azolate frameworks (MAFs) with uncoordinated and coordinated nitrogen atoms composed of zinc coordinated with 3-amino-1,2,4-triazole and 3,5-dimethyl-1,2,4-triazole linkers denoted as MAF-66 and MAF-X5, respectively have been synthesized and characterized using various physicochemical techniques. The uncoordinated N donors present in the MAFs show high adsorption affinity for carbon dioxide. The synthesized MAFs showed promising catalytic activity towards the cycloaddition of carbon dioxide and epoxides under solvent-free conditions with excellent selectivity towards the desired five-membered cyclic carbonates. The importance of uncoordinated N donors and amine groups in the effective catalysis of the cycloaddition of CO2 and epoxides was investigated. Both catalysts were separable by simple filtration and reusable without any considerable loss in the initial activity. Various reaction parameters including temperature, reaction time, and CO2 pressure were studied. A possible reaction mechanism explaining the role of amine groups in the cycloaddition reaction was proposed based on literature and experimental inferences.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.028
      Issue No: Vol. 538 (2017)
  • Layer effect on catalytic activity of Pd-Cu bimetal for CO oxidation
    • Authors: Ji Liu; Xiaofeng Fan; Chang Q. Sun; Weiguang Zhu
      Pages: 66 - 73
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Ji Liu, Xiaofeng Fan, Chang Q. Sun, Weiguang Zhu
      The bimetallic nanoparticles with core-shell structure have attracted much attention due to the excellent catalytic performance recently. We examined the thickness effect of the Pd overlayer/shell on Cu substrate/core on the catalytic ability of the overlayer using first-principle calculations and d-band center theory. It is found that overlayer thickness has the important effect on the d-band center of Pd layer. There is a quasi-linear relationship between the adsorption energies of O, O2, and CO and energy level of d-band center which is modulated by the overlayer thickness. The energy barriers of isolated O2 dissociation and CO oxidation are found to have an opposite trend with the shift of the d-band center. With this rule, the dissociation of O2 with the assistant of nearby CO is found to be easier on the surface of 2L-Pd/Cu(111).
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.019
      Issue No: Vol. 538 (2017)
  • Enhanced selective catalytic reduction of NO over Mn-Ce catalysts with the
           acetic-acid-chelated titania support at low temperature
    • Authors: Bo-Tau Liu; Chung-Jie Huang; Yu-Xuan Ke; Wei-Hong Wang; Han-Lin Kuo; Darren Lin; Vincent Lin; Sung-Hwa Lin
      Pages: 74 - 80
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Bo-Tau Liu, Chung-Jie Huang, Yu-Xuan Ke, Wei-Hong Wang, Han-Lin Kuo, Darren Lin, Vincent Lin, Sung-Hwa Lin
      In the study, we used the titania chelated with acetic acid (TAc) as the supports to prepare the highly active titania supported Mn-Ce catalysts for selective catalytic reduction of NO at low temperature. Characterization of the titania supported catalysts and the corresponding catalytic activity for NO removal were analyzed and evaluated. The TAc supported catalysts showed better Mn-Ce dispersion and catalytic activity for NO removal than the commercial TiO2 supported ones. Besides, the TAc supported catalysts also showed strong bonding at the TAc/TAc and the TAc/substrate interfaces, maintaining the integrity of the film after peeling test. We evaluated the catalytic activity for selective catalytic reduction of NO over the Mn-Ce catalysts wash-coated on ceramic monolith. Compared to the commercial TiO2 supported catalyst, the TAc supported one significantly enhanced the NO conversion by a factor of 1.25 and 1.58 times at 150 and 210°C, respectively. We speculate that the enhancement may arise from highly/uniformly-dispersed active centers on the surface of the TAc and the solidified structure of the coating layer. The well-dispersed active centers and the firm structure led to higher real space time when the NO stream flowed through the channels of the honeycombs, thereby resulting in a higher NO conversion.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.029
      Issue No: Vol. 538 (2017)
  • Total oxidation of methane over supported CuO: Influence of the MgxAlyO
    • Authors: Ionel Popescu; Nathalie Tanchoux; Didier Tichit; Ioan-Cezar Marcu
      Pages: 81 - 90
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Ionel Popescu, Nathalie Tanchoux, Didier Tichit, Ioan-Cezar Marcu
      Copper oxide supported on Al2O3, MgO and Mg(Al)O mixed oxides with Mg/Al atomic ratios of 1, 3 and 5 were prepared by coprecipitation followed by calcination at 750°C. These catalysts have been characterized by XRD, EDX, N2 adsorption, TG-DTG, NH3-TPD, CO2-TPD and H2-TPR, and their catalytic properties in the total oxidation of methane were investigated. Correlations between the physico-chemical properties and the catalytic activities were established. The best activity was obtained for the catalyst presenting a distribution of CuO species going from well distributed and aggregated CuO particles to CuAl2O4 phase on a Mg(Al)O support composed of a mixture of γ-alumina and periclase phases. It also possesses high relative amounts of strong acid and of medium and strong basic sites in this series. All the catalysts tested exhibited very good stabilities for the reaction conditions chosen and time-on-stream up to more than 50h.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.012
      Issue No: Vol. 538 (2017)
  • Glycidol hydrogenolysis on a cheap mesoporous acid saponite supported Ni
           catalyst as alternative approach to 1,3-propanediol synthesis
    • Authors: F.B. Gebretsadik; J. Ruiz-Martinez; P. Salagre; Y. Cesteros
      Pages: 91 - 98
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): F.B. Gebretsadik, J. Ruiz-Martinez, P. Salagre, Y. Cesteros
      This study explores the use of glycidol, as alternative to glycerol, to improve the selectively to 1,3-propanediol (PrD) by hydrogenolysis. The reaction was performed using Ni (with different Ni wt%) supported on an acid delaminated saponite catalysts which are cheaper compared to the expensive catalysts needed to favor the 1,3-PrD formation by glycerol hydrogenolysis. An increase in metallic area and a decrease in the catalyst acidity resulted in higher conversion and selectivity to propanediols (1,2-+1,3-PrD). An acid activation of glycidol during hydrogenolysis promoted the 1,3-PrD formation and increased the 1,3-PrD/1,2-PrD ratio. For the catalyst prepared with 40wt% Ni loading, an increase in the reaction temperature to 423 and 453K led to higher 1,3-PrD/1,2-PrD ratio. The highest 1,3-PrD yield (29%) and 1,3-PrD/1,2-PrD ratio (0.97) at total conversion were obtained at 453K, after 1h. The overall 1,3-PrD yield from glycerol, assuming a two-step synthesis (Glycerol→Glycidol→1,3-PrD) and a yield of 78% for the first step, should be around 23%. This value is comparable to that reported for the hydrogenolysis of glycerol using noble metal catalysts.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.018
