@article{jain_gubbins_pellenq_pikunic_2006, title={Molecular modeling and adsorption properties of porous carbons}, volume={44}, ISSN={["0008-6223"]}, DOI={10.1016/j.carbon.2006.04.034}, abstractNote={In this work, we calculate the adsorption isotherms and isosteric heat of argon in molecular models of saccharose coke obtained via the Hybrid Reverse Monte Carlo method. In the first route (method A), the molecular models were built by considering only carbon atoms, and all other heteroatoms present were neglected. In the second route (method B), the molecular models were built by considering carbon and hydrogen atoms. We find that the models obtained via method B have smaller pores as compared to the models obtained via method A. This is reflected in the adsorption properties. The amount adsorbed is less in models obtained via method B as compared to method A. We also find that the isosteric heat calculated in the models obtained via method B match the experimental data more closely as compared to models obtained from method A.}, number={12}, journal={CARBON}, author={Jain, Surendra K. and Gubbins, Keith E. and Pellenq, Roland J. -M. and Pikunic, Jorge P.}, year={2006}, month={Oct}, pages={2445–2451} }
 @article{jain_pellenq_pikunic_gubbins_2006, title={Molecular modeling of porous carbons using the hybrid reverse Monte Carlo method}, volume={22}, ISSN={["0743-7463"]}, DOI={10.1021/la053402z}, abstractNote={We apply a simulation protocol based on the reverse Monte Carlo (RMC) method, which incorporates an energy constraint, to model porous carbons. This method is called hybrid reverse Monte Carlo (HRMC), since it combines the features of the Monte Carlo and reverse Monte Carlo methods. The use of the energy constraint term helps alleviate the problem of the presence of unrealistic features (such as three- and four-membered carbon rings), reported in previous RMC studies of carbons, and also correctly describes the local environment of carbon atoms. The HRMC protocol is used to develop molecular models of saccharose-based porous carbons in which hydrogen atoms are taken into account explicitly in addition to the carbon atoms. We find that the model reproduces the experimental pair correlation function with good accuracy. The local structure differs from that obtained with a previous model (Pikunic, J.; Clinard, C.; Cohaut, N.; Gubbins, K. E.; Guet, J. M.; Pellenq, R. J.-M.; Rannou, I.; Rouzaud, J. N. Langmuir 2003, 19 (20), 8565). We study the local structure by calculating the nearest neighbor distribution, bond angle distribution, and ring statistics.}, number={24}, journal={LANGMUIR}, author={Jain, Surendra K. and Pellenq, Roland J. -M. and Pikunic, Jorge P. and Gubbins, Keith E.}, year={2006}, month={Nov}, pages={9942–9948} }
 @article{pikunic_llewellyn_pellenq_gubbins_2005, title={Argon and nitrogen adsorption in disordered nanoporous carbons: Simulation and experiment}, volume={21}, ISSN={["0743-7463"]}, DOI={10.1021/la047165w}, abstractNote={We report experimental measurements of the isosteric heats of adsorption for argon and nitrogen in two microporous saccharose-based carbons, using a Tian-Calvet microcalorimeter. These data are used to test recently developed molecular models of these carbons, obtained by a constrained reverse Monte Carlo method. Grand canonical Monte Carlo simulation is used to calculate the adsorption isotherms and isosteric heats for these systems, and the results for the latter are compared to the experimental data. For argon, excellent quantitative agreement is obtained over the entire range of pore filling. In the case of nitrogen, very good agreement is obtained over the range of coverage 0.25 < or = gamma/gamma 0 < or = 0.85, but discrepancies are observed at lower and higher coverages. The discrepancy at low coverage may be due to the presence of oxygenated groups on the pore surfaces, which are not taken into account in the model. The differences at high coverage are believed to arise from the presence of a few mesopores, which again are not included in the model. Pair correlation functions (argon-carbon and argon-argon) are determined from the simulations and are discussed as a function of pore filling. Snapshots of the simulations are presented and provide a picture of the pore filling process.}, number={10}, journal={LANGMUIR}, author={Pikunic, J and Llewellyn, P and Pellenq, R and Gubbins, KE}, year={2005}, month={May}, pages={4431–4440} }
