The potential mean force (PMF) profiles for CO2 translocation through all three pores were computed to understand the underlying energetics that determine transport (Figure ). We quantify the free energy barrier for translocation (∆A) by calculating the differences in PMFs at the center of the pore (z = 0) and the position where the minima in the PMFs are observed on the feed side (adsorbed state; see methods section). We note that PMF computations in the literature are typically carried out for a single molecule translocating under vacuum conditions. In this study, PMF computations are carried out in the mixture to represent the free energy landscape under realistic mixture transport conditions. ∆A for CO2 is the highest for the smallest pore (pore-10), decreasing as the pore size increases (Figure ). Interestingly, ∆A values for pore-10 and pore-13 show a decrease when temperature increases from 298 to 323 K and increase monotonically for higher temperatures thereafter. For pore-16, where the confinement is the least, ∆A increases monotonically with temperature for CO2; however, the opposite is observed for O2, where a slight decrease occurs with increasing temperature (Figure ).