TPD study of the reversible retention of carbon dioxide over montmorillonite intercalated with polyol dendrimers

• Published in: Thermochimica acta Vol. 496; no. 1; pp. 45 - 49
• Main Authors: Azzouz, Abdelkrim, Ursu, Alina-Violeta, Nistor, Denisa, Sajin, Tudor, Assaad, Elias, Roy, René
• Format: Journal Article
• Language: English; Dutch
• Published: Oxford Elsevier B.V 10.12.2009; Elsevier
• Subjects: Carbon dioxide; Chemistry; Exact sciences and technology; General and physical chemistry; Montmorillonite; Organoclay; Polyol dendrimers; Reversible gas capture; Solid-gas interface; Surface physical chemistry; Thermal programmed desorption; Polyol dendrimers; Thermal programmed desorption; Montmorillonite; Reversible gas capture; Organoclay; Carbon dioxide; Organic clay; Gas solid interface; Thermodesorption; Desorption; Polyol; Dendritic structure
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2009.06.023

Organoclays with improved affinity towards carbon dioxide were obtained via montmorillonite intercalation with polyol and amino dendrimers having respectively hydroxyl or amino groups that act as adsorbing sites. Measurements through thermal programmed desorption (TPD) show that higher amounts of CO 2 than predicted by stoichiometry were retained by polyol organoclays, suggesting that more than one CO 2 molecule adsorb on each OH group. The latter displayed optimal base properties tailored for: (i) improved retention capacity of CO 2 by increasing their number; (ii) easy consecutive gas release upon slight heating owing to their weak basicity. Unlike amines, polyols display sufficiently weak basicity to exert only physical interaction towards carbon dioxide molecules. The reversible CO 2 adsorption–desorption equilibrium is discussed here in terms of acid–base interactions between the organoclay surface and surrounding CO 2 molecules. The results obtained herein open new prospects in obtaining microporous materials able to act as lungs that fix reversibly polluting gases.