Journal of Applied Electrochemistry

, Volume 32, Issue 9, pp 1005–1010

Kinetics of hydrogen evolution on submicron size Co, Ni, Pd and Co–Ni alloy powder electrodes by d.c. polarization and a.c. impedance studies

Authors

  • P. Elumalai
    • Solid State and Structural Chemistry UnitIndian Institute of Science
  • H.N. Vasan
    • Solid State and Structural Chemistry UnitIndian Institute of Science
  • N. Munichandraiah
    • Inorganic and Physical ChemistryIndian Institute of Science
  • S.A. Shivashankar
    • Materials Research CenterIndian Institute of Science
Article

DOI: 10.1023/A:1020935218149

Cite this article as:
Elumalai, P., Vasan, H., Munichandraiah, N. et al. Journal of Applied Electrochemistry (2002) 32: 1005. doi:10.1023/A:1020935218149

Abstract

Submicron size Co, Ni and Co–Ni alloy powders have been synthesized by the polyol method using the corresponding metal malonates and Pd powder by reduction of PdOx in methanol. The kinetics of the hydrogen evolution reaction (HER) in 6 M KOH electrolyte have been studied on electrodes made from the pressed powders. The d.c. polarization measurements have resulted in a value close to 120 mV decade−1 for the Tafel slope, suggesting that the HER follows the Volmer–Heyrovsky mechanism. The values of exchange current density (io) are in the range 1–10 mA cm−2 for electrodes fabricated in the study. The a.c. impedance spectra measured at several potentials in the HER region showed a single semicircle in the Nyquist plots. Exchange current density (io) and energy transfer coefficient (α) have been calculated by employing a nonlinear least square-fitting program.

a.c. impedanced.c. polarizationhydrogen evolutionsubmicron size particles

Copyright information

© Kluwer Academic Publishers 2002