Characterization of nanostructured carbon CMK-3 by means of Monte Carlo simulations

Abstract

A structural model of mesoporous carbon (CMK-3) prepared from the templating of SBA-15 silica materials named M_CMK3 and a mixed geometry model, representing the porous space as a collection of slit, cylindrical and M_CMK3 pores, is theoretically evaluated, developed and applied to the characterization of an experimental sample [1]. By using the Monte Carlo simulation method (off lattice), families of N2 adsorption isotherms are generated for cylindrical, slit and M_CMK3 geometries corresponding to different pore sizes. Then, the three geometric families of isotherms (kernels) are used to fit the experimental N2 adsorption data corresponding to CMK-3 materials, allowing for the determination of the micro and mesopore volume and the corresponding Pore Size Distribution (PSD). The same experimental data were fit using different mixed geometry models, and from the analysis of the effect of different kernels on the resulting PSD, it is concluded that the proposed mixed geometry model can capture in more detailed the textural and energetic features of nanostructured carbon CMK-3. Finally, using a virtual solid and pseudo-experimental adsorption data, the importance of the pore geometry and its effects on the PSD and isosteric enthalpy of adsorption are studied.