Influence of the silicon content and chemical disorder of the SAPO STA-7 framework on the CO2 adsorption mechanism: Grand canonical Monte Carlo simulations combined to microcalorimetry measurements

The adsorption properties of carbon dioxide in SAPO STA-7 material have been investigated by combining grand canonical Monte Carlo simulations and microcalorimetry measurements. The computational studies, based on newly derived interatomic potentials to describe the adsorbate/adsorbent interactions, provide both adsorption isotherms and enthalpy profiles as a function of coverage for AlPO4-18 and SAPO STA-7 characterized by two different silicon contents. It is shown that both the silicon content and the microscopic description of the SAPO framework characterized by a chemical disorder created by the introduction of Si atoms significantly modify the CO, adsorption behavior of the material. The originality and the strength of this article is that it combines experimental tools and realistic models to provide a detailed picture of the microscopic adsorption mechanism for each type of zeolite material.