 @article{pikunic_gubbins_2003, title={Molecular dynamics simulations of simple fluids confined in realistic models of nanoporous carbons}, volume={12}, ISSN={["1292-895X"]}, DOI={10.1140/epje/i2003-10052-4}, abstractNote={We present molecular dynamics simulations in the micro-canonical ensemble of a Lennard-Jones model of nitrogen confined in realistic models for saccharose-based carbons developed in our previous work. We calculate the velocity autocorrelation function and mean-squared displacement, and the self-diffusivities from the latter. We observe that the self-diffusivity increases with temperature and exhibits a maximum with loading or adsorbate density. To the best of our knowledge, a maximum in self-diffusivities has not been observed in molecular dynamics simulations of fluids confined in slit pores.}, number={1}, journal={EUROPEAN PHYSICAL JOURNAL E}, author={Pikunic, J and Gubbins, KE}, year={2003}, month={Sep}, pages={35–40} }
 @article{bandosz_biggs_gubbins_hattori_iiyama_kaneko_pikunic_thomson_2003, title={Molecular models of porous carbons}, number={28}, journal={CHEMISTRY AND PHYSICS OF CARBON, VOL. 28}, author={Bandosz, T. J. and Biggs, M. J. and Gubbins, K. E. and Hattori, Y. and Iiyama, T. and Kaneko, K. and Pikunic, J. and Thomson, K. T.}, year={2003}, pages={41–228} }
 @article{pikunic_clinard_cohaut_gubbins_guet_pellenq_rannou_rouzaud_2003, title={Structural Modeling of porous carbons: Constrained reverse Monte Carlo method}, volume={19}, ISSN={["0743-7463"]}, DOI={10.1021/la034595y}, abstractNote={We present a constrained reverse Monte Carlo method for structural modeling of porous carbons. As in the original reverse Monte Carlo method, the procedure is to stochastically change the atomic positions of a system of carbon atoms to minimize the differences between the simulated and the experimental pair correlation functions. However, applying the original reverse Monte Carlo method without further constraints yields nonunique structures for carbons, due to the presence of strong three-body forces. In this respect, the uniqueness theorem of statistical mechanics provides a helpful guide to the design of reverse Monte Carlo methods that give reliable structures. In our method, we constrain the bond angle distribution and the average carbon coordination number to describe the three-body correlations. Using this procedure, we have constructed structural models of two highly disordered porous carbons prepared by pyrolysis of saccharose at two different temperatures. The resulting pair correlation function...}, number={20}, journal={LANGMUIR}, author={Pikunic, J and Clinard, C and Cohaut, N and Gubbins, KE and Guet, JM and Pellenq, RJM and Rannou, I and Rouzaud, JN}, year={2003}, month={Sep}, pages={8565–8582} }
 @article{pikunic_gubbins_pellenq_cohaut_rannou_gueth_clinard_rouzaud_2002, title={Realistic molecular models for saccharose-based carbons}, volume={196}, ISSN={["1873-5584"]}, DOI={10.1016/S0169-4332(02)00039-9}, abstractNote={We used a simulation protocol based on reverse Monte Carlo that we had developed in a previous work to build models for three carbons produced by the pyrolysis of saccharose and subsequent heat treatment at three different temperatures. In order to characterize the resulting models, we calculated the radial distribution function and the pore size distribution of the three structures. From this analysis, we found that the size of the graphene layers increases with the treatment temperature and that the carbons treated at higher temperatures present longer-range correlations. The short-range structural properties are in excellent agreement with HRTEM image analysis results. We performed grand canonical Monte Carlo (GCMC) simulations of nitrogen at 77 K in the resulting structural models to show how our models can be used to predict the effects of heterogeneity on the adsorption properties of carbons.}, number={1-4}, journal={APPLIED SURFACE SCIENCE}, author={Pikunic, J and Gubbins, KE and Pellenq, RJM and Cohaut, N and Rannou, I and Gueth, JM and Clinard, C and Rouzaud, JN}, year={2002}, month={Aug}, pages={98–104} }
