Skip to main content
SpringerLink
Log in

Promotors, poisons and surfactants: Electronic effects of surface doping on metals

  • Published:
Applied Physics A Aims and scope Submit manuscript

Abstract

The interaction of adsorbates with metal surfaces is discussed. It is shown that the evanescent charge density produced by occupied sp derived surface states yields a considerable contribution to the Pauli repulsion experienced by adsorbate particles with a closed-shell electronic structure, e.g. rare-gases or molecules such as H2 or N2. For rare-gases this results in a reduction of the binding energy in the presence of occupied surface states, for molecules this gives rise to an additional contribution to the dissociation barrier. Suitable surface dopants are able to depopulate surface states and thereby to reduce the dissociation barrier. Such dopants can substantially promote catalytic reactions in which the dissociation from the gas phase or a physisorbed precursor is the rate limiting step. In contrast to closed-shell systems the bonding interaction for metal adsorbates on metal substrates is enhanced by occupied surface states. This leads to an extra diffusion barrier at steps, because the surface state amplitude drops to zero at upper step edges. The additional step-edge barrier, which is a kinetic hindrance for layer-by-layer growth, can be reduced by surface dopants depopulating the corresponding surface state. Such dopants promote layer-by-layer growth and act therefore as surfactants. It is concluded that the effect of promoters in catalysis and of surfactants in metal epitaxy is in part due to the same basic mechanism, namely the depopulation of surface states.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. M.P. Kiskinova: Poisoning and Promotion in Catalysis Based on Surface Science Concepts and Experiments, Elsevier, Amsterdam (1993)

    Google Scholar 

  2. H.P. Bonzel: Surf. Sci. Rep.8, 43 (1987)

    Google Scholar 

  3. J.E. Müller:Theory of the Coadsorption of H 2 O and CO with K on the Pt(111) Surface, in: The Chemical Physics of Solid Surfaces, Vol. 6, ed. D.A. King and D.P. Woodruff, Elsevier, Amsterdam (1993) p 29

    Google Scholar 

  4. P.A. Schultz, Ch.H. Patterson, R.P. Messmer: J. Vac. Sci. Technol.A 5, 1061 (1986)

    Google Scholar 

  5. K. Wandelt,Atomic Scale Surface Characterization with Photoemission of Adsorbed Xenon (PAX ), in: Chemistry and Physics of Solid Surfaces, Vol. 8, eds. R. Vanselow and R. Howe, Springer Series in Surface Science22, Springer Verlag, Berlin (1990) p 289

    Google Scholar 

  6. T.V.W. Janssens, G.R. Castro, K. Wandelt, J.W. Niemantsverdriet: Phys. Rev. B49, 14599 (1994)

    Google Scholar 

  7. P.J. Feibelman, D.R. Hamann: Surf. Sci.149, 48 (1985)

    Google Scholar 

  8. M. Henzler: Prog. Surf. Sci.42, 297 (1993)

    Google Scholar 

  9. G. Rosenfeld, N.N. Lipkin, W. Wulfhekel, J. Kliewer, K. Morgenstern, B. Poelsema, G. Comsa:Appl. Phys. A61, 455 (1995)

