Efficient and reusable ordered mesoporous WOx/SnO2 catalyst for oxidative desulfurization of dibenzothiophene

The oxidative desulfurization (ODS) of organic sulfur compounds over tungsten oxide supported on highly ordered mesoporous SnO2 (WOx/meso-SnO2) was investigated. A series of WOx/meso-SnO2 with WOx contents from 10 wt% to 30 wt%, were prepared by conventional wet impregnation. The physico-chemical properties of the WOx/meso-SnO2 catalysts were characterized by X-ray diffraction (XRD), N-2 adsorption-desorption isotherms, electron microscopy, Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and the temperature-programmed reduction of hydrogen (H-2-TPR). The characterization results indicated that these catalysts possessed mesoporous structures with uniform pores, high specific surface areas, and well-dispersed polyoxotungstate species on the surface of meso-SnO2 support. The ODS performances were evaluated in a biphasic system (model oil/acetonitrile, S-initial = 2000 ppm), using H2O2 as an oxidant, and acetonitrile as an extractant. Dibenzothiophene (DBT) in the model oil was removed completely within 60 min at 50 degrees C using 20 wt% WOx/meso-SnO2 catalyst. Additionally, the effect of reaction temperature, H2O2/DBT molar ratio, amount of catalyst and different sulfur-containing substrates on the catalytic performances were also investigated in detail. More importantly, the 20 wt% WOx/meso-SnO2 catalyst exhibited 100% surfur-removal efficiency without any regeneration process, even after six times recycling.

Automated summary

The study investigated the oxidative desulfurization of organic sulfur compounds using tungsten oxide supported on highly ordered mesoporous SnO2 catalyst. The characterization of the catalyst showed that mesoporous structures with high specific surface areas can promote the desulfurization reaction effectively. The 20 wt% WOx/meso-SnO2 catalyst exhibited good sulfur removal efficiency and could be recycled multiple times without regeneration.