LAUSR

Abstract Using periodic dispersion-corrected DFT calculations, the effect of potential inhibiting species (H 2 O, NO, CO, CH 3 Cl and Cl 2 ) on the adsorption of iodine species (I 2 , CH 3 I) has been investigated over different monovalent (H, Li, Na, K, Rb, Cs, Cu and Ag) cation-exchanged faujasite. We have found out that van der Waals interactions play an important role and can contribute up to about 50% of the total adsorption energy for the alkaline series. Both computed adsorption energies at 0 K and adsorption enthalpies for temperatures ranging from 298 to 523 K highlight the following points: (i) CO and H 2 O have been identified as the most important inhibiting species; (ii) Hard cations such as H + or Li + are very sensitive to water whereas soft cations such as Cu + and Ag + can strongly adsorb I 2 and CH 3 I. Therefore, Ag-FAU appears to be the most promising adsorbent in presence of all contaminants, except CO which can inhibit the adsorption of I 2 . These findings can help to improve the filtering devices used in nuclear plants to avoid the release of radioactive iodine in case of severe accident.