催化学报 ›› 2018, Vol. 39 ›› Issue (6): 1110-1120.DOI: 10.1016/S1872-2067(18)63071-2

• 论文 • 上一篇    下一篇

新型高效Brönsted酸性离子液体催化剂体系催化烯烃齐聚反应

王国芹a,b, 宋河远a,b, 李瑞云a,b, 李臻a, 陈静a   

  1. a 中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室, 甘肃兰州 730000;
    b 中国科学院大学, 北京 100049
  • 收稿日期:2017-12-28 修回日期:2018-04-11 出版日期:2018-06-18 发布日期:2018-05-16
  • 通讯作者: 陈静
  • 基金资助:

    国家自然科学基金(21473225).

Olefin oligomerization via new and efficient Brönsted acidic ionic liquid catalyst systems

Guoqin Wanga,b, Heyuan Songa,b, Ruiyun Lia,b, Zhen Lia, Jing Chena   

  1. a State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-12-28 Revised:2018-04-11 Online:2018-06-18 Published:2018-05-16
  • Contact: 10.1016/S1872-2067(18)63071-2
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21473225).

摘要:

烯烃齐聚是重要的化工反应之一,是指低碳烯烃在催化剂存在下发生聚合反应,生成一个或多个单体重复相连的化合物过程.烯烃齐聚反应是一种碳链增长过程,是生成线性α-烯烃的重要过程.齐聚反应主要生成单体的二聚、三聚、四聚或五聚物等低聚体,发生反应的单体主要是低碳烯烃如乙烯、丙烯、正丁烯和异丁烯等.烯烃齐聚产物应用十分广泛,可以用于合成环境友好的液体燃料、长链烷烃润滑油、表面活性剂、增塑剂、汽油柴油添加剂等重要化工产品,同时齐聚产物本身亦是重要的化工中间体和化学试剂.烯烃齐聚反应研究的重点内容是开发新颖高效的催化剂,以满足不同需要,而应用Brönsted酸性功能化离子液体作为催化剂用于齐聚反应的报道较少.
本文考察了新型高效催化剂体系(Brönsted酸性离子液体作为主催化剂,三辛基甲基氯化铵作为助剂)对烯烃齐聚反应的催化性能.合成的Brönsted酸性离子液体通过红外光谱、紫外可见光谱、1H核磁共振和13C核磁共振等进行系列表征,并进一步分析其结构与酸度的关系.结果表明,在相同的反应条件下,Brönsted酸性离子液体[HIMBs]HSO4对烯烃齐聚反应具有最好的催化活性.本文考察了不同离子液体、离子液体用量、不同助剂、助剂用量、反应时间、反应压力、反应温度和不同溶剂等因素对反应的影响,得到了最佳反应条件:催化剂体系为[HIMBs]HSO4与三辛基甲基氯化铵,[HIMBs]HSO4/异丁烯摩尔比为25%,[HIMBs]HSO4/助剂(三辛基甲基氯化铵)摩尔比为20:1,140℃ 8h,反应起始压力为2.0MPa,无添加溶剂(离子液体本身作催化剂和溶剂).在最佳反应条件下对反应物进行了拓展,并研究了催化剂体系的循环使用情况.在最佳反应条件下,异丁烯齐聚反应中反应物转化率为83.21%,三聚物选择性高达35.80%,二聚物选择性为52.02%,四聚物选择性为3.14%.结果表明,本文提出的催化剂体系对烯烃齐聚反应具有较好的催化性能.同时,催化剂体系可以通过静置分层与产物分离,并进行循环使用.根据以往的报道和反应产物分布,推测了烯烃齐聚反应机理.烯烃齐聚反应为酸催化反应,生成碳正离子中间体进行碳链增长,生成齐聚产物.

关键词: Brönsted酸性离子液体, 烯烃, 齐聚反应, 催化反应, 共催化剂

Abstract:

Olefin oligomerization reaction catalyzed by new catalyst systems (a Brönsted-acidic ionic liquid as the main catalyst and tricaprylylmethylammonium chloride as the co-catalyst) has been investigated. The synthesized Brönsted acidic ionic liquids were characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV), 1H nuclear magnetic resonance (NMR), and 13C NMR to analyze their structures and acidities. The influence of different ionic liquids, ionic liquid loading, different co-catalysts, catalyst ratios (mole ratio of ionic liquid to co-catalyst), reaction time, pressure, temperature, solvent, source of reactants, and the recycling of catalyst systems was studied. Among the synthesized ionic liquids, 1-(4-sulfonic acid)butyl-3-hexylimidazolium hydrogen sulfate ([HIMBs]HSO4) exhibited the best catalytic activity under the tested reaction conditions. The conversion of isobutene and selectivity of trimers were 83.21% and 35.80%, respectively, at the optimum reaction conditions. Furthermore, the catalyst system can be easily separated and reused; a feasible reaction mechanism is proposed on the basis of the distribution of experimental products.

Key words: Brönsted acidic ionic liquid, Olefin, Oligomerization, Catalysis, Co-catalyst