Anion-rich porous poly(ionic liquid)s for efficient CO2 conversion into cyclic carbonates through hydrogen bonding synergistic effect

Abstract

Ionic liquids have widely been recognized as highly effective catalysts for the synthesis of cyclic carbonates from CO2 and epoxides. However, the cumbersome separation process hinders the practical application of these catalysts. In this study, a strategy involving free radical polymerization was employed to successfully co-polymerized monomers of ionic liquid and divinylbenzene (DVB), resulting in the fabrication of anion-rich porous poly(ionic liquid)s (PILs) that incorporated a hydrogen bonding site of -NH2-+. The texture properties of the as-prepared PILs were characterized in detail, and they were then utilized as catalysts for the cycloaddition of CO2 and epoxides to form cyclic carbonates. Remarkably, the reaction exhibited a remarkable yield of up to 99 % under solvent- and metal-free conditions. It is noteworthy that PIL-2 demonstrated easy recoverability, with a slight reduction in catalytic activity of about 7 % after five cycles. Additionally, a mechanism based on hydrogen bond synergistic for the conversion of CO2 by anion-rich porous PILs was proposed. This study offers a valuable insight for the development of recyclable poly(ionic liquid)s catalysts for CO2 conversion.