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  Subjects -> ENGINEERING (Total: 2291 journals)
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ENGINEERING (1209 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 18)
AAPG Bulletin     Hybrid Journal   (Followers: 7)
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: 233)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
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: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 8)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
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Advances in Catalysis     Full-text available via subscription   (Followers: 5)
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Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
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Advances in Remote Sensing     Open Access   (Followers: 37)
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: 30)
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: 17)
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: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 16)
Applied Clay Science     Hybrid Journal   (Followers: 5)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 1)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
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: 7)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
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: 8)
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: 8)
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: 5)
Batteries     Open Access   (Followers: 4)
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: 4)
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: 10)
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: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
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     Hybrid Journal   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 42)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Thermal Engineering     Open Access   (Followers: 3)
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: 7)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 8)
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: 22)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 5)
Coatings     Open Access   (Followers: 4)
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: 26)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 262)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 183)
Composites Part B : Engineering     Hybrid Journal   (Followers: 281)
Composites Science and Technology     Hybrid Journal   (Followers: 179)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
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Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
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Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
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Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
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Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 7)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 9)
Control Engineering Practice     Hybrid Journal   (Followers: 42)
Control Theory and Informatics     Open Access   (Followers: 8)
Corrosion Science     Hybrid Journal   (Followers: 25)
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 7 | Last

Journal Cover Applied Catalysis A: General
  [SJR: 1.234]   [H-I: 159]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0926-860X
   Published by Elsevier Homepage  [3043 journals]
  • A re-examination of the catalyst activation and temperature hysteresis in
           methane combustion on Pt/Al2O3
    • Authors: Linxiao Chen; Joseph P. McCann; Steven L. Tait
      Pages: 19 - 30
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Linxiao Chen, Joseph P. McCann, Steven L. Tait
      Methane combustion is an industrially important reaction that has been extensively studied. Supported Pt catalysts on Al2O3 exhibit excellent activity in this reaction owing to their CH bond activation capability. Pt/Al2O3 catalyst remains almost inactive until the conversion increases abruptly at the ignition temperature (Tign ). The temperature hysteresis behavior has been reported, where after ignition, as the temperature is lowered below Tign , the catalyst continues to exhibit high activity. The activation has been previously attributed to the removal of adsorbed oxygen on Pt sites at Tign , while the hysteresis has been explained by the local temperature elevation caused by the reaction heat. In this work, this behavior was re-examined at a small scale in a fixed-bed flow reactor over a range of pre-treatment and reaction mixture conditions. Low-temperature activation was achieved by pre-treating the catalyst with CH4. Carefully designed control experiments yielded observations that cannot be rationalized by the existing theory, suggesting that it is incomplete. Based on these new results, we propose a more comprehensive theory describing the active sites in the oxidation reaction as methane-derived adsorbed carbon active sites, and their formation as the controlling factor in the catalyst activation. The hysteresis can be better explained by the enhanced stability of active sites under reaction conditions. In situ infrared spectroscopy and mass spectrometry studies were conducted in a flow cell, providing strong evidence supporting the theory. The dissociative adsorption of CH4 was studied under a variety of pre-treatment conditions, and proved to be responsible for the active site formation. The fundamental understanding obtained in this work contributes significant insights to the understanding of reaction mechanism.
      Graphical abstract image

      PubDate: 2017-09-26T08:11:30Z
      DOI: 10.1016/j.apcata.2017.09.008
      Issue No: Vol. 549 (2017)
       
  • Direct catalytic hydroxylation of benzene to phenol catalyzed by vanadia
           supported on exfoliated graphitic carbon nitride
    • Authors: Jie Xu; Ye Chen; Ying Hong; Huan Zheng; Dan Ma; Bing Xue; Yong-Xin Li
      Pages: 31 - 39
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Jie Xu, Ye Chen, Ying Hong, Huan Zheng, Dan Ma, Bing Xue, Yong-Xin Li
      Direct hydroxylation of benzene is a sustainable and promising strategy to synthesize phenol. The key topic for the catalytic process is the development of an efficient heterogeneous catalyst. In this work, graphitic carbon nitride (g-C3N4) material was exfoliated and protonated, and then utilized as a support to load vanadia by using VO(acac)2 as a precursor. The synthesized materials were characterized by several techniques including N2 adsorption–desorption, XRD, TG, TEM, SEM, FT-IR, UV–vis, and XPS. The results exhibited that the exfoliation as a simple method could improve the surface area and pore volume of g-C3N4, while protonation was able to facilitate to increase the loading amount of vanadia. In hydroxylation of benzene to phenol in the presence of H2O2, the vanadia catalysts supported on peg-C3N4 demonstrated superior catalytic activity to the catalysts supported on the pristine g-C3N4. Moreover, the effects of protonation conditions including acid concentration and temperature on the final catalytic activity have also been investigated. Under optimized conditions, a maximum yield of phenol reached 15% at 60°C.
      Graphical abstract image

      PubDate: 2017-09-26T08:11:30Z
      DOI: 10.1016/j.apcata.2017.09.015
      Issue No: Vol. 549 (2017)
       
  • Structurally uniform 1-hexene, 1-octene, and 1-decene oligomers:
           Zirconocene/MAO-catalyzed preparation, characterization, and prospects of
           their use as low-viscosity low-temperature oil base stocks
    • Authors: Ilya E. Nifant’ev; Alexander A. Vinogradov; Alexey A. Vinogradov; Igor V. Sedov; Viktor G. Dorokhov; Anton S. Lyadov; Pavel V. Ivchenko
      Pages: 40 - 50
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Ilya E. Nifant’ev, Alexander A. Vinogradov, Alexey A. Vinogradov, Igor V. Sedov, Viktor G. Dorokhov, Anton S. Lyadov, Pavel V. Ivchenko
      An original approach to α-olefin oligomerization as well as novel thermally stable zirconocene catalysts for use in such reactions has been elaborated. The method reported allows the achievement of fractions of lightweight α-olefin oligomers up to 90% yields without considerable formation of byproducts like internal alkenes, alkanes, and higher oligomers. Trimers, tetramers, and pentamers of 1-hexene, 1-octene, and 1-decene were isolated as individual compounds and were hydrogenated. Viscosity characteristics of the isolated saturated and unsaturated hydrocarbons have been studied at various temperatures. The isolated saturated oligomers of 1-octene and 1-decene outperform the traditional electrophilic oligomerization products in terms of viscosity indexes, pour points, and low-temperature viscosity.
      Graphical abstract image

      PubDate: 2017-09-26T08:11:30Z
      DOI: 10.1016/j.apcata.2017.09.016
      Issue No: Vol. 549 (2017)
       
  • Comparing a cobalt-based catalyst with iron-based catalysts for the
           Fischer-Tropsch XTL-process operating at high conversion
    • Authors: E. van Steen; M. Claeys; K.P. Möller; D. Nabaho
      Pages: 51 - 59
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): E. van Steen, M. Claeys, K.P. Möller, D. Nabaho
      The XTL-process is a capital-intensive process. Novel process configurations need to be explored to increase the economic viability of this process. This is typically performed using the known dependencies of the catalyst as a function of the targeted process conditions. However, new process conditions may require catalysts with different characteristics compared to those currently utilised. Here, a set of cobalt- and iron-based Fischer-Tropsch catalysts are evaluated for their suitability in the application of a single-pass XTL-process operating at high conversion of synthesis gas. It is shown that cobalt-based catalysts of a suitable activity may be preferred over iron-based catalysts. The higher selectivity for methane for cobalt-based catalysts is offset by a lower selectivity for C2-C4 resulting in a favourable C5+-selectivity.
      Graphical abstract image

      PubDate: 2017-09-26T08:11:30Z
      DOI: 10.1016/j.apcata.2017.09.019
      Issue No: Vol. 549 (2017)
       
  • Preferential dealumination of Zn/H-ZSM-5 and its high and stable activity
           for ethane dehydroaromatization
    • Authors: Hikaru Saito; Satoshi Inagaki; Kiria Kojima; Qiao Han; Tomohiro Yabe; Shuhei Ogo; Yoshihiro Kubota; Yasushi Sekine
      Pages: 76 - 81
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Hikaru Saito, Satoshi Inagaki, Kiria Kojima, Qiao Han, Tomohiro Yabe, Shuhei Ogo, Yoshihiro Kubota, Yasushi Sekine
      The effect of steam treatment on Zn/H-ZSM-5 catalysts prepared by an ion-exchange method for non-oxidative ethane dehydroaromatization was investigated. Steam treatment of Zn/H-ZSM-5 after Zn loading improved its catalytic stability on aromatic hydrocarbon formation including benzene, toluene and xylene. Temperature programmed oxidation measurements demonstrated that the steam treatment brought suppression of coke formation and it contributed to the improvement in the catalytic stability. Characterization of the local structure of the zeolites by 27Al and 29Si magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy revealed that dealumination of the framework Al in the MFI structure proceeded by steam treatment. Results of temperature programmed desorption of ammonia indicate the decrease in the amount of acid sites by the steam treatment. The slight changes in Zn content and its electronic state indicated that bared Al related with H+, not with Zn2+, in the MFI structure was preferentially dealuminated by steam treatment. The preferential dealumination led to suppression of coke formation by the selective removal of undesirable Brønsted acid sites.
      Graphical abstract image

      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.024
      Issue No: Vol. 549 (2017)
       
