Surface structures of molybdenum oxide highly dispersed on ZrO2 and oxidation of propan-2-ol

Abstract

Decomposition of propan-2-ol over zirconia with various Mo loadings and the surface structure of these catalysts have been studied by FTIR spectroscopy and by using a closed-circulation system. MOZ3.0 catalyst (MoO₃ 3.0 wt %) shows high selectivity to acetone, while catalysts with high MoO₃ loading (>7.5 wt % of MoO₃) show high selectivity to propene. The FTIR spectra of MOZ3.0 are influenced drastically by the adsorption of propan-2-ol and water. Catalysts under the reaction conditions employed exhibit spectra very different from those of calcined samples. The quantitative FTIR characterization of catalysts has shown that there are two types of MoO species present in MOZ7.5, while MOZ3.0 is composed mainly of a single MoO species. The reactivity of surface MoO species varies with MoO₃ loading.