title: A DFT investigation of the adsorption of iodine compounds and water in H-, Na-, Ag-, and Cu- mordenite.
abstract: The potential use of some cation-exchanged mordenite (H(+), Na(+), Cu(+), and Ag(+)) as a selective adsorbent for volatile iodine species (ICH3 and I2), which can be released during a nuclear accident together with a steam carrier gas, is investigated using density functional theory. It is found that in the case of Cu-MOR and Ag-MOR, the absolute values of interaction energies of ICH3 and I2 are higher than that of water which indicates that these forms of zeolite could be suitable for selective adsorption of iodine species. In contrast, the H-MOR and Na-MOR are found to be unsuitable for this purpose. A systematic investigation of all adsorption sites allowed us to analyze the structural effects affecting the adsorption behavior. For the Ag-MOR and Cu-MOR zeolites, the iodine compounds are adsorbed preferentially in the large channel of mordenite (main channel) while water prefers the small channel or the side pocket where it forms stronger hydrogen bonds. The factors governing the interaction energies between the cationic sites and the different molecules are analyzed and the important role of van der Waals interactions in these systems is highlighted.
authors.affiliation: Université de Lorraine, LCP-A2MC, Institut Jean-Barriol FR2843 CNRS, Rue Victor Demange, 57500 Saint-Avold, France.
authors.forename: Siwar
authors.initials: S
authors.lastname: Chibani
authors.affiliation: Université de Lorraine, LCP-A2MC, Institut Jean-Barriol FR2843 CNRS, Rue Victor Demange, 57500 Saint-Avold, France.
authors.forename: Mouheb
authors.initials: M
authors.lastname: Chebbi
authors.affiliation: Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2, UMR CNRS 7036) Institut Jean Barriol, Université de Lorraine BP 239, Boulevard des Aiguillettes, 54506 Vandoeuvre-lès-Nancy, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lebègue
authors.affiliation: Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, SK- 84215 Bratislava, Slovakia.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Bučko
authors.affiliation: Université de Lorraine, LCP-A2MC, Institut Jean-Barriol FR2843 CNRS, Rue Victor Demange, 57500 Saint-Avold, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Badawi