A first-principles study of structure, orbital interactions and atomic oxygen and OH adsorption on Mo-, Sc- and Y-doped nickel bimetallic clusters

Density functional theory (DFT) has been used to study the stability, orbitals interactions and oxygen and hydroxyl chemisorption properties of NinM (1 ⩽ n ⩽ 12) clusters. A single atom doped-nickel clusters increase the stability, and icosahedral Ni12Mo cluster is the most stable structure. Molybdenum atom prefers to exhibit center at the cluster (n ⩾ 10) rather than edge, while Sc and Y atom remain at the edge. The Ni-Mo bond lengths are smaller than the Ni-Sc and Ni-Y. The pDOS results show that the d-d orbitals interactions are mainly dominating on the stability of clusters, while p orbitals have a small effect on the stability. The Mo-doped nanoclusters have the highest oxygen and OH chemisorption energy, and the most favorable adsorption site is on the top Mo site. The larger cluster distortion is found for the Sc- and Y-doped structures compared to other clusters. The oxygen 2p orbitals are strongly hybridizing with the Mo 4d orbitals (n < 9) and a little interaction between oxygen 2p and Ni 3d, 4s and Mo 5s orbitals. The Mo-doped clusters are significantly increased the chemisorption energies that might improve the passive film adherence of nanoalloys.