Silver and Mesoporous Silica Nanocomposites for the Selective Oxidation of Benzyl Alcohol

Abstract

Silver nanoparticles loaded mesoporous SBA-15 nanocomposites prepared by direct synthesis and incipient wetness impregnation methods were evaluated as catalysts for the selective oxidation of benzyl alcohol to benzaldehyde. The prepared nano composites were characterized by Powder XRD, TEM, TGA, BET, FTIR and DRS techniques. Powder XRD confirmed the existence of metallic Ag nano particles in the mesoporous sieves. TEM images showed uniform distribution of Ag nano particles as dark nanostructures in- as well as on- the surface of SBA-15. The surface area of bare SBA-15 significantly changed with the introduction of metal within the silica host. Thus, the physiochemical and catalytic parameters of the synthesized nanocomposites were found to be greatly influenced by the method used for the preparation of the nanocomposites. Moreover, among the different nanocomposites, Ag/AP-SBA-15(T) nanocomposites exhibited the highest catalytic activity for the selective oxidation of benzyl alcohol to benzaldehyde (87 %) and benzyl benzoate in IPA/H2O (1:1) resulting in complete oxidation of the compound.