Heteropolyacid Supported on Nitrogen-doped Onion-Like Carbon as Catalyst for Oxidative Desulfurization

In order to improve the dispersion and reduce the loading content of phosphotungstic acid (H3PW12O40, HPW) on a support, the HPW was immobilized on the surface of nitrogendoped onion-like carbon (NOLC) with the assistance of ultrasonication. The obtained HPW/ NOLC catalysts with an HPW loading of 5%-15% were characterized using various techniques. The results show that the HPW active component was well- dispersed on the NOLC surface. Under the optimum reaction conditions, a complete conversion of dibenzothiophene (DBT) could be achieved using the 10% HPW/NOLC catalyst. This excellent catalytic effect may be ascribed to the good dispersion of HPW on the NOLC surface. Moreover, it was inferred that the nitrogen/oxygen functional groups strengthened the connections between HPW and the NOLC support, which is beneficial for improving the dispersion of HPW on the NOLC surface.