Facile synthesis of a thermally stable imine and benzimidazole functionalized nanoporous polymer (IBFNP) for CO₂ capture application

An imine and benzimidazole functionalized nanoporous polymer (IBFNP) has been synthesized by a single-step condensation reaction between 3,3-diaminobenzidene and terephthaldehyde at 150 C. The IBFNP-1 has a moderately high BET specific surface area of 1040 m²/g with pore diameter centered at 1.4 nm and pore volume of 1.46 cm³/g. The IBFNP-1 could reversibly capture 5.27 mmol/g (23.2 wt%) of CO₂ at 273 K and 1 atm, which is among the best reported microporous organic polymers. The good selectivity of CO₂ over N₂ (65:1) and moderately high isosteric heat of adsorption (33.8 kJ/mol) make this material a good adsorbent for the CO₂ capture application.