Catalysis by Mesoporous SBA 15 modified with metals and metal oxides

Abstract

Catalysts are important materials for the synthesis of bulk chemicals newlinein a cost effective and environmentally benign manner. Compared to newlinehomogeneous catalysts, heterogeneous catalysts have got immense attention newlinein recent years due to the ease of product separation, recyclability, low cost, newlinestability, etc. But the activity may be decreased due to limited number of newlineactive sites on the surfaces. The best strategy to overcome this difficulty newlineis to increase the number of active sites by increasing the surface area of newlinethe catalyst. Nowadays, high surface area materials, nanomaterials, meso newlineand microporous materials are widely used in heterogeneous catalysis. newlineAmong the different kinds of heterogeneous catalysts, porous materials newlineare the effective systems due to their high surface area and tunable newlinestructure. Especially, the demand for mesoporous systems is increasing newlineday by day due to their widespread applications. The inert behaviour, newlinegood hydrothermal stability and high degree of ordering make SBA-15 as newlinethe most important mesoporous materials compared to MCM, HMS, newlineMSU, etc. The catalytic properties of the SBA-15 can be improved newlineaccording to the desire of the chemist by modifying them with organic as newlinewell as inorganic moieties. It is thus an art to tune the properties of the newlineSBA-15 material, which act as a support for the better dispersion of guest newlinemolecules/atoms in accordance with the reaction to be catalyzed. Metal newlineoxides with varying properties can be used for the modification of the newlinesilica surface and it can be used as a platform for the uniform dispersion newlineof metal nanoparticles like that of Au, Ag, Pt, etc. Nanogold particles newlinehave wide variety of catalytic applications in recent decades.High surface area materials ensure the effective dispersion of nanogold newlineand also help to reduce the aggregation and sintering up to some extent newlineduring high temperature treatment.