CO Oxidation at the Au–Cu Interface of Bimetallic Nanoclusters Supported on CeO2(111)

DFT+U calculations of the structure of CeO2(111)-supported Au-based bimetallic nanoclusters (NCs) show that a strong support–metal interaction induces a preferential segregation of the more reactive element to the NC–CeO2 perimeter, generating an interface with the Au component. We studied several Au -based bimetallic NCs (Au-X, X: Ag, Cu, Pd, Pt, Rh, and Ru) and found that (Au–Cu)/CeO2 is optimal for catalyzing CO oxidation via a bifunctional mechanism. O2 preferentially binds to the Cu-rich sites, whereas CO binds to the Au-rich sites. Engineering a two-component system in which the reactants do not compete for binding sites is the key to the high catalytic activity at the interface between the components.