STRUCTURAL MODELING OF POROUS CARBONS USING A HYBRID REVERSE MONTE CARLO METHOD
We present molecular models for 3 saccharose based carbons of different densities obtained using a Reverse Monte Carlo (RMC) protocol which incorporates an energy constraint. The radial distribution functions of the simulated models are in good agreement with experiment. Moreover, 3 and 4 member carbon rings, reported in the literature for many modeling studies of carbon, are absent or extremely rare in our final structural models. These small member rings are high energy structures and are believed to be an artifact of the usual RMC method. The presence of the energy penalty term in our simulation protocol penalizes the formation of these structures. Using a ring connectivity analysis method that we developed, we find that these atomistic models of carbons are made up of defective graphene segments twisted in a complex way. These graphene segments are largely made up of 6 carbon member rings, but also contain some 5 and 7 carbon member rings. We also found that in addition to the graphene segments there are some carbon chains which do not belong to any graphene segments. To characterize our models, we calculated the geometric pore size distribution and also simulated the adsorption of argon at 77.4 K in the models using GCMC simulations. The adsorption isotherm obtained for all three models are representative of microporous carbons.
S.K.JAIN R.J-M.PELLENQ K.E.GUBBINS
CNRS, Campus de Luminy, Case 913 13288 Marseille cedex 09, France Center for High Performance Simulation and Department of Chemical and Biomolecular Engineering, Nort
国际会议
天津
英文
129-137
2006-05-22（万方平台首次上网日期，不代表论文的发表时间）