欢迎访问过程工程学报, 今天是

›› 2007, Vol. 7 ›› Issue (1): 59-62.

• 反应与分离 • 上一篇    下一篇

[Bmim]Cl/AlCl3离子液体催化C16~C18直链烯烃/苯烷基化反应

董斌琦,吴芹,韩明汉,辛洪良   

  1. 清华大学化工系
  • 出版日期:2007-02-20 发布日期:2007-02-20

Alkylation of Benzene with C16~C18 Olefins Catalyzed by [Bmim]Cl/AlCl3 Ionic Liquid

DONG Bin-qi,WU Qin,HAN Ming-han,XIN Hong-liang   

  1. Department of Chemical Engineering, Tsinghua University
  • Online:2007-02-20 Published:2007-02-20

PDF

摘要： 采用不同AlCl3摩尔分数的[Bmim]Cl/AlCl3离子液体，研究了不同工艺条件下C16~C18直链烯烃与苯烷基化反应. 常温下，采用AlCl3摩尔分数为0.67的[Bmim]Cl/AlCl3离子液体催化剂，在苯烯摩尔比为6，AlCl3与烯烃摩尔比为0.04的条件下，30 min内烯烃转化率可以达到98%，2位烷基苯选择性为46%左右. 通过红外乙腈分子探针表征离子液体的Lewis酸性并结合烷基化反应结果表明，离子液体中AlCl3摩尔分数增加，Lewis酸性增强，催化活性增高. 通过红外苯分子探针对离子液体极化能力进行表征，发现离子液体具有较强的极化能力，可以促进碳正离子的稳定性. 另外，还考察了烯烃碳链长度对苯烷基化反应的影响.

关键词: 重烷基苯, 离子液体, 烷基化反应, 红外光谱, Lewis酸

Abstract: The alkylation of benzene with a-C16~C18 olefins catalyzed by 1-butyl-3-methylimidazolium-aluminum chloride ([Bmim]Cl/AlCl3) ionic liquid with different aluminum chloride molar fractions was studied under different reaction conditions. At room temperature, a high conversion rate of 98% of olefins and a high selectivity of 46% of 2-alkylbenzene were obtained within 30 min when the aluminum chloride molar fraction x was 0.67 and molar ratio of AlCl3 in the catalyst to olefins was 0.04. The Lewis acidity strength of the ionic liquids with different molar fractions of aluminum chloride, which was characterized by infrared spectroscopy using acetonitrile molecule as probe, was correlated with the performance of catalyst in alkylation reaction. The ionic liquid showing a strong Lewis acidity strength had good performance in alkylation reaction. Strong polarizabilities of the ionic liquid characterized by FT-IR spectra using benzene as molecule probe could stabilize the carbenium ion intermediate. In addition, the effect of different olefins on alkylation reaction was also investigated.

Key words: heavy alkylbenzene, ionic liquid, alkylation, infrared spectroscopy, Lewis acid