G. Rychlicki et al., DETERMINATION OF CARBON POROSITY FROM LOW-TEMPERATURE NITROGEN ADSORPTION DATA - A COMPARISON OF THE MOST FREQUENTLY USED METHODS, Colloids and surfaces. A, Physicochemical and engineering aspects, 96(1-2), 1995, pp. 105-111
This paper compares the most frequently used procedures for carbon por
osity determination, i.e. the Dubinin-Radushkevich, Dubinin-Izotova, t
and alpha(s) plot, Horvath-Kawazoe (HK) and micropore analysis method
s. The correlations between the obtained results are presented, and th
e importance of the choice of reference material for t and/or alpha(s)
plot construction is displayed. It is concluded that only the HK meth
od predicts smaller pore sizes. Our results show also that nitric acid
oxidation of carbon and desorption in a flow of He in the temperature
range 493-573 K leads to considerable changes in its porosity. Howeve
r, for carbon previously oxidized and desorbed at 573 K, a pore-blocki
ng effect occurs which probably results from the production of anhydri
des in the carbon micropores.