, Volume 1, Issue 1, pp 80–84 | Cite as

The effect of catalyst-electrode potential and work function on the chemisorptive bond of oxygen on Pt interfaced with YSZ

  • S. G. Neophytides
  • C. G. Vayenas


Controlled variation in catalyst-electrode potential of metals interfaced with solid electrolytes leads to the effect of Non-faradaic Modification of Catalytic Activity (NEMCA) which causes dramatic changes in the catalytic activity and selectivity. Its origin was shown to lie in the controlled variation of the work function upon polarization of the catalyst-solid electrolyte interface which is due to ion spillover over the entire gas exposed catalyst surface. In the present work the effect of induced work function changes on the kinetics and energetics of the interaction of oxygen with polycrystalline Pt, interfaced with an yttria stabilized zirconia solid electrolyte, were studied, by means of the temperature programmed desorption technique. It was found that by increasing catalyst potential and work function the O2 desorption peak shifts towards lower temperatures, showing that the binding strength of chemisorbed oxygen species weakens by increasing catalyst work function. The activation energy of desorption of adsorbed O species was measured by the “temperature rate variation technique” and was found to decrease linearly with slope -1 with increasing catalyst work function. This straightforward experimental correlation between catalyst work function and the binding energy of chemisorbed O species is in absolute agreement with previous NEMCA studies which show that the apparent activation energy of all reactions studied, depends linearly on catalyst potential and work function.


Work Function Apparent Activation Energy Solid Electrolyte Temperature Program Desorption Desorption Peak 
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4. References

  1. [1]
    C.G. Vayenas, S. Bebelis, I.V. Yentekakis, and H-G. Lintz, Catal. Today11(3), 303 (1992)CrossRefGoogle Scholar
  2. [2]
    C.G. Vayenas, S. Bebelis, and S. Ladas, Nature (London)343, 625 (1990)CrossRefGoogle Scholar
  3. [3]
    I.V. Yentekakis, and C.G. Vayenas, J. Catal.111, 170 (1990)CrossRefGoogle Scholar
  4. [4]
    C.G. Vayenas, S. Bebelis, and S. Neophytides, J. Phys. Chem.92, 5083 (1988)CrossRefGoogle Scholar
  5. [5]
    S. Bebelis, and C.G. Vayenas, J. Catal.118, 125 (1989)CrossRefGoogle Scholar
  6. [6]
    S. Neophytides, and C.G. Vayenas, J. Catal.118, 147 (1989)CrossRefGoogle Scholar
  7. [7]
    S. Bebelis, and C.G. Vayenas, J. Catal.138, 570 (1992)CrossRefGoogle Scholar
  8. [8]
    S. Bebelis, and C.G. Vayenas, J. Catal.138, 588 (1992)CrossRefGoogle Scholar
  9. [9]
    I.V. Yentekakis, G. Moggridge, C.G. Vayenas, and Lambert, R.M., J. Catal.146, 292 (1994)CrossRefGoogle Scholar
  10. [10]
    S. Ladas, S. Kennou, S. Bebelis, and C.G. Vayenas, J. Phys. Chem.97, 8845 (1993)CrossRefGoogle Scholar
  11. [11]
    S.G. Neophytides, D. Tsiplakides, P. Stonehart, M.M. Jaksic, and C.G. Vayenas, Nature370, 45, (1994)CrossRefGoogle Scholar
  12. [12]
    J.L. Gland, and V.N. Korchak, Surface Science75, 733 (1978)CrossRefGoogle Scholar
  13. [13]
    J.L. Gland, Surface Science93, 487 (1980)CrossRefGoogle Scholar
  14. [14]
    A. Winkler, X. Guo, H.R. Siddiqui, P.L. Hagans, and J.T. Yates, Jr, Surface Science,201, 419 (1988)CrossRefGoogle Scholar
  15. [15]
    M.A. Barteau, E.I. Ko, and R.J. Madix, Surface Science102, 99 (1981)CrossRefGoogle Scholar
  16. [16]
    J. Xue, and R. Dieckemann, Proceedings of the 2nd International Symposium on Ionic and Mixed Conducting Ceramics (T.A. Ramanarayanan et al., Eds.)94–12, 191 (1994)Google Scholar
  17. [17]
    P.R. Norton, K. Griffiths, and P.E. Binder, Surface Science138, 125 (1984)CrossRefGoogle Scholar
  18. [18]
    J.L. Falconer and R.J. Madix, Surface Science48, 393 (1975)CrossRefGoogle Scholar
  19. [19]
    C.T. Cambell, G. Ertl, H. Kuipers and Segner, J. Surface science107, 220 (1981)CrossRefGoogle Scholar

Copyright information

© IfI - Institute for Ionics 1995

Authors and Affiliations

  • S. G. Neophytides
    • 1
  • C. G. Vayenas
    • 1
  1. 1.Department of Chemical Engineering and ICE/HTUniversity of PatrasPatrasGreece

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