Abstract: Sn-doped cerium molybdate[Ce(MoO₄)₂] catalysts were synthesized using a reflux method, with ammonium molybdate, stannous chloride, and cerium nitrate hexahydrate serving as reactants. The structures of the catalysts were subsequently analyzed using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, among other characterization techniques. The results demonstrated that tin was successfully doped into cerium molybdate. The removal of dibenzothiophene (DBT) from a simulated oil was investigated using a Sn-doped cerium molybdate catalyst in the presence of oxygen as the oxidant. It was demonstrated that the doping of Sn ions led to an increase in the concentration of oxygen vacancies in the catalyst, resulting in a 23% enhancement in the desulfurization rate in comparison to the undoped catalyst. After a series of experiments, the optimal reaction conditions were determined to be: 5.0% Sn doping, a reaction temperature of 120 ℃, a catalyst addition of 0.05 g, and an oxygen flow rate of 150 mL/min. Under the optimal conditions, the desulfurization rate reached 98.7%. The catalyst demonstrated the ability to be recycled for five cycles, exhibiting minimal reduction in oxidative desulfurization activity. The desulfurization mechanism of the catalyst was investigated through free radical capture experiments.The results showed that superoxide radical [.O₂^-] was the main active species in the oxidative desulfurization reaction.

Key words: cerium molybdate, Sn-doped, aerobic oxidative desulfurization