All-electron scalar relativistic calculation of the adsorption of NCO species onto small copper clusters

An all-electron scalar relativistic calculation of CunNCO (n = 1–13) clusters has been made using density functional theory with the generalized gradient approximation at BLYP level. In all CunNCO clusters, the NCO species prefered to occupy the single-fold coordination site and the small copper cluster tended to bond with the nitric. The Cun structures were only distorted slightly and the NCO species retained linear structure. The N-C bond-length contraction and C-O bond-length elongation were observed clearly. The reactivity enhancement of NCO species toward CO2 was obvious. But, no reactivity enhancement of NCO to form N2 related to the N-C bond strength could be observed. It seems that the NCO species is more favorably adsorbed by odd-numbered small copper clusters, relatively. Some discrepancies between our work and earlier works were found which may be explained in terms of the scalar relativistic effect. Further studies to focus on the reactivity enhancement of NCO to form N2 are clearly in order.