On the CO2 Harvesting from N2 Using Grazyne Membranes.

Abstract

Separation of carbon dioxide (CO2) from nitrogen (N2) is central to any global warmingremediation technology aimed at reducing atmospheric CO2 content. Chemicalmembranes designed to differentially permeate both molecules are appealing due totheir 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 inCO2/N2 separation. The present study poses grazynes, two-dimensional stripe-basedC-based materials with sp and sp2 C atoms, as suited membranes for CO2/N2separation. The combination of density functional theory and molecular dynamicssimulations allow tackling the energetics, kinetics, and dynamics of the membraneeffectiveness of pore-engineered grazynes in a holistic fashion. The explored grazynesare capable of physisorbing CO2 and N2, thus avoiding material poisoning bymolecular 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 temperaturerange. In particular, low-temperature CO2 separation even for CO2 contents below0.5% are found for [1],[2]{2}-grazyne when controlling the membrane exposure contactto the gases mixture, paving the way for exploring and using grazynes for air CO2remediation.