Determination of the Pore Size Distribution in Porous Catalysts from Nitrogen Isotherm

Abstract

Regarding the nitrogen isotherm for obtaining the pore size distribution in porous catalysts, the capillary condensation models for cylindrical pore structure are reviewed, and it is shown that the traditional Kelvin equation should be modified by taking into consideration of the difference in thermodynamic potentials between the adsorbed state and the bulk liquid. The procedures of calculating the pore size distribution are explained, and anodic aluminas with well-defined cylindrical pores are proven to procide an excellent opportunity for the confirmation of the cylindrical pore model.