An ionic liquid supported on zirconia-modified silica as a catalyst for oxidative desulfurization

The ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) was immobilized on zirconia-modified silica, and the resulting BMIMPF6/ZrO 2 –SiO 2 catalysts were used in oxidative desulfurization (ODS) reactions. Experimental results revealed that 10% BMIMPF6/ZrO 2 –SiO 2 exhibited the highest catalytic activity. The properties of the catalysts were studied by Fourier-transform infrared spectroscopy, X-ray diffraction, temperature-programmed desorption, transmission electron microscopy and X-ray photoelectron spectroscopy. Furthermore, the acidities and dispersion of the catalysts were investigated by temperature-programmed desorption and elemental mapping. The desulfurization rate was 99.8% at the optimum reaction conditions of 0.08 g catalyst, 323 K, and O/S = 6, for 2 h. After seven reuse cycles, the catalyst activity was only decreased to 94.1%. Therefore, BMIMPF6/ZrO 2 –SiO 2 is promising as an industrial catalyst for the ODS process.