N-enriched porous carbons derived from polymeric precursors for CO₂ capture: quantifying the role of ultramicropores and pyridinic-N sites
Year: 2025
Type: preprint
Abstract: Nitrogen-doped porous carbon (NPC) derived from N-containing organic polymer is a promising CO2 adsorbent. However, the nitrogen content in currently prepared organic polymer materials remains low, leading to a low nitrogen content in the synthesized NPCs, which limits their improvement in CO2 adsorption capacity. Furthermore, the roles of different nitrogen groups in CO₂ adsorption remain a subject of ongoing debate. In this work, a series of NPCs with high nitrogen content were obtained by the carbonization of nitrogen rich organic polymer at different temperatures and activation ratios, which was synthesized by acid-catalyzed one-step polycondensation reaction using pyrrole and melamine as monomer and nitrogen source. The results indicated that all the NPCs had a hierarchical porous structure comprising both micropores and mesopores. Among the samples, NPC-550-2 demonstrated the highest BET surface area (1170.9 m²/g), micropore volume (0.95 cm³/g) and nitrogen content (10.21 wt%), resulting in a high CO₂ adsorption capacity of 3.38 mmol/g at 1 bar and 298 K, high adsorption selectivity (52.44) and good recyclability. Furthermore, the effects of pore structure and nitrogen groups on CO2 capture were analyzed and showed that nitrogen groups played an important role in CO₂ adsorption, followed by ultramicropores (<0.63 nm). Specially, both experiment and density functional theory (DFT) calculation revealed that among the nitrogen species, pyridinic nitrogen exhibited greater influence on CO₂ adsorption attributed to the strong acid–base interactions. The work provides a promising porous carbon material for CO2 capture and offers theoretical guidance for designing porous materials with high CO2 adsorption capacity.
Authors: Huijuan Liu, Longfei Liu, Jiayao Cheng, Haijiao XIE, Hongjie Wang
Institution: Hebei University
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
OpenAlex ID: W4413827331