A study on the stability of gold copper bimetallic clusters on the CeO2(110) surface

The stability of AuCu, Au2Cu, AuCu2, Au2Cu2, and Au3Cu clusters on the CeO2(110) surface is related to the favourable interaction between theAu and Cu d-orbitals of the clusters with theO p-orbitals on the CeO2(110) surface. On the most stable AuCu/CeO2(110) systems, two surface Ce(IV)-ions are reduced to Ce(III)-ions however, the relatively lesser stable triatomic AuCu2 cluster can reduce up to three Ce(IV)-ions. The noninteracting Au-atoms in the Au2Cu/CeO2(110) and the Au3Cu/CeO2(110) systems are found to be negatively charged. We conclude that the number of reduced Ce-ions on the CeO2(110) surface can be tuned by altering the compositions of gold-copper clusters.