One-pot synthesis of bromine anion-rich ionic porous organic polymers for CO2 catalytic conversion

Abstract

The porous organic polymers HIP-Br-1 and HIP-Br-2 rich in bromine anions were prepared via a one-pot quaternization method. The contents of N and Br in HIP-Br-1 reached 15.93 wt% and 6.94 wt% respectively. These high content of bromine ions combined with the rich mesoporous and macroporous structures endowed the materials with good catalytic ability. The material exhibited moderate adsorption heat (28–36 kJ mol⁻¹). Catalytic experiments demonstrated that HIP-Br-1 has good catalytic performance. Under mild conditions of 0.4 MPa CO₂, 60 °C, and 9 h, without the use of any co-catalyst or solvent, 93% of propylene oxide was converted to cyclic carbonate. The catalyst showed good repeatability, with the conversion efficiency to cyclic carbonate remaining stable after four catalytic cycles. Density functional theory (DFT) calculations indicated that HIP-Br-1 can effectively activate epoxypropane (PO) and CO₂, thereby enhancing the catalytic activity of cycloaddition reactions. This work explores the one-step synthesis of ion-type porous organic polymers rich in nitrogen atoms.