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Theoretica chimica acta

, Volume 39, Issue 1, pp 61–74 | Cite as

Molecular orbital calculations of the chemisorption and diffusion of oxygen and water on a graphite substrate

  • Michael R. Hayns
Article

Abstract

Semi-empirical molecular orbital calculations have been performed using the macro-molecular orbital model to simulate the chemisorption and diffusion of oxygen and water on a graphite substrate. By comparing with previous calculations of this type we have shown that the method adopted for minimising edge effects by saturating dangling carbon bonds reproduces the surface properties adequately for our purposes. Calculations using model substrates of 16 carbon and 10 hydrogen atoms and 24 carbon and 12 hydrogen atoms have been performed.

The chemisorption and diffusion of oxygen has been studied by means of an equipotential contour map and the diffusion path and activation energy found. Less extensive calculations on water on graphite allow us to give a most probable diffusion path and activation energy. Sufficient results have been obtained to allow some qualitative remarks to be made on the inhibition of oxidation by an H2O mechanism.

Key words

Oxygen, chemisorption and diffusion on graphite Water, chemisorption and diffusion on graphite Chemisorption 

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References

  1. 1.
    Belchar,T.A., Ehrlich,G.: J. Chem. Phys. 42, 2686 (1965)Google Scholar
  2. 2.
    Ehrlich,G., Hudda,F.: J. Chem. Phys. 44, 1039 (1966)Google Scholar
  3. 3.a)
    Grimley,T.B.: Proc. Phys. Soc. 90, 751 (1967)Google Scholar
  4. 3.b)
    Grimley,T.B.: Proc. Phys. Soc. 92, 776 (1967)Google Scholar
  5. 4.
    Bennett,A.J., Falicov,L.M.: Phys. Rev. 151, 512 (1966)Google Scholar
  6. 5.a)
    Bennett,A.J., McCaroll,B., Messmer,R.B.: Surface Science 24, 191 (1971)Google Scholar
  7. 5.b)
    Bennett,A.J., McCaroll,B., Messmer,R.B.: Phys. Rev. B 3, 1397 (1971)Google Scholar
  8. 6.
    Baetzold,R.C.: Surface Science 36, 123 (1972)Google Scholar
  9. 7.
    Schmidt,L.D., Gomer,R.: J. Chem. Phys. 45, 1605 (1966)Google Scholar
  10. 8.
    Glasstone,S., Laidler,K.J., Eyring,H.: The theory of rate processes. New York: McGraw Hill 1941Google Scholar
  11. 9.
    Slater,J.C.: Phys. Rev. 36, 57 (1930)Google Scholar
  12. 10.
    Fano,U.: Phys. Rev. 124, 1866 (1961)Google Scholar
  13. 11.
    Newnes,D.M.: Phys. Rev. 178, 1123 (1969)Google Scholar
  14. 12.
    Löwdin,P.O.: Advan. Phys. 5, 1 (1956)Google Scholar
  15. 13.
    Hayns,M.R., Calais,J.L.: J. Phys. C. Solid State Phys. 6, 2625 (1973)Google Scholar
  16. 14.
    Hoffmann,R.: J. Chem. Phys. 36, 2179 (1962); 36, 2189 (1962); 40, 2474 (1963)Google Scholar
  17. 15.
    Pople,J.A., Santry,D.P., Segal,G.A.: J. Chem. Phys. 43, 5129 (1965)Google Scholar
  18. 16.
    Pople,J.A., Segal,G.A.: J, Chem. Phys. 43, 5136 (1965)Google Scholar
  19. 17.
    Pople,J.A., Nesbet,R.K.: J. Chem. Phys. 22, 571 (1954)Google Scholar
  20. 18.
    Pople,J.A., Beveridge,P.L.: Approximate molecular orbital theory. New York: McGraw Hill 1970Google Scholar
  21. 19.
    Hayns,M.R.: J. Phys. C. Solid State Phys. 2, 15 (1972)Google Scholar
  22. 20.
    Hayns,M.R.: Phys. Rev. B 5, 697 (1972)Google Scholar
  23. 21.
    Hayns,M.R., Dissado,L.A.: Theoret. Chim. Acta (Berl.), in pressGoogle Scholar
  24. 22.
    Goeppert-Mayer,M., Sklar,A.: J. Chem. Phys. 6, 645 (1938)Google Scholar
  25. 23.
    Kanter,M.: Phys. Rev. 107, 655 (1957)Google Scholar
  26. 24.
    Bassini, F., Parravicini, G.P.: Nuovo Cimento 95, (1967)Google Scholar
  27. 25.
    McClure,J.W.: Suppl. J. to J. Phys. and Chem. Solids 32, 127 (1971)Google Scholar
  28. 26.
    Ward,A.F.C.H., Rideal,E.K.: J. Chem. Soc. 3, 117 (1927)Google Scholar
  29. 27.
    Marshall,M. J., Branston-Cook: Can J. Research B 15, 75 (1937)Google Scholar
  30. 28.
    Feates,F.S.: AERE R5748 (1968); AERE R5754 (1968)Google Scholar
  31. 29.
    Montet,G., Feates,F.S., Myers,G.: ANL-7352 Chemistry (TID4500) (1967)Google Scholar
  32. 30.
    McKee,D.W.: Ann. Rev. Mat. Sci. 3, 195 (1973) and references thereinGoogle Scholar

Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • Michael R. Hayns
    • 1
  1. 1.Theoretical Physics DivisonAtomic Energy Research EstablishmentHarwell, Oxfordshire

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