Abstract

Ordered-interconnected porous carbon with nitrogen functionalities is a potential adsorbent for CO<inf>2</inf> capture since it could adsorb CO<inf>2</inf> gas through both physical and chemical mechanisms. Herein, we reported the preparation of ordered-interconnected porous carbons having nitrogen functionalities based on polybenzoxazine using a silica templating method. The CO<inf>2</inf> adsorption measurement was performed at 30 °C and the pressure was varied from 1 to 40 bar. The results showed that the specific surface area (SSA) and pore volume showed a correlation trend indicating the increase with increasing silica templates up to 40 % and the carbon samples contained nitrogen functionalities on the surface (pyrrolic and pyridonic nitrogen, pyridinic nitrogen, and oxidized nitrogen). After CO<inf>2</inf> activation, the nitrogen functionalities are still present on the surface of the porous carbon and the sample based on 40 wt% of silica (AC40%Si-800) exhibited the greatest SSA (1,391 m²/g) with extremely large pore volume (3.77 cm³/g). This led to the largest amount of CO<inf>2</inf> uptake (25.07 mmol/g at 40 bar) recorded to date. For the first time, the computational study revealed that only pyridinic nitrogen (N-6) is capable of chemically adsorbing CO<inf>2</inf> molecules via Lewis acid-base interaction, which synergistically enhanced the adsorption capability.