Catalytic oxidative desulfurization of dibenzothiophene compounds over tungsten oxide catalysts supported on spherical mesoporous TiO₂

A series of WO_x /TiO₂ catalysts with different WO_x loadings (5-20 wt%) were prepared by incipient wetness impregnation method. The synthesized samples were characterized using various physicochemical characterization techniques, such as X-ray diffraction, nitrogen adsorption-desorption, scanning electron microscopy, and Raman spectroscopy. Catalytic performance of all the catalysts was evaluated in oxidative desulfurization of model oil under very mild conditions of atmospheric pressure and 50 °C in a biphasic system using hydrogen peroxide as an oxidant and acetonitrile as an extraction solvent. Excellent catalytic activity for the removal of the sulfur-containing compounds from the model oil was observed with 20 wt% WO_x/TiO₂ catalyst, mainly due to the porosity associated with the TiO₂ support, fine dispersed active tungsten oxide species on the mesoporous TiO₂ support, and strong interaction between the WO_x and the TiO₂ surface. Moreover, without any regeneration process, the catalytic activity of the catalyst was maintained after several recycle tests.