Comparison of DFT characterization methods based on N2, Ar, CO2, and H2 adsorption applied to carbons with various pore size distributions Original Research Article

Adsorption isotherms of N2, Ar, CO2, and H2 were measured on selected activated carbons representing various pore size distributions. Isotherm data were analyzed using the DFT method. A good agreement was obtained between N2 and Ar results in a wide range of pore sizes. Both N2 and Ar results agree with CO2 analysis at 273 K in the range of small micropores where CO2 analysis is most applicable. Also, in this range of pores the analysis of H2 adsorption data at 77 K gives results which are consistent with the results obtained from the more conventional vapor-phase adsorptives. However, the range of PSDs calculated from H2 data extends to pore sizes smaller than those that can be characterized by other adsorbates.