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  Subjects -> ENGINEERING (Total: 2277 journals)
    - CHEMICAL ENGINEERING (191 journals)
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    - ELECTRICAL ENGINEERING (103 journals)
    - ENGINEERING (1204 journals)
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ENGINEERING (1204 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: 19)
AAPG Bulletin     Hybrid Journal   (Followers: 6)
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: 230)
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: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
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: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 12)
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: 7)
Applied Network Science     Open Access  
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)
Arid Zone Journal of Engineering, Technology and Environment     Open Access   (Followers: 2)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
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: 9)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 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: 8)
Biomedical Science and Engineering     Open Access   (Followers: 3)
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  
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: 41)
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: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 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: 3)
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: 254)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 179)
Composites Part B : Engineering     Hybrid Journal   (Followers: 230)
Composites Science and Technology     Hybrid Journal   (Followers: 171)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 14)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 28)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 10)
Computing and Visualization in Science     Hybrid Journal   (Followers: 5)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 30)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 42)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  

        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]
  • Study of coke deposited on a VOx-K2O/γ-Al2O3 catalyst in the
           non-oxidative dehydrogenation of isobutane
    • Authors: Yu-Peng Tian; Xin-Mei Liu; Mark J. Rood; Zi-Feng Yan
      Pages: 1 - 9
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Yu-Peng Tian, Xin-Mei Liu, Mark J. Rood, Zi-Feng Yan
      Coke deposition is commonly identified as the main cause of deactivation for dehydrogenation (DH) catalysts. The VOx-K2O/γ-Al2O3 catalysts for non-oxidative DH of isobutane were studied to better understand the formation and nature of coke. Coke deposition influenced VOx species and acid sites, leading to a deterioration of DH performances. The coke was identified as aliphatic and polyaromatic species. As the DH reaction proceeding, the deposited carbonaceous species progressively transformed from aliphatic into aromatic species, with aromaticity increasing. They continuously shift between metallic VOx species and acid sites. Of note is that the aromatic species eventually condense onto the support resulting in polyaromatic and graphitic carbon mixtures. A possible coke generation process was proposed, which contained consecutive reactions such as cracking, oligomerization, and aromatization. The establishment of the coke formation mechanisms and study of the nature of the deposited coke provide guidance for future DH catalyst optimization while reducing coke formation.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.022
      Issue No: Vol. 545 (2017)
       
  • Dehydration of 1-octanol to di-n-octyl ether in liquid phase with
           simultaneous water removal over ion exchange resins: Effect of
           working-state morphologies
    • Authors: Roger Bringué; Carles Fité; Montserrat Iborra; Javier Tejero; Fidel Cunill
      Pages: 10 - 16
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Roger Bringué, Carles Fité, Montserrat Iborra, Javier Tejero, Fidel Cunill
      The influence of the concentration of polar reactants and products on the working-state morphology of ion exchange catalysts has been investigated over different acidic ion-exchange resins for di-n-octyl ether (DNOE) synthesis from 1-octanol dehydration at 423–448K and atmospheric pressure in a batch reactor equipped with a Dean & Stark device. By removing water formed 1-octanol conversion was practically complete; the olefin formation being the main secondary reaction. When 1-octanol is completely consumed the working-state morphology of ion exchange resins changes, which influences the selectivities towards products. At this point, for microporous resins all reactions stop while with macroreticular ones DNOE decomposes and significant amounts of olefin dimers appears. The best selectivity to DNOE was found in gel-type and macroreticular resins with low crosslinking degree. Macroreticular resins with medium or high crosslinking give good results in olefin formation.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.029
      Issue No: Vol. 545 (2017)
       
  • Oxidative coupling of methane (OCM): Effect of noble metal (M=Pt, Ir, Rh)
           doping on the performance of mesoporous silica MCF-17 supported
           MnxOy-Na2WO4 catalysts
    • Authors: Wen-Chi Liu; Walter T. Ralston; Gérôme Melaet; Gabor A. Somorjai
      Pages: 17 - 23
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Wen-Chi Liu, Walter T. Ralston, Gérôme Melaet, Gabor A. Somorjai
      Noble metal doped M-MnxOy-Na2WO4/SiO2 (M=Pt, Ir, Rh) catalysts were prepared via a wet impregnation method using mesoporous silica MCF-17 as support, and their performance in the oxidative coupling of methane (OCM) was studied in a fixed-bed flow reactor. The reaction was carried out at 750°C under atmospheric pressure with a gas feed composition of CH4:O2 =4:1. The incorporation of the noble metals yielded an enhanced selectivity towards both C2 and C3 hydrocarbons as compared to the undoped MnxOy-Na2WO4/MCF-17 catalyst in the order of Rh-doped > Ir-doped > Pt-doped samples together with a lower olefin to paraffin ratio. On the other hand, the Ir-doped catalyst showed the highest overall yield for C2 production. Elemental analysis, N2-adsorption, and X-ray powder diffraction (XRD) measurements confirmed similar metal loading, surface area, and phase composition for both the undoped and doped catalysts. Electron microscopy analysis showed a near-homogeneous distribution of Na and W but a higher tendency to form aggregates for Mn, with the Rh-doped catalyst being the best in overall elemental dispersion. X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (H2-TPR) results indicate a more reduced nature of the surface oxide species in the noble metal doped catalysts as compared to the undoped one. They also suggest a more optimized strength of interaction between the carbon intermediates and the surface of the noble metal doped catalysts, which in combination with the improved reducibility of Mn and W species and metal dispersion, accounted for the enhanced C2 production on the noble metal doped MnxOy-Na2WO4/MCF-17 catalysts.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.017
      Issue No: Vol. 545 (2017)
       
  • Methane production by sequential supercritical gasification of aqueous
           organic compounds and selective CO2 methanation
    • Authors: F. Frusteri; L. Frusteri; F. Costa; A. Mezzapica; C. Cannilla; G. Bonura
      Pages: 24 - 32
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): F. Frusteri, L. Frusteri, F. Costa, A. Mezzapica, C. Cannilla, G. Bonura
      In this paper, a catalytic process based on supercritical gasification of aqueous organic solutions coupled with a CO2 methanation reactor is proposed. Different catalytic systems have been investigated with the aim to obtain an outlet gaseous stream rich in methane. The stream at exit of supercritical reactor, mainly containing CH4/CO2/H2, was used to feed a fixed bed reactor containing a catalyst to promote the selective hydrogenation of CO2 to methane. The results obtained under supercritical conditions clearly demonstrate that, with an appropriate catalyst, the gasification of diluted organic solutions allows to obtain an outlet stream containing about 50% CH4/40% CO2/10% H2. By feeding a fixed bed reactor, loaded with an efficient methanation catalyst, it has been seen that, even in presence of high methane contents, the CO2 is converted into methane obtaining, at the exit of the methanator, a stream containing a mixture close to the following composition, 60% CH4/38% CO2/2% H2, suitable to be used as a fuel to feed energy generator systems.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.030
      Issue No: Vol. 545 (2017)
       
  • Oxidative esterification of furfural by Au nanoparticles supported CMK-3
           mesoporous catalysts
    • Authors: Ramakrishnan Radhakrishnan; Sivakumar Thiripuranthagan; Arulselvan Devarajan; Sakthivel Kumaravel; Elangovan Erusappan; Kathiravan Kannan
      Pages: 33 - 43
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Ramakrishnan Radhakrishnan, Sivakumar Thiripuranthagan, Arulselvan Devarajan, Sakthivel Kumaravel, Elangovan Erusappan, Kathiravan Kannan
      Furfural which is derived from the hemicellulose fraction of abundant lignocellulose has received significant attention to many researchers as its valorization yields useful products such as fine chemicals and transportation fuels. Methyl 2-furoate is one of the important valorized products of furfural as it finds applications in flavor and fragrance industries. Methyl 2-furoate is generally obtained by oxidation followed by esterification of furfural but under acidic and corrosive conditions. Uniform rods of CMK-3 mesoporous materials were successfully synthesized by using nanocasting method. Au nano particles were impregnated into the pores of CMK-3 by wet impregnation method followed by hydrogen reduction at high temperature (673K). All the catalysts were thoroughly characterized by various analytical techniques. Homogeneous dispersion of Au nano particles ≈3nm size was found over CMK-3 materials. Qualitative and quantitative analyses of Au were made by XPS and ICP techniques. The effect of impregnating metal ions (Ni, Pt and Pd) and supports (SBA-15, graphite, graphene, MWCNT, activated carbon and TiO2) was studied on the catalytic conversion of furfural. Among them, Au/CMK-3 catalyst was found to be the best. Among the Au/CMK-3 catalysts, 5% Au/CMK-3 catalyst showed remarkable conversion of furfural (99.7%) with very high selectivity towards methyl 2-furoate (99.6%). The stability and reusability of the 5% Au/CMK-3 catalyst was found to be very good even after five catalytic cycles.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.031
      Issue No: Vol. 545 (2017)
       
