摘要
采用溶胶-凝胶法制备了以SiO2为载体的固载化离子液体催化剂,并将其首次用于催化碳酸乙烯酯(EC)水解制备乙二醇(EG)的反应.结果表明,固载化碱性离子液体S-[bpim][HCO3]对碳酸乙烯酯水解制EG反应具有良好的催化活性和EG选择性,克服了非均相催化剂活性不高与均相催化剂难以分离的不足.在催化剂浓度为0.0511g/mL、温度140℃、压力0.4MPa及EC/H2O=1:2(摩尔比)、反应时间3h的条件下,EC转化率达99.7%,EG选择性为100%.该催化剂在循环使用5次后,EC转化率无明显下降,EG的选择性始终接近100%.
The SiO2 immobilized ionic liquid catalyst S-[bpim]Br was prepared through sol-gel method. By treatment of S-[bpim]Br with potassium hydrogen carbonate, S-[bpim][HCO3] was obtained. Then, the catalytic activity of SiO2 immobilized ionic liquid in the synthesis of ethylene glycol （EG） via hydrolysis of ethylene carbonate （EC） was studied. The results showed that the immobilized basic ionic liquid S-[bpim][HCO3] exhibited good performance on the hydrolysis of ethylene carbonate and could be separated easily from the reaction system. Moreover, the effects of temperature, molar ratio of EC to H2O, reaction pressure, reaction time, and content of catalyst were also investigated in detail. The optimal reaction conditions were determined as follows： reaction temperature 140 ℃, reaction pressure 0.4 MPa, molar ratio of water to ethylene carbonate 2：1 and reaction time 3 h. Under above conditions, 99.7% EC conversion rate and 100% EG selectivity were obtained. Additionally, the catalyst could be reused at least 5 times with slight loss of its activity.
出处
《过程工程学报》
CAS
CSCD
北大核心
2009年第5期904-909,共6页
The Chinese Journal of Process Engineering
基金
国家自然科学基金资助项目(编号:20876162)
中国科学院知识创新工程重要方向基金资助项目(编号:KGCX2-YW-321)
国家科技支撑计划资助项目(编号:2008BAF33B04)
关键词
碳酸乙烯酯
水解
离子液体
固载
乙二醇
ethylene carbonate
hydrolysis
ionic liquids
immobilization
ethylene glycol
