Preparation of flower-like microspheres MnO2@CeO2 catalyst for desulfurization at room temperature

A flower-like core–shell MnO 2 @CeO 2 composite was synthesized via hydrothermal method. Characterization by X-ray diffraction, Brunauer–Emmett–Teller, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy confirmed a micro-spherical morphology with a high specific surface area (266.4 m 2  g −1 ) and well-defined mesoporous structure (average pore size: 7.4 nm), facilitating active site exposure and reactant adsorption. Under optimal conditions (25 mg catalyst, 1.5 mL 25 wt% peroxymonosulfate, 2 mL acetonitrile, 600 ppm initial sulfur, 40℃), the desulfurization efficiency for dibenzothiophene reached 81.26%. It maintained 71% efficiency after 5 cycles, with stable chemical structure and morphology. Quenching experiments confirm that the primary oxidation of dibenzothiophene to dibenzothiophene sulfoxide is predominantly mediated by sulfate radicals (·SO 4 ⁻), while the subsequent oxidation of dibenzothiophene sulfoxide to dibenzothiophene sulfone relies primarily on hydroxyl radicals (·OH). Kinetic analysis showed tandem reaction behavior with rate constants k 1  = 0.213 min⁻ 1 and k 2  = 0.187 min⁻ 1 . This catalyst offers promising potential for industrial production of ultra-low-sulfur fuels. Graphical