A new isotherm for multilayer adsorption on heterogeneous surfaces

Abstract

An overall adsorption isotherm consisting of a modified BET local isotherm and a Maxwellian adsorption energy distribution is proposed. This isotherm is shown to give excellent agreement with experimental data obtained over a wide range of pressures on heterogeneous adsorbents but is no better than the simple BET isotherm for Aerosil and graphite. The reasons for these observations and the meaning of the parameters obtained are discussed.