  • Synthesis of iron-based metal-organic framework MIL-53 as an efficient
           catalyst to activate persulfate for the degradation of Orange G in aqueous
           solution
    • Authors: Mengjie Pu; Zeyu Guan; Yongwen Ma; Jinquan Wan; Yan Wang; Mark L. Brusseau; Haiyuan Chi
      Pages: 82 - 92
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Mengjie Pu, Zeyu Guan, Yongwen Ma, Jinquan Wan, Yan Wang, Mark L. Brusseau, Haiyuan Chi
      A series of MIL-53(Fe) materials was synthesized using a solvothermal method under different temperature and time conditions and were used as catalysts to activate persulfate and degrade Orange G (OG). Influences of the above conditions on the crystal structure and catalytic behavior were investigated. Degradation of OG under different conditions was evaluated, and the possible activation mechanism was speculated. The results indicate that high synthesis temperature (larger than 170°C) leads to poor crystallinity and low catalytic activity, while MIL-53(Fe) cannot fully develop at low temperature (100 or 120°C). The extension of synthesis time from 5h to 3d can increase the crystallinity of the samples, but weakened the catalytic activity, which was caused by the reduction of BET surface area and the amount of Fe (II)-coordinative unsaturated sites. Among all the samples, MIL-53(Fe)-A possesses the best crystal structure and catalytic activity. In optimal conditions, OG solution can be totally decolorized after degradation for 90min, and a removal rate of 74% for COD was attained after 120min. The initial solution pH had great influence on OG degradation, with the greatest removal in acidic pH environment. ESR spectra showed that sulfate radical (SO4 − ), hydroxyl radical (OH), persulfate radical (S2O8 − ), and superoxide radical (O2 ) exist in this system under acidic conditions. Furthermore, with the increase of pH, the relative amount of O2 increases while that of OH and SO4 − decreases, resulting in a reduced oxidizing capacity of the system.
      Graphical abstract image

      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.021
      Issue No: Vol. 549 (2017)
       
  • Characterization of nickel catalysts with transient methods
    • Authors: Stefan Ewald; Sebastian Standl; Olaf Hinrichsen
      Pages: 93 - 101
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Stefan Ewald, Sebastian Standl, Olaf Hinrichsen
      The Ni surface area is a key factor in catalytic performance of supported Ni catalysts employed in heterogeneously catalyzed reactions. For its characterization, transient measurement techniques are powerful but need a proper experimental design and a high level of accuracy. In this study, several transient methods, namely temperature programmed desorption of H2 (H2-TPD), pulsed H2 chemisorption and N2O chemisorption, were applied and evaluated for the characterization of Ni catalysts. Results were compared with those from static H2 chemisorption. Ni powder, as well as NiAlOx and Ni/γ-Al2O3 with varying Ni loadings, synthesized via precipitation and incipient wetness impregnation, respectively, were used as model catalysts. H2-TPD within the temperature range from 84 to 753K is able to completely describe the interaction of H2 with supported Ni. However, a quantitative analysis of the specific Ni surface area based on H2-TPD is difficult whereas pulsed H2 chemisorption leads to comparable results as obtained from static measurements. Adsorption and pre-treatment conditions have a strong impact on the desorption spectra. Reversible morphologic changes of the Ni surface were revealed by H2-TPD when changing the gas atmosphere during pre‐treatment. N2O chemisorption occurs in three steps including fast oxygen uptake, growth of the oxide layer and subsequent layer thickening due to subsurface and bulk oxidation. A separation of surface and subsurface/bulk oxidation of NiAlOx and Ni/γ-Al2O3, both of which are readily oxidized even under mild conditions, is only achievable at temperatures between 190 and 195K. In this temperature range, the ratio of adsorbed oxygen atoms, O, and the number of Ni surface atoms, NiS, (O/NiS) is 0.38±0.07, which can be applied for specific Ni surface area determination. The experimental mode of N2O chemisorption (flow or titration mode) does not influence the extent of subsurface oxidation. The separation of surface and subsurface/bulk oxidation is more feasible in the case of Ni powder. Here, a suitable temperature for Ni surface area determination lies within 265 and 285K with an O/NiS ratio of 0.96±0.05.
      Graphical abstract image

      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.023
      Issue No: Vol. 549 (2017)
       
  • In-situ construction of novel silver nanoparticle decorated polymeric
           spheres as highly active and stable catalysts for reduction of methylene
           blue dye
    • Authors: Guangfu Liao; Qing Li; Wenzhe Zhao; Qiuhu Pang; Haiyang Gao; Zushun Xu
      Pages: 102 - 111
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Guangfu Liao, Qing Li, Wenzhe Zhao, Qiuhu Pang, Haiyang Gao, Zushun Xu
      A facile strategy has been developed for the preparation of novel silver/poly(styrene-N-isopropylacrylamide-methacrylic acid) (Ag/PSNM) nanocomposite spheres with high catalytic activity and good storage stability. Silver (Ag) nanoparticles are successfully deposited on poly(styrene-N-isopropylacrylamide-methacrylic acid) (PSNM) spheres surfaces via in situ reduction and simultaneously protected by polyvinylpyrrolidone (PVP). The prepared Ag/PSNM nanocomposite spheres show good temperature/pH responsive property and improved thermal property. Moreover, they also exhibit high catalytic activity and good recyclability for the catalytic reduction of methylene blue (MB) to leuco methylene blue (LMB). The result of clock reaction indicate that the redox reaction generates a colorless (LMB) solution which easily reverts back to blue (MB) in air. The catalytic activity increase with the increasing of temperature and the reaction rate constant (k) follows the typical Arrhenius-type dependence on temperature. In addition, the prepared Ag/PSNM nanocomposite spheres show good storage stability and the catalytic activity remains almost unchanged after storage for 90days at room temperature. Therefore, the prepared Ag/PSNM nanocomposite spheres can have a highly potential use in the catalytic degradation of organic dyes in wastewater treatment applications.
      Graphical abstract image

      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.034
      Issue No: Vol. 549 (2017)
       
  • Co-N-doped carbon nanotubes supported on diatomite for highly efficient
           catalysis oxidative carbonylation of amines with CO and air
    • Authors: Jiangwei Li; Dong-huai Tu; Yani Li; Weiqiang Wang; Qinwei Yu; Jianming Yang; Jian Lu
      Pages: 112 - 116
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Jiangwei Li, Dong-huai Tu, Yani Li, Weiqiang Wang, Qinwei Yu, Jianming Yang, Jian Lu
      Cobalt-nitrogen-doped carbon nanotubes stably supported on diatomite were obtained by employing Co(OAc)2/phenanthroline. The resulting material was found to be excellent catalysts for the carbonylation of a variety of amines with CO other than phosgene. Both high activity and selectivity were achieved in this carbonylation process, and it allows air as a cheap oxidizing agent. Moreover the catalyst could be recycled for several times with relatively higher activity compared to homogeneous catalyst palladium acetate.
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      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.030
      Issue No: Vol. 549 (2017)
       
  • Adjusted interactions of nickel nanoparticles with cobalt-modified
           MgAl2O4-SiC for an enhanced catalytic stability during steam reforming of
           propane
    • Authors: Kyung Soo Park; Minji Son; Myung-June Park; Dae Hyun Kim; Jeong Hwa Kim; So Hyun Park; Joon-Hwan Choi; Jong Wook Bae
      Pages: 117 - 133
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Kyung Soo Park, Minji Son, Myung-June Park, Dae Hyun Kim, Jeong Hwa Kim, So Hyun Park, Joon-Hwan Choi, Jong Wook Bae
      Steam reforming of propane (SRP) for the stable production of hydrogen-rich reformates was investigated using the Ni-supported on the cobalt-modified SiC-embedded MgAl2O4 support (denoted as NCMAS). The adjusted interactions of the Ni nanoparticles with the cobalt-modified SiC-embedded MgAl2O4 (MgAl2O4-SiC) and its crystallite size distributions largely altered the catalytic activity and stability of NCMAS. The introductions of SiC on the NCMAS, where SiC has a higher thermal conductivity, also increased the dispersion of smaller MgAl2O4 grains with the less formations of inactive NiAl2O4 species, which resulted in the higher catalytic activity with smaller formations of unreformed light hydrocarbons. The positive roles of cobalt promoter on the MgAl2O4-SiC matrices were mainly attributed to the suppressed aggregation of nickel nanoparticles by their strong and intimate interactions with the cobalt-modified MgAl2O4. The effects of cobalt promoter at an optimal 5wt%Co in the MgAl2O4-SiC (NCMAS(5)) enhanced the oxidation-resistance of the nickel nanoparticles with less formations of inactive metal aluminates by being reversibly re-reduced under the SRP reaction conditions. These phenomena further lessen coke depositions by intimately interacting with highly dispersed oxophilic cobalt or cobalt aluminate species. The optimal NCMAS(5) was applied to derive kinetic parameters using Langmuir-Hinshelwood-Hougen-Watson (LHHW) mechanisms, and the reasonable activation energy of 73 kJ/mol and optimal operating parameters to maximize hydrogen production by SRP reaction was estimated in terms of the reaction conditions such as space velocity, feed ratio and reaction temperature.
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      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.031
      Issue No: Vol. 549 (2017)
       
  • Rapid one-pot catalytic synthesis of double-capped oligoesters from
           lactones
    • Authors: Parichat Piromjitpong; Jiraya Kiriratnikom; Thasanaporn Ungpittagul; Sirilata Yotphan; Khamphee Phomphrai
      Pages: 134 - 140
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Parichat Piromjitpong, Jiraya Kiriratnikom, Thasanaporn Ungpittagul, Sirilata Yotphan, Khamphee Phomphrai
      The rapid one-pot catalytic synthesis of double-capped oligoesters was carried out by the ring-opening polymerization of various cyclic ester monomers (i.e. ε-caprolactone (ε-CL), δ-valerolactone (DVL), γ-butyrolactone (GBL), and L-lactide (L-LA)) followed by the transesterification reaction with a variety of alkyl esters as an end-capping agent. Simple metal amides were found to be an effective catalyst under mild condition. Among them, LiN(SiMe3)2 was shown to be the most active catalyst giving 94% conversion of double-capped oligo(ε-caprolactone) within 5min at room temperature. The average chain length of the oligoesters can be controlled by the adjustment of the ratio of an alkyl ester to monomer, the reaction time and reaction temperature.
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      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.033
      Issue No: Vol. 549 (2017)
       
