CLASSIFICATION OF ALPHA-S PLOTS OBTAINED FROM N2/77 K ABSORPTION ISOTHERMS OF ACTIVATED CARBONS

The alpha-s method has been applied to N2/77 K adsorption isotherms of several activated carbons in order to classify the corresponding alpha-s plots into five groups: alpha-1a, alpha-1b, alpha-1c, alpha-1d and alpha-2. A wide range of preparation procedures, different raw materials and diverse micropore size distributions have been covered. Each type of alpha-s plot could be assigned to the presence of a particular porous texture in the carbon. A comparison of the micropore volumes calculated from the application of the Dubinin-Radushkevich equation, V0 (DR), with those calculated from alpha-s plots, V0 (alpha-s), was also carried out. A relationship between the micropore size distribution of the carbons and the type of alpha-s plot according to the classification is proposed.