      Issue No: Vol. 538 (2017)
  • Mechanistic study of CO oxidation by N2O over Ag7Au6 cluster investigated
           by DFT methods
    • Authors: Yutthana Wongnongwa; Supawadee Namuangruk; Nawee Kungwan; Siriporn Jungsuttiwong
      Pages: 99 - 106
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Yutthana Wongnongwa, Supawadee Namuangruk, Nawee Kungwan, Siriporn Jungsuttiwong
      The potential of Ag7Au6 alloy nanocluster to be a catalyst for the oxidation of CO by N2O has been examined by density functional theory calculations. In the first mechanistic step, an N2O molecule decomposes at the Ag facet site of the Ag7Au6 cluster, yielding an N2 molecule and an Ag7Au6 O intermediate. In the second step, the Ag7Au6‐O intermediate readily reacts with CO to form CO2. The product CO2 desorbs easily from the active Ag7Au6 site, thus avoiding catalyst poisoning. The potential energy surfaces of the doublet- and quartet-states have been systematically elucidated. There is no spin crossing found for the entire reaction and the results show that the reaction preferably follows the doublet state pathway. The activation Gibbs free energy barrier for the first and second steps are 24.6 and 10.6 kcal/mol, respectively, while the Gibbs free energy of the overall reaction is −81.2 kcal/mol. The results reveal that this catalyzed reaction is both thermodynamically and kinetically favorable. Therefore, the Ag7Au6 nanocluster is predicted to be a promising and highly active catalyst for conversion of CO and N2O pollutants to non-harmful products under ambient conditions.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.025
      Issue No: Vol. 538 (2017)
  • Bimetallic Au-Cu alloy nanoparticles on reduced graphene oxide support:
           Synthesis, catalytic activity and investigation of synergistic effect by
           DFT analysis
    • Authors: Lipeeka Rout; Aniket Kumar; Rajendra S. Dhaka; G Naaresh Reddy; Santanab Giri; Priyabrat Dash
      Pages: 107 - 122
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Lipeeka Rout, Aniket Kumar, Rajendra S. Dhaka, G Naaresh Reddy, Santanab Giri, Priyabrat Dash
      Highly active and well defined Au-Cu nanoparticles supported on reduced graphene oxide (rGO) were synthesized by a simple and one-step deposition-precipitation method. The nanoparticles were thoroughly characterized by UV–vis, X-ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), Scanning transmission electron microscope (STEM) with line scanning and line mapping energy dispersive X-ray spectroscopy (EDS), Raman and X-ray photoelectron spectroscopy (XPS). The composition dependant catalytic activity for the synthesized catalyst was evaluated in the reduction of 4-nitrophenol (4-NP). Among different metal and bimetallic Au-Cu compositions, Au3-Cu1 exhibited highest activity with rate constant of 96×10−3 s−1, which is superior to all other reported work. Within the density functional theory framework, theoretical investigations of our catalyst were carried out to find the reason behind its superior catalytic activity. It has been found that unique synergistic effect between the highly dispersed Au-Cu nanoparticles and rGO support helps in the efficient adsorption of 4-NP on Au3-Cu1/rGO catalyst, highlighting the importance of hybrid bimetallic nanoparticle-GO structure for enhanced catalytic activity. Moreover, effect of various support materials such as activated carbon and alumina was studied on the catalytic activity of Au-Cu nanoparticles. In addition, our catalyst demonstrated excellent activity for the reduction of toxic azo dyes (congo red, methyl orange, and erichrome black T), demonstrating its ability for multiple reduction reactions. Moreover, the efficient removal of the produced amines after the reduction reaction was demonstrated via a convenient waste management strategy using an industrial solid waste red mud. Our results will lead to the possibility of designing suitable GO-based bimetallic system with superior catalytic performance in environmental remediation applications.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.017
      Issue No: Vol. 538 (2017)
  • Pd3Cu coupling with nitrogen-doped mesoporous carbon to boost performance
           in glycerol oxidation
    • Authors: Wei Wang; Wangli Jing; Li Sheng; Dan Chai; Yumao Kang; Ziqiang Lei
      Pages: 123 - 130
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Wei Wang, Wangli Jing, Li Sheng, Dan Chai, Yumao Kang, Ziqiang Lei
      An electrocatalyst made by Pd3Cu alloy nanoparticles (NPs) supporting on nitrogen-doped mesoporous carbon (NMC), Pd3Cu/NMC, is applied to glycerol oxidation reaction (GOR). In this study, the nano-Al2O3 as a hard template, phenolic resin and melamine as nitrogen-containing carbon precursor afford a nitrogen-doped mesoporous carbon support that shows satisfactory effect in stabilizing Pd3Cu alloy NPs. Owing to the strong superimposed effect among nitrogen-doping, mesoporous structure and alloying action, the as-prepared Pd3Cu/NMC catalyst has high catalytic performance for GOR in alkaline medium. Notably, compared with Pd/C, the Pd3Cu/NMC exhibits higher oxidation peak current, better stability and lower activation energy. It is also found that glycerol electrooxidation on Pd3Cu/NMC catalyst is a diffusion controlled irreversible process. All results demonstrate Pd3Cu/NMC is an excellent electrocatalyst in GOR.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.027
      Issue No: Vol. 538 (2017)
  • Effect of hydrogen and propylene on the hydrogen peroxide decomposition
           over Pt, PtO and Au catalysts
    • Authors: E. Kertalli; J.C. Schouten; T.A. Nijhuis
      Pages: 131 - 138
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): E. Kertalli, J.C. Schouten, T.A. Nijhuis
      The decomposition of hydrogen peroxide (H2O2) on Pt, PtO and Au catalysts has been investigated in the presence of nitrogen, propylene and hydrogen. H2O2 formation on the catalyst is known to be a key intermediate step for the direct synthesis of propylene oxide (PO) from hydrogen, propylene and oxygen. Therefore, during this reaction, H2O2 is in contact with the catalyst on which it is produced, propylene and hydrogen. In this work we investigate the effect of the simultaneous presence of a metal catalyst (Pt, Au) and these gases on the H2O2 decomposition. The presence of hydrogen favors the decomposition of H2O2 over all the studied catalysts. This is attributed to the combination of direct decomposition and hydrogenation reactions. Furthermore, hydrogen changes the catalyst from an oxidized to a more metallic state accelerating the H2O2 decomposition. We also observed the positive effect of propylene on decreasing the decomposition activity of Pt and Au. The experimental results were used to estimate reaction rate constants. The obtained rate constants hinted to changes of the catalyst during the decomposition as the main reason for reaction rate changes. This was confirmed to happen for Pt but not for the Au catalyst. The decrease of H2O2 decomposition on Au in the presence of propylene is due to their interaction where propylene blocks the Au active sites responsible for the H2O2 decomposition.
