The influence of surface termination on the growth of copper clusters

Abstract

Oxide-supported transition metal catalysts are widely used in a variety of heterogeneous catalytic processes. Knowledge of the interaction of metals with oxide surfaces provides an insight into the understanding of a broad variety of properties of the catalysts. However, relatively little is known about the interfaces due to lack of experimental evidence. In our work, the interaction between copper clusters and α-alumina (0001) surface was studied using the density functional theory. It is found that the outermost Al atoms are the energetically preferred adsorption sites for Cu _n (n = 1–3) clusters. Little effort has been made to investigate the environmental effect of the adsorption of Cu clusters on the α-alumina (0001) surface. We examined adsorption of Cu clusters on fully hydroxylated α-alumina surface and compared the results with that of the clean surface. The surface hydroxylation greatly weakens the adhesion of Cu clusters to the substrate. On the other hand, a hydrogen spillover reaction takes place to strengthen the Cu surface binding. The Cu–alumina system may serve as a prototype interface to help us gain knowledge of the growth pathway of supported metal clusters.

Keywords:

• copper clusters, adsorption
• aluminium oxide
• density functional theory
• heterogeneous catalysis

Notes

1. NIST Standard Reference Database 69: NIST Chemistry WebBook.