Oxidative Dehydrogenation of Methanol to Formaldehyde by Isolated Vanadium, Molybdenum, and Chromium Oxide Clusters Supported on Rutile TiO₂(110)

We use density functional theory to examine some of the important aspects of methanol oxidation to formaldehyde catalyzed by isolated MO3 (M = V, Mo, and Cr) clusters supported on rutile, TiO2(110). Thermodynamic analysis led us to conclude that in the presence of oxygen, the M (M = V, Mo, and Cr) atom takes three oxygen atoms from the gas phase and this MO3 species is the oxidant in the catalyst. We calculate the structure of these clusters, their Bader charge, the structure of the methoxide formed by methanol adsorption, and the activation energy for the dehydrogenation of the methyl group in the methoxide. We find that VO3 is a substantially better catalyst than MoO3 or CrO3.