  • Highly efficient CCl bond cleavage and unprecedented CC bond cleavage of
           environmentally toxic DDT through molecular electrochemical catalysis
    • Authors: Xu Liang; Tingting Huang; Minzhi Li; John Mack; Martijn Wildervanck; Tebello Nyokong; Weihua Zhu
      Pages: 44 - 53
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Xu Liang, Tingting Huang, Minzhi Li, John Mack, Martijn Wildervanck, Tebello Nyokong, Weihua Zhu
      The electrocatalytic properties of a Co(II)octaalkoxyphthalocyanine complex (Co(II)Pc) with eight strongly electron-donating substituents provide the first example of the complete dechlorination of DDT through molecular electrocatalysis, rather than the use of metal electrodes which had been achieved previously. Interaction with a highly nucleophilic [Co(I)Pc]2− species results in rapid cleavage of the C(sp 3 ) Cl, C(sp 2 ) Cl and aromatic C(sp 2 ) Cl bonds. Bis(p-chlorophenyl)methanone (BPCl2) is detected in high yield along with its full dechlorination product, diphenylmethanone (BP) and the conventional CCl bond cleavage products, due to an unprecedented CC bond cleavage reaction that is followed by the formation of a C−O bond. Theoretical calculations are used to analyze trends in the electronic structure of the Co(II)octaalkoxyphthalocyanine complex that account for the efficiency of the CCl bond cleavage reactions, and the reaction process and mechanism are analyzed in depth.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.026
      Issue No: Vol. 545 (2017)
       
  • Trace iron impurities deactivate palladium supported on nitrogen-doped
           carbon nanotubes for nitrobenzene hydrogenation
    • Authors: Baoqiang Dong; Yuhang Li; Xiaomei Ning; Hongjuan Wang; Hao Yu; Feng Peng
      Pages: 54 - 63
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Baoqiang Dong, Yuhang Li, Xiaomei Ning, Hongjuan Wang, Hao Yu, Feng Peng
      Nitrogen-doped carbons can effectively stabilize noble metal particles to achieve high catalytic performances. However, the metallic impurities in carbon nanomaterials, e.g. the residual growth catalysts of carbon nanotubes (CNTs), have some unforeseen effects on the catalysis involving nanocarbons. Herein, we demonstrate that the residual growth catalysts of N-doped CNTs (NCNTs) may significantly deactivate Pd catalysts for the hydrogenation of nitrobenzene. Through high-resolution transmission electron microscopy and CO-stripping, it was determined that the N dopants improved the dispersion of Pd nanoparticles. However, the iron, at ppm level, in residual catalysts encapsulated inside NCNTs can transfer onto the surface of Pd to block active sites so that the activity of Pd/NCNTs was much lower than that of Pd/CNTs. The similar effect was observed for most of the common metallic impurities in carbon materials, including Co, Ni, Mn, Cr, Cu, Zn, Mo, Al and Mg. To exploit the N-doped carbons, we deposited N-doped carbon layers on purified CNTs through pyridine pyrolysis and then supported Pd nanoparticles. By this means, the activity of Pd for nitrobenzene hydrogenation was improved by 3.85 folds compared to conventional CNTs, emphasizing the importance of controlling impurities in N-doped carbon materials for high performance catalysts.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.035
      Issue No: Vol. 545 (2017)
       
  • Nb-modified Mn/Ce/Ti catalyst for the selective catalytic reduction of NO
           with NH3 at low temperature
    • Authors: Baohuai Zhao; Rui Ran; Xingguo Guo; Li Cao; Tengfei Xu; Ze Chen; Xiaodong Wu; Zhichun Si; Duan Weng
      Pages: 64 - 71
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Baohuai Zhao, Rui Ran, Xingguo Guo, Li Cao, Tengfei Xu, Ze Chen, Xiaodong Wu, Zhichun Si, Duan Weng
      Mn/Ce/Ti and Mn/Ce/Nb/Ti catalysts were synthesized using a precipitation method and their catalytic activities for NO selective reduction with NH3 at low temperatures were evaluated. Nb doping not only improved the activity of the catalyst over a wide temperature range but also restricted the generation of NO2 and N2O. The Mn/Ce/Nb/Ti catalyst displayed 100% NO conversion from 150 to 250°C and >90% N2 selectivity below 250°C. The specific surface area of the catalyst was increased and its surface acidity was strengthened after Nb doping. Moreover, Nb doping increased the NO oxidation ability and lowered the NH3 oxidation activity of the catalyst. All the above factors contributed to enhancing the overall NH3-SCR performance of the Mn/Ce/Nb/Ti catalyst compared with that of the Mn/Ce/Ti one. The long-term stability and resistance to H2O and SO2 of the Mn/Ce/Nb/Ti catalyst were also evaluated.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.024
      Issue No: Vol. 545 (2017)
       
  • Selective oxidation of benzyl alcohol through eco-friendly processes using
           mesoporous V-MCM-41, Fe-MCM-41 and Co-MCM-41 materials
    • Authors: Analía L. Cánepa; Verónica R. Elías; Virginia M. Vaschetti; Ema V. Sabre; Griselda A. Eimer; Sandra G. Casuscelli
      Pages: 72 - 78
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Analía L. Cánepa, Verónica R. Elías, Virginia M. Vaschetti, Ema V. Sabre, Griselda A. Eimer, Sandra G. Casuscelli
      MCM-41 nanostructured materials modified with Vanadium, Iron and Cobalt were synthesized by a hydrothermal method. The catalysts were characterized by XRD, UV–Vis-DR, ICP-OES and N2 adsorption. All the catalysts showed good structural order and high specific areas; however the lowest value in these parameters, corresponding to the Co-M(60) sample, could be due to the higher presence of oxide species determined by UV–Vis-DR. These mesoporous metalosilicates were evaluated in the liquid phase oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using H2O2 as oxidant. Results showed that V-M(60) had better catalytic performance than Fe-M(60) and Co-M(60) exhibiting high TON (1100mol/molV), selectivity to BzH (95%) and 31.7% yield at 7h under optimized reaction conditions. The main reason for the enhanced catalytic performance was attributed to the well dispersion of vanadium species in the framework which could be considered as the active sites for the benzyl alcohol oxidation reaction. At the same time, the catalyst could be recovered and effectively reused during three cycles without a significant loss in its activity and selectivity.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.039
      Issue No: Vol. 545 (2017)
       
  • Conversion of propionic acid and 3-pentanone to hydrocarbons on ZSM-5
           catalysts: Reaction pathway and active site
    • Authors: Xuefen Wang; Shuang Ding; Hua Wang; Xiao Liu; Jinyu Han; Qingfeng Ge; Xinli Zhu
      Pages: 79 - 89
      Abstract: Publication date: 5 September 2017
      Source:Applied Catalysis A: General, Volume 545
      Author(s): Xuefen Wang, Shuang Ding, Hua Wang, Xiao Liu, Jinyu Han, Qingfeng Ge, Xinli Zhu
      Conversion of propionic acid to gasoline-range molecules was investigated at 350°C on a series of ZSM-5 catalysts with varying density of Brønsted acid sites (BAS), achieved by ion exchange of proton with Na+. Ketonization of propionic acid to 3-pentanone is the primary reaction, with the sequential aldol condensation to dipentanone alcohol being the secondary. The major reaction pathway for forming the aromatics involves dehydration, cyclization, dehydration and hydride transfer from dipentanone alcohol, leading to the formation of C10 aromatics before being dealkylated to lighter aromatics. Temperature programmed desorption of propionic acid indicates that the reaction initiates with acylium cation formation on BAS through dehydration. Comparing the turnover frequencies of ketonization and aldol condensation on ZSM-5 with varying density of BAS indicates that BAS is the active site for both reactions. The propionic acid feed deactivates the catalyst faster than the 3-pentantone feed due to a stronger adsorption of propionic acid on the acid sites of ZSM-5.
      Graphical abstract image

      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.037
      Issue No: Vol. 545 (2017)
       
  • Influence of acid-base properties of the support on the catalytic
           performances of Pt-based catalysts in a gas-phase hydrogenation of
           acetonitrile
    • Authors: F. Saad; J.D. Comparot; R. Brahmi; M. Bensitel; L. Pirault-Roy
      Pages: 1 - 9
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): F. Saad, J.D. Comparot, R. Brahmi, M. Bensitel, L. Pirault-Roy
      Catalytic performances of Pt-based catalysts supported on various oxides (Al2O3, MgO, SiO2, and CeO2) prepared by a sol-gel method were evaluated by gas-phase hydrogenation of acetonitrile, in order to investigate the influence of acid-base properties of support oxides on products distribution. Acid-base properties were studied by pyridine adsorption followed by FTIR (Lewis and Brønsted acidity), 3,3-dimethyl-1-butene isomerization (Brønsted acidity), and temperature-programmed desorption (TPD) of CO2 (basicity). The results obtained concerning acid-base characterization of the oxides in this paper show a reasonable scale of surface acidity and basicity, as MgO and CeO2 are known to be basic oxides, silica is expected to be a neutral support according the preparation procedure, whereas alumina is an amphoteric one. The performances of the four tested catalysts in terms of the selectivity towards the primary amine are correlated with the amount of basic sites. The more basic the support is, the more it favors the production of primary amines.
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      PubDate: 2017-07-12T03:54:58Z
      DOI: 10.1016/j.apcata.2017.06.038
      Issue No: Vol. 544 (2017)
       
