Modeling Structural Morphology of Microporous Carbons by Reverse Monte Carlo

We present a realistic model of carbon pore morphologies based on molecular simulation. Reverse Monte Carlo (RMC) techniques are used to generate model carbon structures composed of rigid carbon basal plates. Arrangement of the carbon plates is driven by a systematic refinement of simulated carbon−carbon radial distribution functions to match experiment. The RMC procedure was first tested by comparing a model output structure to a hypothetical input structure generated through molecular dynamics techniques. Structural characteristics of the RMC model such as porosity, surface area, pore-size distribution, and surface-averaged energy distributions were in close agreement with those for the input structure, thus validating the RMC method. We also studied the structural characteristics of a model output generated from a real, activated mesocarbon microbead (a-MCMB). The porosity, surface area, and simulated N2 isotherm are compared with experiment. Nitrogen adsorption isotherms for our model carbon structures, generated by grand canonical MC techniques, show a pore morphology that is generally non-slit-like and highly connected with evidence of localized capillary condensation occurring in regions with pores of around 14.5 Å and higher.