  • Controlled silylation of MoVTeNb mixed oxide catalyst for the selective
           oxidation of propane to acrylic acid
    • Authors: Xinlin Tu; Masao Niwa; Akio Arano; Yoshinori Kimata; Eiichi Okazaki; Souichi Nomura
      Pages: 152 - 160
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): Xinlin Tu, Masao Niwa, Akio Arano, Yoshinori Kimata, Eiichi Okazaki, Souichi Nomura
      Acrylic acid is an important industrial chemical, and efficient catalysts for its direct preparation by propane oxidation are highly desirable. For this purpose, neutral silica networks were introduced on the surface of MoVTeNb mixed oxide catalysts by controlled silylation using a methyl silicate oligomer (MS-51). The modified catalysts gave ∼56.5% yield of acrylic acid with a selectivity of 77.1% in the oxidation of propane at 380°C. The catalysts were characterized by X-ray fluorescence, Fourier-transform infrared spectroscopy, Brunauer–Emmett–Teller specific surface area, X-ray diffraction (Rietveld analysis), pyridine desorption, and scanning electron microscopy. MoVTeNb mixed oxide was found to be composed of 90.9% M1 phase and 2.3% M2 phase, and upon silylation, the surface was uniformly covered by a thin SiO2 layer with 0.14 molar ratio with respect to Mo and an estimated thickness of 2.4nm. The amount of acid sites decreased after the first three silylation cycles, but was not affected by repeated cycles. The results of the kinetic study based on the comparison of the simulated contribution of each side reaction were consistent with those of the model reactions using acrylic acid and other reactants: the controlled silylation effectively suppressed acrylic acid oxidation, especially after repeated silylation cycles, which is responsible for the superior performance of the silylated catalysts. Considering the relatively large size of acrylic acid compared to propane and the efficient propane activation by silica-covered catalysts, the controlled silylation was proposed to have two roles, by which further consecutive oxidation is prevented effectively to exhibit excellent performance in oxidation of propane: i) to block the unfavorable acidic sides, ii) to generate a silica layer with pore mouth openings on the surface of MoVTeNb mixed oxide, which allow the entrance of propane but inhibit re-entrance of the produced acrylic acid.
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      PubDate: 2017-10-11T22:48:35Z
      DOI: 10.1016/j.apcata.2017.09.013
      Issue No: Vol. 549 (2017)
       
  • Insight into the role of hydroxyl groups on the ZnCr catalyst for
           isobutanol synthesis from syngas
    • Authors: Xiaofeng Gao; Yingquan Wu; Guohui Yang; Tao Zhang; Xiaoli Li; Hongjuan Xie; Junxuan Pan; Yisheng Tan
      Pages: 1 - 11
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Xiaofeng Gao, Yingquan Wu, Guohui Yang, Tao Zhang, Xiaoli Li, Hongjuan Xie, Junxuan Pan, Yisheng Tan
      A series of ZnO, ZnCr catalysts were prepared by a sol-gel method and ammonia solution was used to adjust the pH of the sol solution. The catalysts were characterized by XRD, in-situ FR-IR, NH3-TPD, in-situ XPS, HRTEM. The results show that lower calcination temperature is helpful to reduce the crystal size and crystallinity of ZnCr nanocrystal, as well as forming a certain amount of structure defects and hydroxyl groups. The hydroxyl groups could be consumed by CO under the interaction between ZnO and ZnCr spinel, resulting in more exposed oxygen vacancies. We find the proper calcination temperature and Zn/Cr molar ratio for the ZnCr catalysts preparation are 400°C and 1.0, respectively. The Zn1Cr1–400∼2.0 catalyst prepared with the pH value of 2 shows more hydroxyl groups and small particle size, exhibiting the best catalytic performance both on the CO conversion (20.9%) and isobutanol selectivity (24.2wt%).
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.022
      Issue No: Vol. 547 (2017)
       
  • Design of selective hydrocracking catalysts for BTX production from
           diesel-boiling-range polycyclic aromatic hydrocarbons
    • Authors: Jaeuk Shin; Youngseok Oh; Yeseul Choi; Jihye Lee; Jung Kyoo Lee
      Pages: 12 - 21
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Jaeuk Shin, Youngseok Oh, Yeseul Choi, Jihye Lee, Jung Kyoo Lee
      Various metallic components (Ni, NiSn, NiW-S, CoMo-S and NiMo-S) with different hydrogenation (HYD) activities were supported on H-Beta or hybrid zeolites (BZ(x), where x denotes the weight percentage of H-ZSM-5 in the physical mixture of H-Beta and H-ZSM-5). These bifunctional catalysts were applied to the hydrocracking (HYC) of tetralin in a fixed-bed down-flow reactor at 4MPa as a model reaction for polycyclic aromatic hydrocarbon (PAH) conversion to high-value benzene, toluene, and xylenes (BTX). From the HYC of tetralin over the series of metals/H-Beta catalysts, it was found that CoMo-S/H-Beta and NiMo-S/H-Beta, whose metallic components show moderate activities in the HYD of tetralin, exhibit higher BTX yields than the other catalysts whose metals have excessively high or low HYD activities. However, these catalysts show limited BTX yield (∼47.3wt% at 425°C) owing to the large coproduction of alkylbenzenes other than BTX. When metals with moderate HYD activities are supported on the hybrid zeolites, the BTX yield is significantly enhanced by the effect of H-ZSM-5 in the dealkylation of alkylbenzenes into BTX. NiMo-S/BZ(10) provides a BTX yield of 54.3wt% and a total 1-ring aromatic yield as high as 63.8wt% (corresponding to 94.4% of the theoretical maximum of 67.6wt%) at 425°C. Therefore, the NiMo-S/BZ(10) catalyst, where the metallic and acidic functions and structural properties of the zeolite are well balanced, show promise as an HYC catalyst for the hydroconversion of PAHs into high-value BTX mixtures.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.019
      Issue No: Vol. 547 (2017)
       
  • Oxidative coupling of methane over Mn-Na2WO4 catalyst supported by
           monolithic SiO2
    • Authors: Cagla Uzunoglu; Aybuke Leba; Ramazan Yildirim
      Pages: 22 - 29
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Cagla Uzunoglu, Aybuke Leba, Ramazan Yildirim
      In this work, oxidative coupling of methane was studied over monolithic Mn/Na2WO4/SiO2 catalysts. The monolithic catalysts were prepared by three different ways as (1) preparation of monolithic silica (monosil) followed by impregnation of Mn and Na2WO4, (2) preparation of monolithic silica with Mn addition during gelation (Mn-monosil) followed by impregnation of Na2WO4 and (3) preparation of monolithic silica as MCM-41 structure (MCM-monosil) followed by impregnation of Mn and Na2WO4. The catalysts were tested in a microflow reactor and the results were compared with those obtained over particulate catalysts. It was found that Mn-monosil performed best and produced C2 yield of 16.2%, which is close to the values obtained over particulate catalyst (19.3%). Mn-monosil was also passed the 10h stability and hysteresis tests successfully. SEM characterization revealed that monolithic catalysts prepared by three different methods had different pore structure; it was also seen from SEM images that Mn-monosil preserved its original form better, and this was also verified by XRD analysis.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.020
      Issue No: Vol. 547 (2017)
       
  • Direct deoxygenation of lignin model compounds into aromatic hydrocarbons
           through hydrogen transfer reaction
    • Authors: Tianye Guo; Qineng Xia; Yi Shao; Xiaohui Liu; Yanqin Wang
      Pages: 30 - 36
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Tianye Guo, Qineng Xia, Yi Shao, Xiaohui Liu, Yanqin Wang
      A new route is reported for the direct deoxygenation of lignin model compounds to aromatic hydrocarbons via the catalytic hydrogen transfer reactions over Ru/Nb2O5-SiO2 catalyst with 2-PrOH as a hydrogen donor. It is found that Ru/Nb2O5-SiO2 catalyst is active for the hydrodeoxygenation of p-cresol with 98.5% conversion and 84.0% yield of toluene at 230°C, owing to the significant promotion effect of NbOx species on CO bond cleavage and the proper transfer hydrogenation activity of Ru. Furthermore, Ru/Nb2O5-SiO2 catalyst also shows excellent performances in the transfer hydrodeoxygenation of various lignin model compounds such as 2-methoxy-4-methyl phenol, benzyl phenyl ether (α-O-4 model compound), 2-(2-methoxyphenyl)oxy-1-phenethanol (β-O-4 model compound) and even the real lignin extracted from birch, into aromatic hydrocarbons with 2-PrOH as the hydrogen donor. The reaction pathway studies of these model compounds demonstrate that the direct deoxygenation (DDO) is the main reaction route over Ru/Nb2O5-SiO2 catalyst in the presence of 2-PrOH. Here, using 2-PrOH as a hydrogen source is found to be more selective to aromatic hydrocarbons than using molecular hydrogen. This work provides a new way for the high selective production of aromatic hydrocarbons from renewable lignin via the catalytic hydrogen transfer reactions.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.07.050
      Issue No: Vol. 547 (2017)
       
  • Characterization of the location of coke deposited on spent HZSM-5 zeolite
           by special temperature-programmed oxidation and isothermal oxidation
           methods
    • Authors: Xiaochao Xian; Chao Ran; Chenglong Nai; Peng Yang; Shuo Zhao; Lichun Dong
      Pages: 37 - 51
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Xiaochao Xian, Chao Ran, Chenglong Nai, Peng Yang, Shuo Zhao, Lichun Dong
      The location of coke deposited on HZSM-5 zeolite catalyst during the supercritical catalytic cracking (400°C, 4.0MPa) of n-dodecane was systematically characterized by special temperature-programmed oxidation (TPO) and isothermal oxidation methods, and a steric hindrance model describing the interactions of the coke deposited on different locations was proposed to support the methods theoretically. Accord to the results, the sharp shoulder peak that appears on the TPO profile at high temperature range (>700°C) with low concentration of oxygen in the oxygen/nitrogen mixed carrier gas (≤2.0 Vol.%) can be ascribed to the characteristic peak representing the oxidation of the coke blocked in micropores, while the appearance of the CO peak during the isothermal oxidation at high temperature (≥550°C) using air as carrier gas provides another method to detect the coke blocked in micropores. Through checking whether the characteristic sharp shoulder peak of the TPO profile appears or not as expected according to the steric hindrance model during the re-oxidation of several samples with different coke content and spatial distribution, which were prepared by partial oxidation of the spent catalyst using TPO and isothermal oxidation methods, the special TPO and isothermal oxidation methods combined with their theoretical support of the steric hindrance model were proved to be self-consistent in the characterization of the location of coke. The location information of coke was further verified by the typical method of nitrogen adsorption-desorption analyses of a series of partially oxidized samples prepared by TPO method.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.023
      Issue No: Vol. 547 (2017)
       