  • Efficient transformation in characteristics of cations supported-reduced
           graphene oxide nanocomposites for the destruction of trichloroethane
    • Authors: Usman Farooq; Muhammad Danish; Shuguang Lu; Mark L. Brusseau; Muhammmad Naqvi; Xiaro Fu; Xiang Zhang; Qian Sui; Zhaofu Qiu
      Pages: 10 - 20
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Usman Farooq, Muhammad Danish, Shuguang Lu, Mark L. Brusseau, Muhammmad Naqvi, Xiaro Fu, Xiang Zhang, Qian Sui, Zhaofu Qiu
      Experiments were conducted to investigate the use of graphene-oxide supported metallic nanocomposites for improving the degradation of trichloroethane (TCA) by sodium percarbonate (SPC). Two methods of production, chemical reduction (CR) and solvo-thermal (ST), were tested for preparation of single (Fe) and binary (Fe-Cu) nanocomposites supported by reduced graphene oxide (rGO). A variety of analytical techniques including N2 adsorption Brunauer-Emmett-Teller (BET), x-ray diffraction (XRD), fourier-transfrom infrared spectroscopy (FTIR), and transmisison electron microscopy (TEM) were applied to characterize the physicochemical and microstructural properties of the synthesized nanocomposites. The characterization indicated that the CR method produced nanocomposites that comprised only mesoporous structure. Conversely, both micro and mesoporous structures were present for samples produced with the ST method. The synthesized single and bimetallic composites produced from the ST method showed higher surface areas, i.e. 93.6m2/g and 119.2m2/g as compared to the ones synthesized via the CR method, i.e. 13.8m2/g and 38.0m2/g respectively. The results of FTIR and XRD analyses confirmed that the ST method produced highly crystalline nanocomposites. SEM and TEM analysis validated that metallic particles with definite morphology well distributed on the surface of rGO. X-ray photoelectron spectroscopy (XPS) analysis confirmed the homogeneity nanocomposites and occurrence of variation in copper oxidation states during degradation process. EDS mapping validate the homogeneous distribution of Cu and Fe at reduced graphene oxide surface. The Fe-Cu/rGO (ST) activated SPC system effectively degraded TCA (92%) in 2.5h at low nanocomposite dose compared to the Fe-Cu/rGO (CR) and only Fe, for which the maximum degradation efficiencies achieved were 81% and 34%. In conclusion, excellent catalytic characteristics were observed for the ST-synthesized single and bimetallic (Fe/rGO, Fe-Cu/rGO) catalysts. These catalysts were successful in improving the degradation of TCA via activated SPC.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.007
      Issue No: Vol. 544 (2017)
       
  • The influence of different promoter oxides on the functionality of hybrid
           CuZn-ferrierite systems for the production of DME from CO2-H2 mixtures
    • Authors: G. Bonura; C. Cannilla; L. Frusteri; F. Frusteri
      Pages: 21 - 29
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): G. Bonura, C. Cannilla, L. Frusteri, F. Frusteri
      In this work the one pot production of dimethylether (DME) by catalytic hydrogenation of carbon dioxide has been studied. The catalytic behaviour of the CuZn-ferrierite hybrid system has been assessed, considering the influence of five different oxides promoters (i.e., ZrO2, CeO2, La2O3, Al2O3, Ga2O3) both on the physico-chemical properties (i.e., surface area, pore volume, copper surface area and dispersion, metal-oxide distribution, acid-base capacity) and on the activity-selectivity pattern. The reaction was carried out in a fixed bed reactor, by feeding CO2 and H2 in the molar ratio 1: 3. The CuZn-FER catalysts doped with Zr, Al or Ga showed a similar behaviour in the DME production, while Ce and La exhibited an inadequate functionality as oxide promoters, mainly evidencing a higher activation energy on the CO2 activation path. The final DME productivity resulted to be driven not so much by specific metallic properties, rather by the presence of an adequate surface balance of acid-base sites that, in a different way, shift the reactions of the global process towards the equilibrium value.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.010
      Issue No: Vol. 544 (2017)
       
  • Three-way catalytic reactions on Rh-based catalyst: Effect of Rh/ceria
           interfaces
    • Authors: Chengxiong Wang; Tingting Zheng; Jun Lu; Xiaodong Wu; Harold Hochstadt; Yunkun Zhao
      Pages: 30 - 39
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Chengxiong Wang, Tingting Zheng, Jun Lu, Xiaodong Wu, Harold Hochstadt, Yunkun Zhao
      Rh-based catalysts were prepared by various methods and it was found that preparation methods play an important role in metal-support interaction (MSI) control which affects the catalytic performance of catalyst. The results suggest that the catalytic reduction of NO is mainly achieved by C3H6 in exhaust and H2 generated from the water-gas shift reaction as well as the steam reforming of C3H8 and CH4. Concentration of water in reaction stream has a significant influence on the water-gas shift and steam reforming reactions. The removal of C3H6 is accomplished by oxygen-induced oxidation instead of steam reforming reaction. In addition, Rh/ceria interactions promote the formation of active oxygen species and surface oxygen vacancy that respectively favors CO oxidation and NO reduction with a high N2 selectivity. Rh@CeO2 system shows high thermal stability due to Rh/ceria interaction.
      Graphical abstract image

      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.003
      Issue No: Vol. 544 (2017)
       
  • Pd3Sn nanoparticles on TiO2 and ZnO supports as catalysts for
           semi-hydrogenation: Synthesis and catalytic performance
    • Authors: Shaun K. Johnston; Nikolay Cherkasov; Elena Pérez-Barrado; Atte Aho; Dmitry Y. Murzin; Alex O. Ibhadon; M. Grazia Francesconi
      Pages: 40 - 45
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Shaun K. Johnston, Nikolay Cherkasov, Elena Pérez-Barrado, Atte Aho, Dmitry Y. Murzin, Alex O. Ibhadon, M. Grazia Francesconi
      The two catalysts Pd3Sn/TiO2 and Pd3Sn/ZnO were prepared via a one-pot procedure based on the “polyol method” with the addition of a capping agent (polyvinylpyrrolidone) to control the particle size distribution. The same procedure was used to prepare Pd/TiO2 and Pd/ZnO for comparison. All four catalysts showed high activity and selectivity for the selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) to 2-methyl-3-buten-2-ol (MBE) in the liquid phase under identical conditions. However, Pd3Sn/TiO2 and Pd3Sn/ZnO show selectivities to alkene significantly higher than that of the Pd catalysts. Specifically, the selectivity increases from 96.4% to 97.4% on TiO2 support, and 96.2% to 97.6% on ZnO support, at 90% conversion. Transition electron microscopy shows nanoparticles evenly dispersed on the support, with mean particle sizes as low as 4.1 (±0.8) nm when Sn is incorporated into the catalyst. Unsupported Pd3Sn was prepared using the same method and characterised by powder X-Ray diffraction followed by the Rietveld refinement. Pd3Sn was found to be single-phase and isostructural to Pd metal with a face centred cubic unit cell.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.005
      Issue No: Vol. 544 (2017)
       
  • CO2 conversion to propylene carbonate catalyzed by ionic liquid containing
           organosilane groups supported on titanate nanotubes/nanowires
    • Authors: Wesley F. Monteiro; Michele O. Vieira; Aline S. Aquino; Michèle O. de Souza; Jeane de Lima; Sandra Einloft; Rosane Ligabue
      Pages: 46 - 54
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Wesley F. Monteiro, Michele O. Vieira, Aline S. Aquino, Michèle O. de Souza, Jeane de Lima, Sandra Einloft, Rosane Ligabue
      The direct conversion of CO2 into propylene carbonate was investigated using pristine sodium titanate nanotubes (TNT) and nanowires (TNW) on which the ionic liquid (IL) 1-methyl-3-(3-trimethoxysilylpropyl)imidazolium chloride was supported, resulting in IL-TNTs and IL-TNWs, respectively. Anchorage of the IL through its organosilane groups (around 28wt%) on the surface of TNT and TNW was confirmed by FTIR, DRX, EDS and TGA analyses. All the nanostructured materials showed good catalytic activity after CO2 cycloaddition to propylene oxide. IL-TNTs and IL-TNWs exhibited high catalytic performance (TOF=46 and 49h−1, respectively) and 100% selectivity in propylene carbonate (propylene/catalyst molar ratio=580, cat/cocat molar ratio=2.4, 4.0MPa of CO2, 383.15K, 6h).
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.011
      Issue No: Vol. 544 (2017)
       
  • Enhancing catalytic activity of lanthanide oxysulfate (La2O2SO4/Pr2O2SO4)
           via facile manipulation of nanoscale catalyst synthesis process and
           reactor configuration
    • Authors: Shuai Tan; Dongmei Li
      Pages: 55 - 65
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Shuai Tan, Dongmei Li
      We recently reported that a facile colloidal synthesis approach can be used to synthesize nanoscale Eu2O2S to significantly enhance activity of rare-earth based catalysts. While extending this method to synthesize other coordinated lanthanide complexes (La and Pr), we discovered that mixed phases of lanthanide monosulfide (LnS) and lanthanide oxysulfate (Ln2O2SO4) (Ln=La, Pr) co-existed in the product, instead of the desired single-phase complex. Utilizing the high oxophilicity of sulfur and Ln elements, we successfully converted LnS impurity to Ln2O2SO4 nanoparticles with unique morphologies by simply heating them in air. By impregnating the resultant nanocatalysts onto a commercial tubular oxide support (referred to as CCR), CO conversion of nanoscale La2O2SO4 for high temperature water-gas-shift (HTS) reaction increased from nearly zero in fixed-bed reactor (FBR) to 35% in CCR module at 500°C. Reactivity comparison among different catalyst size, morphology and type suggests that the enhanced catalytic activity of La2O2SO4/Pr2O2SO4 nanocatalysts in CCR derives from the increased surface area and minimized aggregation.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.015
      Issue No: Vol. 544 (2017)
       
