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

Kexin Zhang

Abstract:

A comprehensive computational study was performed to develop zeolite-templated carbon (ZTC) materials for
efficient carbon dioxide (CO2) and nitrogen (N2) 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 (SCO2=N2 ) of CO2 over N2. A detailed investigation about pore structure-property relationship elucidated that high SCO2=N2 is attributed to the strong confinement effect on CO2 gas molecules in small pores.
Furthermore, with an attempt to further improve SCO2=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 SCO2=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 SCO2 =N2 , observation of the exceptional cases which showed insignificant changes in SCO2 =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 SCO2 =N2 of ZTC.