Influence of vanadate structure and support identity on catalytic activity in the oxidative cleavage of methyl ketones

Abstract

Oxidative ketone scissions are an interesting class of reactions; they yield aldehyde and carboxylic acids as products, and they proceed over reducible oxides in the presence of molecular oxygen. This chemistry can be leveraged in the production of bio-based maleic anhydride (MA) from levulinic acid (LA) over supported vanadium oxides. Here, we probe the role of active site structure and support identity in dictating the rate of ketone oxidation. Specifically, we have prepared supported vanadium oxides in a range of loadings on SiO2, γ-Al2O3, TiO2 and CeO2, and we have quantified their intrinsic activity in the oxidative cleavage of 2-pentanone. FT-Raman spectroscopy and temperature programmed surface oxidation (TPSO) of adsorbed methanol were employed to probe vanadium speciation and oxidation site densities. Our analysis suggests that the intrinsic activity of supported vanadates is sensitive to both vanadium oxide structure and support identity.