  • Understanding the role of oxygen surface groups: The key for a smart
           ruthenium-based carbon-supported heterogeneous catalyst design and
           synthesis
    • Authors: Francisco R. García-García; Esteban Gallegos-Suarez; Marcos Fernández-García; Antonio Guerrero-Ruiz; Inmaculada Rodríguez-Ramos
      Pages: 66 - 76
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Francisco R. García-García, Esteban Gallegos-Suarez, Marcos Fernández-García, Antonio Guerrero-Ruiz, Inmaculada Rodríguez-Ramos
      The aim of this work is to understand the role of oxygen surface groups during the preparation, activation and reaction of heterogeneous ruthenium catalysts supported on activated carbon materials. Hence, non-promoted and sodium promoted ruthenium catalysts supported on two different activated carbon materials, with and without oxygen surface groups, were prepared by successive incipient wetness impregnation and tested in the ammonia decomposition reaction. The catalysts were characterised with a multi-technique approach that involves; nitrogen adsorption isotherms at −196°C (BET and BJH methods), temperature programed oxidation (TPO), scanning electron microscope (SEM), temperature programed desorption (TPD), transmission electron microscopy (TEM), in-situ X-ray absorption near edge structure (XANES), temperature programed reduction (TPR) and microcalorimetry of hydrogen chemisorption. The performance of the different ruthenium supported catalysts during the ammonia decomposition reaction was determined in a constant flow fixed-bed reactor at 1atm, in the temperature range from 350°C to 450°C. This work shows how the oxygen surface groups of the activated carbon can be used to control/influence (i) the final oxidation state of ruthenium particles, (ii) ruthenium particles size, (iii) selective deposition of the sodium promotor. We believe that such use of the presence of surface groups on the activated carbon surface could potentially be employed to improve the catalytic performance of next generation heterogeneous catalysts.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.06.030
      Issue No: Vol. 544 (2017)
       
  • Enhancement of CO bond cleavage to afford aromatics in the
           hydrodeoxygenation of anisole over ruthenium-supporting mesoporous metal
           oxides
    • Authors: Tuan Ngoc Phan; Young-Kwon Park; In-Gu Lee; Chang Hyun Ko
      Pages: 84 - 93
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Tuan Ngoc Phan, Young-Kwon Park, In-Gu Lee, Chang Hyun Ko
      Mesoporous TiO2, Al2O3, silica (SBA-15), and nonporous conventional TiO2 (P25) were used as supports for Ru catalysts in the hydrodeoxygenation (HDO) of anisole. The catalytic reaction was performed in a batch reactor at 200°C and 5–30bar H2 pressure. It was shown that the selectivity of this catalytic system towards benzene strongly depended on the H2 pressure, being higher at low pressure. Moreover, significant differences in the product distribution were observed for these catalysts suggesting the strong influence of the nature of supports on controlling the reaction pathway. The SBA-15-supported Ru catalyst (Ru/SBA-15) catalyzed the reaction primarily by the hydrogenation (HYD) pathway. The mesoporous-Al2O3-supported Ru (Ru/meso-Al2O3) promoted the reaction via the HYD and demethylation pathways simultaneously. Mesoporous-TiO2-supported Ru (Ru/meso-TiO2) and P25-supported Ru (Ru/P25) promoted higher yield of benzene, indicating its high selectivity for the direct deoxygenation (DDO) route. The use of meso-TiO2 facilitated the spillover effect, leading to the formation of numerous Ti3+ defect sites and oxygen vacancies. As a result, Ru/meso-TiO2 with anatase phase exhibited higher selectivity for the DDO pathway compared to nonporous P25 with a mixed rutile and anatase phase. The results indicated that the phase and mesoporous structure of TiO2 plays an important role in promoting its interaction with Ru particles and in selecting the HDO reaction pathway.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.06.029
      Issue No: Vol. 544 (2017)
       
  • On A-doping strategy for tuning the TWC catalytic performance of
           perovskite based catalysts
    • Authors: A. Garbujo; M. Pacella; M.M. Natile; M. Guiotto; J. Fabro; P. Canu; A. Glisenti
      Pages: 94 - 107
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): A. Garbujo, M. Pacella, M.M. Natile, M. Guiotto, J. Fabro, P. Canu, A. Glisenti
      Several perovskites of the type La1-xAxCo0.5Cu0.5O3 (A=K, Sr, Ba; x=0, 0.25, 0.5) and a Sr-doped understoichiometric one, have been prepared by citrate method aiming at application as noble metals free catalysts for automotive application. The catalysts have been characterized by BET, X-ray diffraction (XRD), Temperature Programmed Reduction (TPR), X-Ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM) and the effect of A-doping has been investigated. The catalytic activity was studied in model reactions (CO oxidation, CO assisted NO reduction), and in a complex three way catalysts (TWC) mixture approaching automotive exhaust composition at both stoichiometric and O2-limiting conditions and the obtained results are discussed in relation with characterization results. A-doping induces the formation of highly dispersed cubic CuO particles, as observed in the understoichiometric samples. Doping also influences the surface segregation. La segregation is observed in the undoped LaCo0.5Cu0.5O3 sample whereas K is surface segregated in La0.75K0.25Co0.5Cu0.5O3; Co segregates in the Ba-doped perovskite and Sr in the understoichiometric La0.35Sr0.35Co0.5Cu0.5O3. The reducibility (TPR) is altered by A-doping. The reactivity results suggest that in simple CO+O2 and CO+NO mixtures the activation temperature is increased by any doping, but at 400°C the conversion in the CO assisted NO reduction is not significantly different with respect to the one obtained in the undoped catalyst. Activity with a more complex mixture, simulating actual engine exhaust, reveals the interesting activity of the Sr-doped catalysts, that outperform LaCo0.5Cu0.5O3 at both stoichiometric and O2-lean conditions. NO reduction can be achieved at lean O2 conditions, where it is quantitative from 400°C. The possibility to reach similar or better activity by replacing the use of La, which is a Rare Earth Element, by using Sr is particularly interesting. Stability at high temperatures and at fast fluctuations of O2 in inlet stream for 50% Sr-doped catalyst confirms these results.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.009
      Issue No: Vol. 544 (2017)
       
  • Cu9-Alx-Mgy catalysts for hydrogenation of ethyl acetate to ethanol
    • Authors: Jingxia Tian; Jun Hu; Wenjuan Shan; Peng Wu; Xiaohong Li
      Pages: 108 - 115
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Jingxia Tian, Jun Hu, Wenjuan Shan, Peng Wu, Xiaohong Li
      Cu9-Al x or Cu9-Al x -M y (M=Mg, Ca, Ba or Sr) catalysts were prepared by a deposition-precipitation method, characterized by means of H2-TPR, XRD and N2 sorption, and applied for hydrogenation of ethyl acetate to ethanol in a fixed-bed reactor. The molar ratio of Cu/Al or Cu/Al/M and the reaction parameters were investigated thoroughly. As a result, the Cu9-Al0.5-Mg1.5 catalyst with higher specific surface area, lower initial reduction temperature and better metal dispersion furnished 97.8% ethyl acetate conversion with 98% selectivity to ethanol under optimal reaction conditions. Moreover, the Cu9-Al0.5-Mg1.5 catalyst also showed good lifetime and neither the activity nor selectivity decreased during 210h test. Based on the characterization of the Cu9-Al0.5-Mg1.5 catalyst, the optimal Cu+/Cu0 proportion played a key role in determining the superior performance.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.014
      Issue No: Vol. 544 (2017)
       
  • Do happy catalyst supports work better' Surface coating of silica and
           titania supports with (poly)dopamine and their application in
           hydrotreating
    • Authors: Rajesh Munirathinam; Dorothée Laurenti; Denis Uzio; Gerhard D. Pirngruber
      Pages: 116 - 125
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Rajesh Munirathinam, Dorothée Laurenti, Denis Uzio, Gerhard D. Pirngruber
      In order to meet the demand for cleaner fuels, it is necessary to develop high performing hydrotreating catalysts. Although organic additives are often used to improve the performances of hydrotreating catalysts, bio-polymer additives have not yet been thoroughly investigated. We recently showed that dopamine, a neurotransmitter molecule, which is also frequently found in adhesive bio-polymers, efficiently coats the surface of an alumina carrier material and modifies the interaction with active components of hydrotreating catalysts, i.e. cobalt and molybdenum. The catalytic performance of the CoMoS/Al2O3 catalysts could, thus, be improved. In the present paper we extend the strategy to other carrier materials (silica and titania). The catalysts prepared on (poly)dopamine (Pdop) coated silica showed enhanced activity for the hydrogenation of toluene reaction and the selective HDS of FCC gasoline model feed. Pdop coating lowers the MoS2 nanocrystallites' stacking on silica, thereby improving the accessibility of active edge sites. The origin of this increase in catalytic activity may be found in the higher capacity of Pdop's functional groups to interact with metallic precursors leading to a better dispersion of the active phase. On the contrary, when the interaction between the dopamine and the support is too strong (as observed for TiO2), the functional groups of Pdop are not available for interaction with Co and Mo species, resulting in decreased catalytic activity.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.008
      Issue No: Vol. 544 (2017)
       
