Leaching of Raney nickel composite-coated electrodes

The changes in the morphology and the composition of Raney Ni composite-coated electrodes was investigated during leaching in concentrated NaOH aqueous solutions. The rate of hydrogen generated during leaching is increased by stirring the solution, raising the temperature and increasing the NaOH concentration to 6.09M . The depletion of Al from the Raney Ni particles results in phase transformations and the metal/solution interfacial area increases with time. It is suggested that the electrodeposited Ni has a dominant influence on the H discharge since the electrocatalytic activity is practically independent of the leaching time. Photomicrographs, Graphs, Maps, Spectra. 32 ref.--AA