Estimation of Energetic and Structural Parameters for Argon Adsorption on Nanoporous Zeolites

Gas adsorption on solid surfaces is a significant process that has both current and potential industrial [1]. In addition to the diverse application of zeolites in the chemical industry, these molecular sieves are of particular interest in examining theories of adsorption for nanoporous solids because they posses a regular crystalline structure [2]. Henry’s law adsorption data for zeolites has the same advantages because occupation of cavities averages less than one gas molecule per cavity. By considering a zeolite to consist of a series of interconnected spherical cavities, it is possible to characterize the structure by only two parameters [3]. The driving force for adsorption is the difference in chemical potentials in the adsorbed gas phases, which is in turn determined by the difference between the opposing effects of energetic terms [4].In this work, the temperature dependence of the second gas-solid virial coefficients is used in conjunction with a Lennard-Jones potential to determine the energetic and structure parameters. The effect of structure and temperature on adsorption of Argon onto ZSM-5 and NaX zeolites was investigated by the standard enthalpy of adsorption