      Graphical abstract image Highlights

      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.023
      Issue No: Vol. 538 (2017)
  • K- and Ca-promoted ferrosilicates for the gas-phase epoxidation of
           propylene with O2
    • Authors: Jaime García-Aguilar; Diego Cazorla-Amorós; Ángel Berenguer-Murcia
      Pages: 139 - 147
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Jaime García-Aguilar, Diego Cazorla-Amorós, Ángel Berenguer-Murcia
      In the propylene epoxidation reaction with Fe-SiO2 catalysts the presence of iron oxide particles has a detrimental effect due to the total combustion of propylene on these iron species. Thus, the complete elimination of the iron oxide particles is presented as a preliminary strategy in order to increase the selectivity towards propylene oxide in iron-based catalysts. In this sense, a simple post-treatment of the catalysts with alkali or alkaline-earth elements (such as K or Ca, respectively) has proven effective in the total elimination of these iron oxide particles. Furthermore, the addition of K and Ca has modified the physico-chemical properties of the catalysts, decreasing their superficial acidity and (for higher K or Ca loadings) masking/blocking the active sites responsible for the catalytic reaction. With all this, it is shown that K has a higher efficiency removing the iron oxide particles compared with Ca (for the same molar ratios) and that a higher amount of K (compared to Fe) is required for the complete elimination of the iron oxide particles. A considerable propylene oxide selectivity enhancement (up to 65%) has been obtained for the K-promoted Fe0.005SiO2 and Fe0.01SiO2 catalysts using O2 as sole oxidant.
      Graphical abstract image

      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.031
      Issue No: Vol. 538 (2017)
  • Highly robust magnetically recoverable Ag/Fe2O3 nanocatalyst for
           chemoselective hydrogenation of nitroarenes in water
    • Authors: Astam K. Patra; Nhat Tri Vo; Dukjoon Kim
      Pages: 148 - 156
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Astam K. Patra, Nhat Tri Vo, Dukjoon Kim
      This work reports on additive-free Ag nanoparticles (4–6nm) deposition on magnetic α-Fe2O3 nanocrystals surface by the slow reduction of AgNO3 with NaBH4 in aqueous medium. The EDS analysis revealed that the new materials contain 3.93wt% of Ag nanoparticle on the surface of α-Fe2O3 which are the active suite for hydrogenation reaction. The Ag/Fe2O3 nanocatalysts exhibited good catalytic ability toward chemoselective hydrogenation of nitroarenes in water. LC–MS study suggested that the catalytic reaction pathway is NO2, NHOH, NH2 and certainly skips the nitrosoarene intermediate step. The nanocatalysts are very efficient in the hydrogenation of nitroarenes tolerating H, Br, I, OH, OCH3, COOH and CONH2 functional groups. The nanocatalysts were separated by external magnet and recycled in aqueous medium which offer environmentally and safe approach to this hydrogenation reaction. The catalyst was tested up to 10 recycles and showed no significant loss of catalytic activity.
      Graphical abstract image

      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.007
      Issue No: Vol. 538 (2017)
  • Effect of silicon poisoning on catalytic dry reforming of simulated biogas
    • Authors: Nada H. Elsayed; Anthony Elwell; Babu Joseph; John N. Kuhn
      Pages: 157 - 164
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Nada H. Elsayed, Anthony Elwell, Babu Joseph, John N. Kuhn
      Catalytic reforming of biogas and subsequent fuel synthesis is one means of upgrading. However, biogas, especially landfill gases, are often contaminated with siloxanes. The poisoning effect of decomposed siloxanes on dry reforming was studied over a high temperature catalyst comprised of 1.3wt% Ni-1.0wt% Mg on a ceria zirconia oxide support and a low temperature catalyst composed of 0.16wt% Pt-1.3wt% Ni-1.0wt% Mg on the same support. The effects of siloxane decomposition were simulated by coating the catalyst particles with silica, which is the decomposition product of siloxanes. The catalysts were poisoned using three different simulated poisoning amounts, which were equivalent accumulation of 1 week, 1 month, and 6 months assuming typical siloxane concentrations in landfill gas and reforming space velocities and no removal prior to reforming. Temperature-programmed reduction (TPR) studies showed that the peak reduction temperature increased significantly (248°C–304°C) even at the smallest poisoning amount for the low temperature catalyst and continued to increase with increased silica amounts. A similar trend was observed in the TPR of the high temperature catalyst where the reduction temperature increased from 382°C–407°C at the lowest poisoning amount and continued to increase with higher poisoning amounts. XRD data showed the presence of silica in the poisoned catalysts that were lacking in the unpoisoned catalysts. Furthermore, FT-IR studies showed the presence of both amorphous and crystalline silica peaks in the poisoned catalysts that were not visible in the fresh catalyst. Dry reforming experiments showed that poisoning has adversely affected the catalysts by increasing the temperature in which both 10% (X10) and 50% (X50) conversion of both CH4 as well as CO2 occurs. Methane X10 increased from 454°C for the fresh catalyst to 518°C for 1 week poisoning and reached 587°C for 6 months of poisoning for the low temperature catalyst. Similarly, the high temperature catalyst had an increase in methane X10 from 762°C for the fresh catalyst to 810°C at 1 week poisoning reaching 842°C at 1 month poisoning and never reaching X10 for 6 months of poisoning indicating severe deactivation of the catalyst. Overall, the results of this study indicate substantial Si species removal is required for catalytic conversion of biogas.