  • Aqueous microwave-assisted synthesis of non-interpenetrated metal-organic
           framework for room temperature cycloaddition of CO2 and epoxides
    • Authors: Robin Babu; Seol-Hee Kim; Amal Cherian Kathalikkattil; Roshith Roshan Kuruppathparambil; Dong Woo Kim; Sung June Cho; Dae-Won Park
      Pages: 126 - 136
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Robin Babu, Seol-Hee Kim, Amal Cherian Kathalikkattil, Roshith Roshan Kuruppathparambil, Dong Woo Kim, Sung June Cho, Dae-Won Park
      A multilinker non-interpenetrated metal-organic framework, UMCM-15, was synthesized by using microwave power as an alternative energy-efficient tool for the first time. The synergistic catalytic activity, when combined with a co-catalyst containing a strongly nucleophilic anion, was studied in the solventless room temperature cycloaddition between epoxides and CO2. Unlike previous reports on UMCM-15 synthesized in the high-boiling solvent dimethylformamide, low boiling water/ethanol mixture was used as the solvent herein. This approach holds potential as a sustainable green methodology. Crystal formation during the microwave-assisted (MW) synthesis was monitored at certain time intervals. The favorable role of non-interpenetrated pillared structures in promoting room temperature CO2-epoxide cycloaddition reactions was explained by comparing the catalytic efficiency of the three-linker extended pillar-layered non-interpenetrated UMCM-15 with its analogous pillared structures built from two- and three-fold interpenetrated ([Zn2(BDC)2(4,4′-bipy)] and [Zn2(NDC)2(4,4′-bipy)]) catalytic systems with a single dicarboxylate linker. The efficacy of the microwave-assisted UMCM-15(M) catalyst in cycloaddition reactions was proved by comparing the catalytic activity of UMCM-15(M) with that of the congener made by solvothermal synthesis, UMCM-15(S). In addition, a plausible mechanism for the synergistic operation of the Lewis acid sites and nucleophiles was suggested.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.018
      Issue No: Vol. 544 (2017)
       
  • Toward non-precious nanocomposite photocatalyst: An efficient ternary
           photoanode TiO2 nanotube/Co9S8/polyoxometalate for photoelectrochemical
           water splitting
    • Authors: Ran Liu; Zhixia Sun; Xixi Song; Yuzhuo Zhang; Lin Xu; Lu Xi
      Pages: 137 - 144
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Ran Liu, Zhixia Sun, Xixi Song, Yuzhuo Zhang, Lin Xu, Lu Xi
      At present the photoelectrochemical (PEC) water splitting achieves a very high efficiency, but the development of the efficient and inexpensive photoanode materials is still desired for practical application. Herein, we fabricate a composite photoanode consisting of TiO2 nanotube arrays modified with polyoxometalate (POM) and Co9S8, in which POM aims to facilitate charge separation and Co9S8 acts as good electron transport mediator. It is the first introduction of Co9S8 into PEC water oxidation system. Although these three components are all non-precious inorganic materials, the photocurrent density of the TiO2/Co9S8/POM composite photoanode reaches up to 1.12mA/cm2 at 1.23V vs RHE under simulated solar light illumination, which is among the highest PEC water oxidation photoanodes. Particularly, the TiO2/Co9S8/POM composite photoanode shows an 8.5-fold improvement in photocurrent density compared to the pristine TiO2 nanotube array photoanode. The measurements of EIS and Mott-Schottky plots revealed that the TiO2/Co9S8/POM composite photoanode held the best efficiency of charge separation and transport at the interface as well as the highest carrier density. The aforementioned results demonstrate a feasible approach to improving the PEC water splitting efficiency by dual modification of TiO2 nanotube arrays with low-cost materials.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.020
      Issue No: Vol. 544 (2017)
       
  • Cu3(BTC)2 catalyzed oxidation of silane to silanol using TBHP or water as
           oxidants
    • Authors: Nagaraj Anbu; Amarajothi Dhakshinamoorthy
      Pages: 145 - 153
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Nagaraj Anbu, Amarajothi Dhakshinamoorthy
      In the present work, a series of metal organic frameworks are examined for the conversion of Si-H to Si-OH using either t-butylhydroperoxide (TBHP) or water as oxidants. The reaction is optimized using dimethylphenylsilane (1) as a model substrate. It is observed that Cu3(BTC)2 (BTC: 1,3,5-benzenetricarboxylate) exhibits a comparable activity with Zr(BDC) (BDC: 1,4-benzenedicarboxylate) while the activity of Fe(BTC) is lower than Cu3(BTC)2 using TBHP as oxidant. On the other hand, the reaction of 1 with water in the presence of Cu3(BTC)2 as a catalyst showed complete conversion of 1 with 99% selectivity to the corresponding silanol, but other MOFs like Fe(BTC) and Zr(BDC) are inactive under identical reaction conditions. A series of control experiments indicate that Cu2+ is essential to convert 1 to 2 under the present experimental conditions. Further, Cu2+ in Cu3(BTC)2 acts as redox centre with TBHP whereas it behaves as a Lewis acid using water as oxidant. High conversion and selectivity is observed for all the silanes studied under the present experimental conditions. The catalyst stability is assessed by powder XRD, FT-IR and SEM images and observing no structural deterioration of Cu3(BTC)2 either in TBHP or water as oxidants. Furthermore, hot filtration test indicated the absence of copper under the present reaction conditions, thus confirming the stability of Cu3(BTC)2.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.028
      Issue No: Vol. 544 (2017)
       
  • Ethylene oligomerization in zeolite-grafted Cr(III)-diphosphinoamine
           catalysts using triisobutylaluminium as cocatalyst: Change from
           dimerization to trimerization due to confinement effect
    • Authors: Huaiqi Shao; Jingjing Wang; Ruofei Wang; Liwu Song; Xiaoyan Guo; Tao Jiang
      Pages: 154 - 160
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Huaiqi Shao, Jingjing Wang, Ruofei Wang, Liwu Song, Xiaoyan Guo, Tao Jiang
      Zeolite-supported Cr(III)-diphosphinoamine (Cr(III)-PNP) catalysts were prepared through grafting PNP on HY and NaY zeolites followed by complexing with CrCl3(THF)3 for ethylene oligomerization. The structure of supported Cr(III)-PNP catalysts was characterized by scanning electron microscopy, X-ray diffraction, nitrogen adsorption and desorption, thermogravimetric analyses and Fourier transform infrared, and the influence of the supported pattern on reactivity for ethylene oligomerization were investigated. The results revealed that the complex of Cr(III)-PNP was grafted on silicon hydroxyls in the pore channel of HY zeolite to decrease pore size but to maintain pore structure. Comparing with homogeneous Cr(III)-PNP producing 1-butene as main product, HY-supported catalyst had higher activity and selectivity toward 1-hexene increased from 4.07% to 73.24% using triisobutylaluminium as cocatalyst. The increase is attributed to confinement effect of the pore channel, which increases the stability of the chromacycloheptane intermediate to 1-hexene. The confinement effect for ethylene oligomerization was revealed in experiment.
      Graphical abstract image

      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.07.021
      Issue No: Vol. 544 (2017)
       
  • Effect of pyrolysis oil components on the activity and selectivity of
           nickel-based catalysts during hydrotreatment
    • Authors: Chiara Boscagli; Chengwu Yang; Alexander Welle; Wu Wang; Silke Behrens; Klaus Raffelt; Jan-Dierk Grunwaldt
      Pages: 161 - 172
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Chiara Boscagli, Chengwu Yang, Alexander Welle, Wu Wang, Silke Behrens, Klaus Raffelt, Jan-Dierk Grunwaldt
      Understanding the influence of pyrolysis oil components on the activity, selectivity and deactivation of nickel-based catalysts during hydrodeoxygenation (HDO) is fundamental to optimise the process for long-term operation and to develop new catalyst formulations. In this study, HDO of a bio-oil light phase and an aqueous solution of phenol (as a model compound) were investigated over fresh and regenerated NiCu/Al2O3 in a batch reactor at 250 and 340°C. The produced upgraded oil over the fresh catalyst contained significant quantities of ketones and phenolic compounds, which were not further converted during hydrotreatment. In the bio-oil environment, the regenerated catalyst showed only marginally lower activity (15% less H2 consumption) in comparison to the fresh one. In contrast, phenol in water was completely converted over fresh NiCu/Al2O3 with high selectivity towards cyclohexanol at 250°C and cyclohexane at 340°C. Once exposed to bio-oil the catalyst no longer showed activity towards phenol conversion in water. Characterization of the spent catalysts indicated the formation of Ni3S2 in addition to coke and alkali metal deposition on the catalyst surface. Other nickel-based catalysts (with different supports and loadings) and two bio-oils with varying sulphur concentration and no minerals were also investigated. Overall the results elucidated that the catalyst activity, selectivity and deactivation of certain reaction paths was mainly determined by the presence of sulphur. By limiting the effects of sulphur poisoning, Ni-catalysts may be considered for the production of fine chemicals, such as ketones and phenols, in addition to fuel synthesis.
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      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.025
      Issue No: Vol. 544 (2017)
       
  • Kinetic Modelling of the catalytic oxidation of
           2-(methylmercapto)-benzothiazole under mild conditions
    • Authors: A. Córdoba; C. Saux; L.B. Pierella
      Pages: 173 - 180
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): A. Córdoba, C. Saux, L.B. Pierella
      2-(Methylmercapto)-benzothiazole oxidation was performed over Copper modified zeolites. The microporous materials were synthesized by the hydrothermal crystallization method and later modified with metal incorporation by wet impregnation. The solid catalysts were characterized by means of X-ray diffraction, surface area determinations, inductively coupled plasma emission spectrophotometry, temperature programmed reduction and Fourier transformed infrared spectroscopy. Reaction parameters (Copper content, nature of the solvent, hydrogen peroxide concentration, reaction time, catalyst mass and reaction temperature) were evaluated to reach the optimum reaction conditions. Kinetic modelling and kinetic parameter estimation based on experimental kinetic data were included. Cu(II) species were confirmed as the active sites of the catalysts, being Y zeolite the optimal support. Thus, Fenton-like reaction mechanism with reactive oxygen species as hydroxyl and hydroperoxyl radicals (HO, HO2 ) was confirmed. Reactions rates constants values and activation energy were determined by non-linear least-square parameter estimation. Also, homogeneous catalytic system was evaluated in order to discard diffusional limitations.
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      PubDate: 2017-08-03T10:56:10Z
      DOI: 10.1016/j.apcata.2017.07.001
      Issue No: Vol. 544 (2017)
       