  • Isotopic H/D exchange on graphenes. A combined experimental and
           theoretical study
    • Authors: German Sastre; Amparo Forneli; Valer Almasan; Vasile I. Parvulescu; Hermenegildo Garcia
      Pages: 52 - 59
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): German Sastre, Amparo Forneli, Valer Almasan, Vasile I. Parvulescu, Hermenegildo Garcia
      Adsorption of H2/D2 on graphene (G), graphene oxide (GO), single walled carbon nanotube (SWCNT), N-doped graphene [(N)G], and a sample of active carbon (C) has led to the detection of HD, indicating dissociative chemisorption of hydrogen on the surface of the material. The amount of HD detected follows the order G>SWCNT>GO∼(N)G∼C, G giving about five-fold higher H2/D2 adsorption and HD exchange level than SWCNT and about ten-fold larger values than that of the other samples. Quantum-chemistry calculations modeling a carbon atom vacancy on a G cluster estimates an activation barrier for H2 dissociation of ca. 84kJ/mol for a mechanism involving under coordinated carbon atoms at the defect site.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.018
      Issue No: Vol. 547 (2017)
       
  • Mechanistic evaluation of ferrite AFe2O4 (A=Co, Ni, Cu, and Zn) catalytic
           performance in oxalic acid ozonation
    • Authors: Fengzhen Zhang; Chaohai Wei; Kaiyi Wu; Hongtao Zhou; Yun Hu; Sergei Preis
      Pages: 60 - 68
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Fengzhen Zhang, Chaohai Wei, Kaiyi Wu, Hongtao Zhou, Yun Hu, Sergei Preis
      Spinel ferrites AFe2O4 (A=Co, Ni, Cu, and Zn) synthesized by citrate sol-gel method were tested for their catalytic performance in ozonation of aqueous oxalic acid. The objectives of this work include the evaluation of catalytic activity and ferrites stability in mineralization of oxalic acid together with exploring the activation mechanisms of ferrite catalysts in catalytic ozonation process. The results indicated that CoFe2O4 was the most active in catalyzing oxalic acid mineralization, removing 68.3% of TOC within 120min in the reaction conditions of initial pH 2.3, oxalic acid concentration 5mM, inlet ozone concentration 14±1mgL−1, catalyst dose 1.0gL−1. All catalysts exhibited satisfactory composition stability in a batch experiment, although losing up to 4.67% of the catalyst mass in Fe3+ leaching from ZnFe2O4. H2-Temperature programmed reduction and cyclic voltammetry scan analysis revealed that these spinel ferrites had the potential reducibility and the electron donating ability to ozone molecule, respectively. Additionally, X-ray photoelectron spectroscopy showed that the surface metal ions’ valence state and the surface oxygen species played important roles in catalytic ozonation process. The reaction rate constant of oxalic acid mineralization were well fitted to non-linearly depend on variable metal valence and linearly depend on surface hydroxyl group density. The radical-based mechanistic reaction pathways involving A2+-A3+-A2+ cycle and positively charged surface hydroxyl groups were proposed.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.025
      Issue No: Vol. 547 (2017)
       
  • DFT study reveals geometric and electronic synergisms of palladium-mercury
           alloy catalyst used for hydrogen peroxide formation
    • Authors: Mawan Nugraha; Meng-Che Tsai; John Rick; Wei-Nien Su; Hung-Lung Chou; Bing Joe Hwang
      Pages: 69 - 74
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Mawan Nugraha, Meng-Che Tsai, John Rick, Wei-Nien Su, Hung-Lung Chou, Bing Joe Hwang
      One of the main obstacles confronting the direct synthesis of hydrogen peroxide (H2O2) is how to maintain the unbroken OO bonding of the intermediate species on the catalytic surface. To address this challenge Pd-Hg alloys have been used with initial reports suggesting their performance offers advantages when compared to monometallic Pd and Pd-Au alloys; however, the interactions of O2 with Pd-Hg alloys are not well characterised. In this study, density functional theory (DFT) calculations, employed to investigate O2 adsorption on the Pd and Pd-Hg alloy surfaces, suggested O2 adsorption can occur via either a superoxo or a peroxo pathway and that when Hg is alloyed to Pd there are more surface adsorbed superoxo groups compared to adsorption on a monometallic Pd surface. The Hg in Pd6Hg3/Pd(111) results in an electronic surface structure different to that of Pd(111) and a reduced O2 adsorption energy. The stronger O2 surface interactions, when combined with weaker OO bonding (of the adsorbed O2), which result from the presence of Hg on the Pd-Hg surface leads to synergistic geometric and electronic effects that result in an increased selectivity during of the synthesis of H2O2.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.021
      Issue No: Vol. 547 (2017)
       
  • Hydrogen from pyroligneous acid via modified bimetal Al-SBA-15 catalysts
    • Authors: Xiwei Xu; Yan Sun; Zhiyu Li; Xiaodong Chen; Enchen Jiang
      Pages: 75 - 85
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Xiwei Xu, Yan Sun, Zhiyu Li, Xiaodong Chen, Enchen Jiang
      Hydrogen gas was produced from the catalytic reformation of pyroligneous acid (PA)with modified bimetallic Al-SBA-15 catalysts. Al-SBA-15 catalysts with different aluminum loading contents were prepared through one-step hydrothermal synthesis. Monometallic M-Al-SBA-15 (M=Ni, Fe, Co, and Sn) and bimetallic M/N-Al-SBA-15 (M-N=Ni-Fe, Ni-Sn, and Ni-Co) catalysts were synthesized through impregnation. The catalysts were characterized via N2 adsorption-desorption, scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XRD), and X-ray photoelectron spectroscopy(XPS) analysis and so on. Bimetallic M-N-Al-SBA-15 catalysts exhibited higher catalytic activity and carbon deposition resistance than monometallic M-Al-SBA-15 catalysts. Sn facilitated the combination of Ni with Al into a NiAl2O4 spinel in the carrier. Ni/Sn-Al-SBA-15 bimetallic catalyst showed excellent catalytic activity and carbon deposition resistance. The H2 yield was 30.1mg/g and H2 content remained 40% after 16h under the optimal reaction conditions via the Ni/Sn-Al-SBA-15 catalyst.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.030
      Issue No: Vol. 547 (2017)
       
  • Incorporation of molybdenum into Pd and Pt catalysts supported on
           commercial silica for hydrodeoxygenation reaction of dibenzofuran
    • Authors: D. Ballesteros-Plata; A. Infantes-Molina; M. Rodríguez-Cuadrado; E. Rodríguez-Aguado; P. Braos-García; E. Rodríguez-Castellón
      Pages: 86 - 95
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): D. Ballesteros-Plata, A. Infantes-Molina, M. Rodríguez-Cuadrado, E. Rodríguez-Aguado, P. Braos-García, E. Rodríguez-Castellón
      Molybdenum was incorporated into catalysts based on noble metals (Pt or Pd) and supported on silica in order to evaluate how its presence can modify the catalytic response of monometallic catalysts for hydrodeoxygenation (HDO). To this end, the catalysts were evaluated in the hydrodeoxygenation (HDO) reaction of dibenzofuran (DBF) and characterized by different experimental techniques to understand its structure, texture and acidic properties. Catalytic results showed that the active phase had much influence on the activity and selectivity to different reaction products, although, in all cases, bicyclohexane (BCH) was the main reaction product observed. Molybdenum played a very important role in the case of bimetallic catalysts, mainly in the case of palladium. Molybdenum species improved the selectivity to O-free products related to its capacity to break the CO bond. However, molybdenum activity was nil in the absence of noble metal. Moreover, regardless of the noble metal employed, the reducibility, acidity and dispersion of the molybdenum species changed and this is possibly associated to a synergism effect between noble metal and Mo.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.034
      Issue No: Vol. 547 (2017)
       
  • The effect of calcination atmosphere upon the photocatalytic performance
           of Au-La2O3/TiO2 for hydrogen production from formic acid
    • Authors: Minghui Wu; Meng Zhang; Tao Lv; Minxue Guo; Jianjun Li; Chika A. Okonkwo; Qing Liu; Lishan Jia
      Pages: 96 - 104
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Minghui Wu, Meng Zhang, Tao Lv, Minxue Guo, Jianjun Li, Chika A. Okonkwo, Qing Liu, Lishan Jia
      A simple modified sol-gel method by calcinating titanium dioxide precursor with gold and lanthanum in heat treatment under H2/CO2 atmosphere has been proposed to prepare highly photocatalytic Au-La2O3/TiO2 (ALT) hybrid. Characterization results show that gold nanoparticles with small particle size are embedded in a nearly homogeneous component, which may induce a strong interaction of La and Au co-doping to obtain an appropriately modified bandgap structure and extend the absorption edge to visible light region. The formation of La2O2CO3 on the surface could facilitate to the basicity optimization of the photocatalyst and contribute to the CH bond cleavage in HCOO- to release H2 and CO2 from formic acid (FA). The large surface area and small-sized mesopores structure could provide more active sites for the adsorption of reactant molecules and improve the photocatalytic activity. Benefiting from these positive effects, the ALT photocatalyst calcinating in H2/CO2 demonstrated a great potential in FA photocatalytic decomposition under simulated sunlight irradiation and produced an optimal H2 generation rate of 178.4μmol g c a t − 1 h−1 (14.9mmol g A u − 1 h−1), which was approximately 1.3, 1.9 and 2.6 times higher than the same catalysts calcinating in H2, CO2, and N2, respectively.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.027
      Issue No: Vol. 547 (2017)
       
  • Nanoscale Ziegler catalysts based on bis(acetylacetonate)nickel in the
           arene hydrogenation reactions
    • Authors: Yuliya Yu. Titova; Fedor K. Schmidt
      Pages: 105 - 114
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Yuliya Yu. Titova, Fedor K. Schmidt
      The turnover frequencies of catalytic systems based on Ni(acac)2–AlEt3 or AlEt2(OEt) in the hydrogenation of benzene and its methyl-substituted homologs (toluene, three isomers of xylene, and 1,3,5-trimethylbenzene) have been determined at temperatures of 80–120°C, initial PH2 =15bar, and different ratios of Al/Ni. The size and nature of the nanoparticles forming in the systems based on Ni(acac)2–AlEt3 or AlEt2(OEt) under the benzene hydrogenation condition shave been resolved by high-resolution electron microscopy and X-ray microanalysis. This study included the performance of competitive hydrogenation reactions of benzene with toluene or three xylene isomers. The relative adsorption constants of toluene and three xylene isomers have been determined and the stereochemistry of the hydrogen addition to the arene ring has also been elucidated.
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.029
      Issue No: Vol. 547 (2017)
       
