Gravimetric Adsorption Studies of Hydrogen on Granular Metal Surfaces Using a Vacuum Microbalance

  • D. A. Cadenhead
  • N. J. Wagner


A Cahn RG microbalance has been incorporated into a high-vacuum gravimetric adsorption apparatus for hydrogen adsorption studies from 77 to 273 K on granular metal surfaces. A study was undertaken to eliminate or minimize the expected thermomolecular flow (TMF) effects and make gravimetric adsorption results meaningful under these conditions.

Pressure- and temperature-dependent TMF effects were found to be associated with the balance beam, hangdown wires, and sample container. The balance beam of the Cahn balance was found to exhibit a small reproducible pressure-dependent apparent weight change which, because of the design of the balance, could not be eliminated. Temperature gradients along the walls of sample and reference hangdown tubes were minimized by silvering the walls and by submerging the tubes to a depth of 55 cm in a well-stirred constant-temperature bath at the desired temperature.

The experimental arrangement used minimized but did not eliminate TMF. The remaining forces were found to be reproducible for a fixed geometry and were determined from blank runs made on the system. A sample of pure copper, which does not adsorb hydrogen at the temperatures investigated, was used to verify the calibration curve. Using these calibration curves, hydrogen adsorption studies were obtained for a reduced-oxide nickel alloy sample over the temperature range 77 to 273 K and the pressure range 10−6 to 10−2 torr.


Adsorption Study Silver Film Balance Beam Thorium Oxide Granular Metal 
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  1. 1.
    A. W. Czanderna, Ultramicrobalance review, in: S. P. Wolsky and E. J. Zdanuk (eds.), Ultra Micro Weight Determination in Controlled Environment, Inter science. New York (1969), Chapter 2.Google Scholar
  2. 2.
    O. M. Katz and E. A. Gulbransen, The effect of pressure on microgravimetric studies in hydrogen, in: M. Katz (ed.). Vacuum Microbalance Techniques, Vol. 1, Plenum Press, New York (1961), p. 111.Google Scholar
  3. 3.
    A. W. Czanderna, The effect of the thermomolecular flow of gases on a microbalance suspension, in: M. Katz (ed.). Vacuum Microbalance Techniques, Vol. 1, Plenum Press, New York (1961), p. 129.Google Scholar
  4. 4.
    A. W. Czanderna, Precision equilibrium studies in the thermomolecular flow region, in: P. M. Waters (ed.), Vacuum Microbalance Techniques, Vol. 4, Plenum Press, New York (1965), p. 69.Google Scholar
  5. 5.
    J. M. Thomas and B. R. Williams, Application of a metal vacuum microbalance to the study of solid surfaces by physical adsorption, ibid., p. 209.Google Scholar
  6. 6.
    H. L. Gruber and C. S. Shipley, Application of an automatic recording vacuum microbalance to the study of catalyst surfaces, in: K. H. Behrndt (ed.). Vacuum Microbalance Techniques, Vol. 3, Plenum Press, New York (1963), p. 131.Google Scholar
  7. 7.
    E. L. Fuller, H. F. Holmes, and C. Secoy, Gravimetric adsorption studies of thorium oxide surfaces with a vacuum microbalance, ibid., p. 109.Google Scholar
  8. 8.
    D. A. Cadenhead and N. J. Wagner, Low-temperature hydrogen adsorption on copper — nickel alloys, J. Phys. Chem., 72, 2775 (1968).CrossRefGoogle Scholar
  9. 9.
    H. O. Willard, L. L. Merritt, Jr., and J. A. Dean, Instrumental Methods of Analysis, D. Van Nostrand Company, Inc., Princeton, New Jersey, 3rd ed. (1958), pp. 482–483.Google Scholar
  10. 10.
    B. Evans and T. E. White, A gravimetric study of the influence of water on the adsorption properties of low-surface- area glass fibers, in: A. W. Czanderna (ed.). Vacuum Microbalance Techniques, Vol. 6, Plenum Press, New York (1967), p. 157.Google Scholar
  11. 11.
    J. Pritchard, Surface-potential study of the chemisorption of hydrogen and carbon monoxide on evaporated copper and gold films, Trans. Faraday Soc, 59, 437 (1963).CrossRefGoogle Scholar
  12. 12.
    R. N. Lee and H. E. Farnsworth, LEED studies of adsorption on clean (100) copper surfaces, Surface Science, 3, 461 (1965).CrossRefGoogle Scholar
  13. 13.
    P. A. Faeth and C. B. Willingham, The assembly, calibration, and operation of a gas adsorption apparatus for the measurement of surface area pore volume distribution and density of finely divided solids, Mellon Inst, of Ind. Research Bull. (1955).Google Scholar
  14. 14.
    P. A. Cutting, A temperature error in the gravimetric determination of adsorption isotherms, in: C. H. Massen and J. Van Bechum (eds.), Vacuum Microbalance Techniques, Vol. 7, Plenum Press, New York (1970), p. 71.Google Scholar
  15. 15.
    C. H. Massen and J. A. Poulis, Cavity forces, an error in adsorption measurements, in: A. W. Czanderna (ed.), Vacuum Microbalance Techniques, Vol. 6, Plenum Press, New York (1967), p. 17.Google Scholar
  16. 16.
    J. M. Thomas and J. A. Poulis, Disturbances arising from thermomolecular flow in microbalance experiments, in: K. H. Behrndt (ed.). Vacuum Microbalance Techniques, Vol. 3, Plenum Press, New York (1963), p. 15.Google Scholar
  17. 17.
    C. H. Massen, B. Pelupessy, J. M. Thomas, and J. A. Poulis, Knudsen forces in the intermediate pressure range, in: K. H. Behrndt (ed.), Vacuum Microbalance Techniques, Vol. 5, Plenum Press, New York (1966), p. 1.Google Scholar
  18. 18.
    T. Steensland and K. S. Fførland, A contribution to the theory of the thermomolecular flow effect in microbalances, ibid., p. 17.Google Scholar
  19. 19.
    K. Behrndt, C. H. Massen, J. A. Poulis, and T. Steensland, Longitudinal thermomolecular flow at intermediate pressures — a comparison, ibid., p. 33.Google Scholar
  20. 20.
    A. Voet, T. B. Lamont, and D. Sweigart, Surface area and porosity of carbon blacks. Carbon, 6, 707 (1968).CrossRefGoogle Scholar
  21. 21.
    M. W. Roberts and K. W. Sykes, Nickel powder with adsorptive properties approaching those of evaporated nickel films. Trans. Faraday Soc., 54, 548 (1958).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1971

Authors and Affiliations

  • D. A. Cadenhead
    • 1
  • N. J. Wagner
    • 1
  1. 1.Department of ChemistryState University of New York at BuffaloBuffaloUSA

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