PHOSPHATE-BONDED COMPOSITE ELECTRODES FOR HYDROGEN EVOLUTION

A new process of cementing metallic powders to produce high surface area cathodes for alkaline water electrolysis is described. The binding compound is a tridimensional polymer of aluminium phosphate (AlPO4). Phosphate-bonded composite electrodes give a low-polarization performance for hydrogen evolution in 1 m KOH aqueous solution in the case of 95 wt% Pt and 98 wt% Ni. When electrode materials are prepared with nickel powder, the electrocatalytic activity for the hydrogen evolution reaction, the chemical stability and the electrical conductivity depend on the Ni content and morphology of the electrode. The best performance and chemical stability with Ni as the starting material are obtained for spiky filamentary particles produced by the decomposition of nickel carbonyl. © 1990 Chapman and Hall Ltd.