Creation of Oxygen Vacancies in MoO3/SiO2 by Thermal Decomposition of Pre-Impregnated Citric Acid Under N2 and Their Positive Role in Oxidative Desulfurization of Dibenzothiophene

Abstract

The XPS, XANES, and UV–Vis results revealed that oxygen vacancies were formed in the surface of MoO3/SiO2 by impregnation of the catalyst with citric acid followed by a temperature-programmed heating under N2 atmosphere. The presence of the induction period during the oxidative desulfurization (ODS) of dibenzothiophene over these Mo-based catalysts using cumene hydroperoxide as the oxidant suggests that the reaction would follow a free radical mechanism. Both the higher ODS activity and the faster deactivation of the modified catalysts give evidences that the oxygen vacancies should possess a high ODS activity.