STUDIES OF THE HYDROGEN EVOLUTION REACTION ON LANTHANUM PHOSPHATE-BONDED COMPOSITE NICKEL-RUTHENIUM ELECTRODES IN 1-M ALKALINE-SOLUTIONS

The electrocatalytic properties of lanthanum phosphate-bonded composit e nickel-ruthenium electrodes for the hydrogen and oxygen evolution re actions were studied in 1 M KOH at 25-degrees-C. Ruthenium was chemica lly deposited on nickel powder particles prior to polymerization of Ni /Ru powder with lanthanum phosphate. X-ray diffraction (XRD), X-ray fl uorescence (XRF), BET, differential thermal analysis (DTA), scanning e lectron microscopy (SEM), EDX and u.v./vis. spectrophotometry were use d to investigate the composition, morphology and characteristics of th e electrodes. The influence of the ruthenium content and polymerizatio n temperature on the electrocatalytic activity for hydrogen and oxygen evolution were studied. The mechanism and kinetics of the hydrogen ev olution reaction (HER) were investigated using both steady-state polar ization and a.c. impedance techniques.