      Graphical abstract image

      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.024
      Issue No: Vol. 538 (2017)
  • YSZ monoliths promoted with Co as catalysts for the production of H2 by
           steam reforming of ethanol
    • Authors: Cyril Gaudillere; Juan Jose González; Antonio Chica; José M. Serra
      Pages: 165 - 173
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Cyril Gaudillere, Juan Jose González, Antonio Chica, José M. Serra
      Steam reforming of ethanol was investigated between 400°C and 600°C over 3mol% Y2O3 doped ZrO2 monolith infiltrated with Co, known as an effective catalyst for this reaction. Monoliths were fabricated by implementing the freeze-casting technique in order to obtain hierarchical, vertical and highly ordered porous microstructure resulting in very low pressure drop, high surface area and accessibility to active sites. Catalytic monoliths were firstly loaded with 3wt% of Co. Catalytic activity of Co-containing monolith was compared with the catalytic activity of a powdered material with the same chemical composition than the catalytic monolith. The results show a clear improvement all over the temperature range of the ethanol conversion and H2 yield and a decrease of the by-products contents when using a freeze-cast monolith support. The incorporation of La enabled a strong decrease in coke deposition over the activated monolith. The effect of the addition of 0.25wt.% of Pt was also studied. Pt makes possible to inhibit carbon deposition but has a detrimental effect on ethanol conversion at temperatures above 500°C and on H2 selectivity at low temperature. A higher Pt loading of 0.8wt% did not bring any beneficial effect and was even detrimental at low temperature. Finally, the beneficial effect of the implementation of freeze-cast monolith in comparison with the not structured fixed-bed configuration is explained by the difference of packing since and improved fluid dynamics at similar GHSV, the former one promotes in a higher proportion the Water Gas Shift Reaction (WGSR) further in the monolith length.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.008
      Issue No: Vol. 538 (2017)
  • Anchoring effect and oxygen redox property of Co/La0.7Sr0.3AlO3-δ
           perovskite catalyst on toluene steam reforming reaction
    • Authors: Kent Takise; Shota Manabe; Keisuke Muraguchi; Takuma Higo; Shuhei Ogo; Yasushi Sekine
      Pages: 181 - 189
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Kent Takise, Shota Manabe, Keisuke Muraguchi, Takuma Higo, Shuhei Ogo, Yasushi Sekine
      To elucidate specific functions of supports, we investigated steam reforming of toluene as a model compound of biomass tar over Co catalyst supported on perovskite-type oxide. Co-supported La0.7Sr0.3AlO3-δ catalyst showed the highest activity among various Co-supported catalysts. STEM measurements and XPS measurements revealed the coexistence of La cation and lattice oxygen defect produces an anchoring effect to Co particles. The lattice oxygen release rate on each catalyst was measured with H2 18O steady-state isotopic transient kinetic analysis (SSITKA). The anchoring effect, higher dispersion of Co and redox property, are important for the high catalytic performance of Co/La0.7Sr0.3AlO3-δ catalyst on toluene steam reforming.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.026
      Issue No: Vol. 538 (2017)
  • Effect of sequence of P and Co addition over silica for Fischer-Tropsch
    • Authors: Muthu Kumaran Gnanamani; Gary Jacobs; Uschi M. Graham; Venkat Ramana Rao Pendyala; Michela Martinelli; Aimee MacLennan; Yongfeng Hu; Burtron H. Davis
      Pages: 190 - 198
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Muthu Kumaran Gnanamani, Gary Jacobs, Uschi M. Graham, Venkat Ramana Rao Pendyala, Michela Martinelli, Aimee MacLennan, Yongfeng Hu, Burtron H. Davis
      The effect of the sequence of phosphorous and cobalt addition to silica on the activity and product selectivity for Fischer-Tropsch synthesis was investigated using a slurry phase continuously stirred-tank reactor. Advantages of P-modified silica supported cobalt included higher activity and C5+ selectivity in comparison with both the undoped and P-doped cobalt silica catalysts. Results of hydrogen chemisorption revealed that cobalt dispersion was higher for all three P-containing cobalt catalysts compared to the undoped cobalt catalyst. H2-TPR profiles indicate P increases the fraction of high-temperature reducible cobalt oxide species and these surface species were dominant in the case of co-impregnated and P-doped cobalt silica catalysts. P-modified silica had enhanced FT activity likely by altering the surface interactions of cobalt with the hydroxyl groups on silica.
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      PubDate: 2017-04-04T03:14:28Z
      DOI: 10.1016/j.apcata.2017.03.033
      Issue No: Vol. 538 (2017)
  • Role of intermediates in reaction pathways from ethene to hydrocarbons
           over H-ZSM-5
    • Authors: Rakesh Batchu; Vladimir V. Galvita; Konstantinos Alexopoulos; Kristof Van der Borght; Hilde Poelman; Marie-Françoise Reyniers; Guy B. Marin
      Pages: 207 - 220
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Rakesh Batchu, Vladimir V. Galvita, Konstantinos Alexopoulos, Kristof Van der Borght, Hilde Poelman, Marie-Françoise Reyniers, Guy B. Marin
      Insight in ethene to hydrocarbon transformation over a H-ZSM-5 catalyst was obtained by means of temporal analysis of products (TAP) in the temperature range 598–698K with pulses of higher olefins, dienes, cyclodienes and aromatics. Pulses of propene, 1-butene and 1-hexene allowed to identify the cracking routes from ethene oligomerization products. When pulsing benzene or ethylbenzene, only accumulation of aromatics occurred. In-situ temperature programmed desorption (TPD) experiments after pulsing identified aromatics as long-lived surface species. The role of intermediates was assessed by means of pre-adsorption of the different feeds before pulsing ethene, in so-called pump-probe experiments. Butene enhanced propene formation, while all other olefins favored butene production via aliphatic surface intermediates. The latter were also intermediates in the conversion of hexadiene to butene and aromatics, while cyclohexadiene was converted to propene and aromatics via aromatic surface intermediates. In contrast to ethylbenzene pulses alone, aromatics alkylation participated towards light olefin production via sidechain/paring mechanisms. Isotope experiments of 13C2H4 over a catalyst coked during continuous flow experiments with 12C only showed scrambling in both propene and butene products, stressing the role of long-lived aromatic surface intermediates.
