A new approach to separate hydrogen from carbon dioxide using graphdiyne-like membrane

In order to separate a mixture of hydrogen ([Formula: see text] ) and carbon dioxide ([Formula: see text] ) gases, we have proposed a new approach employing the graphdiyne-like membrane (GDY-H) using density functional theory (DFT) calculations and molecular dynamics (MD) simulations. GDY-H is constructed by removing one-third diacetylenic ([Formula: see text]) bonds linkages and replacing with hydrogen atoms in graphdiyne structure. Our DFT calculations exhibit poor selectivity and good permeances for [Formula: see text] /[Formula: see text] gases passing through this membrane. To improve the performance of the GDY-H membrane for [Formula: see text] /[Formula: see text] separation, we have placed two layers of GDY-H adjacent to each other which the distance between them is 2 nm. Then, we have inserted 1,3,5-triaminobenzene between two layers. In this approach, the selectivity of [Formula: see text] /[Formula: see text] is increased from 5.65 to completely purified [Formula: see text] gas at 300 K. Furthermore, GDY-H membrane represents excellent permeance, about [Formula: see text] gas permeation unit (GPU), for [Formula: see text] molecule at temperatures above 20 K. The [Formula: see text] permeance is much higher than the value of the usual industrial limits. Moreover, our proposed approach shows a good balance between the selectivity and permeance parameters for the gas separation which is an essential factor for [Formula: see text] purification and [Formula: see text] capture processes in the industry.