碱性离子液体催化合成碳酸甲乙酯反应动力学

摘要

The transesterification reaction of dimethyl carbonate ( DMC) and diethyl carbonate ( DEC) for the synthesis of ethyl methyl carbonate ( EMC ) in the presence of several basic liquids was studied . Among these catalysts,1-butyl-3-methylimidazolium butyrate [C4mim][CH3(CH2)2COO] exhibited the best catalysis activity .The effects of reaction temperature ,catalyst loading and reactants molar ratio on the conversion of DEC on reaction rate were studied .Under the reaction temperature 363.15 K,catalyst load-ing 6%( based on the mass of all reactants),n(DMC)∶n(DEC)=1.5∶1,reaction time 6 h,the conver-sion of DEC was 50%.A pseudo-homogeneous ( PH) kinetic model was used to correlate the experimen-tal data.The activation energies of the positive and reverse reactions were 56.10,46.70 kJ/mol,and the pre-exponential factors were 1.17 ▍105,1.57 ▍103 L2/(mol· min· g),respectively.%以不同碱性离子液体催化碳酸二甲酯（DMC）与碳酸二乙酯（DEC）酯交换反应合成碳酸甲乙酯（EMC），研究了反应温度、催化剂的用量、反应物摩尔配比等因素对反应速率的影响。结果表明，碱性离子液体1-丁基-3-甲基咪唑丁酸盐[C4mim][CH3（CH2）2COO]显示出高的催化活性，在反应温度363．15 K，催化剂用量6％（占反应物总质量百分数），n（DMC）∶n（DEC）＝1．5∶1，反应时间6 h的条件下，DEC转化率达50％。建立了拟均相动力学模型，得出正逆反应活化能分别为56．10，46．70 kJ／mol，指前因子分别为1．17▍105，1．57▍103 L2／（mol· min· g）。