Oxidation of dibenzothiophene with cumene hydroperoxide on MoO3/SiO2 modified with alkaline earth metals

Article abstract of DOI:10.1016/j.cattod.2009.04.026

Catalytic oxidation of dibenzothiophene (DBT) in decalin was performed using an oil-soluble oxidant, cumene hydroperoxide (CHP), over molybdenum oxide (MoO₃) supported on silica. The effects of MoO₃ loading, reaction time and the molar ratio of CHP/DBT were investigated. At a MoO₃ loading of 15 wt%, the conversion of DBT reached 82% at 70 °C, WHSV 30 h^-1, and O/S molar ratio 3. Alkaline earth metals, such as Ca, Ba, Sr and Mg were introduced on the surface of silica, prior to the impregnation of MoO₃. The results showed that the activity in the oxidation of DBT with CHP decreased in the order: MoO₃/Ca-SiO₂ > MoO₃/Ba-SiO₂ > MoO₃/SiO₂ > MoO₃/Sr-SiO₂ > MoO₃/Mg-SiO₂. The MoO₃/Ca-SiO₂ catalysts were characterized by XRD. The DBT conversions on MoO₃/Ca-SiO₂ catalysts with various Ca/Mo ratios were studied. When the Ca/Mo ratio was 0.05, the DBT conversion was the highest (95%) at 60 °C, WHSV 30 h^-1, and O/S molar ratio 3.0.