Deep oxidative desulfurization of model fuels catalysed by immobilized ionic liquid on MIL-100(Fe)

Deep desulfurization of fossil fuels has become urgently required because of the serious pollution by the large-scale use of fossil fuels. In this study, [PrSO₃HMIm]HSO₄@MIL-100(Fe) was synthesized by wet-impregnation of the ionic liquid (IL) of [PrSO₃HMIm]HSO₄ on MIL-100(Fe). The construction of [PrSO₃HMIm]HSO₄@MIL-100(Fe) was then confirmed by X-ray powder diffraction, N₂ adsorption-desorption experiments, infrared spectroscopy and elemental analysis, and then applied in the oxidative desulfurization of model fuels. In comparison with the corresponding IL, [PrSO₃HMIm]HSO₄@MIL-100(Fe) showed an enhanced performance in the desulfurization rate of model fuels due to the increase of the mass transfer rate. Under the optimized conditions (oxidant to sulphur ratio = 25, oil to acetonitrile ratio = 1, and temperature = 60 °C), a sulphur removal rate of 99.3% was observed (initial sulphur concentration = 50 ppm). The sulphur removal of three sulphur compounds by catalytic oxidation and extraction followed the order of dibenzothiophene (DBT) > thiophene (T) > benzothiophene (BT).