Journal of Chemical Physics
Feedback | Help | Exit
The Journal of Chemical Physics
Search:
   
 
 
 
Previous Article
Nonionic surfactant mixtures. I. Phase equilibria in C10E4–H2O and closed-loop coexistence
A detailed phase diagram for mixtures of the homogeneous nonionic surfactant 3,6,9,12-tetraoxadocosanol (C10E4) with water is presented. Closed-loop coexistence is shown to be a prominent feature in t...
Next Article
Interaction energies in nematogens
The effect of steric exclusions between rods in correlating positional with rotational hinderances is used to calculate the mean field a rod sees in a fluid of other rods with which it interacts via a...

A molecular beam study of the catalytic oxidation of CO on a Pt(111) surface

J. Chem. Phys. 73, 5862 (1980); doi:10.1063/1.440029

Issue Date: 1 December 1980

You are logged in to this journal.

C. T. Campbell, G. Ertl, H. Kuipers, and J. Segner
Institut für Physikalische Chemie, Universität München, Sophienstrasse 11, 8000 München 2, West Germany
The oxidation of carbon monoxide catalyzed by Pt(111) was studied in ultrahigh vacuum using reactive molecular beam–surface scattering. Under all conditions studied, the reaction follows a Langmuir–Hinshelwood mechanism: the combination of a chemisorbed CO molecule and an oxygen adatom. When both reactants are at low coverage, the reaction proceeds with an activation energy E<sup>*</sup><sub>LH</sub> =24.1 kcal/mole and a pre-exponential upsilon4 =0.11 cm2 particles−1 sec−1. At very high oxygen coverage, E<sup>*</sup><sub>LH</sub> decreases to about 11.7 kcal/mole and upsilon4 to about 2×10−6 cm2 particles−1 sec−1. This is largely attributed to the corresponding increase in the energy of the adsorbed reactants. When a CO molecule incident from the gas phase strikes the surface presaturated with oxygen, it enters a weakly held precursor state to chemisorption. Desorption from this state causes a decrease in chemisorption probability with temperature. Once chemisorbed, the CO molecule then has almost unit probability of reacting to produce CO2 below 540 K. The CO2 product angular distribution varies from cosgamma to cos4gamma depending sensitively upon the adsorbed reactant concentrations. The Journal of Chemical Physics is copyrighted by The American Institute of Physics.
Permalink: http://link.aip.org/link/?JCPSA6/73/5862/1
FULL TEXT OPTIONS   (FREE)
Download PDF (1100 kB) View Cart

KEYWORDS and PACS

Keywords
PACS
  • 82.65.Jv
    Physical chemistry Surface processes Heterogeneous catalysis at surfaces and other surface reactions
  • 79.20.Rf
    Electron and ion emission by liquids and solids; impact phenomena Impact phenomena, including electron spectra and sputtering Atomic and molecular beam interactions
  • 34.50.Lf
    Atomic and molecular collision processes and interactions Inelastic scattering of atoms and molecules Chemical reactions, energy disposal, and angular distribution, as studied by atomic and molecular beams
  • YEAR: 1980

PUBLICATION DATA

ISSN:
0021-9606 (print)   1089-7690 (online)
Publisher:
AIP is a member of CrossRef AIP

