Preparation of highly dispersed WO3/few layer g-C3N4 and its enhancement of catalytic oxidative desulfurization activity

Abstract

A supported catalyst of WO3/few layer g-C3N4 composite was synthesized by a facile “in situ calcination” technique. Functional ionic liquid [(C16H33)2N(CH3)2]2W2O11 was prepared and used as the precursor of WO3 nanoparticles. Large surface specific area (203.01 m2 g−1) few layer g-C3N4 was obtained through multiple thermal condensations, and it is a desirable support for WO3 nanoparticles. The composition and morphology of the supported catalysts were systematically characterized by FT-IR, XRD, XPS, N2 adsorption-desorption isotherms, SEM and TEM. It was found that WO3 nanoparticles highly dispersed on the surface of few layer g-C3N4. Then, the catalytic oxidative desulfurization performance of the supported catalyst was investigated in detail. Various refractory aromatic sulfur containing compounds including DBT, 4-MDBT, 4,6-DMDBT and 3-MBT were completely removed under the following conditions: m(catalyst) = 0.05 g, T = 50 °C, O/S = 3, V(model oil) = 5 mL. The oxidation product of DBT was detected by GC–MS analysis and the probable mechanism was discussed. Moreover, WO3/few layer g-C3N4 catalyst remained highly active for six consecutive cycles with no loss in activity (100% DBT conversion), indicating that the supported catalyst WO3/few layer g-C3N4 has high stability and excellent desulfurization activity.