Hydrogen evolution reaction on the AB5 metal hydride electrode

The production technique of hydrogen is one of the main research objects. Metal hydride has been widely used in secondary battery and hydrogen storage fields. In this paper, the hydrogen evolution reaction characteristics at AB(5)-type metal hydride electrode, as the hydrogen electrolysis electrode, have been investigated by linear polarization and alternate current impedance techniques. The Heyrovsky's reaction and Volmer's reactions have been found in the electrochemical impedance spectroscopy in the frequency region of 100 kHz-0.1 Hz. The galvonostat tests show that the overpotential of the hydrogen evolution reaction is very small. The morphology and structure of the electrode material were examined by scanning electron microscopy and X-ray diffraction, respectively. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.