Engineering the Pore Structure and Functionality of Ionic Porous Polymers for Separating Acetylene over Carbon Dioxide

Abstract

AbstractPrecise engineering of organic porous polymers to realize the selective separation of structurally similar gases presents a great challenge. In this study, a new class of ionic porous polymers P(Ph3Im‐Br‐nDVB) with a high ionic density and microporous surface area are constructed through a facile copolymerization strategy, providing an efficient path to rational control over pore structure and functionality. The first example of ionic porous organic polymers is reported to address the challenge of discriminating the subtle difference of C2H2 and CO2, which have almost identical molecular sizes and similar physicochemical properties, which achieve the highest C2H2/CO2 selectivity (17.9) among porous organic polymers. These ionic porous polymers exhibit high stability and excellent dynamic breakthrough performance for binary C2H2/CO2 mixtures, indicating their practical feasibility. Modeling studies reveal that anions are the specific binding sites for preferential C2H2 capture because of Br−···HCCH interactions. This study not only demonstrates an efficient strategy to build novel ionic porous polymers integrating abundant micropores and ionic sites but also sheds some light on the development of functionalized materials for the separation of structurally similar gas molecules.