This thesis presents a fundamental investigation on the role of the structure of microporous silicon carbide-derived carbon (SiCDC) and its functionalisation in the adsorption equilibria and transport of gases. The SiCDCs with different particle size distributions were synthesized in our laboratory and characterized using a combination of techniques including scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Xray diffraction (XRD), helium pycnometry, thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), Raman spectroscopy, and gas adsorption.Based on the characterisation results, a bidisperse pore structure model is proposed for the synthesized SiCDC to explain the kinetics. In the mathematical modelling of adsorption kinetics, the internal structure of SiCDC is assumed to have ultra-microporous grains with larger particle scale micropores forming the intergrain pathways. It is shown that CH 4 adsorption kinetics is governed by two distinct diffusional resistances, arising from slow grain scale diffusion in ultra-micropores and faster particle scale diffusion in large micropores. For CO 2 , it is found that the adsorption kinetics is strongly influenced by a barrier resistance at the grain surface where entry into the ultra-microporosity occurs. The uptake of CO 2 in the bidisperse pore structure of CDCs occurs through rapid diffusion in the large particle-scale micropores, in which a Henry law isotherm holds, and a combination of barrier resistance at the grain surface and diffusional resistance in the grain interior with a Langmuirian isotherm. It is shown that the grain scale activation energies are comparable with values for carbon molecular sieves, and consistent with values expected for the size range of the ultra-micropores, while the activation energies for transport in the larger particle scale micropores are comparable to those for conventional activated carbons.The experimental uptake-based data are compared with self-diffusivities obtained through equilibrium molecular dynamics (EMD) simulations using a realistic model of SiCDC developed by the hybrid reverse Monte Carlo (HRMC) method. It is observed that MD-based CO 2 diffusivities are as much as two orders of magnitude larger than the CO 2 particle scale diffusion coefficients, however such discrepancy is not found for The findings of this thesis should aid better understanding of the gas adsorption and diffusion mechanism in microporous CDCs.iv
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