Relationship between pore volumes and surface areas derived from the evaluation of N2-sorption data by DR-, BET- and t-plot

Three of the most common methods to analyze sorption isotherms with respect to micropore volume and specific surface, respectively, are the Brunauer–Emmett–Teller (BET) theory, established for the specific surface area of meso- and macroporous materials, the t-plot-method, which separates micropore from multilayer adsorption and the micropore analysis based on the work of Dubinin and Radushkevich (DR). While BET-analysis is assumed to be sensitive to multilayer adsorption on the external surface area, the DR-method is expected to be in particular sensitive to the micropores. However, the data for a series of synthetic carbons investigated reveal that the values derived by both methods are equivalent, despite the different underlying assumptions.