Boosting oxidative-adsorptive desulfurization of fuel oil by constructing a mesoporous coupled desulfurizer with bimetal of MoO3 and WO3

MoO₃-WO₃/SBA-15 was prepared by using an SBA-15 mesoporous molecular sieve as a support to load ammonium metatungstate and ammonium molybdate, and the coupled desulfurizer was characterized via XRD, N₂ adsorption–desorption, SEM, TEM, FTIR, XPS, NH₃-TPD, and zeta potential analysis. The oxidative-adsorptive desulfurization (OADS) performance of the coupled desulfurizer was investigated using a dodecane solution containing dibenzothiophene as the model oil. MoO₃-WO₃/SBA-15 exhibits outstanding performance, which stems from the strong interaction between Mo⁶⁺ and W⁶⁺. This interaction enhances the electronegativity of the coupled desulfurizer and the formation of more acid sites. Consequently, the dispersal of the coupled desulfurizer in the oil is improved, and the dispersion of active components is also facilitated, which is helpful for the adsorption of sulfides. At room temperature (25 °C), with a coupled desulfurizer amount of 2%(w), and an O/S molar ratio of 10:1, the optimal desulfurization rate achieved was 97.50%. After five cycles, the desulfurization rate remained at 80.00%, whereas the desulfurization rate after the first regeneration still reached 96.40%. The coupled desulfurizer was also applied in real diesel oil, and the desulfurization rate reached 91.90%. FTIR spectra and comparative tests indicated that the main active species in the desulfurizer were molybdenum peroxide and tungsten peroxide.