Abstract
Islands of different size and shape (square or linear, finite or infinite) are introduced at the FCC positions above a single (100) layer of atoms (one s orbital per atom) in order to represent the roughness of the surface. The extended Hückel method with periodic boundary conditions shows the overlap populationbetween the surface atoms near the islands to be strongly modified. Certain bonds are dramatically weakened, others dramatically strengthened. As immediate consequences the surface is prepared for subsequent restructuring and is activated for heterogeneous catalysis. Depending on the nature of the island (island specificity) and on the band occupancy (metal specificity), a given bond may be catalytically active or not.
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J.N. Allison and W.A. Goddard III, Surf. Sci. 115 (1982) 553;
A. Rosen, E.J. Baerends and D.E. Ellis, Surf. Sci. 82 (1979) 139;
P.S. Bagus, Phys. Rev. B 23 (1981) 2065; Phys. Rev. B 23 (1981) 5464;
A. Gavezzotti and M. Simonetta, Surf. Sci. 99 (1980) 453;
A.B. Andersen and T. Hubbard, Surf. Sci. 99 (1980) 384.
C. Thuault-Cytermann, M-C. Desjonquères and D. Spanjaard, J. Phys. C. Solid. State Phys 16 (1983) 5689;
J. Jardin, M-C. Desjonquères and D. Spanjaard, Surf. Sci. 162 (1985) 224.
J.-Y. Saillard and R. Hoffmann, J. Amer. Chem. Soc. 106 (1984) 2006.
L. Salem, J. Phys. Chem. 89 (1985) 5576.
G.A. Somorjai, private communication (Jan 31, 1989).
G.A. Somorjai, in:Chemistry in Two Dimensions: Surfaces (Cornell University Press, Ithaca 1981).
G.A. Somorjai and M.A. Van Hove, Progr. Surf. Sc. 30 (1989) 201;
R.M. Nix and G.A. Somorjai, Perspectives in quantum chemistry (Plenary Lectures of the 6th Int. Congress in Quantum Chemistry, 1988) eds. J. Jortner and B. Pullman (Kluwer Academic Publishers, Dordrecht, 1989) p. 97;
J.F. Onuferko, D.P. Woodruff and B.W. Holland, Surf. Sci. 87 (1979) 357.
B. Marchon, D.F. Ogletree, M. Salmeron and W. Siekhaus, J. Vac. Sci. Technol. A6 (1988) 531;
G.A. Somorjai and M.A. Van Hove, Cat. Lett. (1988) 433;
M.A. Van Hove, R.J. Koestner, P.C. Stair, J-P. Sibérian, L.L. Kesmodel, I. Bartos and G.A. Somorjai, Surf. Sci. 103 (1981) 189;
M. Henzler, Surf. Sci. 19 (1970) 159;
R.W, Joyner and G.A. Somorjai, in:Surface and Defect Properties of Surfaces, eds. M.W. Roberts and J.M. Thomas, Vol 2 (The Chem. Soc. Publ. London, 1973) p. 1.
M.-H. Whangbo and R. Hoffmann, J. Amer. Chem. Soc. 100 (1978) 6093;
C. Minot, M.a. Van Hove and G.A. Somorjai, Surf. Sci. 127 (1982) 441.
L. Salem,The Molecular Orbital Theory of Conjugated Systems (Benjamin, N.Y., 1966) p. 117, and equations (3–30) for the case of 6 atoms.
R. Hoffmann and C. Zheng, in:Quantum Chemistry-The Challenge of Transition Metals and Coordination Chemistry, ed. A. Veillard (D. Reidel Publishers, 1986) p. 425;
J. Silvestre and R. Hoffmann, Langmuir 1 (1985) 621.
F. Scitz,The Modem Theory of Solids (McGraw-Hill, New York, 1940) p. 325;
J. Friedel, Advances Physics 45 (1954) 446, in particular sections 2.1.1;
S. Golden, J. Koutecky and L. Salem studies some years ago the surface states formed by attaching two atoms at the end of a linear polyenic chain (abstract submitted to the 6th ICC Congress, London, 1976, unpublished).
L. Salem,The Molecular Orbital Theory of Conjugated Systems (Benjamin, N.Y., 1966) p. 134.
R.S. Mulliken, J. Chem. Phys. 23 (1955) 1833, 1841, 2338, 2343; 26 (1962) 3428;
F. Pilar,Elementary Quantum Chemistry (McGraw-Hill, N.Y., 1968) p. 499.
For a review article see: M.D. Morse, Chem. Rev. 86 (1986) 1049. From high resolution studies of optical bands: M.D. Morse, G.P. Hansen, P.R.R. Langridge-Smith, L.-S. Zheng, M.E. Geusic, D.L. Michalopolous and R.e. Smalley, J. Chem. Phys. 80 (1984) 5400. Theoretical calculations give 2.21 Å (EHT-A.B. Anderson, J. Chem. Phys. 66 (1977) 5108), 2.18 Å (local spin densities- J. Harris and R.O. Jones, J. Chem. Phys. 70 (1979) 830) and 2.28 Å (RHF-A. Wolf and H.-H. Schmidtke, Int. J. Quantum Chemistry 40 (1980) 239.
Inorg. Chem. 24 (1985) 117.
W. Pushta, W. Nitchtl, W. Oed, N. Bickel, K. Heinz and K. Mueller, to be published; W. Oed, B. Doetsch, L. Hammer, K. Heinz and K. Mueller, to be published.
K. Fukui, Topics in Current Chemistry 15 (1970) 1.
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Minot, C., Lowe, J.P. & Salem, L. Dramatic bond strength alterations induced on a “rough” surface by small superficial metallic islands. I. Effect of island size and shape. Catal Lett 4, 195–215 (1990). https://doi.org/10.1007/BF00765936
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DOI: https://doi.org/10.1007/BF00765936