Preparation of MoO3-CeO2-SiO2 Oxidative Desulfurization Catalysts by a Sol-Gel Procedure

MoO3-CeO2-SiO2 mixed oxides were prepared by the sol-gel method. The catalysts were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The catalyst activity for the oxidative desulfurization of dibenzothiophene (DBT) with cumene hydroperoxide as the oxidant in toluene was investigated at 40 °C and atmospheric pressure. The optimum Mo/Si and Ce/Si molar ratios were 0.1 and 0.02, respectively. Crystalline MoO3 was observed in the MoO3-CeO2-SiO2 catalysts. The introduction of CeO2 promoted the high dispersion of MoO3 over SiO2. Mo6+ was the predominant species in MoO3/SiO2, and Mo5+ species appeared after the introduction of CeO2. The presence of Mo5+ may be responsible for the good performance of MoO3-CeO2-SiO2 in the oxidative desulfurization of DBT.