Preparation of highly dispersed tungsten species within mesoporous silica by ionic liquid and their enhanced catalytic activity for oxidative desulfurization

A series of W-containing mesoporous silicas with different calcination temperatures were in situ synthesized by using [(n-C8H17)3NCH3]2W2O11 not merely as a novel template but also the W precursors. The catalysts were characterized by N2 adsorption–desorption, XRD, XPS, HRTEM, EDS, ICP, FTIR, and UV–vis DRS analysis. The N2 adsorption–desorption and HRTEM results indicated that these catalysts possessed mesoporous structure with relatively uniform pores and large internal surface areas. The XRD, ICP and HRTEM results indicated that the W species were highly dispersed on the surface and into the mesoporous silicas matrix. The catalysts also showed excellent catalytic performance on the removal of refractory bulky molecule sulfur compounds from the model oil with H2O2. Based on the removal of DBT in the model oil, the optimal calcination temperature of the catalysts is 450 °C. The catalytic activity of different sulfur-containing substrates was also investigated. After 8-times recycling, the sulfur removal could still reach 99.2% without any significant decrease.