 @inbook{pikunic_clinard_cohaut_gubbins_guet_pellenq_rannou_rouzaud_2002, title={Reconstruction Method for the Characterization of Porous Carbons}, ISBN={9780444512611}, ISSN={0167-2991}, url={http://dx.doi.org/10.1016/s0167-2991(02)80215-4}, DOI={10.1016/s0167-2991(02)80215-4}, booktitle={Characterization of Porous Solids VI, Proceedings of the 6th International Symposium on the Characterization of Porous Solids (COPS-VI)}, publisher={Elsevier}, author={Pikunic, J. and Clinard, C. and Cohaut, N. and Gubbins, K.E. and Guet, J.-M. and Pellenq, R.J.-M. and Rannou, I. and Rouzaud, J.-N.}, year={2002}, pages={19–26} }
 @article{turner_brennan_pikunic_gubbins_2002, title={Simulation of chemical reaction equilibria and kinetics in heterogeneous carbon micropores}, volume={196}, ISSN={["0169-4332"]}, DOI={10.1016/S0169-4332(02)00074-0}, abstractNote={We present a simulation study which shows how the equilibrium yield and kinetics of chemical reactions can be enhanced by tailoring the structure and surface chemistry of the catalyst support material. Equilibrium results are presented for the ammonia synthesis reaction, N2+3H2↔2NH3, occurring within various carbon supports, representing a range of chemical and physical surface heterogeneity. Using a simulation technique known as Reactive Monte Carlo (RxMC), we find that surface activation and pore width are primary factors in determining the conversion of the ammonia synthesis reaction while effects of surface corrugation are small. We probe the kinetic effects of physical confinement within microporous carbons by studying the bimolecular hydrogen iodide decomposition reaction, 2HI→H2+I2, in carbon slit-pores and nanotubes. The rate constant of this reaction is measured by combining the quasi-equilibrium hypothesis of transition-state theory (TST) with the RxMC simulation technique. The kinetic simulations represent a new method for probing reaction kinetics in non-ideal environments and show accurate results when applied to the hydrogen iodide decomposition reaction.}, number={1-4}, journal={APPLIED SURFACE SCIENCE}, author={Turner, CH and Brennan, JK and Pikunic, J and Gubbins, KE}, year={2002}, month={Aug}, pages={366–374} }
 @article{turner_pikunic_gubbins_2001, title={Influence of chemical and physical surface heterogeneity on chemical reaction equilibria in carbon micropores}, volume={99}, ISSN={["1362-3028"]}, DOI={10.1080/00268970110087254}, abstractNote={Recent simulation results are presented for the equilibrium yield of the ammonia synthesis reaction in various model microporous carbons. It is found that the reaction equilibria within the micropores is affected by many factors, including pore size, pore shape, connectivity, surface roughness, and surface chemical activation. In order to probe these effects, reactive Monte Carlo simulations of the reaction were performed in several microporous carbon models: smooth slit-shaped carbon pores, a realistic carbon model generated from experimental diffraction data, single-walled carbon nanotubes, and smooth slit-shaped pores activated by carboxyl surface groups. The simulations show that the ammonia conversion is most sensitive to the carbon pore width and to the amount of surface chemical activation. Effects of surface corrugation and pore connectivity on the equilibrium reaction yield are minimal.}, number={24}, journal={MOLECULAR PHYSICS}, author={Turner, CH and Pikunic, J and Gubbins, KE}, year={2001}, month={Dec}, pages={1991–2001} }