Surface electronic structure-catalytic activity correlation of partially reduced molybdenum oxide(s) for the isomerization of light alkenes and alkanes

Abstract

Catalytic activity-surface electronic structure correlation was carried out using surface XPS-UPS techniques. In situ reduction by hydrogen, were carried out at similar experimental conditions to those employed for the catalytic reactions. In the case of MoO3 deposited on TiO2, the reduction to MoO2 state with the bifunctional MoO2(H x)ac phase on its surface starts at 573 K and reaches a stable state at temperatures between 653-673 K. In the case of alumina support, a strong metal-support interaction takes place during the catalyst preparation, leading to Al2(MoO4)3 complex formation as characterized by XRD. The reduction process(s) of this complex by hydrogen as a function of temperature is different from what is observed in the case of titania support. The changes in the chemical structure of the sample surface in both systems were tested for the catalytic reactions of 1-pentene and n-pentane © 2008 IOP Publishing Ltd.