Permeance of H2 through porous graphene from molecular dynamics

A recent experiment (Koenig et al., 2012 [151) demonstrated the capability of porous graphene as one-atom-thin membrane to separate gases by molecular sieving. A quantitative connection between the measured leak rate and the simulated gas permeance has yet to be established. Using H-2 as a model gas, here we determine its permeance through porous graphene from molecular dynamics (MD) simulations. Trajectories are used to directly obtain H-2 flux, pressure drop across the graphene membrane, and subsequently, H-2 permeance. The permeance is determined to be on the order of 10(5) GPU (gas permeance unit) for pressure driving forces ranging from 2 to 163 atm. By relating to the experimental leak rate, we then use the permeation data to estimate the pore density in the experimentally created porous graphene. (C) 2013 Elsevier Ltd. All rights reserved.