The new correlation between microporosity of strictly microporous activated carbons and fractal dimension on the basis of the Polanyi-Dubinin theory of adsorption

摘要

Adsorption on microporous fractal carbons is investigated in terms of their microporous structure. The structure is characterised by the micropore-size distribution (MSD) proposed by Pfeifer and Avnir, and the considereations are limited only to the range of micropores, following the IUPAC classification. Beginning with numberical studies performed for model solids with different microporosity, a new relationship between the parameters of the Dubinin-Astakhov equation (adsorption energy, E_0, and parameter, n_DA) and the fractal dimension (D) is derived. The obtained results are compared with those published by Jaroniec et al. and Ehrburger-Dolle. The general conclusion is that if adsorption proceeds by a micropore filling mechanism and the proe size distribution function is assumed to be the Pfeifer and Avnir one, the relationship between D and parameaters of the Dubinin-Astakhov equation is more complicated than has been presumed up to the present.