Highly porous nitrogen-doped polyimine-based carbons with adjustable microstructures for CO2 capture

A series of highly porous nitrogen doped porous carbons (NPCs) have been successfully prepared using a novel porous polyimine as the precursor. The resulting NPCs have a high specific surface area of up to 3195 m(2) g(-1), high pore volume and micropore volume (up to 1.58 and 1.38 cm(3) g(-1), respectively), narrow micropore size distributions, and adjustable nitrogen (1.52-5.05 wt%) depending on the activation temperatures (600-750 degrees C). The CO2 uptakes of the NPCs prepared at higher temperatures (700-750 degrees C) are lower than those prepared at milder conditions (600-650 degrees C). At 1 bar, NPC-650 demonstrates the best CO2 capture performance and could efficiently adsorb CO2 molecules of 3.10 mmol g(-1) (136 mg g(-1)) and 5.26 mmol g(-1) (231.3 mg g(-1)), at 25 and 0 degrees C, respectively. The NPCs also show good a initial CO2/N-2 adsorption selectivity of up to 23.4 and an adsorption ratio of CO2/N-2 (6.6) at 1 bar. Meanwhile, these NPCs exhibit a high stability and facile regeneration/recyclability without evident loss of the CO2 capture capacities.