  • Selective dealumination of HZSM-5 zeolite boosts propylene by modifying
           1-butene cracking pathway
    • Authors: María Ibáñez; Eva Epelde; Andrés T. Aguayo; Ana G. Gayubo; Javier Bilbao; Pedro Castaño
      Pages: 1 - 9
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): María Ibáñez, Eva Epelde, Andrés T. Aguayo, Ana G. Gayubo, Javier Bilbao, Pedro Castaño
      An HZSM-5 zeolite was dealuminated by steaming with its self-adsorbed water at mild temperatures (300, 400 or 500°C), characterized and tested in the transformation of 1-butene into propylene. The structural, porous-surface and acidic properties of the catalysts (unmodified and steamed) were characterized using N2 adsorption-desorption isotherms, tert-butylamine adsorption-TPD, XRD, 29Si and 27Al MAS-NMR, and FTIR spectroscopies, and the results pointed to the following evidences: (i) dealumination took place transforming specific strong acid, framework tetrahedral Al sitings (located within the micropores) into distorted and extra-framework species; and (ii) the porous-surface properties were less sensible to the treatment. The acid site density was shifted towards the intersections of the zeolite micropores (of weaker acidity), resulting in the selective inhibition of hydrogen transfer pathway, thus lowering the selectivity of paraffins, aromatics and ultimately, coke deposition. Overall, the performance of the 500°C-steamed catalyst compared with the parent one was enhanced: propylene selectivity was boosted 69%, coke deposition dropped by 34%, whereas the initial conversion only fell 6%.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.06.008
      Issue No: Vol. 543 (2017)
       
  • Hydrodeoxygenation of guaiacol on tungstated zirconia supported Ru
           catalysts
    • Authors: Adid Adep Dwiatmoko; Inho Kim; Lipeng Zhou; Jae-Wook Choi; Dong Jin Suh; Jungho Jae; Jeong-Myeong Ha
      Pages: 10 - 16
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Adid Adep Dwiatmoko, Inho Kim, Lipeng Zhou, Jae-Wook Choi, Dong Jin Suh, Jungho Jae, Jeong-Myeong Ha
      Ru nanoparticles supported on tungstated zirconia (WZr) were prepared and used for the catalytic hydrodeoxygenation of guaiacol to deoxygenated hydrocarbon fuels. The tuning of tungsten, from 5 to 20wt%, adjusted the number of acid sites on the tungstated zirconia and the size of the Ru nanoparticles. The optimum fraction of tungsten was determined for the optimum hydrodeoxygenation activity. The conversion of guaiacol reached a maximum of 96.8% for 10wt% of tungsten. Increasing the tungsten fraction increased the number of acid sites and the dispersion of Ru, but the formation of tungsten oxide (WOx) particles with too large fraction of tungsten inhibited the formation of smaller Ru nanoparticles, thus reducing the catalytic activity.
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      PubDate: 2017-07-23T11:24:54Z
      DOI: 10.1016/j.apcata.2017.05.037
      Issue No: Vol. 543 (2017)
       
  • New insights in evaluation of acid sites in micro-mesoporous zeolite-like
           materials using potentiometric titration method
    • Authors: Nataliya D. Shcherban; Svitlana M. Filonenko; Roman Yu. Barakov; Sergii A. Sergiienko; Kai Yu; Ivo Heinmaa; Ari Ivaska; Dmitry Yu. Murzin
      Pages: 34 - 42
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Nataliya D. Shcherban, Svitlana M. Filonenko, Roman Yu. Barakov, Sergii A. Sergiienko, Kai Yu, Ivo Heinmaa, Ari Ivaska, Dmitry Yu. Murzin
      Potentiometric titration was used to characterize the acid-base properties of micro-mesoporous zeolite-like materials obtained via dual template synthesis using sol-precursors of Beta zeolite and micellar templates. The obtained results were compared with other methods of acidity determination (ammonia TPD, pyridine ad(de)sorption). The acid sites with the strength comparable to Beta zeolite (lg K values 4.3–4.7) were found in low-crystalline and X-ray amorphous micro-mesoporous materials. The strongest acid sites were observed in conventional Beta zeolite and a low-crystalline (degree of crystallinity ca. 0.1) micro-mesoporous material prepared on its basis (lg K 4.3) in concentration of 450 and 100μmol/g, respectively. A change from acidic to alkaline reaction media in the second stage of micro-mesoporous materials preparation led to an increase of the acid sites concentration from 190 to 600μmol/g concomitant with formation of a high fraction of comparatively strong acid sites (lg K 4.7, 200μmol/g). A high content of acid sites in low-crystalline and X-ray amorphous samples was assigned to acidity of zeolite precursors rather than zeolite crystals.
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      PubDate: 2017-06-21T17:06:01Z
      DOI: 10.1016/j.apcata.2017.05.039
      Issue No: Vol. 543 (2017)
       
  • Enhancement of palladium-catalyzed direct desulfurization by yttrium
           addition
    • Authors: Ali Mansouri; Natalia Semagina
      Pages: 43 - 50
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Ali Mansouri, Natalia Semagina
      Bimetallic Pd-Y nanoparticles were synthesized by yttrium precursor reduction on the surface of colloidal Pd seeds catalyzed by palladium hydride. The addition of yttrium improved the thermal stability of the Pd nanoparticles to agglomeration. The nanoparticles before and/or after deposition on alumina were characterized by TEM, XPS, STEM with elemental mapping, temperature-programmed reduction, CO chemisorption and CO-DRIFT spectroscopy. The supported catalysts were evaluated in hydrodesulfurization (HDS) of 4,6-dimethydibenzothiophene at 350°C and 1MPa. Yttrium addition did not alter the overall HDS rate but increased the direct desulfurization selectivity from 71% to 84% and suppressed cracking twice as much as monometallic Pd catalyst did. The study demonstrates that PdY structures could be a promising candidate for low-pressure HDS of refractory sulfur compounds.
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      PubDate: 2017-06-21T17:06:01Z
      DOI: 10.1016/j.apcata.2017.06.016
      Issue No: Vol. 543 (2017)
       
  • Promotion on light olefins production through modulating the reaction
           pathways for n-pentane catalytic cracking over ZSM-5 based catalysts
    • Authors: Xu Hou; Yuan Qiu; Enxian Yuan; Fuqiang Li; Zaizheng Li; Shuang Ji; Zhenning Yang; Guozhu Liu; Xiangwen Zhang
      Pages: 51 - 60
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Xu Hou, Yuan Qiu, Enxian Yuan, Fuqiang Li, Zaizheng Li, Shuang Ji, Zhenning Yang, Guozhu Liu, Xiangwen Zhang
      Insights into reaction mechanism were vital to direct naphtha catalytic cracking process to produce light olefins. In order to reveal influences of reaction pathways modulation on light olefins production, Zr-ZSM-5, Ag-ZSM-5, and the regenerated HZSM-5 (ZSM-5(R2)) were prepared and employed in n-pentane catalytic cracking. It was found that light olefins yield obtained over Zr-ZSM-5, Ag-ZSM-5, and ZSM-5(R2) at 500°C was 58%, 81%, and 113% higher than that over the parent HZSM-5 (12.0%), respectively. Promotion on light olefins production caused by Zr-incorporation can be attributed to the enhancement of hydride transfer reactions increasing the utilization of Brønsted acid sites and the catalytic activity accompanied with the proximate stability compared to the parent HZSM-5. Different from Zr-ZSM-5, Ag-ZSM-5 and ZSM-5(R2) respectively introduced dehydrogenation cracking and redox cracking to n-pentane catalytic cracking, which selectively promoted the formation of light olefins and significantly enhanced n-pentane protolytic cracking. However, both Ag-ZSM-5 and ZSM-5(R2) went through a rapid deactivation at 550°C, which was probably due the selective enhancement of alkenes accelerating the side reactions to coke formation.
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      PubDate: 2017-06-21T17:06:01Z
      DOI: 10.1016/j.apcata.2017.06.013
      Issue No: Vol. 543 (2017)
       
  • Highly efficient single atom cobalt catalyst for selective oxidation of
           alcohols
    • Authors: Min Li; Shujie Wu; Xiaoyuan Yang; Jing Hu; Ling Peng; Lu Bai; Qisheng Huo; Jingqi Guan
      Pages: 61 - 66
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Min Li, Shujie Wu, Xiaoyuan Yang, Jing Hu, Ling Peng, Lu Bai, Qisheng Huo, Jingqi Guan
      Catalysts with atomically dispersed active sites are highly desirable to maximize atom efficiency. Herein, we reported atomically cobalt dispersed onto nitrogen-doped graphene (denoted as Co-NG) by heat-treating cobalt salts and graphene oxide in ammonia atmosphere. The Co-NG catalyst was characterized by various analysis techniques, such as XPS, XRD, Raman, TEM, SEM, HAADF-STEM and nitrogen adsorption. Characterization results showed that the surface O content decreased as the doping temperature increased, while the surface N content kept increasing up to 7.94 at% at the doping temperature of 750°C. The coordination of N with Co should improve the catalytic behavior of Co-NG. The Co-NG catalyst has extremely high atom efficiency and shows high activity and excellent stability for the selective oxidation of various alcohols (e.g. benzyl alcohol, 4-chloro-benzyl alcohol, 4-methyl-benzyl alcohol, 4-methoxy-benzyl alcohol, 4-hydroxy-benzyl alcohol, phenethyl alcohol, 2-methyl heptanol, etc) by oxygen molecule. For example, 94.8% benzyl alcohol conversion and 97.5% benzaldehyde selectivity can be achieved over Co-NG after reaction for 5h, and the catalyst yields an average TOF of over 500h−1.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.018
      Issue No: Vol. 543 (2017)
       
