Structure and reactivity of Pd doped Ag surfaces

We have performed first principles calculations for clean and Pd doped Ag(1 1 1) and Ag(1 0 0) surfaces, with and without adsorbed O and CO. Our results for the structure of the Pd doped Ag surfaces indicate that Pd atoms are located lower than the surrounding Ag surface atoms. We find that O atoms adsorbed on Pd doped Ag(1 1 1) reside at the fee hollow sites, the site next to Pd being slightly favored. Moreover, we provide results for O and CO, co-adsorption on the clean and Pd doped Ag(1 1 1) surfaces, indicating that Pd can act as an electronic promoter for the CO oxidation reaction. (C) 2003 Elsevier Science B.V. All rights reserved.