  • Ga and In modified ceria as supports for cobalt-catalyzed Fischer-Tropsch
           synthesis
    • Authors: Muthu Kumaran Gnanamani; Gary Jacobs; Wilson D. Shafer; Michela Martinelli; Donald C. Cronauer; A. Jeremy Kropf; Christopher L. Marshall; Burtron H. Davis
      Pages: 115 - 123
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Muthu Kumaran Gnanamani, Gary Jacobs, Wilson D. Shafer, Michela Martinelli, Donald C. Cronauer, A. Jeremy Kropf, Christopher L. Marshall, Burtron H. Davis
      Ga- and In-modified ceria (Ce0.8Ga0.2O2, Ce0.8In0.2O2) materials were used as supports for cobalt-catalyzed Fischer-Tropsch synthesis (FTS). The addition of Ga to ceria was found to improve CO conversion for cobalt-catalyzed FTS, while the addition of In tended to decrease it. A similar trend was observed with the Ag-promoted cobalt/ceria catalysts. Doping of ceria with Ga or In decreased methane and increased the selectivity to olefins and alcohols for Ag-promoted cobalt/ceria. The sum of the products of olefins and alcohols for various catalysts exhibited a decreasing trend as follows: Ag-Co/Ce-Ga>Ag-Co/Ce-In>Ag-Co/Ce. Results of H2-TPR-XANES showed that adding of Ga or In to ceria increases the fraction of Ce3+ in the surface shell for both unpromoted and Ag-promoted catalysts in the range of temperature typical of catalyst activation. This partially reduced ceria plays an important role in controlling the product selectivity of cobalt-catalyzed FT synthesis.
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      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.08.026
      Issue No: Vol. 547 (2017)
       
  • Gold nanoparticles deposited on surface modified carbon materials as
           reusable catalysts for hydrocarboxylation of cyclohexane
    • Authors: A.P.C. Ribeiro; L.M.D.R.S. Martins; S.A.C. Carabineiro; J.L. Figueiredo; A.J.L. Pombeiro
      Pages: 124 - 131
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): A.P.C. Ribeiro, L.M.D.R.S. Martins, S.A.C. Carabineiro, J.L. Figueiredo, A.J.L. Pombeiro
      Gold nanoparticles were deposited on different carbon materials and used as catalysts for the alkane hydrocarboxylation reaction. Cyclohexane hydrocarboxylation to cyclohexanecarboxylic acid was carried out in the presence of CO and water, peroxodisulfate, in water/acetonitrile medium, at ca. 50°C, with gold nanoparticles deposited by a colloidal method on carbon nanotubes and activated carbon with three different surface chemistries: in their original forms (CNT or AC, respectively), oxidized with HNO3 (-ox) or oxidized with HNO3 and subsequently treated with NaOH (-ox-Na). Au/CNT-ox-Na was the best catalyst, yielding cyclohexanecarboxylic acid up to 88.2% yield, with excellent recyclability (97.5% of the initial activity was maintained after five consecutive catalytic cycles).
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      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.028
      Issue No: Vol. 547 (2017)
       
  • MnOx-CeO2 supported on Cu-SSZ-13: A novel SCR catalyst in a wide
           temperature range
    • Authors: Qingling Liu; Zhenchao Fu; Lei Ma; Hejingying Niu; Caixia Liu; Junhua Li; Ziyin Zhang
      Pages: 146 - 154
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Qingling Liu, Zhenchao Fu, Lei Ma, Hejingying Niu, Caixia Liu, Junhua Li, Ziyin Zhang
      A novel Mn-Ce/Cu-SSZ-13 catalyst was synthesized for the selective catalytic reduction of NO with NH3 (NH3-SCR) over a wide temperature range. The NO x conversions of this catalyst were above 90% from 125°C to 450°C. The catalyst also possessed good H2O and SO2 resistances at 300°C and possessed higher activities than Cu-SSZ-13 at 80°C to175°C and Mn-Ce at above 200°C. TPD and in situ DRIFTS analyses showed that bridging nitrate groups on Cu-SSZ-13 could not participate in the SCR reaction. Moreover, NH3 was easily adsorbed to form NH4NO3, which encased the surface of the catalyst, thereby blocking the pores and deactivating the active sites. However, for Mn-Ce/Cu-SSZ-13, the bridging nitrates were adsorbed onto the surface and then converted to monodentate nitrates, which acted as the active species for the SCR reaction at low temperature. This phenomenon might be the primary reason for the enhanced SCR performance of Mn-Ce/Cu-SSZ-13 compared with Cu-SSZ-13 at low temperature.
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      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.08.024
      Issue No: Vol. 547 (2017)
       
  • Performances of promoted cobalt catalysts supported on mesoporous alumina
           for Fischer-Tropsch synthesis
    • Authors: Vahid Vosoughi; Ajay K. Dalai; Nicolas Abatzoglou; Yongfeng Hu
      Pages: 155 - 163
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Vahid Vosoughi, Ajay K. Dalai, Nicolas Abatzoglou, Yongfeng Hu
      Noble metals (Ru, Re, Pt, Ir) and transition metals (Mn, Y) with their atomic ratio of 0.01 to cobalt were used as promoters on the cobalt catalysts supported on mesoporous alumina. The cobalt loading was 15wt% and all catalysts were tested for Fischer-Tropsch synthesis in a fixed-bed reactor. The process conditions for activity test were: 230 °C and 400 psi, GHSV=900h−1, and H 2 C O = 2.0 . The selectivity test for the promoted and unpromoted catalysts was performed at CO conversion ≈50% by adjusting the syngas flowrate. Addition of promoters increased the cobalt dispersion on mesoporous alumina support. The highest increase in dispersion from 4.7% to 7.6% resulted from addition of Ru. Promoters positively impacted the cobalt dispersion in the decreasing order of: Ru < Re < Pt < Ir < Mn < Y. The reduction temperature for all promoted catalysts were shifted to lower temperature. The maximum decrease in temperature happened with platinum by ΔT ∼−150°C for the 1st reduction temperature and ΔT ∼−270°C for the 2nd reduction temperature. The reducibility of the CoOx species on mesoporous alumina was extensively improved by noble metals addition and modestly enhanced by Mn and Y. Significant increase in CO conversion and C5+ of the promoted catalysts were observed. CO conversion was increased from ∼60% to ∼86, 84, 82, 80% as a result of Ru, Re, Ir, Pt addition. Addition of Ru and Re promoters favored the heavy molecular weight hydrocarbons’ (C5+) selectivity and improved it from 81.7% to 84.2 and 83.1%, respectively.
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      PubDate: 2017-09-08T03:35:11Z
      DOI: 10.1016/j.apcata.2017.08.032
      Issue No: Vol. 547 (2017)
       
  • SAPO-18 and SAPO-34 catalysts for propylene production from the
           oligomerization-cracking of ethylene or 1-butene
    • Authors: Eva Epelde; María Ibáñez; José Valecillos; Andrés T. Aguayo; Ana G. Gayubo; Javier Bilbao; Pedro Castaño
      Pages: 176 - 182
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Eva Epelde, María Ibáñez, José Valecillos, Andrés T. Aguayo, Ana G. Gayubo, Javier Bilbao, Pedro Castaño
      The performance of SAPO-18 and SAPO-34 catalysts has been compared during the conversion of ethylene or 1-butene to propylene. This comparison has been made in terms of activity (conversion), selectivity and stability against coke deposition. The SAPOs were synthesized, agglomerated, calcined, characterized and tested in a fixed-bed reactor at 500°C. The spent catalysts (after 5h on stream) were characterized to assign the location and nature of coke. The results point to the higher activity and stability of SAPO-18 catalyst in the conversions of each reactant (ethylene or 1-butene), which has been explained on the basis of its acidity, pore topology and above all, the faster diffusion of aromatics causing deactivation. Thus, the SAPO-18 catalyst suffers slower coke deposition, while this coke is of lighter nature (more aliphatic and less aromatic). The advantages of SAPO-18 over SAPO-34 catalyst are more relevant for the transformation of 1-butene, where the propylene selectivity and yield increase over time, as secondary reactions are selectively neglected and coke condensation is slowed down.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.08.036
      Issue No: Vol. 547 (2017)
       
  • Hydrogenation of 2-benzylpyridine over alumina-supported Ru catalysts: Use
           of Ru3(CO)12 as a Ru precursor
    • Authors: Tae Wan Kim; Jinho Oh; Young-Woong Suh
      Pages: 183 - 190
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Tae Wan Kim, Jinho Oh, Young-Woong Suh
      Although Ru3(CO)12 becomes a popular precursor for supported Ru catalysts nowadays, the activities of the catalysts prepared by thermolysis of the supported Ru3(CO)12 under different atmospheres have been rarely compared. We herein report the preparation of alumina-supported Ru samples by thermal activation of Ru3(CO)12 in air, H2 or N2, followed by activity test in the hydrogenation of 2-benzylpyridine (BPy). When the supported Ru3(CO)12 was activated in air, RuO2 particles of 12–15nm diameters were produced by complete oxidation of carbonyl groups. In contrast, thermal activation in H2 and N2 induced the formation of highly dispersed Ru0 particles of 1.4–2.3nm diameters. In such activations methane was produced, suggesting that direct hydrogenation of CO coordinated to the Ru surface complex occurred in H2 while the coordinated CO reacted with ruthenium hydride species in N2. In the activity test for BPy hydrogenation, the samples prepared in H2 and N2 showed superior H2 storage efficiencies and higher rate constants compared to those prepared in air (reduced before the reaction). Additionally, the former samples were examined to be relatively stable even though exposed to ambient air for 7 days. Therefore, H2 and N2 gases are recommended for thermal activation of alumina-supported Ru3(CO)12.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.08.038
      Issue No: Vol. 547 (2017)
       
