Study on the oxidative desulfurization performance of SiO₂-supported divanadium-substituted phosphotungstate hybrid material

The Keggin type H₅PW₁₀V₂O₄₀ was synthesized by Na₂HPO₄, NaVO₃ and Na₂WO₄·12H₂O. The divanadium-substituted phosphotungstate hybrid material Bmim₅PW₁₀V₂O₄₀ was synthesized by reacting H₅PW₁₀V₂O₄₀ and 1-butyl-3-methylimidazolium bromide (BmimBr). The FT-IR, XRD and UV-vis characterization results show that the Bmim₅PW₁₀V₂O₄₀ hybrid materials possess Keggin structure and the interactions between the Bmim⁺ and the PW₁₀V₂O₄₀^5-. The SiO₂-supported Bmim₅PW₁₀V₂O₄₀/SiO₂ was prepared and used for oxidative desulfurization of dibenzothiophene (DBT) with the H₂O₂ as the oxidant. The experimental results show that the DBT conversion can reach 100% in the Bmim₅PW₁₀V₂O₄₀/SiO₂-H₂O₂ oxidation system under the conditions of 40℃, oxigen/sulfur mol ratio 3.0 and 50 min reaction time. The catalyst was easily separated by centrifugation and could be reused for seven times without decreasing in oxidative desulfurization activity after drying treatment.