Theoretical Study of the Structures and Chemical Ordering of Palladium–Gold Nanoalloys Supported on MgO(100)

Bimetallic nanoparticles composed of palladium and gold are particularly interesting from the viewpoint of their catalytic properties, for example, for selective hydrogenation and alcohol oxidation. More accurate catalytic modeling is achieved by the inclusion of the substrate (e.g., metal oxides). In this work, the structures and chemical ordering (atomic segregation) of Pd?Au clusters supported on MgO(100) were studied using a combined empirical potential?density functional theory approach. The focus is on 30- and 40-atom clusters, including variation in the bimetallic composition. Consistent with the available experimental findings, Pd atoms preferentially bind to the substrate oxygen sites. Good cluster-substrate epitaxy is observed, but there is a strong dependence on the size and composition of the clusters.