Carbohydrate based hyper-crosslinked organic polymers with -OH functional groups for CO₂ separation

Recently, microporous organic polymers, especially those hyper-crosslinked from functionalized aromatic monomers, have been shown to be effective for CO₂ capture and storage with considerable capacity and selectivity. Herein, a class of novel microporous hyper-crosslinked polymers (HCPs), based on green and renewable carbohydrates, was synthesized by Friedel-Crafts alkylation for carbon capture and storage by hydrogen bonding and dipole-quadrupole interactions. These carbohydrate polymers, which have BET surface areas around 800 m² g^-1, can absorb a considerable amount of CO₂ with the CO₂/N₂ selectivity up to 42 at 273 K, and 96 under 100 kPa in the mixed gases (0.15 mol CO₂ and 0.85 mol N₂). Furthermore, we experimentally and computationally studied the structures of carbohydrate backbones and determined several features that govern their CO₂ absorption ability, which sheds light on understanding the structure/function relationship for designing better CO₂ separation materials.