  • Improving 1,3-butadiene yield by Cs promotion in ethanol conversion
    • Authors: Pratap T. Patil; Dapeng Liu; Yan Liu; Jie Chang; Armando Borgna
      Pages: 67 - 74
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Pratap T. Patil, Dapeng Liu, Yan Liu, Jie Chang, Armando Borgna
      Gas phase conversion of ethanol into butadiene was studied over silica-supported ZnO, ZrO2 and ZnO-ZrO2 catalysts in a fixed-bed reactor. Surface active sites were characterised using a variety of techniques including temperature-programmed desorption (TPD) of NH3 and CO2 as well as Fourier transform infrared (FTIR) spectroscopy of adsorbed pyridine. An increased concentration of acid and base sites was found in the following order: ZnO<ZrO2 <ZnO-ZrO2. In addition, new acid and base sites were generated when alkaline metal promoters were introduced. Typical reaction products for all catalysts include acetaldehyde, butadiene, ethylene, propylene, butenes, diethyl ether and C4 oxygenates. Compared to single oxide supported catalysts, a remarkable acid-base synergetic effect was observed on the binary oxides supported catalysts with or without alkali metal modification. The improved catalytic activity and selectivity can be attributed to the right balance between acid and base sites, minimising dehydration to ethylene while promoting dehydrogenation to acetaldehyde. Furthermore, the existence of acid-base pairs with the appropriate configuration and strength promotes the aldol condensation and Meerwein-Ponndorf-Verley (MPV) reduction efficiently.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.05.025
      Issue No: Vol. 543 (2017)
       
  • Effects of Mn addition on dehydrogenation of methylcyclohexane over
           Pt/Al2O3 catalyst
    • Authors: Atsushi Nakano; Shota Manabe; Takuma Higo; Hirofumi Seki; Satoshi Nagatake; Tomohiro Yabe; Shuhei Ogo; Tomomi Nagatsuka; Yukihiro Sugiura; Hideshi Iki; Yasushi Sekine
      Pages: 75 - 81
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Atsushi Nakano, Shota Manabe, Takuma Higo, Hirofumi Seki, Satoshi Nagatake, Tomohiro Yabe, Shuhei Ogo, Tomomi Nagatsuka, Yukihiro Sugiura, Hideshi Iki, Yasushi Sekine
      Methylcyclohexane (MCH) is a prospective hydrogen carrier candidate. Although Pt/Al2O3 catalyst shows high conversion for dehydrogenation of MCH at 623K, methane formation and deactivation caused by coke deposition are issues over the catalyst. Results of this study demonstrate that Mn addition to Pt/Al2O3 brought higher selectivity and stability for dehydrogenation of MCH than with Pt/Al2O3 alone. Although Pt and Mn do not form an alloy structure, Pt and Mn form an adjacent structure, and the unsaturated coordination of Pt which promotes methane formation and deactivation decreased. Pt-Mn/Al2O3 shows high catalytic performance by virtue of the coverage of such sites by MnOx.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.017
      Issue No: Vol. 543 (2017)
       
  • Applications of light olefin oligomerization to the production of fuels
           and chemicals
    • Authors: Christopher P. Nicholas
      Pages: 82 - 97
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Christopher P. Nicholas
      The oligomerization of the light olefins ethene, propene, and butenes into fuels and chemicals has been investigated and commercially practiced for many years. While the area appears on the surface to be mature, many advances have been made in recent years. In this feature article, I discuss the mechanisms of reaction and showcase catalysts and processes useful for oligomerization from both the open and patent literature. Commercially practiced processes are spotlighted. Among the catalysts utilized in the art are acidic catalysts such as solid phosphoric acid and zeolites, as well as metal based catalysts including aluminum alkyls, and nickel and zirconium based complexes and solids. A short section on catalysts and processes which utilize a metallacycle mechanism in order to achieve high selectivity to 1-hexene or 1-octene is followed by a discussion of multi-functional materials possessing both acid and metal active sites. Finally, processes where oligomerization is a key step in a multi-step or multi-reaction process are discussed.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.011
      Issue No: Vol. 543 (2017)
       
  • RWGS reaction employing Ni/Mg(Al,Ni)O − The role of the O vacancies
    • Authors: Michelly T. Rodrigues; Priscila C. Zonetti; Odivaldo C. Alves; Eduardo F. Soua-Aguiar; Luizs P. Borges; Lucia E.G. Appel
      Pages: 98 - 103
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Michelly T. Rodrigues, Priscila C. Zonetti, Odivaldo C. Alves, Eduardo F. Soua-Aguiar, Luizs P. Borges, Lucia E.G. Appel
      The performance of Ni supported on Mg(Al)O catalysts was evaluated in the RWGS reaction. The catalysts were characterized by TPR, EPR, TPSR, XRD, XPS, cyclohexane dehydrogenation reaction, atomic absorption and N2 physisorption. Two different catalytic systems were prepared by impregnation using water or ethanol as solvents of the Ni precursor. When ethanol was employed, Ni diffuses into the Mg(Al)O particles generating a homogeneous distribution of this metal through the catalyst particle leading to a Mg(Al,Ni)O solid solution, a very small amount of Nio and NiAl2O4. On the other hand, hydrotalcite is generated on the external layers of Mg(Al)O when water is the solvent. Nickel is trapped in the hydrotalcite structure. After calcination and reduction its concentration on the catalyst surface is higher than the one in the bulk. Both Mg(Al,Ni)O and Nio are observed on the catalyst surface. Oxygen vacancies were also observed for the two catalysts via EPR analyses due to the replacement of Mg by Al in the MgO lattice. The Mg(Al,Ni)O vacancies are active species for the reduction of CO2 to CO. These species and Nio are the catalytic sites of the RWGS reaction. Increasing the Nio concentration on the catalysts surface the activity of the catalysts increases as well. As far as we are concerned, this is the first time that Mg(Al)O or Mg(Al,Ni)O vacancies are associated with the performance of a catalytic system. This work exhibits that Ni/Mg(Al,Ni)O is a promising catalytic system for the RWGS reaction.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.026
      Issue No: Vol. 543 (2017)
       
  • Dicationic ionic liquids/heteropoly acid composites as heterogeneous
           catalysts for cyclohexene oxidation with molecular oxygen under
           solvent-free condition: Insights from theory and experiments
    • Authors: Fahime Nezampour; Mehran Ghiaci; Hossein Farrokhpour
      Pages: 104 - 114
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Fahime Nezampour, Mehran Ghiaci, Hossein Farrokhpour
      This study describes solvent-free oxidation of cyclohexene using dicationic ionic liquids (DIL)/heteropoly acid (HPA) composites with molecular oxygen. Structural characterization of the DIL/HPA composites was carried out by different techniques such as ICP, FT-IR, 1H NMR, BET, TGA, XRD, FESEM, EDX and TEM. Characterization results confirmed that heteropoly acids i.e., tungstophosphoric (H3PW12O40, TPA) and molybdophosphoric acid (H3PMo12O40, MPA) were incorporated with DILs without distortion of the Keggin structure of the heteropoly acids. Two different dicationic ionic liquids with linear and aromatic linkage, DIL-L and DIL-A, were prepared and applied for synthesis of the composites. Effective parameters including the effect of temperature, time, oxygen pressure, amount of the selected catalyst, i.e., DIL-L/tungstophosphoric acid was thoroughly investigated. The catalyst was found to be stable and recyclable. The main product of the reaction was cyclohexene-2-one (Cy-one) at 70°C and 15bar oxygen pressure after 6h. Additionally, theoretical calculations at the PM6 semi-empirical method was performed on DILs/HPA complexes with different number of DIL molecules to explore the capacity of HPA in interaction with DILs and obtained the orientations of DILs around the Keggin oxoanion of the HPA. The calculations showed that the maximum number of DIL molecules around the [H2PW12O40]− oxoanion was five and the interaction of DIL-L withthe oxoanion was stronger than that of DIL-A which was in agreement with the experimental data.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.025
      Issue No: Vol. 543 (2017)
       
  • Effect of La, Mg and Mo additives on dispersion and thermostability of Ni
           species on KIT-6 for CO methanation
    • Authors: Yuhao Lv; Zhong Xin; Xin Meng; Miao Tao; Zhicheng Bian; Jia Gu; Wenli Gao
      Pages: 125 - 132
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Yuhao Lv, Zhong Xin, Xin Meng, Miao Tao, Zhicheng Bian, Jia Gu, Wenli Gao
      Ni catalysts supported on mesoporous silica KIT-6 with and without promoters (La, Mg and Mo) were prepared by co-impregnation and their catalytic performances on CO methanation were conducted in fixed-bed reactor. As a result, promoters had a negligible benefit to the dispersion of Ni particles since Ni species were highly dispersed on KIT-6. While the metal Ni surface area was reduced due to partial coverage of metal Ni by promoters. Besides the improvement of the promoters (La and Mo) on CO methanation activity, a suitable Ni- support interaction can hindrance the aggregation of Ni particles on 0.5MoNi/KIT-6 during thermal treatment. While the aggregation of Ni particles was severe on Ni/KIT-6 and 0.3LaNi/KIT-6 due to the weak interaction between Ni and support. Furthermore, Mg enhanced the interaction between Ni and KIT-6 by forming NiO-MgO solid solution, but simultaneously some “unsupported” free and “surface rich” Ni species was formed, which would aggregate into larger particles (ca. 25×40nm) during thermal treatment. It was worth mentioning that high pressure (3MPa) improved the catalytic activities and thermostability of catalysts for CO methanation but the aggregation of metal particles were more severe after thermal treatment in reactants under high temperature.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.05.038
      Issue No: Vol. 543 (2017)
       
