A computational study to design zeolite-templated carbon materials with high performance for CO2/N2 separation

A comprehensive computational study was performed to develop zeolite-templated carbon (ZTC) materials for efficient carbon dioxide (CO2) and nitrogen (N-2) separation. From the previously reported ZTC structure library, our screening based on the grand canonical Monte Carlo simulations identified the types of top ZTCs having high selectivity (S-CO2/N2) of CO2 over N-2. A detailed investigation about pore structure-property relationship elucidated that high S-CO2/N2 is attributed to the strong confinement effect on CO2 gas molecules in small pores. Furthermore, with an attempt to further improve S-CO2/N2 we investigated two approaches which are nitrogen doping and ionic liquid incorporation. Our simulations predicted that nitrogen-doped or ionic liquid incorporated ZTCs exhibited enhanced S-CO2/N2 due to strong interaction between CO2 and negatively charged nitrogen atom or anions in ionic liquid, respectively. While both approaches have provided promises in upgrading ZTCs for high S-CO2/N2 observation of the exceptional cases which showed insignificant changes in S-CO2/N2 suggested that design strategy might be altered in accordance with the structural feature of ZTC, representatively, pore topology. Our case study for ZTC-IRR demonstrates that a strategy devised with a deep understanding of pore topology can significantly improve S-CO2/N2 of ZTC.