Investigation into geometric configurations and electronic properties of CeO2-supported gold clusters

Abstract

A detailed understanding of the geometric structure and electronic properties of gold nanoparticles on the ceria surface is crucial for comprehending their unique catalytic activity. Using the first-principles method based on density functional theory, the adsorption of Aux (x = 1–4) clusters on the CeO2(111) surface was studied. It was discovered that the standing configurations of Au2 and Au3, as well as the tetrahedral structure of Au4, are the most stable adsorption structures. The stability of these configurations is jointly determined by the number and strength of Au-Au bonds, the Au-O bonding energy, and the interaction dynamics between the clusters and the substrate. The analysis of Bader charge, difference charge density and density of states suggested that lattice relaxation and electronic localization occur in the reduced Ce3+. The reduced amount and location of Ce3+ are significantly influenced by the position and charge transfer amount of Aux cluster. The adsorption of CO on Au4/CeO2(111) indicated that stronger Au-C bonding energy due to the hybridization of Au-5d and C-2p, thereby enhancing the catalytic activity for CO oxidation reactions.