Tris-imidazolinium-based porous poly(ionic liquid)s as an efficient catalyst for decarboxylation of cyclic carbonate to epoxide

Yang Li; Liguo Wang; Yan Cao; Shuang Xu; Peng He; Huiquan Li; Hui Liu

doi:10.1039/d1ra01039e

Tris-imidazolinium-based porous poly(ionic liquid)s as an efficient catalyst for decarboxylation of cyclic carbonate to epoxide

RSC Adv. 2021 Apr 15;11(23):14193-14202. doi: 10.1039/d1ra01039e. eCollection 2021 Apr 13.

Authors

Yang Li¹, Liguo Wang^{2

3

4

5}, Yan Cao², Shuang Xu², Peng He², Huiquan Li^{2

3

4}, Hui Liu¹

Affiliations

¹ State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Energy Environmental Catalysis, College of Chemical Engineering, Beijing University of Chemical Technology Beijing 100029 China hliu@mail.buct.edu.cn.
² CAS Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Clean Production Technology, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 China lgwang@ipe.ac.cn.
³ Sino-Danish College, University of Chinese Academy of Sciences Beijing 100049 China.
⁴ Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences Beijing 10049 China.
⁵ Dalian National Laboratory for Clean Energy Dalian 116023 China.

Abstract

A series of imidazolinium-based porous poly(ionic liquid)s (PILs) with different anions prepared by free-radical copolymerization of an arene-bridged tris-vinylimidazolium salt and divinylbenzene (DVB) were constructed. The as-prepared PILs were characterized by BET, SEM, TEM, TGA and Elemental Analysis (EA), and the results showed that they had plentiful ionic sites, and abundant and stable mesopores. In particular, the density of ionic sites and pore structure of PILs could be controlled by adjusting the content of DVB. Moreover, the PILs were used as efficient heterogeneous catalysts for the decarboxylation of cyclic carbonates to epoxides for the first time. Results showed that the catalytic activity of PILs was positively correlated with the nucleophilicity of the anions in PILs, and PDVB-[PhTVIM]Cl-1 with a chloride anion-enriched skeleton displayed the best catalytic performance. Without any solvent or cocatalyst, PDVB-[PhTVIM]Cl-1 achieved a TOF value of 108.1 h^-1 and the yield of butylene oxide of 89.6%, which was even better than the homogeneous IL-based catalysts (TOF value: 8.7 h^-1) that had been previously reported. Meanwhile, PDVB-[PhTVIM]Cl-1 also exhibited excellent recyclability and substrate compatibility.