A DFT investigation of the adsorption of iodine compounds and water in H-, Na-, Ag-, and Cu- mordenite
- Université de Lorraine, LCP-A2MC, Institut Jean-Barriol FR2843 CNRS, Rue Victor Demange, 57500 Saint-Avold (France)
- 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)
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, SK- 84215 Bratislava (Slovakia)
The potential use of some cation-exchanged mordenite (H{sup +}, Na{sup +}, Cu{sup +}, and Ag{sup +}) as a selective adsorbent for volatile iodine species (ICH{sub 3} and I{sub 2}), 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 ICH{sub 3} and I{sub 2} 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.
- OSTI ID:
- 22676017
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 24 Vol. 144; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
Similar Records
Influence of multiply charged cations on the properties of redox sites in mordenite
Electron spin-echo and electron spin-resonance studies of cupric ion-adsorbate interactions in hydrogen, sodium, potassium, and calcium mordenite