Grand Canonical Monte Carlo Simulation of Adsorption of Nitrogen and Oxygen in Realistic Nanoporous Carbon Models

Adsorption of nitrogen and oxygen in nanoporous carbons (NPC) is simulated using grand canonical Monte Carlo simulations, where the Steele potential (developed for gas interactions with graphite) is used to represent gas-carbon interactions. NPC models used for the adsorption simulations are developed using an isothermal-isobaric (constant NpT) ensemble Monte Carlo algorithm whereby an initial polymer chain is evolved through a series of atomic displacement and bond rearrangement steps into the final carbon structure. These constant NpT carbon models are representative of real NPCs in terms of local structure and chemical composition. Predictions of nitrogen and oxygen sorption from our model NPCs show good agreement with experimental data. The isosteric heats of adsorption of both adsorbates lie within the range of experimental values for NPCs. Furthermore, the adsorption isotherms of the two gases showsemi-quantitative match with experimental adsorption isotherms. (C) 2010 American Institute of Chemical Engineers AIChE J, 57: 1496-1505, 2011