Interface engineering of quaternary ammonium phosphotungstate for efficient oxidative desulfurization of high-sulfur petroleum coke

Reducing the sulfur content in high-sulfur petroleum coke (HSPC) has become an urgent issue, however, remains a great challenge with the development of petroleum refining industry. Herein, a highly-efficient catalyst quaternary ammonium phosphotungstate ionic liquid [(C4H9)4N]3PW12O40 (C4@HPA) was initiated to activate H2O2, and the sulfur content of HSPC was remarkably decreased from 4.46 wt.% to 2.76 wt.% at a relatively mild temperature (70 oC), which is discernible below than 1400 oC in industry. The characterization results showed that only sulfate can be removed, while sulfoxide and sulfone were retained in petroleum coke. Moreover, the desulfurization activity of C4@HPA/H2O2 to thiophene sulfides decreases as follows: Thiophene > 2-Methylthiophene > 2,5-Dimethylthiophene > Dibenzothiophene > 4-Methyldibenzothiophene. It reveals that the sulfur of 4-MDBT is the most difficult to be removed. Therefore, this founding here may shine light on the understanding and construction of efficient catalyst for desulfurization of high-sulfur petroleum coke in industry.