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 AlPO 4 -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 2 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.