Monte Carlo simulation of carbon dioxide adsorption on highly crystalline carbonaceous materials obtained by chemical synthesis

In this work we examine, using Monte Carlo simulations, the adsorption capacities and isosteric heats of adsorption of new crystalline materials that have been synthesized in the laboratory but not yet explored for carbon dioxide adsorption. These included carbon nanocones (CNC), twisted macrocycles (C68, C72), nanographenes (COR, COR-Cl), and rylene propellers (TPH, TPH-Se). The materials were characterized by argon adsorption isotherms, showing high specific surface areas between 958–2370 m2/g. CO2 adsorption capacities at 273 K and 1 bar ranged from 1.15 (Formula presented.) 3.71 mmol/g. The twisted macrocycle C72 exhibited the highest micropore volume and consequently the greatest carbon dioxide adsorption at low pressures. TPH-Se displayed the highest capacity at 1 bar due to larger pores. Isosteric heats of adsorption were below 20 kJ/mol for all materials, lower than typical activated carbons. This study demonstrates the potential of crystalline carbons for selective CO2 capture and provides insight into relating structure and adsorption properties.