Graphene-based semi-coke porous carbon with N-rich hierarchical sandwich-like structure for efficient separation of CO2/N2

Abstract The semi-coke based porous carbon has the advantage of low price for carbon dioxide adsorption. However, its selectivity and adsorption capacity is not ideal. Therefore, we proposed a new strategy for preparing graphene based semi-coke porous carbon with a nitrogen-rich layered sandwich structure. The specific surface area of the porous carbon was 701.53 m2 g−1, the microporosity was 74%, and the adsorption capacity of CO2 at 298 K and 30 bar reached 7.11 mmol∙g−1. This is because the layer spacing contributes to the superior CO2 transport and storage. Additionally, the CO2/N2 selectivity of CO2 was greatly improved due to the introduction of secondary amino acids. Therefore, the excellent separation selectivity of the binary mixture (CO2/N2 = 28.24, at 298 K) was achieved. Finally, the adsorption heat and cycle stability analysis demonstrated that it has outstanding cycle regeneration ability. The strategy proposed in this work provides a new idea for the commercial application and development of porous carbon.