Silica supported amorphous molybdenum catalysts prepared via sol-gel method and its catalytic activity

被引:43
作者
Adam, Farook [1 ]
Iqbal, Anwar [1 ]
机构
[1] Univ Sains Malaysia, Sch Chem Sci, George Town 11800, Malaysia
关键词
Amorphous molybdenum-silica catalyst; Oxidation of styrene; Sol-gel technique; Heterogeneous catalyst; Benzaldehyde; STYRENE OXIDATION; MOLECULAR-SIEVES; MCM-41; CYCLOHEXANE; EPOXIDATION; COMPLEXES; H2O2; FE;
D O I
10.1016/j.micromeso.2010.10.037
中图分类号
O69 [应用化学];
学科分类号
081704 ;
摘要
Silica supported amorphous molybdenum catalysts had been synthesized in alkali, neutral and acidic medium via sal-gel technique. The catalysts were found to be amorphous and free from bulk MoO3. UV-Vis diffuse reflectance analysis and XPS analysis indicated the co-existence of Mo5+ and Mo6+ species when the incorporation was done in acidic medium. The catalytic activity was tested in the liquid phase oxidation of styrene by using hydrogen peroxide as oxidant. The catalyst prepared in acidic medium showed better catalytic activity compared to the catalysts prepared in alkali and neutral medium. The co-existence of Mo5+ and Mo6+ species is believed to enhance the catalytic activity. Benzaldehyde was the major product detected. The structure of the catalyst was proposed based on the results obtained from XPS, Si-29 MAS NMR, UV-Vis diffuse reflectance and FT-IR spectroscopy. (C) 2010 Elsevier Inc. All rights reserved.
引用
收藏
页码:119 / 127
页数:9
相关论文
共 35 条
[1]  
Adam F., 2006, J. Phys. Sci, V17, P1, DOI DOI 10.1016/S1872-2067(12)60751-7
[2]   Esterification via saccharine mediated silica solid catalyst [J].
Adam, Farook ;
Hello, Kasim Mohammed ;
Osman, Hasnah .
APPLIED CATALYSIS A-GENERAL, 2009, 365 (02) :165-172
[3]   Chromium modified silica from rice husk as an oxidative catalyst [J].
Adam, Farook ;
Fook, Cheah Luen .
JOURNAL OF POROUS MATERIALS, 2009, 16 (03) :291-298
[4]   The complete conversion of cyclohexane into cyclohexanol and cyclohexanone by a simple silica-chromium heterogeneous catalyst [J].
Adam, Farook ;
Retnam, Premalatha ;
Iqbal, Anwar .
APPLIED CATALYSIS A-GENERAL, 2009, 357 (01) :93-99
[5]   The benzylation of xylenes using heterogeneous catalysts from rice husk ash silica modified with gallium, indium and iron [J].
Adam, Farool ;
Ahmed, Adil Elhag .
CHEMICAL ENGINEERING JOURNAL, 2008, 145 (02) :328-334
[6]   Indium incorporated silica from rice husk and its catalytic activity [J].
Ahmed, Adil Elhag ;
Adam, Farook .
MICROPOROUS AND MESOPOROUS MATERIALS, 2007, 103 (1-3) :284-295
[7]   The benzylation of benzene using aluminium, gallium and iron incorporated silica from rice husk ash [J].
Ahmed, Adil Elhag ;
Adam, Farook .
MICROPOROUS AND MESOPOROUS MATERIALS, 2009, 118 (1-3) :35-43
[8]   The catalytic active sites in partially reduced MoO3 for the hydroisomerization of 1-pentene and n-pentane [J].
Al-Kandari, H ;
Al-Kharafi, F ;
Al-Awadi, N ;
El-Dusouqui, OM ;
Ali, SA ;
Katrib, A .
APPLIED CATALYSIS A-GENERAL, 2005, 295 (01) :1-10
[9]   Comparison of liquid-phase olefin epoxidation over MoOx inserted within mesoporous silica (MCM-41, SBA-15) and grafted onto silica [J].
Bakala, PC ;
Briot, E ;
Salles, L ;
Brégeault, JM .
APPLIED CATALYSIS A-GENERAL, 2006, 300 (02) :91-99
[10]   Molybdenum species on alumina and silica supports for soot combustion [J].
Braun, S ;
Appel, LG ;
Schmal, M .
CATALYSIS COMMUNICATIONS, 2005, 6 (01) :7-12