Page 156 - 《精细化工》2020年第7期

第 37 卷第 7 期 精 细 化 工 Vol.37, No.7
202 0 年 7 月 FINE CHEMICALS July 2020

催化与分离提纯技术
高热稳定强碱性离子液体用于碳酸二甲酯合成

刘 菊 1,2 ，石 磊 1,2* ，陈 飞 1,2 ，邓文杰 1,2 ，范家麒 1,2 ，许光文 1,2*

（1. 沈阳化工大学 资源化工与材料教育部重点实验室，辽宁 沈阳 110142；2. 沈阳化工大学 能源与化
工产业技术研究院，辽宁 沈阳 110142）

摘要：以咪唑、氢氧化钾和 1-乙基-3-甲基咪唑溴盐（[Emim]Br）为原料，制得 1-乙基-3-甲基咪唑咪唑盐
（[Emim]IM）。并考察了一系列咪唑类离子液体对催化碳酸乙烯酯（EC）与甲醇（MeOH）酯交换合成碳酸二
甲酯（DMC）的影响。根据 GC-MS 分析，推测了反应机理及路径。结果表明：提高碱强度、增加阴离子半径
或缩短咪唑阳离子烷基取代基碳链长度均有利于促进酯交换反应的进行。离子液体[Emim]IM 具有阴、阳离子作
用相对较弱、阴离子电负性较强的特性，将其用于催化 EC 与 MeOH 酯交换合成 DMC。结果显示，[Emim]IM
活性与甲醇钠相当。在反应温度为 68 ℃，n(EC)∶n(MeOH)=1∶10，催化剂用量为反应原料总质量的 0.3%时，
1 min 即达到反应平衡，DMC 选择性为 100%，收率为 88.70%。随着温度升高、MeOH 含量增加，DMC 收率逐
渐升高。即使在 0 ℃下反应，[Emim]IM 仍具有较好的催化活性，与商业化的最优 1,3-二甲基咪唑碘盐（[Mmim]I）
离子液体催化效率相当。催化剂重复使用 20 次，DMC 收率一直维持在 88%~90%，展现出极佳的稳定性。
关键词：碳酸二甲酯；碳酸乙烯酯；酯交换反应；离子液体；强碱性；催化技术
中图分类号：TQ225.5；TQ426.94 文献标识码：A 文章编号：1003-5214 (2020) 07-1438-09

Thermostable strong alkalinity ionic liquid using for
synthesis of dimethyl carbonate

1,2
1,2
1,2
1,2
LIU Ju , SHI Lei 1,2* , CHEN Fei , DENG Wenjie , FAN Jiaqi , XU Guangwen 1,2*
（1. Key Laboratory on Resources Chemicals and Materials of Ministry of Education, Shenyang University of Chemical
Technology, Shenyang 110142, Liaoning, China; 2. Institute of Industrial Chemistry and Energy Technology, Shenyang
University of Chemical Technology, Shenyang 110142, Liaoning, China）
Abstract: 1-Ethyl-3-methylimidazole salt ([Emim]IM) was prepared from imidazole, potassium hydroxide
and 1-ethyl-3-methylimidazole bromide ([Emim]Br). The effects of a series of imidazole ionic liquids on
the transesterification of ethylene carbonate (EC) with methanol to synthesize dimethyl carbonate (DMC)
were investigated. The reaction mechanism and route were proposed according to GC-MS analysis results.
The results showed that increasing the base strength, increasing the anion radius or shortening the length of
imidazole cationic alkyl substituent carbon chain were all beneficial to promote the transesterification.
[Emim]IM had the characteristics of relatively weak anion and cation action and strong electronegativity of
anions. It was used to catalyze synthesis of DMC. It was found that the catalytic activity of [Emim]IM was
consistent with that of sodium methoxide. The reaction equilibrium was reached in 1 min, the selectivity
and yield of DMC were 100% and 88.70% under the conditions of reaction temperature 68 ℃, catalyst
amount 0.3% of the total mass of reaction raw material, n(EC)∶n(MeOH)=1∶10. With the increasing of
reaction temperature and MeOH content, the yield of DMC increased gradually. [Emim]IM still exhibited
better activity even if the reaction was carried out at 0 ℃, which was equivalent to that of commercial
optimal ionic liquid 1, 3-dimethylimidazole iodized salt ([Mmim]I). After reused for 20 times, the yield of
DMC was maintained at 88%~90%, showing that [Emim]IM had excellent stability.

收稿日期：2020-01-04; 定用日期：2020-03-18; DOI: 10.13550/j.jxhg.20200012
基金项目：国家重点研发计划（2018YFB0604500）；国家自然科学基金（21303106）；辽宁省高等学校创新人才（LR2016015）
作者简介：刘 菊（1993—），女，硕士生，E-mail：1304504017@qq.com。联系人：石 磊（1982—），男，教授，E-mail：shilei1982
@dicp.ac.cn；许光文（1968—），男，教授，E-mail：gwxu@syuct.edu.cn。