Preparation of H3PMo12O40 catalyst immobilized on surface modified mesostructured cellular foam (SM-MCF) silica and its application to the ethanol conversion reaction

Surface of mesostructured cellular foam (MCF) silica was modified by grafting 3-aminopropyl-triethoxysilane (APTES) to have the positive charge, and thus, to provide sites for the immobilization of H3PMo12O40. By taking advantage of the overall negative charge of [PMo12O40](3-), H3PMo12O40 catalyst was chemically immobilized on the aminopropyl group of surface modified MCF (SM-MCF) silica as a charge matching component. It was revealed that H3PMo12O40 species were finely and molecularly dispersed on the SM-MCF silica via chemical immobilization. In the vapor-phase ethanol conversion reaction, the H3PMo12O40/SM-MCF silica catalyst showed a higher ethanol conversion than the bulk H3PMo12O40 catalyst. Furthermore, the H3PMo12O40/SM-MCF silica catalyst exhibited an enhanced oxidation catalytic activity (formation of acetaldehyde) and a suppressed acid catalytic activity (formation of ethylene and diethylether) compared to the mother catalyst. The enhanced ethanol conversion and oxidation catalytic activity of H3PMo12O40/SM-MCF silicacatalyst was attributed to fine dispersion of H3PMo12O40 species on the SM-MCF silica via chemical immobilization. (c) 2006 Elsevier B.V. All rights reserved.