Preparation, characterization and catalytic activity of heteropolyacids supported on mesoporous silica and carbon

Abstract

HPA was impregnated on mesoporous silica (SBA-15, MCM-41), commercial silica (ML369) and activated carbon, as well as on mesoporous carbons (CMK-1, CMK-3). The resulting materials were investigated by means of XRD, BET and catalytic probe reactions of liquid-phase esterification of hexanoic acid with propanol-1 and acylation of 2-methoxynaphthalene with acetic anhydride. The catalytic performance was optimal with loading of around 40wt% HPA. H3PW12O40 (PW) was more active than H4SiW12O40 (SiW) for esterification, irrespective of the supports used. Solvent used in the impregnation and hydrophobic/hydrophilic nature of the support could influence the performance of the catalyst in these acid catalyzed reactions.