Activated carbons are porous carbonaceous materials that
serve a broad range of practical applications including
catalysis, gas purification and separation, and other vapour
and liquid phase adsorption-based technologies. The pore
structure, as well as the specific surface area, of these
materials can vary greatly between carbons activated using
different methods and under differing conditions, and it
depends also on the choice of raw material. Activated carbons
can contain pores in the macro- (d > 50 nm), meso- (50 nm >
d > 2 nm) and microporous (d < 2 nm) regimes, according to
the IUPAC classification . The pore structure of a particular
carbon is crucial to its practical application and so the
determination of the pore size distribution (PSD) is an
important characterization measurement in the study of these
materials. In addition, activated carbons are non-crystalline
materials that cannot be characterized easily by X-ray powder
diffraction. As a result, alternative methods for the
determination of their microstructure are of significant interest.
The measurement of the adsorption behaviour of different
probe molecules, and the subsequent analysis of the data to
obtain a PSD, is one of the alternative methods that can
complement small angle scattering and other characterisation
techniques. So-called ‘classical’ methods of pore size
distribution determination include Dubinin-Astakhov (DA),
Dubinin-Radushkevich (DR) and Horvoe-Kawazoe (HK)
Analysis .
