Application of a H4SiMo12O40@SiO2 catalyst with a hollow core–shell structure to oxidative desulfurization

Abstract

Designing a catalyst with excellent recyclability to improve oxidative desulfurization continues to challenge many researchers. In this study, a H₄SiMo₁₂O₄₀@SiO₂ catalyst with a core–shell structure was successfully prepared and applied to desulfurize a model oil. Various characterization methods demonstrated that the synthesized H₄SiMo₁₂O₄₀@SiO₂ catalyst presents a hollow spherical structure and that the active H₄SiMo₁₂O₄₀ species is incorporated into the mesoporous SiO₂ shell. Under optimal reaction conditions, the desulfurization rate of dibenzothiophene is nearly 100%, and the activation energy of the oxidation reaction of dibenzothiophene is 22.08 kJ mol⁻¹. These results reveal the excellent catalytic activity of H₄SiMo₁₂O₄₀@SiO₂ for oxidative desulfurization. The catalyst can be recycled by up to 13 times without significant reductions in catalytic activity; such enhanced recyclability may be attributed to the core–shell structure of the synthesized catalyst.