Formation of Ag2, Au2 and AgAu particles on MgO(100). DFT study on the role of support induced charge transfer in metal-metal interactions

FUENTE, SILVIA; PATRICIA GABRIELA, BELELLI; MARÍA MARTA, BRANDA; RICARDO MARIO, FERULLO; NORBERTO JORGE, CASTELLANI

APPLIED SURFACE SCIENCE

Elsevier

Lugar: Amsterdam; Año: 2009 vol. 255 p. 7380 - 7384

0169-4332

The formation of Ag2,Au2 and AgAu particles oriented perpendicularly to the MgO(1 0 0) surface was studied using the density functional theory. While the support induces a slight enhancement of the Ag-Ag bond (by 0.3-0.4 eV), the Au-Au bond is strongly enhanced (by 0.8-1.1 eV). Concerning the bimetallic particle, the Ag-Au bond stabilization depends on the relative position of each atom. Thus, in general terms, the strength of the metal-metal bond is determined by the nature of the terminal atom; the bond is stronger in Au-terminal particles. The partial electronic charge transfer to the terminal Au atom and its ability to polarize this charge are responsible for this energetic stabilization.