Adsorption of carbon dioxide in SAPO STA-7 and AlPO-18: Grand Canonical Monte Carlo simulations and microcalorimetry measurements

• Published in: Adsorption : journal of the International Adsorption Society Vol. 14; no. 2-3; pp. 207 - 213
• Main Authors: Deroche, Irena, Gaberova, Lucia, Maurin, Guillaume, Llewellyn, Philip, Castro, Maria, Wright, Paul
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.06.2008
• Subjects: Chemistry; Chemistry and Materials Science; Engineering Thermodynamics; Heat and Mass Transfer; Industrial Chemistry/Chemical Engineering; Surfaces and Interfaces; Thin Films; Grand Canonical Monte Carlo; STA-7; Adsorption; AlPO-18; SAPO; Microcalorimetry; CO; Isotherms and enthalpies of adsorption
• ISSN: 0929-5607; 1572-8757
• DOI: 10.1007/s10450-007-9098-1

The adsorption properties of carbon dioxide in SAPO STA-7 has been investigated by combining Grand Canonical Monte Carlo simulation and microcalorimetry. The modeling approach, based on both newly derived interatomic potentials for describing the interaction between CO 2 and the Brønsted acid sites, and a realistic description of the silicon distribution within the framework, provides isotherms and evolutions of the differential enthalpy of adsorption as a function of coverage for the STA-7 material characterised by a silicon fraction of 0.19. The simulated results are revealed to be in good agreement with the experimental data that allowed us to provide a possible microscopic mechanism of CO 2 adsorption in this material. These whole results are thus compared to those obtained for the purely aluminophosphate form of the AlPO-18. It is clearly emphasized that distinct adsorption behaviours are observed in these two systems, depending on the energetic characteristics of their surfaces.