摘要
合成并表征了2-吡咯烷酮硫酸氢盐([Hnhp]HSO4)、1-甲基-2-吡咯烷酮硫酸氢盐([Hnmp]HSO4)、1-甲基咪唑硫酸氢盐([Hmim]HSO4)、1-(3-磺酸基)-丙基-3-甲基咪唑硫酸氢盐([C3SO3Hmim]HSO4)和1-(3-磺酸基)-丙基-2-吡咯烷酮硫酸氢盐([C3SO3Hnhp]HSO4)等以HSO4-为阴离子的质子酸离子液体,并以乙酸和正丁醇的酯化反应考察了这些离子液体的催化活性.结果表明,当n(n-BuOH)∶n(MeCO2H)∶n([C3SO3Hnhp]HSO4)=1.2∶1∶0.005,反应温度为120℃和反应时间为1 h时,酯收率可达99%以上;反应结束后离子液体与酯产物可分成两相,而且该离子液体重复使用8次,催化活性没有明显下降.探讨了阳离子结构及Br nsted酸性对催化活性的影响,考察了离子液体与酯化反应相关组分的互溶性.结果表明,离子液体的分相性能对催化效果有较大的影响,离子液体的催化活性与其酸性、溶解性密切相关.
A series of BrOEnsted acidic ionic liquids, including 2-pyrrolidonium hydrogen sulfate （[ Hnhp] HSO4 ）, 1-methyl-2-pyrrolidonium hydrogen sulfate （[Hnmp]HSO4）, 1-methylimidazolium hydrogen sulfate （[Hmim]- HSO4 ）, 1- （3-sulfonic acid） propyl-3-methylimidazolium hydrogen sulfate （ [ C3SO3 Hmim ] HSO4 ）, and 1- （3-sulfonic acid）propyl-2-pyrrolidonium hydrogen sulfate （[ C3SO3Hnhp] HSO4 ）, were synthesized and characterized. The catalytic activity of the acidic ionic liquids for the esterification of acetic acid with n-butanol was measured. Under the optimized conditions of n （n-BuOH） ： n （MeCO2H） ： n （ [ C3SO3 Hnhp ] HNO4 ） = 1.2 ： 1 ： 0. 005, 120℃ , and 1 h, the yield of n-butyl acetate could be greater than 99 %. The reaction system exhibited good biphasic behavior when the reaction was completed. There was no appreciable decrease in the yield of n-butyl acetate after the esterification was repeated 8 times. The miscibility of the five acidic ionic liquids with the related components of the reaction was investigated, and their biphasic effects on ester yields were examined. The structure- reactivity and Broensted acidity-catalytic activity relationships were also studied. The acidity and miscibility of the acidic ionic liquids are the important factors relevant to the catalytic activity for the esterification reaction. The activity of the acidic ionic liquids is in good agreement with their acidity order.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2007年第8期743-748,共6页
基金
广州市科技计划项目(2005 J1-C0231)
广东省科技计划项目(2006B13801007).
