Focusing on the structure of bimetallic PdAg and PtAg surfaces, the structure differs depending on whether these surfaces were fabricated by using Ag as substrate or Ag as deposit material, or whether they represent surfaces of bulk alloys. As expected from the much lower cohesion energy of Ag than Pt or Pd, intermixing / surface alloy formation and also bulk dissolution are activated already at rather low temperatures, at room temperature and slightly above when the noble metals are deposited on Ag . Furthermore, for Pd deposition, encapsulation of the Pd islands is observed before the onset of intermixing or bulk diffusion . Hence, the formation of well-defined, kinetically stabilized monolayer films and surface alloys is not possible under these conditions. This is different when using Pd or Pt as substrate, where the much higher cohesion energy points already to higher kinetic barriers for exchange / surface intermixing and bulk dissolution of Ag. As a result, well-defined Ag films with thicknesses from the submonolayer to the a few atomic layers can be produced both on Pd and Pt . Only upon annealing to  450 -500 K (Pd ) or  620 K (Pt( )) surface exchange and intermixing set in, which at these conditions is confined to the topmost layer ('surface confined intermixing') .