Investigation of the cathodically-induced precipitation of ceramic precursor films

The formation of a cathodically-induced precipitate of aluminium (oxy)-hydroxide is optimised for large palladium working electrodes (> 1 cm2), when a reductive current of -20 mA cm-2 is applied to the hydrogen sorbing cathode. Crucial in the experimental design is that the working and counter electrodes are parallel to each other. This maintains an even current distribution and hence precipitate forms across the whole surface of the electrode. A method for reusing the palladium for repeated hydrogen sorption has been established, so that the palladium could be used indefinitely. The method requires cleaning the palladium in sulfuric acid, acetone and cerium(IV) sulfate solution to remove deposit residue, organics and hydrogen respectively. [Continues.]