    Google Scholar 

  10. R.L. Schwoebel, E.J. Shipsey: J. Appl. Phys.37, 3682 (1966)

    Google Scholar 

  11. G. Ehrlich, F.G. Hudda: J. Chem. Phys.44, 1039 (1966)

    Google Scholar 

  12. G. Rosenfeld, R. Servaty, C. Teichert, B. Poelsema, G. Comsa: Phys. Rev. Lett.71, 895 (1993)

    Google Scholar 

  13. S. Oppo, V. Fiorentini, M. Scheffler: Phys. Rev. Lett.71, 2437 (1993)

    Google Scholar 

  14. St. Esch, M. Hohage, Th. Michely, G. Comsa: Phys. Rev. Lett.72, 518 (1994)

    Google Scholar 

  15. N. Memmel, E. Bertel: Phys. Rev. Lett.75, 485 (1995)

    Google Scholar 

  16. J. Harris, A. Liebsch: J. Phys. C15, 2275 (1982)

    Google Scholar 

  17. P. Roos, E. Bertel, K.D. Rendulic: Chem. Phys. Lett.232, 537 (1995)

    Google Scholar 

  18. E. Bertel: Surf. Sci.331-333, 1136 (1995)

    Google Scholar 

  19. E. Zaremba; W. Kohn: Phys. Rev. B15, 1769 (1977)

    Google Scholar 

  20. K. Wandelt, B. Gumhalter: Surf. Sci.140, 355 (1984)

    Google Scholar 

  21. M. Wolf, E. Knoesel, T. Hertel: Phys. Rev. B Rapid Commun., in print

  22. W.R. Merry, R.E. Jordan, D.F. Padowitz, C.B. Harris: Surf. Sci.295, 393 (1992)

    Google Scholar 

  23. K. Kern, R. David, R.L. Palmer, G. Comsa: Surf. Sci.175, L669 (1986)

    Google Scholar 

  24. M. Potthoff, G. Hilgers, N. Miller, U. Heinzmann, L. Haunert, J. Braun, G. Borstel: Surf. Sci.322, 193 (1995); G. Hilgers, M. Potthoff, N. Müller, U. Heinzmann: Surf. Sci.322, 207 (1995)

    Google Scholar 

  25. M. Petersen, S. Wilke, P. Ruggerone, B. Kohler, M. ScheflJer: Phys. Rev. Lett.76, 995 (1996);d states do play an important role, because in Pd and Pt they provide a large DOS atE F and therefore the charge driven back into the metal is mainly accommodated into thed states. The surface states or resonances which are responsible for the repulsive interaction are in generalspd hybride states, but the overlap with the rare-gas atom is essentially due to thesp admixture in the wavefunction

    Google Scholar 

  26. S.D. Kevan, R.H. Gaylord: Phys. Rev. B36, 5809 (1987)

    Google Scholar 

  27. E. Bertel: Surf. Sci. Lett., in print

  28. J. Tersoff, D.R. Hamann: Phys. Rev. B31, 805 (1985)

    Google Scholar 

  29. S. Horch, P. Zeppenfeld, G. Comsa: Appl. Phys. A60, 147 (1995)

    Google Scholar 

  30. K. Wandelt, J.E. Hulse: J. Chem. Phys.80, 1340 (1984)

    Google Scholar 

  31. P. Zeppenfeld, S. Horch, G. Comsa: Phys. Rev. Lett.73, 1259 (1994)

    Google Scholar 

  32. B. Hammer, J.K. Nørskov: Surf. Sci.343, 211 (1995)

    Google Scholar 

  33. P.M. Holmblad, J. Hvolbæk Larsen, I. Chorkendorff, L. Pleth Nielsen, F. Besenbacher, I. Stensgaard, E. Lægsgaard, P. Kratzer, B. Hammer, J.K. Nørskov: Catal. Lett.40, 131 (1996)

    Google Scholar 

  34. M. Bowker,Promotion in Ammonia Synthesis, in: The Chemical Physics of Solid Surfaces, Vol. 6, eds. D.A. King, D.P. Woodruff: Elsevier, Amsterdam (1993) p 225

