Immobilization of a heteropolyacid catalyst on the aminopropyl-functionalized mesostructured cellular foam (MCF) silica

Mesostructured cellular foam (MCF) silica with high surface area (>600 m2/g) and large pore volume (≈1.16 cm3/g) was synthesized via a surfactant templating method. The MCF silica was then modified by grafting 3-aminopropyl-triethoxysilane (APTES) to create a positive charge on the surface, and thus, to provide sites for the immobilization of H3PMo12O40. By taking advantage of the overall negative charge of [PMo12O40]3−, the H3PMo12O40 catalyst was chemically immobilized on the aminopropyl group of the surface modified MCF silica as a charge matching component. The mesopore structure of MCF silica was maintained even after the surface modification step and the subsequent immobilization step of H3PMo12O40. The H3PMo12O40 species were finely and molecularly dispersed on the surface modified MCF silica via chemical immobilization.