Adsorption of NO, NO 2 and H 2 O in divalent cation faujasite type zeolites: a density functional theory screening approach.

Emissions of diesel exhaust gas in confined work environments are a major health and safety concern, because of exposition to nitrogen oxides (NO x ). Removal of these pollutants from exhaust gas calls for engineering of an optimum sorbent for the selective trapping of NO and NO 2 in the presence of water. To this end, periodic density functional theory calculations along with a recent dispersion correction scheme, namely the Tkatchenko-Scheffler scheme coupled with iterative Hirshfeld partitioning TS/HI, were performed to investigate the interactions between NO, NO 2 , H 2 O and a series of divalent cation (Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Fe 2+ , Cu 2+ , Zn 2+ , Pd 2+ , and Pt 2+ ) faujasites. This enabled the identification of the optimum zeolites to selectively capture NO x in the presence of H 2 O, with respect to two important criteria, such as thermodynamic affinity and regeneration. Our results revealed that Pt 2+ and Pd 2+ containing faujasites are the best candidates for effective capture of both NO and NO 2 molecules, which paves the way towards the use of these sorbents to address this challenging application.