Effects of Activation on the Structure and Adsorption Properties of a Nanoporous Carbon Using Molecular Simulation

Abstract

We present a study on the effects of activation on a saccharose-based carbon using molecular simulation. A constrained Reverse Monte Carlo method is used to build molecular models that match the experimental structure factors of both activated and unactivated carbon, using appropriate constraints for bond angle and coordination number to describe the three body correlation. The semi-coke sample, that is named CS1000, is obtained by pyrolyzing pure saccharose at 1000 • C under nitrogen flow. An activated form of this carbon, CS1000a, was obtained by heating CS1000 in an atmosphere of CO 2 for 20 hours. We built molecular models for CS1000 and CS1000a and also simulated the TEM images of the model. We perform GCMC simulation of a Lennard-Jones model of Argon on the resulting models to obtain the adsorption isotherms. We then study the difference in the morphology of CS1000 and CS1000a that lead to different adsorption properties in carbon upon activation.

Freezing of Fluids Confined in a Disordered Nanoporous Structure

“…Gubbins and coworkers [16,17] have shown that the structural models obtained using RMC simulations with appropriate threebody constraints are in good agreement with experimental data from transmission electronic microscopy, gas adsorption, and calorimetry [16]. In this Letter, we report a simulation study of freezing of Ar in such a realistic model of disordered porous carbons.…”

“…This structural model of saccharose-based carbon was obtained using a constrained RMC technique [17], which consists of generating atomic configurations that match the pair correlation function of the real system. Two other constraints were simultaneously minimized in the simulation to account for three-body forces: (i) The fraction of 3-coordinated C atoms must be equal to that determined from experiment, and (ii) the average C-C-C bond angle must be distributed about 2=3 (sp 2 hybridization).…”

Competitive adsorption of a binary CO2–CH4mixture in nanoporous carbons: effects of edge-functionalization

“…[12][13][14][15][16][17][18][19][20][21][22] Jain et al [15][16][17] developed a new molecular modeling on NPCs by using the reverse Monte Carlo (RMC) method, and found that the calculated adsorption amount and isosteric heat were in good agreement with the experimental results. Brochard et al 18 studied the competitive adsorption of binary CO 2 /CH 4 mixture in NPCs, and described the desorption behavior of CH 4 with the CO 2 -injection in detail.…”

GCMC simulations in zeolite MFI and activated carbon for benzene removal from exhaust gaseous streams

“…Gubbins using the Hybrid Reverse Monte Carlo method (HRMC), and is now freely available in literature [9,10]. In Figure 1 the 3D structures used in this work are shown: zeolites MFI and NaY, and disordered, activated carbon cs1000a.…”

“…The atom positions of the disordered structure cs1000a, have been obtained with the HRMC method [9,10]. This method uses an algorithm which attempts to simultaneously minimize the error in the radial distribution function and also the total energy of the system, thus matching the experimental data obtained for the real structure, such as structure factor, porosity and density.…”