Theoretical Study of OH Adsorption on ‎PdxCu3-x (x = 0-3) Nano Clusters‎

   Adsorption of OH on the PdxCu3-x(x=0-3) small clusters is investigated by density functional theory calculations. It is found that OH adsorbs in three possible modes including on top, bridge and hollow sites while the structures where OH bridges between two atoms are the most stable structures. The Pd-Pd, Pd-Cu and Cu-Cu equilibrium distances for most of the systems increase after OH adsorption and variations are higher for Pd-Pd equilibrium distances compared to Pd-Cu and Cu-Cu equilibrium distances. Adsorption of OH on Cu atom is more favored than on Pd atom. With increasing copper content of the nano-clusters the adsorption energy of OH drops to a minimum and increases with further increasing in copper content.