  • Bimetallic Pd-Fe supported on γ-Al2O3 catalyst used in the ring opening
           of 2-methylfuran to selective formation of alcohols
    • Authors: Gloria Lourdes Dimas-Rivera; Javier Rivera De la Rosa; Carlos J. Lucio-Ortiz; Daniela Xulú Martínez-Vargas; Ladislao Sandoval-Rangel; Domingo Ixtcoatl García Gutiérrez; Carolina Solis Maldonado
      Pages: 133 - 140
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Gloria Lourdes Dimas-Rivera, Javier Rivera De la Rosa, Carlos J. Lucio-Ortiz, Daniela Xulú Martínez-Vargas, Ladislao Sandoval-Rangel, Domingo Ixtcoatl García Gutiérrez, Carolina Solis Maldonado
      This work presents the hydrogenation of 2-methylfuran (2-MF) in gaseous fluid phase into a catalytic reactor in order to obtain products with good properties to be used as biofuel. Bimetallic nanoparticles were obtained by impregnation on Al2O3 from the classic catalytic metals used in hydrogenation reactions such as platinum and palladium, combined with iron, to observe the catalytic activity and the selectivity to form interest biofuel compounds. Pt, Pd, Pt-Fe and Pd-Fe catalysts (with 0.5% wt. metal content) supported on alumina were reduced at 450°C and tested. At 200°C, Pt/Al2O3 and Pt-Fe/Al2O3 catalysts presented less than 19% conversion and the main formed product was pentene (90% selectivity). The Pd/Al2O3 catalyst conversion of 2-MF was of 5% at 200°C, obtaining 1-pentanol and 1-butanol as products, together with a 28% of selectivity. The Pd-Fe/Al2O3 catalyst presented the highest conversion of 2-MF at 200°C of 31%, the production of alcohols such as 1-pentanol, 2-pentanol and 1-butanol summed a selectivity of 39%. Since the Pd-Fe/Al2O3 catalyst presented the best performance, it was analyzed under high-resolution transmission electron microscopy technique. The HRTEM image revealed the presence of 5nm size nanoparticles over the alumina, and Pd and Fe oxide nanoparticles were identified measuring the interplanar distances of exposed planes. A FePd3 nanoparticle alloy was also identified, which was the difference in having a greater hydrogenation efficiency for the 2-MF molecule.
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      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.019
      Issue No: Vol. 543 (2017)
       
  • Influence of a carbon nanotube support and supercritical fluid reaction
           medium on Fe-catalyzed Fischer-Tropsch synthesis
    • Authors: David P. Roe; Rui Xu; Christopher B. Roberts
      Pages: 141 - 149
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): David P. Roe, Rui Xu, Christopher B. Roberts
      To investigate the influence of a supercritical fluid reaction medium on nanoparticle-catalyzed Fischer-Tropsch synthesis (FTS), Fe-based nanoparticle catalysts supported on carbon nanotubes were prepared and tested under both gas phase and supercritical FTS operating conditions. The nanoparticle catalysts displayed high activity, low CH4 selectivity, and elevated oxygenate selectivity. Conversion and selectivity towards heavy, unhydrogenated products were elevated under supercritical operation. With K promotion, aldehydes were produced under both gas phase and supercritical conditions. This study demonstrated the necessity of K promotion for aldehyde production and demonstrated that appreciable amounts of aldehydes can be produced in gas phase, Fe-catalyzed FTS.
      Graphical abstract image

      PubDate: 2017-07-02T12:53:59Z
      DOI: 10.1016/j.apcata.2017.06.020
      Issue No: Vol. 543 (2017)
       
  • TiO2-doped Mn2O3-Na2WO4/SiO2 catalyst for oxidative coupling of methane:
           Solution combustion synthesis and MnTiO3-dependent low-temperature
           activity improvement
    • Authors: Pengwei Wang; Guofeng Zhao Liu Yong
      Abstract: Publication date: 25 August 2017
      Source:Applied Catalysis A: General, Volume 544
      Author(s): Pengwei Wang, Guofeng Zhao, Ye Liu, Yong Lu
      The Mn2O3-Na2WO4/SiO2 catalyst is the most promising one among the enormous catalysts for the oxidative coupling of methane (OCM) but only at above 800°C. No doubt that lowering temperature of the OCM process is at the forefront of this catalysis field. A promising low-temperature active and selective TiO2-doped Mn2O3 Na2WO4/SiO2 catalyst, consisting of 6wt% TiO2, 6wt% Mn2O3, 10wt% Na2WO4 and SiO2 in balance, is developed by solution combustion synthesis (SCS) method. This catalyst is capable of converting 20% CH4 with 70% selectivity to C2-C3 hydrocarbons even at 700°C (catalyst bed temperature) and is stable for at least 250h without deactivation sign, for a feed gas of 50% CH4 in air using a gas hourly space velocity of 8000mLgcat. −1 h−1. In contrast, the non-TiO2-doped SCS catalyst is almost inactive at 700°C whereas it can achieve reactivity (∼24% CH4 conversion and ∼74% C2-C3 selectivity) comparable to the TiO2-doped one at 800°C. XRD and Raman results evidently reveal that the formation of MnTiO3 during the OCM process appears to be important for the low-temperature OCM activity improvement by TiO2-doping.
      Graphical abstract image

      PubDate: 2017-07-23T11:24:54Z
       
  • Transition-metal incorporated heteropolyacid-ionic liquid composite
           catalysts with tunable Brønsted/Lewis acidity for acetalization of
           benzaldehyde with ethylene glycol
    • Authors: Xiaoxiang Han; Kai Ouyang Chunhua Xiong Xiujuan Tang Qing Chen
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Xiaoxiang Han, Kai Ouyang, Chunhua Xiong, Xiujuan Tang, Qing Chen, Kuiwu Wang, Li-Li Liu, Chin-Te Hung, Shang-Bin Liu
      A series of transition-metal (M=Mn, Fe, Co, Ni, Cu) ion-exchanged tungstophosphoric acid (H3PW12O40; TPA)-based ionic liquid (IL) catalysts, synthesized by incorporating metal and methylimidazolium propyl sulfobetaine (MIMPS) zwitterionic IL precursors onto TPA, were exploited for acetalization of benzaldehyde (BzH) with ethylene glycol (EG). These organic-inorganic, water-soluble M-MIMPS-TPA composite salts possess not only strong Brønsted and Lewis acidities but also exhibited unique self-separation property desirable for catalyst separation and recycling. The superior acetalization activities observed for these novel M-MIMPS-TPA catalysts are attributed to their strong acidity, Brønsted/Lewis acid synergy, and low mass transport resistance. Among them, the Ni[MIMPSH]PW12O40 catalyst showed extraordinary catalytic performance and durability with a benzaldehyde glycol acetal selectivity and yield of 99.0 and 94.6%, respectively, in excellent agreement with results from response surface methodology. Further kinetic study gave rise to an activation energy of 34.11kJ/mol for the acetalization reaction, surpassing most reported catalysts.
      Graphical abstract image

      PubDate: 2017-07-02T12:53:59Z
       
  • A safer and greener chlorohydrination of allyl chloride with H2O2 and HCl
           over hollow titanium silicate zeolite
    • Authors: Xinxin Peng; Changjiu Xia Min Lin Xingtian Shu Bin Zhu
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis A: General, Volume 543
      Author(s): Xinxin Peng, Changjiu Xia, Min Lin, Xingtian Shu, Bin Zhu, Baorong Wang, Yao Zhang, Yibin Luo, Xuhong Mu
      Industrial production of dichloropropanols through chlorohydrination of allyl chloride suffers from a series of disadvantages such as use of hazardous Cl2, low atom economy, low dichloropropanol concentration and serious pollution. In this work, a safer and greener route for chlorohydrination of allyl chloride with H2O2 and HCl over hollow titanium silicate (HTS) at mild condition is developed. Unlike the traditional Cl2-based chlorohydrination, this novel method is initiated via synergistic effect of Lewis acidity (HTS) and Brønsted acidity (HCl) to promote occurrence of oxidation, protonation and nucleophilic reaction of allyl chloride simultaneously and hence dichloropropanols are generated. Owing to a completely different reaction route, the formation of 1,2,3-trichloropropane by-product is depressed and the content of dichloropropanol exceeded 22wt%, which increase by about 4 times compared with traditional Cl2-based chlorohydrination (the content of dichloropropanol is below 4wt%). At the optimized conditions, both of the allyl chloride conversion and dichloropropanol selectivity could approach 99% simultaneously and the waste is minimized. What’s more, the HTS was reusable. Concentrated HCl solution treatment was adopted to test HTS’s stability. The characterization and catalytic evaluation results reveal that, although parts of the framework Ti species have transformed into non-framework Ti and then leached into the solution, HTS remains structural stable, and the allyl chloride conversion and dichloropropanol selectivity didn’t decrease obviously during the treatment.
      Graphical abstract image

      PubDate: 2017-06-21T17:06:01Z
       
 
 
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