Observation of a low-energy adsorbate core-level satellite for CO bonded to palladium: Coordination-dependent effects

Research output: Contribution to journalArticle


A strong low-energy shake-up satellite for CO adsorbed on Pd is observed. The occurrence of the satellite is established for the CO/1 ML Pd/Mo(110) system at a coverage where CO adsorbs exclusively on-top. Comparisons with CO adsorbed on Pd single-crystal surfaces and small supported Pd particles indicate that the strongly increased satellite intensity is due to the decreased CO-Pd interaction strength for on-top adsorbed CO. This can be used to get further insight into the structure and bonding properties of the adsorbate system. Since a low-energy shake-up feature may be misinterpreted as a chemically shifted component, the conclusion is that great care has to be taken in the evaluation of adsorbate core-level spectra for systems with large variations in adsorption strength depending on the adsorbate sites. Large variations in the CO site distribution may furthermore occur depending on the nature of the Pd substrate: Adsorption of CO on 1 ML Pd/Mo(110) leads to an overlayer dominated by an on-top species and, likewise, the CO overlayer formed on small Pd particles after large doses has a large fraction of on-top bonded species. This is in strong contrast to Pd single-crystal surfaces, where CO adsorbed in more highly coordinated sites is abundant.


  • A. Sandell
  • A. Beutler
  • R. Nyholm
  • J. N. Andersen
  • S. Andersson
  • P. A. Brühwiler
  • N. Mårtensson
  • J. Libuda
  • K. Wolter
  • O. Seiferth
  • M. Bäumer
  • H. Kuhlenbeck
  • H. J. Freund
External organisations
  • Uppsala University
  • Fritz Haber Institute of the Max Planck Society
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Accelerator Physics and Instrumentation
Original languageEnglish
Pages (from-to)13199-13208
Number of pages10
JournalPhysical Review B (Condensed Matter)
Issue number20
StatePublished - 1998 May 15