Structural stability and magnetic properties of CumConNO (m plus n=2-7) clusters

摘要

A theoretical study of NO adsorption on CumCon (2 <= m + n <= 7) clusters was carried out using a density functional method. Generally, NO is absorbed at the top site via the N atom, except in Cu3NO and Cu5NO clusters, where NO is located at the bridge site. Co2NO, Co3NO, Cu2Co2NO, Co5NO, Cu2Co4NO and Cu6CoNO clusters have larger adsorption energies, indicating that NO of these clusters are more easily adsorbed. After adsorption, N-O bond is weakened and the activity is enhanced as a result of vibration frequency of N-O bond getting lower than that of a single NO molecule. Cu2CoNO, Cu3CoNO, Cu2Co2NO, Cu3Co3NO and CuCo5NO clusters are more stable than their neighbours, while CuCoNO, Co3NO, Cu3CoNO, Cu2Co3NO, Cu3Co3NO and Cu6CoNO clusters display stronger chemical stability. Magnetic and electronic properties are also discussed. The magnetic moment is affected by charge transfer and the spd hybridization.