Raney-Nickel Cathodes from Al - Mo - Ni Precursor Alloys for Alkalıne Water Electrolysis

Abstract

Three different Ni-Al-Mo alloys (68 to 75 at.%Al, 2 to 10 at.%Mo) where used to investigate the influence of Mo on Rancey-Ni cathodes using metallography, X-ray diffraction and electron probe microanalysis as well as the electrochemical determination of the electrode potentials. The as-cast alloys were gas atomized and the powders were used to prepare layers of Ni-Al-Mo on Ni sheets by vacuum-plasma spraying. Leaching of Al out of the Al-rich phases Ni{sub 2}Al{sub 3} and NiAl{sub 3} in a solution of 25 wt.%KOH left a nanocrystalline Ni layer of high porosity and surface area (>60 m{sup 2}/g) with outstanding catalytic activity. The influence of the Mo content on the catalytic activity and lifetime of these electrodes was investigated when employed as cathodes for hydrogen production. (orig.).