Preparation of hexagonal boron nitride supported phosphomolybdic tungstic acid catalysts with different alkyl substituted imidazolium cations: Insight into hydrophobicity and electron transfer

In this study, a series of hexagonal boron nitride (h-BN) supported phosphomolybdic tungstic acid (POM) catalysts with different alkyl substituted imidazolium cations were successfully synthesized. The oxidative desulfurization (ODS) performance of the different catalysts was evaluated. The ODS of benzothiophene (BT), dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and actual diesel was conducted by using [C12mim]3PMo6W6O40/h-BN as the catalyst and H2O2 as the oxidant. The [C12mim]3PMo6W6O40/h-BN catalyst was analyzed by FT-IR, XPS, XRD, TEM, contact angle testing, and nitrogen adsorption–desorption. In addition, DBT was converted completely in 20 min under the optimum conditions. We also showed evidence that electron transfer between [C12mim]3PMo6W6O40 and h-BN can promote oxidative desulfurization. In addition, even after 20 cycles, the activity of the catalyst did not decrease obviously. Finally, the catalytic mechanism occurring during the ODS process was investigated.