Tuning the electrophilicity of vanadium-substituted polyoxometalate based ionic liquids for high-efficiency aerobic oxidative desulfurization

Sulfur compounds in oil phase were captured into the catalyst phase, then oxidized to their corresponding sulfones in the presence of molecular oxygen. [Display omitted] •A series of electrophilicity-tunable ionic liquids were successfully synthesized via a facile ion exchange method.•Both cation and anion parts in ionic liquid played an important role in ODS process.•The prepared ionic liquid [C4VIM]PMoV2 exhibited high efficiency in aerobic ODS process under mild conditions.•The structure-function relationship was investigated in detail from various methods. With increasing stringent standard of sulfur content in fuels, deep desulfurization with high-efficiency is necessary for ecological and environmental demands. Herein, vanadium-substituted polyoxometalate-based ionic liquids with tunable electrophilicity were facilely synthesized through ion exchange method, and applied in the aerobic oxidative desulfurization. The experimental results indicated that both imidazole cation and polyoxometalate anion played a vital role in the desulfurization process. The prepared materials have a good performance on the degradation of aromatic sulfur compounds, which can reach up to 98.9 % under optimal conditions. Moreover, the structure-function relationship was also investigated in detail, as well as the proposed mechanism.