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      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.03.013
      Issue No: Vol. 538 (2017)
  • Preparation of mesoporous carbon nitride materials using urea and
           formaldehyde as precursors and catalytic application as solid bases
    • Authors: Jie Xu; Yue Wang; Jie-Kun Shang; Dan Ma; Yong-Xin Li
      Pages: 221 - 229
      Abstract: Publication date: 25 May 2017
      Source:Applied Catalysis A: General, Volume 538
      Author(s): Jie Xu, Yue Wang, Jie-Kun Shang, Dan Ma, Yong-Xin Li
      A series of mesoporous carbon nitride materials have been fabricated using inexpensive and eco-friendly urea and formaldehyde as precursors and mesocellular silica foam (MCF) as a template through a nanocasting approach. Several techniques, including XRD, TEM, elemental analysis, FT-IR, XPS, and CO2-TPD have been applied to characterize the physicochemical properties of the mesoCN materials, and the results show that the materials possess high surface areas (331–355m2 g−1), relatively concentrated pore size of ca. 6nm, and abundant and multiple nitrogen-containing species. As heterogeneous base catalysts, mesoCN materials demonstrate high catalytic activity and selectivity in both Knoevenagel condensation and transesterification reactions.
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      PubDate: 2017-04-11T02:09:53Z
      DOI: 10.1016/j.apcata.2017.03.035
      Issue No: Vol. 538 (2017)
  • SO42−/TiO2 promotion on HZSM-5 for catalytic cracking of paraffin
    • Authors: Xu Hou; Yuan Qiu; Enxian Yuan; Xiangwen Zhang; Guozhu Liu
      Pages: 12 - 23
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Xu Hou, Yuan Qiu, Enxian Yuan, Xiangwen Zhang, Guozhu Liu
      A new kind of SO4 2−/TiO2/ZSM-5 catalysts were prepared by the sequential TiO2-CLD and sulfation of commercial HZSM-5 zeolite. Characterization results revealed that the external surface of ZSM-5 crystallite was wrapped by SO4 2−/TiO2 phase; at the same time, the unique MFI-structure and pore properties were well preserved, and the new L acid sites were generated on the external surface. The surface SO4 2−/TiO2 phase promoted the paraffin saturation adsorption by 8%, and significantly enhanced the diffusion process in the ZSM-5 based catalysts. Compared to the parent HZSM-5 zeolite, a significant promotion of catalytic activity in n-pentane cracking was observed over the SO4 2−/TiO2/ZSM-5 catalysts, which was probably due to the enhancement of sorption process for the gas-phase n-pentane molecules into HZSM-5 crystallite caused by the surface SO4 2−/TiO2 phase. Moreover, the SO4 2−/TiO2/ZSM-5 catalysts with a suitable TiO2-loading exhibited excellent catalytic stability and coke-resistance ability in normal-paraffin cracking. A possible role of the surface SO4 2−/TiO2 phase in coke formation was proposed that it effectively hindered the routes from olefins to aromatic hydrocarbons, and thus restrained the accumulation of coke deposit on the external surface.
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      PubDate: 2017-03-09T13:30:15Z
      DOI: 10.1016/j.apcata.2017.03.002
      Issue No: Vol. 537 (2017)
  • Surfactant-directed mesoporous zeolites with enhanced catalytic activity
           in tetrahydropyranylation of alcohols: Effect of framework type and
    • Authors: Hye Sun Shin; Maksym Opanasenko; Carlos Palomino Cabello; Ryong Ryoo; Jiří Čejka
      Pages: 24 - 32
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Hye Sun Shin, Maksym Opanasenko, Carlos Palomino Cabello, Ryong Ryoo, Jiří Čejka
      Nanosponge zeolite beta was hydrothermally synthesized using multi-quarternary ammonium surfactant as a meso-micro hierarchical structure directing agent. The nanosponge morphology of the beta zeolite consisted of randomly interconnected nanocrystals with thickness of 10–20nm. The beta nanosponges with highly mesoporous structure exhibited enhanced catalytic activity in tetrahydropyranylation of alcohols (methanol, 1-octanol, cyclohexanol and 2-adamantanol) when compared with the conventional beta zeolites and nanosponge zeolites of MTW and MFI framework types. The enhanced catalytic performance (∼60% conversion with 90–100% selectivity towards tetrahydropyranyl ether and over two times higher initial rate compared to other zeolites) of hierarchical beta nanosponges can be attributed to the high accessibility of acid sites and facile diffusion of reactants and products through the mesopores.
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      PubDate: 2017-03-09T13:30:15Z
      DOI: 10.1016/j.apcata.2017.02.019
      Issue No: Vol. 537 (2017)
  • Porous silicon carbide as a support for Mn/Na/W/SiC catalyst in the
           oxidative coupling of methane
    • Authors: Huan Wang; Roman Schmack; Benjamin Paul; Matthias Albrecht; Sergey Sokolov; Stefan Rümmler; Evgenii V. Kondratenko; Ralph Kraehnert
      Pages: 33 - 39
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Huan Wang, Roman Schmack, Benjamin Paul, Matthias Albrecht, Sergey Sokolov, Stefan Rümmler, Evgenii V. Kondratenko, Ralph Kraehnert
      Efficient conversion of methane to higher hydrocarbons via oxidative coupling of methane “OCM” is one of the dream reactions in heterogeneous catalysis. Promising yields of C2 hydrocarbons were reported for nanostructured catalysts based on Mn/Na/W-SiO2. However, the exact role of the nanostructure could not be studied so far due to collapse of the pore structure of the SiO2 support at typical OCM temperatures. We investigate porous SiC as an alternative catalyst support for OCM catalysis. Mn/Na/W/SiC catalysts with different pore size were synthesized via impregnation, calcined under different atmospheres and then studied in OCM. The calcination critically impacts the pore structure and surface area of the obtained catalysts. Calcination in nitrogen preserves the support’s structure significantly better than calcination in air. However, the nitrogen-calcined catalysts show a strong loss of porosity during OCM testing. The loss of porosity is caused by the presence of Na, which induces a melting of the surface layer that typically protects SiC against bulk oxidation. OCM tests suggest that the activity and C2 yield of Mn/Na/W/SiC catalysts depend critically on the supports stability, i.e. the surface area retained under reaction conditions.