  • Easily recoverable micron-sized silica-walled TS-1 colloidosomes:
           Preparation and application as liquid-phase alkene epoxidation catalysts
    • Authors: Guojun Lv; Fumin Wang; Xubin Zhang
      Pages: 191 - 198
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Guojun Lv, Fumin Wang, Xubin Zhang
      Ultrafine hierarchical TS-1 zeolite (<300nm) generally expresses eminent catalytic activity for liquid-phase alkene epoxidation, but encounters serious separation difficulties. Micron-sized silica-walled TS-1 colloidosomes, which were synthesized via an interfacial sol-gel method, can effectively resolve fine TS-1 zeolite separation problems. The interfacial sol-gel process involves construction of a stable W/O Pickering emulsion stabilized by fine TS-1 particles and alkali-catalyzed hydrolysis of silica precursor methyl-trimethoxysilane at the oil-water interface. The successful preparation of TS-1 colloidosome was verified by Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). The prepared TS-1 colloidosome dimension is tailorable according to water-to-oil volume ratio (Rw/o) and ratio of TS-1 wt to oil volume (Rs/o). On the same time, X-ray diffraction patterns and UV–vis spectra disclosed that the interfacial sol-gel process had no effect on the MFI structure of hierarchical TS-1 particles. The catalytic results showed that the prepared TS-1 colloidosome was a very active and stable catalyst for liquid-phase alkene epoxidation reactions.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.001
      Issue No: Vol. 547 (2017)
       
  • Characterization and catalytic activity of CuO/TiO2-ZrO2 for low
           temperature CO oxidation
    • Authors: Masashi Kikugawa; Kiyoshi Yamazaki; Hirofumi Shinjoh
      Pages: 199 - 204
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Masashi Kikugawa, Kiyoshi Yamazaki, Hirofumi Shinjoh
      In this study, catalysts with different loadings of CuO supported on TZ20 (TiO2:ZrO2 =80:20) composite oxides were prepared by the co-precipitation method and characterized by XRD, TEM, and H2-TPR measurements, and N2O decomposition experiments were conducted to determine the number of Cu sites. In addition, the relationship between the CuO states and CO oxidation activities of CuO/TZ20 was revealed. In our previous study, the CO oxidation activities of the CuO catalysts were as high as those observed for precious metal catalysts after simulated diesel exhaust aging tests. The TZ20 surface is covered with three types of Cu species. These species change with increasing CuO loading, going from isolated Cu2+, CuO layer, and finally to CuO particles at high CuO loadings. The CuO layer was the most readily reduced, as well as the most active site for CO oxidation. The amount of Cu forming CuO layers increased with increasing CuO loading; however, at CuO loadings larger than 5wt%, the amount of Cu forming CuO layers and the CO oxidation activity both remained constant. Additionally we indicated that adjusting the calcination condition caused the redispersion of CuO particles to the CuO layer and had the potential to improve the CO oxidation activities of CuO/TZ20.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.005
      Issue No: Vol. 547 (2017)
       
  • Surfactant-assisted formation of silver titanates as active catalysts for
           methanol electro-oxidation
    • Authors: Mohamed Mokhtar Mohamed; M. Khairy; Salah Eid
      Pages: 205 - 213
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Mohamed Mokhtar Mohamed, M. Khairy, Salah Eid
      Silver nanoparticles successfully incorporated in titanate nanosheets and synthesized hydrothermally via employing cetyltrimethylammonium bromide (CTAB) and triblock copolymer (pluronic F127) assisted templates were thoroughly characterized using transmission electron microscopy-selected area electron diffraction (TEM-SAED), X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, N2 sorptiometry, FTIR and Raman spectroscopy. The dispersed Ag nanoparticles of uniform size (2–3nm) were found to contact intimately with titanateF127 nanosheets to show superior crystallinity, wider layer distances and higher surface area and pore volume (SBET =51.1m2 g−1,Vp =0.081cm3g−1) than Ag/titanateCTAB (7.2m2 g−1, 0.02cm3 g−1). This constructed Ag/titanateF127 exhibits markedly improved electrocatalytic (1.4-fold) and photoelectrocatalytic (4.0-fold) activities and stabilities towards methanol oxidation than that of Ag/titanateCTAB; as determined using cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The enhanced activity of Ag/titanateF127 was also attributed to electron transfer across the interface potential of the composite Ag-titanateF127 as well as the delay of charge recombination that has been substantiated not only via exposed Ag but also through the non-decomposed carbon template. This enhanced electron transfer and electronic conductivity was established by impedance spectroscopy, and exhibits the maximum obtained photocurrent density (2.0mAcm−2) under visible light illumination (λ>420nm, 88W). The results revealed that the template F127 had a significant effect not only on enhancing the titanate crystallinity and exhibiting a surface plasmon resonance band; unlike Ag/titanateCTAB, but also in acquiring a high pore volume value and widened layers, which all work towards improving the Ag-titanateF127 durability for methanol oxidation.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.08.031
      Issue No: Vol. 547 (2017)
       
  • Elecreoreduction of CO2 to formic acid on Cu: Role of water bilayer in
           modeling electrochemical interface
    • Authors: Shan Ping Liu; Ming Zhao; Yong Fu Zhu; Wang Gao; Qing Jiang
      Pages: 214 - 218
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Shan Ping Liu, Ming Zhao, Yong Fu Zhu, Wang Gao, Qing Jiang
      Solid–liquid interface, which is the location that electrochemical reaction occurs, is essential for CO2 reduction. However, different theoretical calculations often use different models of solid–liquid interface and predict conflicting mechanisms, e.g. for the formation of HCOOH. To address this issue, we adopt different structures of solid–liquid interface to mimic the reaction circumstance using density functional theory calculations. We find that the reaction barriers and energies are sensitive to the reaction circumstance, such as the state of water molecules, the number of water molecules, and the available surface sites, whereas the selectivity of CO2 reduction can be hardly changed once a water bilayer network on Cu surface is used. In particular, a solid–liquid interface built from 4-6-4 water rings (5H2O/1H) can present an appropriate description of the solvent, predicting the formation pathways of HCOOH in reasonable agreement with the experiments. These results confirm the role of water bilayer networks in describing solid–liquid interface in the electrocatalysis, which serves as an important basis for the future studies.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.002
      Issue No: Vol. 547 (2017)
       
  • Structure–activity relationships of Fe-Co/K-Al2O3 catalysts calcined at
           different temperatures for CO2 hydrogenation to light olefins
    • Authors: Thanapa Numpilai; Thongthai Witoon; Narong Chanlek; Wanwisa Limphirat; Giuseppe Bonura; Metta Chareonpanich; Jumras Limtrakul
      Pages: 219 - 229
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Thanapa Numpilai, Thongthai Witoon, Narong Chanlek, Wanwisa Limphirat, Giuseppe Bonura, Metta Chareonpanich, Jumras Limtrakul
      Fe-Co/K-Al2O3 catalyst has been reported to be active and selective for olefin production from CO2 hydrogenation. However, the effect of calcination temperature on the physicochemical properties of Fe-Co/K-Al2O3 catalysts as well as their catalytic activity in CO2 hydrogenation to olefins has not yet been addressed. Here, we show that the calcination temperature (400–800°C) has significant impacts on metal oxides crystallite size, on the interaction between Fe2O3 and other metal oxides and on the transformation of potassium phases, which affect CO2 conversion, product selectivity as well as yield of olefins. The Fe-Co/K-Al2O3 catalyst calcined at 400°C achieves the highest CO2 conversion, hydrocarbons selectivity and olefins yield of 49.0%, 90.6% and 18.1%, respectively. The CO2 conversion and hydrocarbons selectivity decrease with ascending calcination temperature which is ascribed to the increase of metal oxides crystallite size, inducing stronger interactions between Fe2O3 and other metal oxides. Unlike the CO2 conversion and hydrocarbons selectivity, the olefins to paraffins (O/P) ratio followed a volcano-shaped trend as the function of calcination temperature with a maximum at 7.6 over the Fe-Co/K-Al2O3 catalyst calcined at 700°C. This volcanic trend is attributed to the interplay among the positive effect of high calcination temperature on the complete decomposition of KNO3 to K2O, a stronger interaction between Fe2O3 and K2O and the formation of KAlO2 phase, favorably suppressing the hydrogenation of olefins, and the negative effect of high calcination temperature on the increase of the particle size of the active phase and lower dispersion of mixed metal oxides due to a drastic decrease in BET surface area.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.006
      Issue No: Vol. 547 (2017)
       
  • Basic anion-exchange resin (AER)-supported Au-Pd alloy nanoparticles for
           the oxidation of 5-hydroxymethyl-2-furfural (HMF) into 2,5-furan
           dicarboxylic acid (FDCA)
    • Authors: Churchil A. Antonyraj; Nhan Thanh Thien Huynh; Seok-Kyu Park; Seunghan Shin; Yong Jin Kim; Sangyong Kim; Kwan-Young Lee; Jin Ku Cho
      Pages: 230 - 236
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Churchil A. Antonyraj, Nhan Thanh Thien Huynh, Seok-Kyu Park, Seunghan Shin, Yong Jin Kim, Sangyong Kim, Kwan-Young Lee, Jin Ku Cho
      Au-Pd alloy nanoparticles supported on basic anion-exchange resin (AER) have exceptional catalytic activity for the oxidation of 5-hydroxymethyl-2-furfural (HMF) into 2,5-furan dicarboxylic acid (FDCA) with an equimolar amount of base. SEM-EDX and TEM analyses show that 5–20nm Au-Pd alloy nanoparticles are well dispersed both on the resin surface and inside resin spheres by a simple procedure without any assistance of additives. XPS analysis reveals that Au- and Pd metals exist in an alloy form on the AER support, which is confirmed by a comparison study with a mixture of AER-supported monometallic nanoparticles (AER-supported Au and AER-supported Pd). In the presence of a 1:1 ratio of Au-Pd alloy nanoparticles over Amberlite IRA-743 resin with O2 (10bar) at 373K in an equimolar Na2CO3 aqueous solution, HMF is oxidized to FDCA with a 93.2% yield. On the other hand, mixture of AER-supported Au and AER-supported Pd affords only a 52% FDCA yield under identical conditions. This catalyst can be used 6 times without any significant loss of activity. FDCA is also obtained from HMF with an 82.9% yield in air (40bar).
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.012
      Issue No: Vol. 547 (2017)
       
