Construction of 3D TiO2 nanoflower for deep catalytic oxidative desulfurization in diesel: Role of oxygen vacancy and Ti3+

To prevent SOx emission and produce low-sulfur diesel oil, we develop a 3D assembly TiO2 nanoflower catalyst with controllable oxygen vacancies for oxidative desulfurization (ODS) in diesel oil. The roles of oxygen vacancy (OV) and associated Ti3+ in TiO2 are fully discussed: the increased OV and Ti3+ are beneficial for the promoted chemical adsorption of peroxy groups, from − 0.5 eV to − 1.26 eV; also facile to the reduction of the energy barriers of O-O and O-H bonds cleavage, respectively by 1.38 eV and 1.24 eV, thus greatly boosting the generation of hydroxyl radicals·OH and superoxide radicals·O2-. Besides, the ODS reaction undergoes two possible pathways, the mechanism and the kinetics are investigated. Above all, the 100% ODS rate can be obtained in only 30 min under optimal conditions, showing a promising perspective of oxygen vacancy engineering for converting hazardous sulfides into high-value chemicals.