▎ 摘　　要

Graphene-based laminates show great potential in gas separation, where graphene slit serving as an important part has significant effect on the gas transport. In this study, molecular dynamics simulations were performed to investigate the mechanism of the CO2 and N-2 permeation through graphene slit. CO2 was confirmed to permeate through the slit mainly via surface flux, thus the adsorption capacity of graphene largely determines the CO2 permeability. Besides, the N-2 permeation is greatly dominated by direct flux, the contribution of which increases with enlarging the graphene slit. The adsorption capacity of graphene was modified to adjust the permselective transport of the CO2/N-2 mixture. Increasing the gas-graphene interaction obviously enhanced the N-2 permeation and retarded the CO2 permeation. A triple enhancement of the gas-graphene attraction could achieve a quadruple increase of the N-2/CO2 selectivity. This work guides to improve the performance of graphene-based membranes in the CO2/N-2 mixture separation.