Theoretical Studies of the Adsorption and Dissociation of Two NO Molecules on Cu2O(111) Surface

The adsorption and dissociation of two NO molecules on Cu2O(111) surface have been studied with the periodic slab model by using the density functional theory (DFT) and the generalized gradient approximation (GGA) with the Perdew- Burke-Ernzerhof (PBE) exchange-correlation functional. Three kinds of structures, Cu+(NO)(NO), Cu+(NO)(ON), and Cu+(ON)(ON), with the singlet and triplet states were considered. Their corresponding adsorption energies and Mulliken charges were calculated. The calculated results indicate that in the optimized Cu+(ON)(ON) configuration, two adsorbed NO molecules form a dimeric species with a much shorter NN bond length (about 124.4 pm). Such a configuration contributes to the dissociation of NO, leading to the formation of Cu-O surface species with elimination of N2 or N2O.