Surface studies and catalytic properties of the bifunctional bulk MoO2 system

Abstract

X-ray photoelectron spectroscopy measurements of commercial bulk MoO2 revealed the presence of MoO3 and Mo2O5 phases in the sample surface region. In situ hydrogen reduction at different temperatures up to 650 K enabled to be reduced Mo6+ and Mo5+ to Mo4+. Bulk MoO2 as prepared by hydrogen reduction of the initial samples showed very interesting catalytic properties in terms of isomerization reactions of alkanes. This catalytic activity was attributed to the MoO2 phase on the surface, which had both metallic and acidic functions (bifunctional mechanism). In addition, inelastic mean free paths in MoO2 catalyst were measured experimentally by elastic peak electron spectroscopy (EPES).