Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (6): 1110-1120.DOI: 10.1016/S1872-2067(18)63071-2

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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).

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