Silver clusters binding energy

Room temperature deposition of silver on Pd(lOO) produces a rather sharp Ag/Pd interface [62]. The interaction with a palladium surface induces a shift of Ag 3d core levels to lower binding energies (up to 0.7 eV) while the Pd 3d level BE, is virtually unchanged. In the same time silver deposition alters the palladium valence band already at small silver coverage. Annealing of the Ag/Pd system at 520 K induces inter-diffusion of Ag and Pd atoms at all silver coverage. In the case when silver multilayer was deposited on the palladium surface, the layered silver transforms into a clustered structure slightly enriched with Pd atoms. A hybridization of the localized Pd 4d level and the silver sp-band produces virtual bound state at 2eV below the Fermi level. 

The nature of bonding of the adsorbed species to the model cluster of metal surfaces can be analyzed in terms of the so-called constrained space orbital variation (CSOV) method. For halogen anions adsorbed on various silver surfaces, it has been found that Pauli repulsion, metal polarization, and charge transfer to the metal surface mainly contribute to the binding energy of the ions [104, 301]. 

Table 1. Binding energies ( o ), bond distances between the nearrat atoms of silver and oxygesi t

The DFT study of adsorption of silver dimer on rutile (110) surface within the cluster and periodic models shows that the interaction occurs both with chain oxygen atoms of the surface and with atoms located between the chains of 0(2c) atoms. Positive binding energy of Ag2 with rutile surface during adsorption between the oxygen chains was obtained only for the periodic model. The latter is concluded to be the preferable for theoretical study of Ag /Ti02 systems. 

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