Agile construction of bifunctional bipyridine-based hyper-cross-linked ionic polymers for efficient CO2 adsorption and conversion

Porous organic polymers (POPs) are a very promising CO 2 adsorption material due to their well-developed pore structure and high specific surface area, but they generally have no catalytic activity for cycloaddition of CO 2 and epoxides. Introducing ionic sites into the polymer backbone can endow POPs with unique properties such as both adsorption and catalytic conversion of CO 2 . In this work, several novel bipyridine-based hyper-cross-linked ionic polymers (HCIPs) were fabricated by using a one-pot method with simultaneous quaternization and Friedel-Crafts reactions, and HCIPs with hierarchical pore structure and high specific surface area (up to 1448 m 2 ·g −1 ) are acquired by adjusting the structure of polymerized monomers. The plentiful micro-mesoporous and indigenous ion pair active centers of the as-prepared HCIPs are conducive to the adsorption and conversion of CO 2 . The results showed that these bipyridine-based HCIPs can not only effectively adsorb CO 2 , but also serve as the metal-free catalysts for cycloaddition of CO 2 with epoxides, affording the highest CO 2 uptake of 2.75 mmol·g −1 at 0 °C and 1.0 bar and moderate to good yields of cyclic carbonates. This study provides a feasible strategy for the design and synthesis of structurally controllable HCIPs for adsorption and conversion of CO 2 . • Bipyridine-based hyper-cross-linked ionic polymers (HCIPs) are fabricated by a one-pot method. • HCIPs as bifunctional materials for CO 2 adsorption and conversion. • HCIPs exhibit high specific surface area (up to 1448 m 2 ·g −1 ) and abundant ultramicropore. • HCIPs serve as the recyclable catalysts for cycloaddition of CO 2 with epoxides. • Moderate to good yields of cyclic carbonates are acquired under metal- and solvent-free conditions.