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      PubDate: 2017-03-09T13:30:15Z
      DOI: 10.1016/j.apcata.2017.02.018
      Issue No: Vol. 537 (2017)
  • Improving the ceria-mediated water and carbon dioxide splitting through
           the addition of chromium
    • Authors: Sotiria Mostrou; Robert Büchel; Sotiris E. Pratsinis; Jeroen A. van Bokhoven
      Pages: 40 - 49
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Sotiria Mostrou, Robert Büchel, Sotiris E. Pratsinis, Jeroen A. van Bokhoven
      The solar thermochemical water and carbon dioxide splitting, mediated by ceria, has a great potential to produce “green” syngas. Chromium was added to ceria to improve the syngas production. Three preparation methods were applied, resulting in different morphologies allowing to investigate the role of chromium. The samples were characterized by X‐ray diffraction, Raman and X-ray spectroscopy, and electron microscopy. Materials made by polymerized-complex-method and dry-impregnation consisted of two crystal phases: ceria and chromia. In contrast, materials made by flame-spray pyrolysis exhibited a homogeneous Cr-doped ceria phase, and chromia was found only at a chromium-content higher than 25mol%. The chromium-doped ceria released additional oxygen during the formation of CeCrO3 perovskite, which did not enhance hydrogen or carbon monoxide production. All chromia-containing samples exhibited improved oxygen exchange capacity, possibly due to a redox cycle of chromia itself, and significantly improved the activity of water and carbon dioxide splitting. Hydrogen production increased from 3.2 to 6.7mL/g and the time to reach redox equilibrium was shorten from 41 to 3min. The best hydrogen and carbon dioxide production rates were up to 20 and 500 times higher than pure ceria, respectively. The presence of chromium is therefore crucial as a catalyst, promoter, and oxygen storage enhancer. This work emphasises the importance of a catalysed re‐oxidation reaction and demonstrates that a metal oxide, becoming active in situ, can catalyse water and carbon dioxide splitting.
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      PubDate: 2017-03-16T02:37:15Z
      DOI: 10.1016/j.apcata.2017.03.001
      Issue No: Vol. 537 (2017)
  • Platinum nanoparticles onto pegylated poly(lactic acid) stereocomplex for
           highly selective hydrogenation of aromatic nitrocompounds to anilines
    • Authors: Werner Oberhauser; Claudio Evangelisti; Cristina Tiozzo; Mattia Bartoli; Marco Frediani; Elisa Passaglia; Luca Rosi
      Pages: 50 - 58
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Werner Oberhauser, Claudio Evangelisti, Cristina Tiozzo, Mattia Bartoli, Marco Frediani, Elisa Passaglia, Luca Rosi
      A stereocomplexed poly(lactic acid)-polyethyleneglycol copolymer was synthesized and successfully used as recyclable support for Pt nanoparticles, generated by the metal vapor synthesis technique. The confinement of the Pt nanoparticles were determined by thermal analysis. Hydrogenation reactions of chlorinated aromatic nitro compounds, containing other reducible functional groups, to the corresponding anilines occurred with the latter supported Pt nanoparticles in MeOH under very mild reaction conditions (i.e. 30°C, p(H2)=5.0bar). The covalently attached polyethyleneglycol polymer significantly increased the catalytic activity of the supported Pt nanoparticles compared to an analogous catalytic system which did not contain polyethyleneglycol but the same sized Pt nanoparticles.
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      PubDate: 2017-03-16T02:37:15Z
      DOI: 10.1016/j.apcata.2017.03.003
      Issue No: Vol. 537 (2017)
  • SiO2-supported Fe & FeMn colloids—Fischer-Tropsch synthesis
           on 3D model catalysts
    • Authors: Mohammadhassan Dad; Remco J. Lancee; Matthys Janse van Vuuren; Jan van de Loosdrecht; J.W. Hans Niemantsverdriet; Hans O.A. Fredriksson
      Pages: 83 - 92
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Mohammadhassan Dad, Remco J. Lancee, Matthys Janse van Vuuren, Jan van de Loosdrecht, J.W. Hans Niemantsverdriet, Hans O.A. Fredriksson
      A well-defined model catalyst constituting a compromise between high surface area, porous, industrial catalysts and a planar model catalyst has been developed. It allows for measurements of catalytic activity in micro reactors, where diffusion problems are kept at a minimum, while characterization both by surface science techniques and by bulk techniques can be applied. Monodisperse, non-porous SiO2 microspheres with diameter 875±25nm have been synthesized, serving as the large area model support. These where then impregnated with pre-formed, monodisperse, colloidal Fe and FeMn nanoparticles resulting in a three-dimensional equivalent of a flat, Fe(-Mn)/SiO2 model catalysts. Characterization with electron microscopy (SEM and TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), before and after catalytic testing was performed. It was shown that the model catalysts can be used in Fischer-Tropsch synthesis experiments under industrially relevant conditions. The FTS experiments reveal that compared to the pure Fe catalyst, FeMn shows more stable activity, higher selectivity towards olefins and lower selectivity toward CH4 and CO2. Significant amounts of hydrocarbons on the catalyst surfaces and some minor indications of sintering were detected after the reaction. Formation of FeCx was detected for the Fe catalyst while no significant amounts could be seen on the Mn-promoted catalyst.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.02.023
      Issue No: Vol. 537 (2017)
  • Efficient eco-sustainable ionic liquid-polyoxometalate desulfurization
           processes for model and real diesel
    • Authors: Diana Julião; Rita Valença; Jorge C. Ribeiro; Baltazar de Castro; Salete S. Balula
      Pages: 93 - 99
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Diana Julião, Rita Valença, Jorge C. Ribeiro, Baltazar de Castro, Salete S. Balula
      This work presents a successful recycling system based in homogeneous polyoxometalate catalysts to desulfurize model and real diesels. Various Keggin-type polyoxometates entrapped in a room temperature ionic liquid (RTIL) phase were investigated. The desulfurization process here proposed conciliates efficiently an extraction and an oxidative catalytic process under sustainable and moderate conditions (H2O2 as oxidant, 50°C). The ionic liquid acts as an extraction solvent and also as an effective immobilization medium for the active homogeneous catalysts. The zinc-polyoxometalates presented high stability and high capacity to be recycled for various consecutive cycles with no loss of desulfurization efficiency. Complete desulfurization of model diesel was achieved at short reaction time (3h). Under the same experimental conditions, 80% of sulfur was removed from real diesel (Sinitial =2300ppm).
