Hypercrosslinked Ionic Polymers with High Ionic Content for Efficient Conversion of Carbon Dioxide into Cyclic Carbonates

Abstract

The effective conversion of carbon dioxide (CO2) into cyclic carbonates requires porous materials with high ionic content and large specific surface area. Herein, we developed a new systematic post-synthetic modification strategy for synthesizing imidazolium-based hypercrosslinked ionic polymers (HIPs) with high ionic content (up to 2.1 mmol g−1) and large specific surface area (385 m2 g−1) from porous hypercrosslinked polymers (HCPs) through addition reaction and quaternization. The obtained HIPs were efficient in CO2 capture and conversion. Under the synergistic effect of high ionic content, large specific surface area, and plentiful micro/mesoporosity, the metal-free catalyst [HCP-CH2-Im][Cl]-1 exhibited quantitative selectivities, high catalytic yields, and good substrate compatibility for the conversion of CO2 into cyclic carbonates at atmospheric pressure (0.1 MPa) in a shorter reaction time in the absence of cocatalysts, solvents, and additives. High catalytic yields (styrene oxide, 120 °C, 8 h, 94% yield; 100 °C, 20 h, 93% yield) can be achieved by appropriately extending the reaction times at low temperature, and the reaction times are shorter than other porous materials under the same conditions. This work provides a new strategy for synthesizing an efficient metal-free heterogeneous catalyst with high ionic content and a large specific surface area from HCPs for the conversion of CO2 into cyclic carbonates. It also demonstrates that the ionic content and specific surface area must be coordinated to obtain high catalytic activity for CO2 cycloaddition reaction.

Carbon Dioxide Capture by Emerging Innovative Polymers: Status and Perspectives

“…Generally, HIPs are primarily synthesized through the crosslinking of ionic and neutral monomers, the in situ generation of ionic sites during hypercrosslinking, and postfunctionalization strategies. [125] To date, numerous HIPs materials have been synthesized for CO 2 capture and Reproduced with permission. [116] Copyright 2023, American Chemical Society.…”

Maximizing the ionic liquid content and specific surface area in hierarchically nanoporous hypercrosslinked poly(ionic liquid)s towards the efficient conversion of CO2 into cyclic carbonates

“…Even so, the TOF value over HPMBr0.5 (80 °C, 24 h) is 9 times that of 0.68 h −1 for COF-IL (80 °C, 48 h), more than 4 times that of 1.4 h −1 for IM-iPHP-2 (80 °C, 48 h), 6 times that of 1.0 h −1 for IP 3 (100 °C, 24 h), about 1.5 times that of 4.4 h −1 for DB10%-Pa-Tp (120 °C, 96 h), and even more than 2 times that of 2.6 h −1 for [HCP-CH 2 -Im][Cl]-1 (140 °C, 4 h). 14,31,35,51,69 The good catalytic performance of HPMBr0.5 inspires us to examine the substrate compatibility of epoxides at atmospheric pressure (Table 2). For the styrene oxide (SO), HPMBr0.5 can provide 94.7% yield and 98.5% selectivity of target styrene carbonate within 36 h, accompanied by a TOF of 3.8 h −1 (entry 6).…”

Chemical Fixation of Carbon Dioxide into Cyclic Carbonates Catalyzed by Porous Materials

“…In 2022, Lin′s team [59] developed a new systematic post‐synthetic modification strategy for synthesizing imidazolium‐based HCPs named [HCP‐CH 2 ‐Im][Cl]‐1 (Scheme 13). [HCP‐CH 2 ‐Im][Cl]‐1 could convert CO 2 into cyclic carbonate with a yield of 94 % at normal pressure with no auxiliary catalyst, solvent, and additive.…”