杂多酸离子液体负载氨基化Fe3O4磁性复合材料的制备及其超声辅助催化脱硫性能

以N-甲基咪唑、溴代正丁烷、磷钨酸为原料制备了1-丁基-3-甲基咪唑磷钨酸离子液体BMIM]₃PW₁₂O₄₀，将其通过超声浸渍法负载于氨基化Fe₃O₄（Fe₃O₄-NH₂），得到枣糕型结构的BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料，通过FTIR、XRD、XPS、TEM、振动样品磁强计（VSM）、SEM等对其组成、形貌等进行表征。以BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料为催化剂，以H₂O₂为氧化剂，催化氧化以二苯并噻吩为硫源的正辛烷模拟油样，通过单因素法分别考察了超声时间、H₂O₂用量、反应温度和催化剂用量等因素对脱硫效果的影响，并初步探讨了BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料催化脱硫机制。结果表明:0.5 g/LBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料超声辅助催化氧化浓度为500 mg/g模拟油样，在323 K下H₂O₂与二苯并噻吩的摩尔比n（O）:n（S）为8:1经超声10 min时，催化脱硫率达到最佳，为88.13%；重复使用5次后，BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料对模拟油样的催化降解率仅下降了2.51%。说明该材料具有良好的催化脱硫性能，并可重复使用。催化机制初步研究表明，活性中心可能为杂多酸阴离子、Fe₃O₄-NH₂和离子液体分别起到载体和协同增容作用。 

Preparation of heteropoly acid ionic liquids supported amino-functionalized Fe3O4 magnetic composite and its catalytic property for ultrasound-assisted desulfurization

The 1-butyl-3-methylimidazolium phosphotungstic acid ionic liquid(BMIM]₃PW₁₂O₄₀), was prepared from N-methylimidazole, bromo-n-butane and phosphotungstic acid. It was loaded on amino-functionalized Fe₃O₄(Fe₃O₄-NH₂) by ultrasonic impregnation method. A jujube-like structureBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂ magnetic composite was obtained. TheBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂ magnetic composite was characterized by FTIR, XRD, XPS, TEM, vibrating sample magnetometer (VSM) and SEM. TheBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂ magnetic composite was used as catalyst for the oxidation of n-octane simulated oil samples with dibenzothiophene (DBT) as sulfur source, via hydrogen peroxide as oxidant. The effects of ultrasonic time, H₂O₂ usage amount, reactive temperature and catalyst dosage on desulfurization were investigated. The catalytic desulfurization mechanism was discussed. The results showed that the optimized catalytic degradation rate reached 88.13% with the H₂O₂ to DBT n(O):n(S) molar ratio of 8:1 at 323 K when 0.5 g/LBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂ was used for the desulfurization of simulated oil sample with the concentration of dibenzothiophene at 500 mg/g for 10 mins. After reused for 5 times, the catalytic degradation rate decreased only 2.51%, which indicated that theBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂ magnetic composite was of good catalytic desulfurization performance and can be reused. The primary desulfurization mechanism study shows that the catalytic active center might be the heteropoly acid anion of theBMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂ magnetic composite, with the Fe₃O₄-NH₂ serving as a supporter and the ionic liquid as a cooperative compatibilizer, respectively.