Mechanistic Study of Selective Oxidation of Methanol over a Monolayer V₂O₅/CeO₂ Catalyst

Abstract

An operando Fourier transform infrared spectroscopy (FTIRS) study of the oxidation of methanol over a monolayer V 2 O 5 /CeO 2 catalyst was carried out at atmospheric pressure in a temperature range of 150−300 °C. It was found that the oxidation starts at 200 °C, when the main products� methyl formate and dimethoxymethane�are formed with a selectivity of 62 and 38%, respectively. An increase in the reaction temperature initiates the formation of formaldehyde, CO, and CO 2 , and at 300 °C, CO becomes the main reaction product. The main reaction intermediates are methoxy groups, formates, dioxymethylene species, and adsorbed formaldehyde. According to X-ray photoelectron spectroscopy (XPS) studies, the reaction involves a reversible reduction of V 5+ and Ce 4+ cations, indicating that both vanadia and ceria are involved in the oxidation of methanol. A reaction mechanism of the oxidation of methanol over supported vanadium oxide catalysts is discussed.