SiO_2负载磷钨钒杂多酸杂化材料的制备及其氧化脱硫性能的研究

利用磷酸氢二钠、偏钒酸纳和钨酸钠为原料,合成了具有Keggin结构的磷钨钒杂多化合物(H5PW10V2O40),并与1-丁基-3-甲基咪唑溴(BmimBr)离子液体反应生成一种杂多酸杂化材料(Bmim]5PW10V2O40)。利用红外光谱(FT-IR)、X射线衍射光谱(XRD)和紫外可见光谱(UV-vis)对所合成的杂多酸杂化材料进行表征。结果表明,Bmim]5PW10V2O40具有咪唑阳离子基团和Keggin型杂多阴离子基团的结构特征,并且两种基团之间存在相互作用。以SiO_2为载体制备负载型的杂多酸杂化材料催化剂Bmim]5PW10V2O40/SiO_2,以H2O_2作为氧化剂,考察该催化剂对模拟油中DBT的氧化性能,并优化氧化反应条件,在反应温度40℃,O/S物质的量比为3.0的条件下,反应50min,模拟油品中的DBT的转化率可以达到100%。催化剂可以通过离心法分离,经过干燥之后,可以循环使用至少七次,而对DBT的氧化活性没有降低。

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 Bmim]₅PW₁₀V₂O₄₀ was synthesized by reacting H₅PW₁₀V₂O₄₀ and 1-butyl-3-methylimidazolium bromide (Bmim]Br). The FT-IR, XRD and UV-vis characterization results show that the Bmim]₅PW₁₀V₂O₄₀ hybrid materials possess Keggin structure and the interactions between the Bmim]⁺ and the PW₁₀V₂O₄₀]^5-. The SiO₂-supported Bmim]₅PW₁₀V₂O₄₀/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 Bmim]₅PW₁₀V₂O₄₀/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.