title: Cocatalyst-Free Hybrid Ionic Liquid (IL)-Based Porous Materials for Efficient Synthesis of Cyclic Carbonates through a Cooperative Activation Pathway.
abstract: Cocatalyst-free ionic liquid (IL)-based porous polymers (Px-Vy-OHzR) functionalized with an intermolecular hydroxyl group were prepared by means of radical copolymerization of 1-butyl-3-vinylimidazolium bromide, (4-vinylphenyl)methanol (VBzOH), and divinylbenzene (DVB) under solvothermal conditions. As the ratio of 4-vinylphenylmethanol in the initial mixture increased, the content of the hydroxyl groups in the polymer increased from 3.35 to 5.35 mmol g-1and the Brunauer-Emmett-Teller (BET) surface area of the polymer decreased sharply from 365 to 2.5 m2g-1. In the carbonation of CO2and epoxides, the turnover frequency (TOF) of Px-Vy-OHzR increased gradually from 25 to 67 h-1as the OH ratio increased irrespective of the sharp decrease in BET surface area, which suggests the existence of a cooperative activation effect between OH and ILs. To obtain a high OH content while still maintaining a high BET surface area, hybrid porous materials (SBA-[VxOHy]R-n) were prepared by means of copolymerization of 1-ethyl-3-vinylimidazolium bromide and 4-vinylphenylmethanol in the mesopores of SBA-15. SBA-[VxOHy]R-n was more active than its polymer counterpart (TOF: 188 versus 71 h-1) in the cycloaddition of CO2with propyl oxide owing to the combined effect of the high BET surface area and the high OH content. The hybridization of mesoporous materials with polymers represents an efficient strategy for the preparation of high-performance solid catalysts for chemical transformations.
authors.affiliation: State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, 116023, China.|International College, University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Sanjeevi
authors.initials: S
authors.lastname: Jayakumar
authors.affiliation: State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, 116023, China.
authors.forename: He
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, 116023, China.
authors.forename: Yaopeng
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, 116023, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, 116023, China.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Yang
keywords: carbon; cooperative phenomena; cycloaddition; ionic liquids; polymers