Interaction of carbon monoxide with Cu-Pd and Cu-Ni bimetallic clusters

Interaction of CO with Cu-Pd and Cu-Ni bimetallic clusters deposited on a Z nO substrate has been investigated by core-level spectroscopy. The surface reactivity of both these alloy clusters increases with the decrease in clus ter size, giving rise to dissociative adsorption at small cluster size. The surface reactivity also increases with the increase in Pd or Ni content an d the reactivity of the alloy clusters is unlike that of either component m etal. Thus, dissociative adsorption occurs on small Cu-Pd clusters unlike o n either Cu or Pd clusters of comparable size. The reactivity of the Cu-Ni clusters, on the other hand, falls somewhere between those of Cu and Ni clu sters.