A density functional theory study on the adsorption and dissociation of N 2O on Cu 2O(1 1 1) surface

Abstract

Density functional theory has been employed to investigate the adsorption and the dissociation of an N 2O at different sites on perfect and defective Cu 2O(1 1 1) surfaces. The calculations are performed on periodic systems using slab model. The Lewis acid site, Cu CUS, and Lewis base site, O SUF are considered for adsorption. Adsorption energies and the energies of the dissociation reaction N 2O → N 2 + O(s) at different sites are calculated. The calculations show that adsorption of N 2O is more favorable on Cu CUS adsorption site energetically. Cu CUS site exhibits a very high activity. The Cu CUS–N 2O reaction is exothermic with a reaction energy of 77.45 kJ mol −1 and an activation energy of 88.82 kJ mol −1, whereas the O SUF–N 2O reaction is endothermic with a reaction energy of 205.21 kJ mol −1 and an activation energy of 256.19 kJ mol −1. The calculations for defective surface indicate that O vacancy cannot obviously improve the catalytic activity of Cu 2O.