A DFT study of PtAu bimetallic clusters adsorbed on MgO/Ag(100) ultrathin films

We have performed density functional theory calculations on the properties of small PtAu(n) (n = 1-4) bimetallic clusters adsorbed on ultrathin MgO films deposited over the Ag(100) substrate. The PtAu bimetallic clusters show the occurrence of a charge transfer from the MgO/Ag interface to the supported nanoparticle with the formation of cluster anions. The Pt atom, which exhibits a stronger bonding with the oxide film and a higher diffusion barrier compared to Au, acts as a nucleation site for the bimetallic cluster and limits its diffusion on the surface.