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.02.021
      Issue No: Vol. 537 (2017)
  • Investigation of structures and metallic environment of the Ni/Nb2O5 by
           different in situ treatments – Effect on the partial oxidation of
    • Authors: Liniker Fabricio de Sousa; Fabio Souza Toniolo; Sandra Marcela Landi; Martin Schmal
      Pages: 100 - 110
      Abstract: Publication date: 5 May 2017
      Source:Applied Catalysis A: General, Volume 537
      Author(s): Liniker Fabricio de Sousa, Fabio Souza Toniolo, Sandra Marcela Landi, Martin Schmal
      We investigated the structure and interface of the Ni/Nb2O5 under different treatment conditions and its effect on the partial oxidation of methane. In situ investigation of the catalyst reduced in H2 at different temperatures (300, 400 and 500°C) indicated the occurrence of SMSI effect for the sample reduced at the higher temperature, caused by either decoration and/or electronic factors, evaluated by CO chemisorption, X-ray diffraction, HRTEM and UV–vis diffuse reflectance spectroscopy. Under reaction conditions (CH4/O2/N2/Ar=2/1/1/6, GHSV=250mLg−1 h−1), the catalysts reduced at 300 and 400°C showed two nickel sites: NiNbO4 and NiNb2O6, which were active for syngas production (H2 +CO). On the other hand, the catalyst reduced at 500°C showed, besides NiNbO4 and NiNb2O6, the Nb2O5/Niδ+ site (where δ=2 or 3) obtained from the reoxidation of NbOx species priorly generated by SMSI effect. We attribute the activity for methane coupling reactions to this Nb2O5/Niδ+ site (where δ=2 or 3).
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.015
      Issue No: Vol. 537 (2017)
  • Deactivation study of Pd/Al2O3 catalyst for hydrogenation of benzonitrile
           in fixed-bed reactor
    • Authors: Chengyong Dai; Fanghua Liu; Wenxiang Zhang; Yonggang Li; Chunli Ning; Xueguang Wang; Chunlei Zhang
      Abstract: Publication date: Available online 27 March 2017
      Source:Applied Catalysis A: General
      Author(s): Chengyong Dai, Fanghua Liu, Wenxiang Zhang, Yonggang Li, Chunli Ning, Xueguang Wang, Chunlei Zhang
      The Pd/Al2O3 catalyst was prepared by the impregnation method to investigate the deactivation and mechanism of coke formation on metal catalysts for the selective hydrogenation of benzonitrile in a continuous fixed-bed reactor under mild conditions. The Pd/Al2O3 catalyst exhibited the initial benzonitrile conversion of ∼100% with a high benzylamine selectivity of ∼86%, and continuous deactivation during the long-term reaction period of ∼1500h. The comparative investigation of the Pd/Al2O3 catalysts before and after the benzonitrile hydrogenation demonstrated that the deactivation of the Pd/Al2O3 was mainly attributed to carbonaceous compounds deposited on the catalyst. The carbonaceous species contained the aromatic ring conjugated with C=N double bond and tertiary amine groups, which were chemically bound onto the surface of Pd particles, leading to the irreversible loss of metallic active sites. Moreover, the carbon deposition also resulted in partial blockage of the support pores. This study is helpful to understand the deactivation and formation mechanism of carbonaceous compounds on the surface of metal catalysts for the hydrogenation reaction.
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      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.030
  • Lifetime of the H3PW12O40 heteropolyacid in the methanol-to-DME process: a
           question of pre-treatment
    • Authors: Josefine Schnee; Eric M. Gaigneaux
      Abstract: Publication date: Available online 27 March 2017
      Source:Applied Catalysis A: General
      Author(s): Josefine Schnee, Eric M. Gaigneaux
      H3PW12O40 is a Keggin heteropolyacid (HPA) that nowadays attracts more and more attention as catalyst for the gas phase dehydration of methanol to dimethylether. Here, we investigate its performance in the latter reaction at 250–300°C, namely under coking conditions. Actually, we address the question whether the elsewhere elucidated procedure allowing to activate the bulk of the H3PW12O40 solid is beneficial or not under conditions leading to the rapid coking/deactivation of H3PW12O40’s surface (through which the bulk gets accessed). Unprecedented, our results show that pre-activating the bulk is actually crucial in the latter conditions, as it allows drastically increasing H3PW12O40’s lifetime (up to 5 times at 300°C). Indeed, once activated, the bulk stays accessible beyond the deactivation of the surface. However, with its 24 times more protons than provided by the surface, and with the conversion over the latter protons being diffusion-limited, it then contains continuously enough fresh protons being able to take over the job of the other bulk protons that are deactivated (in the sense that they are capped within coke molecules) until having all been solicited/deactivated. As a consequence, the catalyst bed gets fully exploited until the last of its available bulk protons has contributed to the reaction, instead of getting only scarcely exploited as it is the case when the reaction is purely surface-type. So, the results of this work bring considerable insight on how to use a Keggin HPA-based catalyst in a more sustainable way. Furthermore, they allow understanding the performance obtained upon submitting a Keggin HPA to a temperature programmed reaction of methanol from 25 to 300°C. Indeed, throughout such a reaction, the deactivation profile (e.g. drastic conversion drops vs slow ones) is governed by the nature of the protons (surface vs bulk-type) that are getting deactivated.
      Graphical abstract image

      PubDate: 2017-03-28T03:54:08Z
      DOI: 10.1016/j.apcata.2017.03.034
  • Visible light responsive TiO2 nanoparticles modified using Ce and La for
           photocatalytic reduction of CO2: Effect of Ce dopant content
    • Authors: Khozema Ahmed Ali; Ahmad Zuhairi Abdullah; Abdul Rahman Mohamed
      Abstract: Publication date: Available online 20 March 2017
      Source:Applied Catalysis A: General
      Author(s): Khozema Ahmed Ali, Ahmad Zuhairi Abdullah, Abdul Rahman Mohamed
      Photocatalytic reduction of CO2 in aqueous solution was performed using TiO2 photocatalysts modified with Ce and La under fluorescent light irradiation. The photocatalysts were prepared using modified sol gel method with Ce doping content varied between 0–2 wt%. Comprehensive characterization using XRD, XPS, nitrogen physisorption, SEM, EDX, PL and UV- vis spectroscopy revealed that the introduction of cerium affected the surface, structural and optical properties of the photocatalyts. Among all the doped photocatalysts, 1.5wt% Ce/La/TiO2 showed the highest photocatalytic activity under fluorescent light irradiation. In the liquid phase, a maximum yield of 317.7μmol/g-cat for CH3OH was achieved whereas CH4 and CO were the main products in the gas phase with maximum yields of 262.8 and 119.4μmol/g-cat, repsectively. The addition of Ce and La was found to inhibit the growth of anatase TiO2, increase the surface area and improve the optical properties of the photocatalyst. The existence of Ce3+/Ce4+ mixture was also found to effectively inhibit the electron-hole recombination, enhancing the photocatalytic activity of Ce/La co-doped TiO2.
