Nitrogen-doped porous carbon for excellent CO2 capture: A novel method for preparation and performance evaluation

Heteroatomic doped porous carbon (HPCs) is a promising advanced material, showing great application potential in greenhouse gas capture. Here, in-situ N-doped porous carbon (NPC) was developed via a novel and readily scalable strategy one-step solvent-free melt polycondensation assisted by organic potassium salts, followed by pyrolysis and activation. As both a template and an activator, the added C6H5K3O7 played an important role to create abundant microporous structure. The as-fabricated NPC-650-0.5 showed a rich N content (6.11 at.%), abundant narrow micro-porosity (0.3437 cm(3).g(-1)), and a high surface area (1209.37 m(2).g(-1)) and delivered an excellent CO2 static adsorption capacity (4.16 mmol.g(-1) and 8.40 mmol.g(-1) at 100 and 500 kPa), a fast adsorption kinetics (circa 98% of balance capacity in 12 min), moderate heat of adsorption (25 to 30 kJ/mol), high selectivity of CO2/N-2, and outstanding uninterrupted recyclability. Both the narrow micropore volume and N-doping sites had strong effects on the CO2 adsorption capacity, indicating a physical and chemical adsorption process with the mechanism being multi-layer adsorption by the micropore filling. This work highlights the great potential of the NPC-650-0.5 for capturing CO2 and offers new insights into a green activator and a simple and easy-to-scale method for preparing HPCs.