Size-dependent surface electronic structure of V2O5/TiO2 for ultra-deep aerobic oxidative desulfurization of diesel

Herein, a series of V2O5/TiO2 with various V2O5 size (3 ∼ 10 nm) were elaborately designed and controllably fabricated through a citric acid-assisted hydrothermal dispersion of active metal strategy. The structure and properties of supported V-based catalysts were characterized by conventional technical methods, and their catalytic activities and reaction kinetics were probed for aerobic ODS of dibenzothiophene (DBT). The results unveil that the V2O5 size plays a decisive role in influencing the V5+/V4+ and redox property of V2O5/TiO2 catalysts. V2O5/TiO2-1 with the smallest V2O5 size (∼3 nm) exhibits the highest oxidative desulfurization activity with almost 100% DBT conversion within 80 min at 120 °C because of its optimal V5+/V4+ and redox property as well as the lowest apparent activation energy (Ea = 43.0 kJ/mol). Further increasing the V2O5 size from 3 nm to 10 nm leads to the perceptible increase of Ea to 53.5 kJ/mol, thereby decreasing the ODS activity of V2O5/TiO2-3 sharply.