MCM-41-supported platinum carbonyl cluster-derived catalysts for asymmetric and nonasymmetric hydrogenation reactions
DSpace at IIT Bombay
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Title |
MCM-41-supported platinum carbonyl cluster-derived catalysts for asymmetric and nonasymmetric hydrogenation reactions
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Creator |
BASU, SUSMIT
MAPA, MAITRI GOPINATH, CHINNAKONDA S DOBLE, MUKESH BHADURI, SUMIT LAHIRI, GOUTAM KUMAR |
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Subject |
x-ray photoelectron spectroscopy
hydrogenation transmission electron microscopy reaction kinetics platinum compounds |
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Description |
Anionic platinum carbonyl cluster ([Pt12(CO)24]2−) was ion-paired with the 3-chloropropyltrimethoxysilyl-ammonium group chemically bound to the surface of MCM-41. The materials undergo quick decarbonylation and have been characterized before decarbonylation by IR and UV–vis spectroscopy and after decarbonylation by XPS and TEM. They have been used as catalysts for the hydrogenations of methyl pyruvate, acetophenone, nitrobenzene, benzonitrile, and ethylacetoacetate. The support and the quaternary ammonium groups have significant effects on surface platinum concentration, crystallite size, and observed activity. In the hydrogenation of the prochiral substrates methyl pyruvate or acetophenone, the cinchonidine-based catalyst gives significant enantioselectivity under optimum conditions. A kinetic model that includes an enantioselective product-formation step and a hydrogen pressure-dependent step for the deactivation of the enantioselective sites gives reasonable agreement between predicted and observed enantioselectivity. The model is also in accordance with the XPS and TEM data.
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Publisher |
Elsevier
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Date |
2009-04-03T09:05:57Z
2011-11-25T20:41:02Z 2011-12-26T13:08:40Z 2011-12-27T05:33:57Z 2009-04-03T09:05:57Z 2011-11-25T20:41:02Z 2011-12-26T13:08:40Z 2011-12-27T05:33:57Z 2006 |
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Type |
Article
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Identifier |
Journal of Catalysis 239(1), 154-161
0021-9517 http://dx.doi.org/10.1016/j.jcat.2006.01.032 http://hdl.handle.net/10054/1130 http://dspace.library.iitb.ac.in/xmlui/handle/10054/1130 |
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Language |
en
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