Ionic-containing hyper-crosslinked polymer: A promising bifunctional material for CO2 capture and conversion

Abstract

Hyper-crosslinked polymers (HCPs) are a category of porous materials with the high specific surface area, abundant pore canal, and tunable structure. A very challenging topic is to fabricate ion-pair active sites into the skeleton structure of HCPs, which can endow HCPs with specific CO2 separation and catalytic characters. In this work, a series of hyper-crosslinked polymers with the high specific surface area and tunable ion-pair active sites are fabricated by using a one-pot method with simultaneous quaternization and Friedel-Crafts reactions. These ion-pair-containing hyper-crosslinked polymers (IHCPs) are served as adsorbents for selective separation of CO2 from CH4 and N2. It is found that CO2 uptake of IHCP-2 reaches 2.87 mmol·g−1 at 273 K and 1 bar, which is higher than that of the same type of ionic polymers that have been reported in the literature. The high CO2 adsorption capacity is due to the abundant microporous and high specific surface area of as-prepared IHCPs. More importantly, these IHCPs can also be used as recyclable catalysts for cycloaddition of CO2 and epoxides under metal- and cocatalyst-free conditions, affording corresponding cyclic carbonates in excellent yields. The high catalytic activity is attributed to synergistic contributions of the hierarchical pores and nucleophilic ion pair’s structure. This research provides an alternative strategy for development of bifunctional function materials towards efficient CO2 capture and conversion.