[(CH₃)NC₁₆H₃₃]₄W₁₀O₃₂/H₂O₂/[Bmim]PF₆离子液体乳液催化氧化脱硫性能的研究

Catalytic OxidativeDesulfurizationUsing[(CH₃)NC₁₆H₃₃]₄W₁₀O₃₂/H₂O₂/[Bmim]PF₆System

摘要: 油品中有机含硫化物经高温燃烧后产生的硫氧化物，不仅对汽车发动机具有腐蚀作用，而且排入空气中会造成严重的环境问题。首先，制备了疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF₆)和双亲型催化剂[(CH₃)₃NC₁₆H₃₃]₄W₁₀O₃₂，采用红外光谱(FT-IR)，紫外-可见光谱(UV-Vis)和TG-DSC热分析等方法对它们结构进行了相应的表征；研究了H₂O₂为氧化剂、[(CH₃)₃NC₁₆H₃₃]₄W₁₀O₃₂和[Bmim]PF₆构建的离子液体乳液体系催化氧化模拟油中二苯并噻吩(DBT)的反应活性；实验结果表明，随H₂O₂和催化剂用量的增加、反应温度的升高和反应时间的延长，DBT脱除率单调增加；离子液体乳液脱硫体系最佳反应条件为：以[(CH₃)₃NC₁₆H₃₃]₄W₁₀O₃₂为催化剂，模拟油用量5 mL、离子液体[Bmim]PF₆用量为1 mL、反应温度T = 70℃、反应时间t = 3.0 h、n(催化剂):n(DBT) = 1:10和n(H₂O₂):n(DBT) = 2时，DBT脱除率可达98.7%，其脱硫效果好于仅用离子液体萃取脱硫体系和乳液催化氧化脱硫体系的脱硫效果。最后，对离子液体乳液催化氧化脱硫体系的脱硫机理进行了探讨。

Abstract: Sulfur-containing compounds in transportation fuels are converted by combustion to SOx, which is a major source of air pollution and damages exhaust devices. For the environmental protection purpose, in the paper, hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF₆) and surfactant-type decatungstate were synthesized and characterized by means of FT-IR, UV-Vis and TG-DSC. The amphiphilic decatungstate was assembled in hydrophobic ionic liquid emulsions system with 30 wt% H₂O₂ as oxidant, which has been found suitable for the deep removal of DBT in fuels. In this catalytic oxidation desulfurization system, the role of the main factors affecting the process including reaction temperature, reaction time, O/S molar ratio, and catalyst dosage, were investigated in detail. The results demonstrated that the favorable operating conditions were recommended as reaction temperature T = 70˚C, reaction time t = 3 h, V(oil) = 5 mL, V([Bmim]PF6) = 1 mL, n(DBT)/n([(CH₃)₃NC₁₆H₃₃]₄W₁₀O₃₂) = 10:1, n(H₂O₂):n(DBT) = 2, [(CH₃)₃NC₁₆H₃₃]₄W₁₀O₃₂ as catalyst and the removal of sulfur to 98.7%. We also found that the ionic liquid emulsion catalytic oxidative desulfurization system was also superior to the simple extrac-tion with hydrophobic ionic liquid or the catalytic oxidative [Bmim]PF6. Furthermore, the me-chanism of catalytic oxidation desulfurization was elaborated.