    Google Scholar 

  35. Ch. Resch, H.F. Berger, K.D. Rendulic, E. Bertel: Surf. Sci. Lett.316, L1105 (1994)

    Google Scholar 

  36. N. Memmel, G. Rangelov, E. Bertel, V. Dose: Phys. Rev. B43, 6938 (1991)

    Google Scholar 

  37. P. Sandl, E. Bertel: Surf. Sci. Lett.302, L325 (1994)

    Google Scholar 

  38. G.M. Watson, P.A. Bruhwiler, E.W. Plummer, H.-J. Sagner, K.-H. Frank: Phys. Rev. Lett.65, 468 (1990)

    Google Scholar 

  39. N. Fischer, S. Schuppler, Th. Fauster, W. Steinmann: Surf. Sci.314, 89 (1994)

    Google Scholar 

  40. Ch. Resch, V. Zhukov, A. Lugstein, H.F. Berger, A. Winkler, K.D. Rendulic: Chem. Phys.177, 421 (1993)

    Google Scholar 

  41. J.K. Brown, A.C. Luntz, P.A. Schultz: J. Chem. Phys.95, 3767 (1991)

    Google Scholar 

  42. E. Bertel, P. Roos, J. Lehmann: Phys. Rev. B52, R14384 (1995)

    Google Scholar 

  43. E. Bertel, P. Sandl, K.D. Rendulic, M. Beutl: Ber. Bunsenges. Phys. Chem.100, 114 (1996)

    Google Scholar 

  44. F. Passek, M. Donath: Phys. Rev. Lett.71, 2122 (1993)

    Google Scholar 

  45. S.D. Kevan, N.G. Stoffel, N.V. Smith: Phys. Rev. B31, 3348 (1985)

    Google Scholar 

  46. N.V. Smith, C.T. Chen: Surf. Sci.247, 133 (1991)

    Google Scholar 

  47. E. Bertel: Phys. Rev. B50, 4925 (1994)

    Google Scholar 

  48. R.J. Behm:Alkali Adsorption and Alkali induced Reconstructions on fcc(1 10) Metal Surfaces, in: Physics and Chemistry of Alkali Metal Adsorption, eds. H.P. Bonzel, A.M. Bradshaw, G. Ertl, Materials Science Monographs57, Elsevier, Amsterdam (1989) 111

    Google Scholar 

  49. E. Bertel:Surface States and Chemical Reactivity of Metals, in: Electronic Surface and Interface States on Metallic Systems, eds. E. Bertel and M. Donath, World Scientific, Singapore (1995) p 13

    Google Scholar 

  50. P. Kratzer, B. Hammer, J.K. Nørskov: Surf. Sci.359, 45 (1996)

    Google Scholar 

  51. R. Matzdorf, R. Paniago, G. Meister, A. Goldmann: Solid State Commun.96, 799 (1995)

    Google Scholar 

  52. J.K. Nørskov:Adsorbate-Adsorbate Interactions on Metal Surfaces, in: The Chemical Physics of Solid Surfaces, Vol. 6, eds. D.A. King and D.P. Woodruff, Elsevier, Amsterdam (1993) p 1

    Google Scholar 

  53. G. Ertl: Catal. Rev.-Sci. Eng.21, 201 (1980)

    Google Scholar 

  54. L.J. Whitman, C.E. Bartosch, W. Ho, G. Strasser, M. Grunze: Phys. Rev. Lett.56, 1984 (1986)

    Google Scholar 

  55. L.J. Whitman, C.E. Bartosch, W. Ho: J. Chem. Phys.85, 3688 (1986)

    Google Scholar 

  56. Inspection of the Fe band structure reveals ap-sd bandgap atE F in the minority bands above the N1′ point. On Fe(1 10) the N1′ wavefunction projects as ap z type wavefunction onto the center of the SBZ and has therefore a large decay length. More precisely, with the N1 wavefunction it will form a\(p_z d_{z^2 } \) hybride surface state. This state dominates the charge density at larger distances from the surface. On the Fe(100) surface the N1′ point projects onto the edges of the SBZ. The corresponding surface state has nodal planes going through the atoms. The same applies to the Fe(111) surface

  57. See for instance the references cited in ref. 42

  58. W.C.A.N. Ceelen, A.W. Denier van der Gon, J. Falta, A. Hille, G. Materlik: Verhandl. DPG (VI)31, 034.5 (1996)

    Google Scholar 

  59. H.A. van der Vegt, H.M. van Pixteren, M. Lohmeier, E. Vlieg: Phys. Rev. Lett.68, 3335 (1992)

    Google Scholar 

  60. R. Kunkel, B. Poelsema, L.K. Verheij, G. Comsa: Phys. Rev. Lett.65, 733 (1990)

    Google Scholar 

  61. J.K. Nørskov: Rep. Prog. Phys.53, 1253 (1990)

    Google Scholar 

  62. H. Wolter, M. Schmidt, K. Wandelt: Surf. Sci.298, 173 (1993); M. Schmidt, H. Wolter, K. Wandelt: Surf. Sci.307-309, 507 (1994)

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Max-Planck-Institut für Plasmaphysik, Abteilung Oberflächenphysik, EURATOM-Association, P.O. Box 1533, D-85740, Garching, Germany

    E. Bertel & N. Memmel

Authors
  1. E. Bertel
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. N. Memmel
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bertel, E., Memmel, N. Promotors, poisons and surfactants: Electronic effects of surface doping on metals. Appl. Phys. A 63, 523–531 (1996). https://doi.org/10.1007/BF01567208

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01567208

PACS

Search

Navigation