SiO2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

摘要

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( H5 PW10 V2 O40),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SiO2为载体制备负载型的杂多酸杂化材料催化剂[ Bmim]5 PW10 V2 O40/SiO2,以H2 O2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50 min,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。%The Keggin type H5 PW10 V2 O40 was synthesized by Na2 HPO4 , NaVO3 and Na2 WO4·12H2 O. The divanadium-substituted phosphotungstate hybrid material [ Bmim ] 5 PW10 V2 O40 was synthesized by reacting H5 PW10 V2 O40 and 1-butyl-3-methylimidazolium bromide ( [ Bmim] Br) . The FT-IR, XRD and UV-vis characterization results show that the [ Bmim ] 5 PW10 V2 O40 hybrid materials possess Keggin structure and the interactions between the [ Bmim]+and the [ PW10 V2 O40 ] 5-. The SiO2-supported [ Bmim] 5 PW10 V2 O40/SiO2 was prepared and used for oxidative desulfurization of dibenzothiophene ( DBT) with the H2 O2 as the oxidant. The experimental results show that the DBT conversion can reach 100% in the [ Bmim ] 5 PW10 V2 O40/SiO2-H2 O2 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.