REFERENCES (54)
View in Separate Window/Tab
  1. I. Langmuir, Trans. Faraday Soc. 17, 621, 672 (1922).
  2. T. Matsushima, D. B. Almy, and J. M. White, Surf. Sci. 67, 89 (1977).
  3. H. P. Bonzel and R. Ku, Surf. Sci. 33, 91 (1972). [Inspec] [ISI] [ChemPort]
  4. H. P. Bonzel and J. J. Burton, Surf. Sci. 52, 223 (1975).
  5. R. L. Palmer and J. N. Smith, J. Chem. Phys. 60, 1453 (1974). [ISI] [ChemPort]
  6. R. A. Shigeishi and D. A. King, Surf. Sci. 75, L397 (1978). [Inspec] [ISI]
  7. H. Hopster, H. Ibach, and G. Comsa, J. Catal. 46, 37 (1977). [ISI]
  8. N. Pacia, A. Cassuto, A. Pentenero, and B. Weber, J. Catal. 41, 455 (1976).
  9. H. P. Bonzel and R. Ku, Surf. Sci. 40, 85 (1973). [Inspec]
  10. M. Alnot, J. Fusy, and A. Cassuto, Surf. Sci. 57, 651 (1976). [Inspec] [ChemPort]
  11. T. Matsushima, Surf. Sci. 79, 63 (1979). [Inspec] [ChemPort]
  12. T. Matsushima, J. Catal. 55, 337 (1978). [ChemPort]
  13. Y. Nishiyama and H. Wise, J. Catal. 32, 50 (1974). [ChemPort]
  14. J. M. White and A. Golchet, J. Chem. Phys. 66, 5744 (1977). [ISI] [ChemPort]
  15. H. P. Bonzel and R. Ku, J. Vac. Sci. Technol. 9, 663 (1972). [ISI] [ChemPort]
  16. R. Ducros and R. P. Merrill, Surf. Sci. 55, 227 (1976). [Inspec] [ISI] [ChemPort]
  17. E. McCarthy, J. Zahradnik, G. Kuczynski, and J. J. Carberry, J. Catal. 39, 29 (1972).
  18. J. A. Strozier, Surf. Sci. 87, 161 (1979). [Inspec] [ChemPort]
  19. W. L. Winterbottom, Surface Sci. 36, 205 (1973).
  20. G. Doyen, C. T. Campbell, G. Ertl, H. Kuipers, and J. Segner (in preparation).
  21. G. K. Hori and L. D. Schmidt, J. Catal. 38, 335 (1975). [ChemPort]
  22. J. P. Dauchot and J. Van Cakenberghe, Proc. 2nd Internat. Conf. Solid Surfaces, Japan, 1974;
    23. J. Appl. Phys. Suppl. 2, PT.2, 533 (1974).
  23. C. A. Becker, J. P. Cowin, L. Wharton, and D. J. Auerbach, J. Chem. Phys. 67, 3394 (1977). [ISI] [ChemPort]
  24. L. Wharton (personal communication).
  25. R. J. Madix (personal communication).
  26. A. Golchet and J. M. White, J. Catal. 53, 266 (1978). [ISI] [ChemPort]
  27. T. Engel and G. Ertl, Chem. Phys. Lett. 54, 95 (1978). [Inspec] [ChemPort]
  28. T. Engel and G. Ertl, J. Chem. Phys. 69, 1267 (1978).
  29. C. T. Campbell, G. Ertl, H. Kuipers, and J. Segner (to be published).
  30. T. Engel, J. Chem. Phys. 69, 373 (1978). [ISI] [ChemPort]
  31. (a) A. G. Stoll, D. L. Smith, and R. P. Merrill, J. Chem. Phys. 54, 163 (1971). [ISI]
    32. (b) J. E. Hurst, C. A. Becker, J. P. Cowin, K. C. Janda, and L. Wharton, Phys. Rev. Lett. 43, 1175 (1979). [ISI] [ChemPort]
  32. H. Niehus and G. Comsa, Surf. Sci. 93, L147 (1980).
  33. (a) P. R. Norton, Surf. Sci. 44, 624 (1974); [Inspec]
    34. (b) P. R. Norton and P. J. Richards, Surf. Sci. 49, 567 (1975). [Inspec] [ChemPort]
  34. (a) C. T. Campbell, S. K. Shi and J. M. White, J. Vac. Sci. Technol. 16, 605 (1979). [ISI]
    35. (b) C. T. Campbell, S. K. Shi, and J. M. White, J. Phys. Chem. (in press).
  35. R. C. Baetzold and G. A. Somorjai, J. Catal. 45, 94 (1976). [ISI]
  36. S. K. Shi and J. M. White (to be published).
  37. H. Conrad, G. Ertl, and J. Küppers, Surf. Sci. 76, 323 (1978).
  38. J. L. Taylor, D. E. Ibbotson, and W. H. Weinberg, J. Catal. (in press).
  39. G. E. Thomas and W. H. Weinberg, J. Chem. Phys. 70, 954 (1979).
  40. T. L. Brown and D. J. Darensbourg, Inorg. Chem. 6, 971 (1967). [ChemPort]
  41. I. Kobal, M. Senegacnik, and B. Barlic, J. Chem. Phys. 69, 174 (1978). [ISI] [ChemPort]
  42. G. Comsa, Proc. 7th Internat. Vac. Congr. and 3rd Internat. Conf. Solid Surfaces, Vienna, 1317, 1977.
  43. R. L. Palmer and J. N. Smith, Catal. Rev.-Sci. Eng. 12, 279 (1975).
  44. M. Balooch, M. J. Cardillo, D. R. Miller, and R. E. Stickney, Surf. Sci. 46, 358 (1974). [Inspec] [ISI] [ChemPort]
  45. (a) G. Comsa and R. David, Chem. Phys. Lett. 49, 512 (1977). [Inspec] [ISI] [ChemPort]
    46. (b) G. Comsa, R. David, and B. J. Schumacher, Surf. Sci. 85, 45 (1979). [Inspec] [ISI] [ChemPort]
  46. M. Van Willigen, Phys. Lett. A 28, 80 (1968). [Inspec] [ChemPort]
  47. M. J. Cardillo, C. S. Y. Ching, E. F. Greene, and G. E. Becker, J. Vac. Sci. Technol. 15, 423 (1978). [ISI]
  48. L. H. Dubois and G. A. Somorjai, Surf. Sci. 91, 514 (1980). [Inspec] [ISI] [ChemPort]
  49. L. D. Schmidt, Catal. Rev. 9, 115 (1974).
  50. V. P. Ivanov, G. K. Boreskov, V. I. Savchenko, W. F. Egelhoff, and W. H. Weinberg, J. Catal. 48, 269 (1977).
  51. P. A. Zhdan, G. K. Boreskov, W. F. Egelhoff, and W. H. Weinberg, Surf. Sci. 61, 377 (1976). [Inspec] [ISI]
  52. T. Matsushima and J. M. White, J. Catal. 39, 265 (1975).
  53. G. Ertl and M. Neumann, Z. Phys. Chem. N. F. 90, 127 (1974). [Inspec]
  54. C. T. Campbell, S. K. Shi, and J. M. White, Appl. Surf. Sci. 2, 382 (1979). [Inspec]

Copyright © American Institute of Physics