Functionalized PCN-777-supported Lindqvist-type polyoxometalate derivatives for oxidative desulfurization: Role of electron-donating effect and hydrophobicity

Abstract

The electronic structure and hydrophobicity of heterogeneous catalysts are of great importance to catalytic performance. A novel catalyst of functionalized PCN-777-supported Lindqvist-type polyoxometalate derivatives was designed and prepared. The hydrophobicity of the catalyst was improved by simple surface modification. The catalyst was applied in the ODS of dibenzothiophene (DBT) in this study, and the support and catalyst were characterized by Fourier transform infrared (FT-IR), contact angle test, and other methods. Systematic characterization and ODS experiments further confirmed the electron-donating effect of functionalized PCN-777 (tBu-PCN-777) with high hydrophobicity on [C12Py]3(NH4)3Mo7O24. The electron-donating effect leads to a narrow bandgap and high electron density of Mo active sites, ensuring that the catalyst [C12Py]3(NH4)3Mo7O24/tBu-PCN-777-35% exhibits excellent ODS activity. In particular, [C12Py]3(NH4)3Mo7O24/tBu-PCN-777-35% completely removed DBT at 60 °C in 50 min, and it continued to be stable after 30 cycles. The sulfur removal efficiency of real diesel oil reached 92.26%. This study demonstrates that functionalized PCN-777 has desulfurization potential and provides new ideas for increasing ODS catalytic activity from the design of electron-donating effect and hydrophobicity.