  • High efficient conversion of furfural to 2-methylfuran over Ni-Cu/Al2O3
           catalyst with formic acid as a hydrogen donor
    • Authors: Zhaolin Fu; Ze Wang; Weigang Lin; Wenli Song; Songgeng Li
      Pages: 248 - 255
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Zhaolin Fu, Ze Wang, Weigang Lin, Wenli Song, Songgeng Li
      Conversion of furfural to 2-methylfuran over Cu/Al2O3, Ni/Al2O3 and Ni-Cu/Al2O3 catalysts were investigated with formic acid as a hydrogen donor. Ni/Al2O3 showed a high catalytic activity but a moderate selectivity to 2-methylfuran. Contrarily, Cu/Al2O3 showed a low catalytic activity but a high selectivity for carbonyl reduction. Over the bimetallic catalysts Ni-10%Cu/Al2O3, by increasing Ni content, more furfural was converted with the reduction of carbonyl primarily. The effect of reaction solvent and the fraction of formic acid were also studied. The result showed that isopropanol solvent could contribute to the formation of furfuryl alcohol with 96% selectivity through the transfer hydrogenation process. Formic acid could decompose to H2 and CO2, remarkably promoting the hydrogenolysis of furfuryl alcohol to 2-methylfuran. Finally, 100% conversion and 92mol% yield of 2-methylfuran could be obtained over 10%Ni-10%Cu/Al2O3. It was attributed to the synergic effect of Ni-Cu metals, with increased affinity for carbonyl reduction.
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      PubDate: 2017-09-20T08:07:00Z
      DOI: 10.1016/j.apcata.2017.09.011
      Issue No: Vol. 547 (2017)
       
  • Conversion of guaiacol over different Re active phases supported on
           CeO2-Al2O3
    • Authors: C. Alvarez; K. Cruces; R. Garcia; C. Sepulveda; J.L.G. Fierro; I.T. Ghampson; N. Escalona
      Pages: 256 - 264
      Abstract: Publication date: Available online 8 September 2017
      Source:Applied Catalysis A: General
      Author(s): C. Alvarez, K. Cruces, R. Garcia, C. Sepulveda, J.L.G. Fierro, I.T. Ghampson, N. Escalona
      The effect of Al2O3 modification by CeO2 addition (14wt.% to obtain a maximum monolayer coverage) on the catalytic activity of three supported Re active phases (Re, ReOx and ReSx) for guaiacol conversion was studied. A 10wt.% loading of Re was impregnated into CeO2-Al2O3 support and used to prepare the three rhenium active phases by calcination, reduction or sulfidation steps. The catalysts were characterized by different techniques in order to explain the catalytic behavior of the solids studied. The catalysts were then evaluated in a batch reactor at 300°C and 5MPa of H2. The characterization results showed that the addition of CeO2 modified the acidity of the support as well as the metal-support interaction, and consequently the catalytic activity. In fact, CeO2 addition doubled the activity of Re and ReSx catalysts in comparison to the corresponding γ-Al2O3-supported catalysts. These results were attributed to a higher dispersion of active sites in the case of metallic Re catalyst and higher concentration of non-stoichiometric sulfur species (ReS2-x) in the case of ReSx catalyst. On the other hand, a similar catalytic activity was observed over the two supported ReOx catalysts, indicating that the role of ReOx active phase on guaiacol conversion outweighs structural and surface modification induced by CeO2 addition. In relation to products distribution, it was observed that CeO2 addition enhanced phenol formation and generally led to higher degree of deoxygenation which is most likely related to decrease in acidity.
      Graphical abstract image

      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.010
      Issue No: Vol. 547 (2017)
       
  • Dialkylpyrazolium ionic liquids as novel catalyst for efficient fixation
           of CO2 with metal- and solvent-free
    • Authors: Yuan Ma; Ci Chen; Tengfei Wang; Jingshun Zhang; JiaJia Wu; Xiangdong Liu; Tiegang Ren; Li Wang; Jinglai Zhang
      Pages: 265 - 273
      Abstract: Publication date: Available online 8 September 2017
      Source:Applied Catalysis A: General
      Author(s): Yuan Ma, Ci Chen, Tengfei Wang, Jingshun Zhang, JiaJia Wu, Xiangdong Liu, Tiegang Ren, Li Wang, Jinglai Zhang
      The efficient fixation of CO2 without co-catalyst and solvent under metal-free condition is still an urgent topic in sustainable chemistry. In this work, a series of dialkylpyrazolium ionic liquids are employed to promote the cycloaddition of CO2 and PO to produce PC. They would be easily synthesized by a simple one-pot reaction. The effect of alkyl chain length in cation and different anion is explored. Diethylpyrazolium iodide presents the excellent catalytic activity with the product yield of 96% and selectivity of 99% in a benign condition. Moreover, the catalyst could be reused for at least five times without significant loss of catalytic activity. An intensive structure-activity research testifies that the cycloaddition of CO2 with PO is activated by a synergistic effect from both cation and anion of ILs. To confirm it, the detailed mechanism is investigated by density functional theory associated with the non-covalent interactions and atoms in molecule analysis. Besides the electrostatic interaction between cation of ionic liquid and PO, the noncovalent interaction, especially for hydrogen bond, plays a vital role in promoting the reaction.
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      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.009
      Issue No: Vol. 547 (2017)
       
  • Catalytic fast pyrolysis of cellulose in a microreactor system using
           hierarchical zsm-5 zeolites treated with various alkalis
    • Authors: Kai Qiao; Xu Shi; Feng Zhou; Hao Chen; Jie Fu; Huixia Ma; He Huang
      Pages: 274 - 282
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Kai Qiao, Xu Shi, Feng Zhou, Hao Chen, Jie Fu, Huixia Ma, He Huang
      Hierarchical ZSM-5 catalysts were prepared by desilication using NaOH, Na2CO3 and TPAOH with different concentrations under the same treatment conditions. Their structures and acidities were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption and desorption (N2-BET) and ammonia temperature-programmed desorption (NH3-TPD). The catalytic fast pyrolysis (CFP) of cellulose to produce aromatics over the hierarchical ZSM-5 catalysts prepared using different alkali treatments was investigated. The alkali treatment by Na2CO3 (0.4∼0.8M) was much milder than treatment by NaOH, which allowed the desilication process to be highly controllable, resulting in an increase of both the amount and strength of the strong acid sites, and the formation of hierarchical structures combining micro- and mesoporosity. The organic hydroxide TPAOH did not change the pore structure of ZSM-5, but it greatly increased the relative crystallinity. The CFP of cellulose with HZSM-5 produced 35.5% liquid aromatic hydrocarbons and 32.7% coke. The yield of aromatics increased after Na2CO3 treatment but decreased after NaOH treatment. In addition, the yield of coke showed the opposite trend. The highest aromatic yield (38.2%) and lowest coke yield were obtained in the CFP of cellulose with the desilicated zeolite treated with 0.6M Na2CO3. The increased acidity in hierarchical ZSM-5 treated with Na2CO3 increased the selectivity of highly valuable aromatics, such as benzene, toluene, and xylene, and decreased the selectivity of large aromatics. TPAOH-treated HZSM-5 showed a slightly increased yield of aromatics due to the repair effect of TPAOH, but this treatment did not form a mesoporous structure.
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      PubDate: 2017-09-20T08:07:00Z
      DOI: 10.1016/j.apcata.2017.07.034
      Issue No: Vol. 547 (2017)
       
  • Corrigendum to Improving the selectivity in hydrocracking of phenanthrene
           over mesoporous Al-SBA-15 based Fe-W catalysts by enhancing mesoporosity
           and acidity [ Applied Catalysis A: General 510 (2016) 98–109]
    • Authors: Jonatan R. Restrepo-Garcia; Víctor G. Baldovino-Medrano; Sonia A. Giraldo
      Pages: 283 - 284
      Abstract: Publication date: 25 October 2017
      Source:Applied Catalysis A: General, Volume 547
      Author(s): Jonatan R. Restrepo-Garcia, Víctor G. Baldovino-Medrano, Sonia A. Giraldo


      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.020
      Issue No: Vol. 547 (2017)
       
  • An attempt to improve Ag-based catalysts for allyl alcohol oxidative
           dehydrogenation to acrolein
    • Authors: T.T.N. Nguyen; Huchede Blanco Morfin J.L. Rousset Massin Aouine J.M.M.
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): T.T.N. Nguyen, M. Huchede, E. Blanco, F. Morfin, J.L. Rousset, L. Massin, M. Aouine, V. Bellière-Baca, J.M.M. Millet
      The oxidative dehydrogenation of allyl alcohol to acrolein over bulk alloyed and supported silver catalysts has been studied, with the aim of designing optimal Ag-based catalysts for this specific reaction. All of the tested catalysts were highly active and selective to acrolein at temperatures ranging between 340 and 380°C. The results show that the alloying of Ag with Au or Cu leads to alloys with upper surface compositions comprising approximately between 35 and 65% silver. Although these elements improve the activity of Ag catalysts, they decrease their selectivity, leading to lower acrolein yields. Various different Ag catalyst supports were prepared (LaPO4, Carbon nanotubes CNT, TiO2, Al2O3 and SiO2) using the impregnation method, and subsequently tested. This study reveals that the catalyst with the best performance is Ag/SiO2 with a yield in acrolein of 87.2% at 360°C. The results obtained with the tested catalysts are discussed, and the reasons of performance improvement or degradation caused by the presence of Au or Cu on the active silver sites, or by the presence of the supports, are raised.
      Graphical abstract image

