The MD simulation configuration used to analyze gas transport consists of graphene hosting 16 identical pores dividing feed and permeate chambers. The simulation box is enclosed in the zdirection by walls made of pristine graphene (Figure ) with potentials similar to the literature. At the start of the simulation, the feed side has an equimolar CO2/O2 mixture while the permeate side is under vacuum. ) O-functionalized graphene pores in this study. Pore-10, pore-13, and pore-16 are prepared by removing 10, 13, and 16 carbon atoms, respectively, from the graphene lattice, followed by pore edge termination with ether and C=O.