Amorphous TiO2-supported Keggin-type ionic liquid catalyst catalytic oxidation of dibenzothiophene in diesel

Abstract Supported ionic liquid (IL) catalysts [C n mim]3PMo12O40/Am TiO2 (amorphous TiO2) were synthesized through a one-step method for extraction coupled catalytic oxidative desulfurization (ECODS) system. Characterizations such as FTIR, DRS, wide-angle XRD, N2 adsorption–desorption and XPS were applied to analyze the morphology and Keggin structure of the catalysts. In ECODS with hydrogen peroxide as the oxidant, it was found that ILs with longer alkyl chains in the cationic moiety had a better effect on the removal of dibenzothiophene. The desulfurization could reach 100% under optimal conditions, and GC–MS analysis was employed to detect the oxidized product after the reaction. Factors affecting the desulfurization efficiencies were discussed, and a possible mechanism was proposed. In addition, cyclic experiments were also conducted to investigate the recyclability of the supported catalyst. The catalytic activity of [C16mim]3PMo12O40/Am TiO2 only dropped from 100% to 92.9% after ten cycles, demonstrating the good recycling performance of the catalyst and its potential industrial application.