      Graphical abstract image

      PubDate: 2017-03-21T08:28:03Z
      DOI: 10.1016/j.apcata.2017.03.022
  • Catalytic upgrading of furfuryl alcohol to bio-products: Catalysts
           screening and kinetic analysis
    • Authors: M. Paniagua; J.A. Melero; J. Iglesias; G. Morales; B. Hernández; C. López-Aguado
      Abstract: Publication date: Available online 6 March 2017
      Source:Applied Catalysis A: General
      Author(s): M. Paniagua, J.A. Melero, J. Iglesias, G. Morales, B. Hernández, C. López-Aguado
      The conversion of furfuryl alcohol, a highly versatile biomass-derived platform molecule, into a large variety of bio-products, including ethers, lactones and levulinates, has been evaluated in alcohol media using different solid acid catalysts, such as commercial zeolites, sulfonic acid-functionalized materials, and sulfated zirconia. Reaction pathways and mechanisms have been correlated to the particular type of catalyst used, aiming to establish the influence of the main physico-chemical properties of the materials on the extent of furfuryl alcohol conversion, as well as on the predominant reaction pathway followed. Mechanistic and kinetics modelling studies for each type of catalyst have been developed and compared, providing an useful tool for the selection of the most suitable solid acid catalyst for the production of each of the reaction intermediates in the cascade from furfuryl alcohol to alkyl levulinate.
      Graphical abstract image

      PubDate: 2017-03-09T13:30:15Z
      DOI: 10.1016/j.apcata.2017.03.004
  • Dehydration of sorbitol to isosorbide over sulfonic acid resins under
           solvent-free conditions
    • Authors: María José Ginés Molina; Ramón Moreno-Tost; José Santamaría-González; Pedro Maireles-Torres
      Abstract: Publication date: Available online 6 March 2017
      Source:Applied Catalysis A: General
      Author(s): María José Ginés Molina, Ramón Moreno-Tost, José Santamaría-González, Pedro Maireles-Torres
      Different commercial sulfonic acid resins (Purolite and Amberlyst type) have been evaluated as acid catalysts for the dehydration of sorbitol to isosorbide. These acidic resins differ in their acid properties, as well as in their thermal and mechanical stabilities. Dehydration of sorbitol has been carried out under solvent-free conditions, by melting sorbitol. At the beginning of reaction, different sorbitans (monodehydration products) were detected, whose dehydration and subsequent cyclization lead to the formation of isosorbide. A maximum yield of 75% is reached after 12h at 413K, by using a 5wt% of Purolite CT269, at atmospheric pressure. This resin maintains its catalytic activity after four runs, and the stability is corroborated by the negligible presence of sulphur species (coming from sulfonic acid leaching) in the reaction medium. This suitable catalytic performance can be explained by its high acid capacity (5.2meqg−1) and mechanical and thermal stabilities associated to the macroreticular structure.
      Graphical abstract image

      PubDate: 2017-03-09T13:30:15Z
      DOI: 10.1016/j.apcata.2017.03.006
  • Skeletal Isomerization of n-Pentane: A Comparative Study on Catalytic
           Properties of Pt/WOx−ZrO2 and Pt/ZSM-22
    • Authors: Wei Li; Kebin Chi; Hao Liu; Huaijun Ma; Wei Qu; Congxin Wang; Guang Lv; Zhijian Tian
      Abstract: Publication date: Available online 6 March 2017
      Source:Applied Catalysis A: General
      Author(s): Wei Li, Kebin Chi, Hao Liu, Huaijun Ma, Wei Qu, Congxin Wang, Guang Lv, Zhijian Tian
      Pt/WO x −ZrO2 and Pt/ZSM-22 were prepared and used as catalysts for the n-pentane hydroisomerization reactions. The physico-chemical properties of the supports were characterized by XRD, N2 adsorption, NH3-TPD and 1-pentene isomerization reaction. The reducibility and adsorbability of the catalysts were evaluated via H2-TPR, H2-TPD and CO adsorption. Under the reaction condition of WHSV=1h−1, pn -pentane,0 =0.24bar and ambient pressure, the yields of isopentane over Pt/WO x −ZrO2 and Pt/ZSM-22 can reach 52% (at 300°C) and 61% (at 340°C) respectively. The selectivities to isopentane over these two catalysts are well above 95%. The hydroisomerization mechanisms over these catalysts are discussed.
      Graphical abstract image

      PubDate: 2017-03-09T13:30:15Z
      DOI: 10.1016/j.apcata.2017.03.005
  • Kinetic modelling of temperature-programmed reduction of cobalt oxide by
    • Authors: Chao’en Li; Lisa Wong; Liangguang Tang; Nicola V.Y. Scarlett; Ken Chiang; Jim Patel; Nick Burke; Valerie Sage
      Abstract: Publication date: Available online 3 March 2017
      Source:Applied Catalysis A: General
      Author(s): Chao’en Li, Lisa Wong, Liangguang Tang, Nicola V.Y. Scarlett, Ken Chiang, Jim Patel, Nick Burke, Valerie Sage
      The reduction activities and mechanisms of cobalt-based catalysts are of great interest to industry and researchers, due to their applications in Fischer–Tropsch synthesis. Here, we investigated the reduction of alumina‐supported cobalt catalysts by hydrogen using temperature-programmed reduction. We propose a five-step reduction mechanism that incorporates both amorphous and crystalline Co3O4, and includes the interaction between CoO and the Al2O3 support. Based on our proposed mechanism, we developed a kinetic model of the reduction process. The modelling results of catalysts promoted with ruthenium and lanthanum in contrast with un-promoted catalyst clearly show that the promoter improves reducibility of the catalyst. The effect of Co3O4 crystallinity was also investigated by the reduction of fresh in comparison of pre-oxidised catalyst. We conclude that high crystallinity significantly increases the difficulty of reducing Co3O4. The interaction between CoO and Al2O3 under reduction conditions to form CoAl2O4 was quantitatively simulated. The kinetic modelling confirms that the support plays an important role in catalyst reduction via the interaction between the catalyst and the support. Those kinetic modelling results are supported by in situ X-ray diffraction studies of the reduction process.
      Graphical abstract image

      PubDate: 2017-03-03T13:30:13Z
      DOI: 10.1016/j.apcata.2017.02.022
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