High surface area nickel cathodes from electrocomposites

Abstract Raney-nickel cathodes prepared by different methods are increasingly applied in the two most important electrochemical technologies, i.e. chloralkali and water electrolysis. The effectiveness in enhancing the catalytic activity of nickel electrodes by employing three types of particulate materials, namely Raney-nickel, aluminium and alumina powders during the cathodic codeposition of nickel has been investigated. The amount of codeposited precursor depended on its specific gravity and the geometrical arrangement of the substrate (cathode). Composites produced by keeping the substrate horizontal during the deposition exhibited higher catalytic activity. The Tafel parameters for hydrogen evolution have been compared for the above three types of electrodes with those of mild steel and nickel. Cyclic voltammograms indicated high tolerance to current reversals with electrodes prepared using an aluminium precursor. The catalytic activity was in the order of cathodes from NiAl > NiAl2O3 > NiRaneyNi composites.