Micropore structure of template-derived carbons studied using adsorption of gases with different molecular diameters

Abstract

The microstructural properties of carbons obtained by carbonization of poly(furfuryl alcohol) within different smectite matrices have been studied by gas adsorption. A method based on the analysis of the gas adsorption data using the relationship between the adsorption energy and micropore size, has been applied to evaluate micropore size distributions. The range of sensitivity of the method in relation to the adsorbate molecular size is discussed. Three adsorbates, CH₄, CF₄ and SF₆, having different molecular diameters were used and analyses of their adsorption data have been used either to cross-validate the results obtained or for complementary information. The relationships between the pore size distribution, the adsorption energy distribution and the isosteric heat of adsorption are discussed. The calculated pore size distributions for the synthetic carbons show differences related to the structure of the mineral matrix.