磺酸功能化离子液体催化甘油与甲醇醚化反应

Etherification of glycerol with methanol catalyzed by SO_3H-functioned ionic liquids

考察了[HSO3-bmim]CF3SO3、[HSO3-bmim]P-TSA、[HSO3-bmim]HSO4和[HSO3-bmim]H2PO4四种磺酸功能化离子液体对甘油与甲醇醚化反应的影响。结果表明,离子液体的催化性能与其酸强度相关联,[HSO3-bmim]CF3SO3离子液体的酸强度最强,其催化性能也最好。以[HSO3-bmim]CF3SO3为催化剂,在w([HSO3-bmim]CF3SO3)/w(甘油)=0.5∶1(质量比)、n(甲醇)/n(甘油)=8∶1(摩尔比)、反应温度190℃、反应时间8h时,甘油的转化率为84.5%,单甲基甘油醚的选择性为41.4%,二甲基甘油醚和三甲基甘油醚的联合选择性为34.1%。在此基础上,提出了离子液体[HSO3-bmim]CF3SO3催化甘油与甲醇醚化反应的反应机理。

The catalytic performance of some SO3H-functionalized ionic liquids （ [HSO3-bmim]CF3SO3, [HSO3-bmim]P-TSA, [HSO3-bmim] HSO4 and [HSO3-bmim] H2PO4） in the etherification of glycerol with methanol was evaluated, and the results showed that the catalytic performance of the ionic liquids correlated well with their acid strength. [HSO3-bmim]CF3SO3 had the highest acid strength and showed the best catalytic performance. Under the suitable reaction conditions of mass ratio of [HSO3-bmim]CF3SO3 to glycerol 0.5 ： 1, molar ratio of methanol to glycerol 8： 1, reaction temperature 190℃ and reaction time 8 h, conversion of glycerol was 84.5%, selectivity to methyl glycerol ethers and total selectivity to both dimethyl glycerol ethers and trimethyl glycerol ethers were 41.4% and 34.1%, respectively. In addition, the reaction mechanism for etherification of glycerol with methanol in the presence of [HSO3-bmim]CF3SO3 was proposed.