On the CO₂ Harvesting from N₂ Using Grazyne Membranes

Abstract

Separation of carbon dioxide (CO2) from nitrogen (N2) is central to any global warming remediation technology aimed at reducing atmospheric CO2 content. Chemical membranes designed to differentially permeate both molecules are appealing due to their simple use, being environmentally friendly, with high surface areas, compact, easy to maintain and cost‐effective, still, the field is growing due to the difficulties in CO2/N2 separation. The present study poses grazynes, two‐dimensional stripe‐based C‐based materials with sp and sp2 C atoms, as suited membranes for CO2/N2 separation. The combination of density functional theory and molecular dynamics simulations allow tackling the energetics, kinetics, and dynamics of the membrane effectiveness of pore‐engineered grazynes in a holistic fashion. The explored grazynes are capable of physisorbing CO2 and N2, thus avoiding material poisoning by molecular decoration, while the diffusion of CO2 through the pores is found to be rapid, yet easier than that of N2, in the rate order of the s‐1 in the 100‐500 K temperature range. In particular, low‐temperature CO2 separation even for CO2 contents below 0.5% are found for [1],[2]{2}‐grazyne when controlling the membrane exposure contact to the gases mixture, paving the way for exploring and using grazynes for air CO2 remediation.