Nucleation of Cu_n (n = 1–5) Clusters and Equilibrium Morphology of Cu Particles Supported on CeO₂ Surface: A Density Functional Theory Study

In the present work, the interactions between Cu n ( n = 1–5) clusters and three low-index structural CeO 2 (111, 110, 100) surfaces were investigated using density functional theory calculations. The atomic Cu prefers to aggregate into large clusters on the CeO 2 (111) surface, whereas it is unfavorable on both CeO 2 (110) and CeO 2 (100) surfaces. Once the planar Cu 4-p cluster is formed, it would convert into the three-dimensional (3D) tetrahedral Cu 4-t cluster on CeO 2 (110) and CeO 2 (111) surfaces, i.e., two-dimensional to 3D transition growth is thermodynamically favorable and kinetically feasible on CeO 2 (110) and CeO 2 (111) surfaces. The effects of the ceria support structure on the morphology of the large Cu nanoparticle were examined using calculated adhesion and interfacial energies of periodic Cu( khl )/CeO 2 model systems. The calculated macroscopic contact angles (θ > 100°) of various model systems suggest that the supported Cu nanoparticle is in bad wetting conditions. Finally, the morphologies of large Cu nanoparticles on different CeO 2 surfaces were predicted using the Wulff–Kaichew construction principle.