Oxidative Desulfurization of Dibenzothiophene Catalyzed by Polyoxometalate-Based Ionic Liquid

A polyoxometalate-based ionic liquid, 1-(4-sulfonic acid) methylimidazolium phosphotungstate ([MIMBS]3PW12O40), was synthesized and characterized by Fourier transform infrared spectrum, nuclear magnetic resonance, electrospray ionization mass spectrum and thermogravimetric analyzer. [MIMBS]3PW12O40exhibited high activity for the extractive catalytic oxidative desulfurization process, together with H2O2and CH3CN/H2O. The sulfur removal of DBT could reach 99.9% under wild conditions, and the catalyst could be used three times with only a slight decline in activity.