The mechanisms study of the porous graphene for the purification of the mixed gases: A multi-scale computational method

Abstract Molecular dynamic (MD) simulations, grand canonical Monte Carlo (GCMC) simulations, and density functional theory (DFT) were used to study the ability of four different graphene slices with H-deactivated pores (HP6, HP10, HP13, and HP16) for the separation of H 2 from the mixed gases. It was found that the HP10, with its proper pore size of 2.96 A, can effectively separate H 2 from CO. The HP13 can effectively separate H 2 from CO 2 and CH 4 with its high H 2 selectivity of 5.8 × 10 10 and 6.4 × 10 24 , respectively. Different from the other studies on the permeation of gas only induced by size sieving, the porous graphene can exhibit high H 2 selectivity and permeability over other gases. It was further revealed that the adsorption energy, barrier energy, size sieving, gas distribution, and gas motion also play a role in blocking the transmission of the mixed gas through the porous graphene.