Nitrogen-doped mesoporous carbon for carbon capture - A molecular simulation study

Using molecular simulation, we investigate the effect of nitrogen doping on adsorption capacity and selectivity of CO ₂ versus N ₂ in model mesoporous carbon. We show that nitrogen doping greatly enhances CO ₂ adsorption capacity; with a 7 wt % dopant concentration, the adsorption capacity at 1 bar and 298 K increases from 3 to 12 mmol/g (or 48% uptake by weight). This great enhancement is due to the preferred interaction between CO ₂ and the electronegative nitrogen. The nitrogen doping coupled with the mesoporosity also leads to a much higher working capacity for adsorption of the CO ₂/N ₂ mixture in nitrogen-doped mesoporous carbon. In addition, the CO ₂/N ₂ selectivity is almost 5 times greater than in nondoped carbon at ambient conditions. This work indicates that nitrogen doping is a promising strategy to create mesoporous carbons for high-capacity, selective carbon capture.