One-pot extraction and aerobic oxidative desulfurization with highly dispersed V2O5/SBA-15 catalyst in ionic liquids

Abstract

Catalytic oxidation of thiophenic sulfides for separation from refined oils has turned out to be a hot topic from the angle of environmental protection. In this work, a series of pristine V2O5/SBA-15 composites, which could activate molecular oxygen (O2) in air directly, have been prepared by a simple impregnation method. The successful loading and good dispersion of V2O5 on SBA-15 was, then, confirmed by multiple techniques. After this, one-pot extraction and aerobic oxidative desulfurization (EAODS) of oils was achieved under comparatively mild conditions. Here, sulfur removal of dibenzothiophene (DBT), as one of the most stubborn residuals in the hydro-desulfurization (HDS) process, could reach up to 99.3% (<3.5 ppm), meeting the latest restrict rules. In addition, excellent sulfur removal performance with different types of oils was achieved, indicating the practicability of this reaction system. A possible reaction process was proposed based on the results from electron spin-resonance spectroscopy (ESR), selective quenching experiments, and gas chromatography-mass spectrometry (GC-MS) measurement. Besides, the reaction system could be recycled at least 6 times without a significant decrease on sulfur removal.