The Adsorption and Growth of Agn(n = 1~4) Clusters on Cubic, Monoclinic, and Tetragonal ZrO2 Surfaces: A First-Principles Study
Supported metal nanoparticles are widely used as catalysts in the industrial production of chemicals, but still suffer from deactivation because of metal leaching and sintering at high temperature. In this work, the adsorption and growth of Agn (n = 1 ~ 4) on cubic zirconia (c-ZrO2) (1 1 1), monoclinic zirconia (m-ZrO2) ( 1 1), and tetragonal zirconia (t-ZrO2) (1 0 1) surfaces has been examined by the aid of the first-principles calculation and periodic supercell model. The results show that the adsorption of a single silver atom on different zirconia surfaces follow the trend t-ZrO2 (1 0 1) > m-ZrO2 ( 1 1) > c-ZrO2 (1 1 1). Growth of Agn (n = 2 ~ 4) on different zirconia surfaces are thermodynamically feasible and the supports can improve the dispersion of silver particles, especially the surface of t-ZrO2 (1 0 1). The Bader charge analysis was conducted on the most stable adsorption structure of different zirconia surfaces for a single silver atom. The results show that no major charge transfer was observed when the silver atoms adsorbed on the stoichiometric c-ZrO2 (1 1 1), t-ZrO2 (1 0 1) and m-ZrO2 ( 1 1) surfaces, the silver’s unpaired electron remains largely localized on the metal adatom upon adsorption. The findings could help to understand the metal cluster-support interactions and design new catalysts for this kind of reaction.