Abstract
Palladium thin films (220, 460 and 1350 Å thick) were fabricated by physical vapor deposition and characterized electrochemically. The reversible hydrogen storage capacity of the films was determined by electrochemical cycling. The hydrogen solubility of the thin films was larger in the α-phase but smaller in the β-phase than that of the bulk. The hydrogen diffusion coefficient, DH, in the Pd films was measured by the electrochemical stripping method in the Pd-H solid solution (α-phase) at the temperatures ranging from 280 to 330 K. A well-defined potential range was found for applying the electrochemical stripping technique. The DH decreases with decreasing film thickness and is 2-3 orders of magnitude smaller than that in the bulk. The DH vs 1/T plots show that all the thin films follow the Arrhenius behavior, DH = D0 exp(-Ea/RT), with approximately the same activation energy Ea and a decreasing prefactor D0 as the film thickness decreases.
| Original language | English |
|---|---|
| Pages (from-to) | 281-291 |
| Number of pages | 11 |
| Journal | International Journal of Hydrogen Energy |
| Volume | 21 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1996 |
Bibliographical note
Funding Information:Acknowledgements~~ The authors would like to thank R. Waldo for EPMA. We would also like to thank W. J. Meng, D. N. Belton, F. T. Wagner, M. A. Habib, C. L. Dimaggio, T. E. Moylan and S. J. Schmieg for helpful discussions. This work is supported by the General Motors Corporation.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology
