Liquid-phase Oxidative Desulfurization of Dibenzothiophene Catalyzed by Silica-supported Ammonium Molybdophosphate Catalyst

Silica-supported ammonium molybdophosphate catalysts with different loadings were prepared by a sol-gel method and characterized with X-ray diffraction, infrared spectrometry, and scanning electron microscopy. In addition, the catalytic activity of these catalysts in oxidative desulfurization of dibenzothiophene with H2O2 as the oxidant was also evaluated. Results indicated that ammonium molybdophosphate still retained the Keggin structure after supported on silica, and dibenzothiophenes were oxidized effectively with H2O2 in the presence of these catalysts in the n-hexane/AcOH biphasic system to give corresponding sulfone as the product. The effects of various parameters such as temperature and reaction time were also systematically studied.