      PubDate: 2017-10-11T22:48:35Z
       
  • Effect of γ-alumina nanorods on CO hydrogenation to higher alcohols over
           lithium-promoted CuZn-based catalysts
    • Authors: SuMin Choi; YoungJong Kang SangWoo Kim
      Abstract: Publication date: 5 January 2018
      Source:Applied Catalysis A: General, Volume 549
      Author(s): SuMin Choi, YoungJong Kang, SangWoo Kim
      To achieve high catalytic activities and long-term stability to produce higher alcohols via CO hydrogenation, the catalytic activities were tuned by controlling the loading amounts of γ-alumina nanorods and Al3+ ions added to modify Cu-Zn catalysts promoted with Li. The selectivity of higher alcohols and the CO conversion to higher alcohols over a Li-modified Cu0.45Zn0.45Al0.1 catalyst supported on 10% nanorods were 1.8 and 2.7 times higher than those with a Cu-Zn catalyst without nanorods and Al3+ ions, respectively. The introduction of the thermally and chemically stable γ-Al2O3 nanorod support and of Al3+ to the modified catalysts improves the catalytic activities by decreasing the crystalline size of CuO and increasing the total basicity. Along with the nanorods, a refractory CuAl2O4 formed by the thermal reaction of CuO and Al3+ enhances the long-term stability by increasing the resistance to sintering of the catalyst.
      Graphical abstract image

      PubDate: 2017-10-11T22:48:35Z
       
  • Direct synthesis of long-chain alcohols from syngas over CoMn catalysts
    • Authors: Yanzhang Yang; Tiejun Lin; Xingzhen Qi; Fei Yu; Yunlei An; Zhengjia Li; Yuanyuan Dai; Liangshu Zhong; Hui Wang; Yuhan Sun
      Abstract: Publication date: Available online 2 October 2017
      Source:Applied Catalysis A: General
      Author(s): Yanzhang Yang, Tiejun Lin, Xingzhen Qi, Fei Yu, Yunlei An, Zhengjia Li, Yuanyuan Dai, Liangshu Zhong, Hui Wang, Yuhan Sun
      CoMn model catalysts were prepared by co-precipitation and evaluated for higher alcohol synthesis (HAS) via syngas. The selectivity to oxygenates (mainly alcohols and aldehydes) was found to be higher than 20C% for the Na-promoted CoMn catalyst. Among the oxygenates, C2+ and C6+ fractions accounted for >90wt% and ∼50wt%, respectively. Metallic Co0 particles and MnCO3 were found in both Na-promoted and unpromoted CoMn catalysts after the reaction, whereas Co2C nanoparticles could only be observed in the spent Na-promoted catalyst. The addition of Na benefited the carbonization of cobalt and increased the selectivity to oxygenates and CO2. Our studies thus suggested that Co/Co2C were the bifunctional dual-sites for the oxygenates formation over the Na-promoted CoMn catalyst, where Co catalyzed CO dissociation and chain propagation, while Co2C was responsible for CO non-dissociative activation and subsequent insertion. In addition, the sole Co2C nanoparticles with certain exposed facets may also act as another kind of active dual-sites for oxygenates formation.
      Graphical abstract image

      PubDate: 2017-10-04T07:28:43Z
      DOI: 10.1016/j.apcata.2017.09.037
       
  • Variability of particle configurations achievable by 2-nozzle flame
           syntheses of the Au-Pd-TiO2 system and their catalytic behaviors in the
           selective hydrogenation of acetylene
    • Authors: Boontida Pongthawornsakun; Okorn Mekasuwandumrong; Francisco J.Cadete Santos Aires; Robert Büchel; Alfons Baiker; Sotiris E. Pratsinis; Joongjai Panpranot
      Abstract: Publication date: Available online 12 September 2017
      Source:Applied Catalysis A: General
      Author(s): Boontida Pongthawornsakun, Okorn Mekasuwandumrong, Francisco J.Cadete Santos Aires, Robert Büchel, Alfons Baiker, Sotiris E. Pratsinis, Joongjai Panpranot
      Catalysts with Au and Pd supported on TiO2 (Au:Pd 1:1wt/wt%) were prepared by 1- and 2-nozzle flame spray pyrolysis (FSP). The 2-nozzle configuration allowed to synthesize various particle configurations by separate or co-feeding of the metal precursor solutions to the two nozzles. For the Au-Pd/TiO2 system, four different catalyst particle configurations were investigated: “TiO2 +AuPd”, “Pd/TiO2 +Au”, “Au/TiO2 +Pd”, and “Pd/TiO2 +Au/TiO2”, where+separates the corresponding precursor solutions fed to the two nozzles. There were no significant differences in the specific surface areas and the average TiO2 crystallite sizes of the catalysts (100m2/g and 16–17nm, respectively) with the exception of “Pd/TiO2 +Au/TiO2”, which exhibited larger surface area and smaller crystallite size (152m2/g, 12nm) due to halving of the Ti precursor concentration in each nozzle. As revealed by CO chemisorption, XPS, and STEM-EDX results, the catalyst properties varied largely in terms of bimetallic AuPd particle compositions, the interaction between metal–metal and metal-support, and the location of Pd (or AuPd) on the TiO2. Among the catalysts studied, “TiO2 +AuPd” prepared with the 2-nozzle system exhibited the highest conversion of acetylene (∼50%) at 40°C with high selectivity to ethylene (>95%). Co-feeding the noble metal precursors together with the Ti precursor afforded less active catalysts due to the formation of Ti-O species partially covering the most active bimetallic AuPd particles. Compared to the commercially available acetylene hydrogenation catalyst and the AuPd/TiO2 prepared by conventional co-impregnation and deposition-precipitation, all the FSP-AuPd/TiO2 catalysts showed superior performances under the reaction conditions used.
      Graphical abstract image

      PubDate: 2017-09-14T09:21:19Z
      DOI: 10.1016/j.apcata.2017.09.014
       
  • Heteropoly acid supported on silicalite−1 possesing intracrystalline
           nanovoids prepared using biomass − an efficient and recyclable catalyst
           for esterification of levulinic acid
    • Authors: K. Manikandan; K.K. Cheralathan
      Abstract: Publication date: Available online 6 September 2017
      Source:Applied Catalysis A: General
      Author(s): K. Manikandan, K.K. Cheralathan
      Graphical abstract image

      PubDate: 2017-09-08T03:35:11Z
      DOI: 10.1016/j.apcata.2017.09.007
       
  • 5-Hydroxymethylfurfural Catalytic Oxidation Under Mild Conditions by Co
           (II), Fe (III) And Cu (II) Salen Complexes Supported on SBA-15: Synthesis,
           Characterization and Activity
    • Authors: Daniela Xulú Martínez-Vargas; Javier Rivera De La Rosa; Ladislao Sandoval-Rangel; Jorge Luis Guzmán-Mar; Marco A. Garza-Navarro; Carlos J. Lucio-Ortiz; David A. De Haro-Del Río
      Abstract: Publication date: Available online 1 September 2017
      Source:Applied Catalysis A: General
      Author(s): Daniela Xulú Martínez-Vargas, Javier Rivera De La Rosa, Ladislao Sandoval-Rangel, Jorge Luis Guzmán-Mar, Marco A. Garza-Navarro, Carlos J. Lucio-Ortiz, David A. De Haro-Del Río
      In the present work, an alternative system of 5-hydroxymethylfurfural (HMF) oxidation was studied, in an effort to avoid the use of expensive precious metal catalysts, high pressures and systems not environmentally friendly. The catalysts tested were Co (II), Fe (II) and Cu (II) Salen complexes supported on SBA-15 (Co Salen/SBA-15, Fe Salen/SBA-15 and Cu Salen/SBA-15 respectively). The reaction was carried out in aqueous medium at room temperature (25°C ±1) and atmospheric pressure, using hydrogen peroxide (H2O2) as the only oxidant agent. The effect of various reaction conditions such as H2O2 content, oxidant agent amount, different transition metals present in the catalyst and temperature were evaluated. The HMF and the reaction products such as; 2,5-diformylfuran (DFF), 2,5-furandicarboxylic acid (FDCA), 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) and 5-formyl-2-furancarboxylic acid (FFCA) were followed by high performance liquid chromatography (HPLC) measurements. The selectivity and reaction kinetics under different reaction conditions was studied. The different synthesized catalysts were extensively characterized by UV-vis spectroscopy, subsequently by FTIR, DR-UV-vis, AA and XPS spectroscopy and through nitrogen physorption, which was related to its catalytic activity. The successful synthesis of SBA-15 support was confirmed by its textural properties and STEM. From the experimental data obtained a reaction mechanism with parallel reactions was proposed founding that the oxidation route of the alcohol group in HMF is favored over of the oxidation of the aldehyde group on the other side of the molecule.
      Graphical abstract image

      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.035
       
  • Application of Magnetic Resonance Imaging and Raman Imaging to study the
           impact of phosphorus in impregnation of hydrotreatment catalysts
    • Authors: L. Catita; A.-A. Quoineaud; D. Espinat; C. Pichon; O. Delpoux
      Abstract: Publication date: Available online 30 August 2017
      Source:Applied Catalysis A: General
      Author(s): L. Catita, A.-A. Quoineaud, D. Espinat, C. Pichon, O. Delpoux
      Magnetic Resonance Imaging is applied, for the first time, to monitor in-situ the impregnation step of hydrotreatment catalysts with an aqueous solution composed simultaneously of molybdenum, cobalt and phosphorus. This technique provides information about spatial distribution of all metal precursors inside the catalyst pellet with a significantly improved spatial resolution of 39μm×39μm compared to the literature. Streamline Raman Imaging yields complementary information about molybdenum speciation at equilibrium. For a molybdenum based catalyst, a slow transport of molybdenum complexes through γ-alumina is observed by Magnetic Resonance Imaging, which suggests a strong interaction between metal precursor and the support. Presence of polymeric molybdenum ions is found near the edges as well as the formation of an Anderson-type heteropolyanion. In the presence of phosphorus, interaction between molybdenum and γ-alumina is weaken since a preferential adsorption to phopshorus is observed. This phenomenon results in an increase in the transport rate of molybdenum complexes. When phosphorus is added to a molybdenum based catalysts promoted by cobalt, preferential interactions between metal promotor and the support are observed rather than with molybdenum species. This innovative Magnetic Resonance Imaging −Streamline Raman Imaging methodology allows a better control of the deposition process during impregnation and to identify the descriptors that most influence this preparation step. Finally, this methodology can be applied to other type of supported catalysts.
      Graphical abstract image

      PubDate: 2017-09-02T10:48:31Z
      DOI: 10.1016/j.apcata.2017.08.039
       
 
 
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