| abstract |
A method for the preparation of an electrocatalyst which comprises (a) electrodepositing less than a complete monomolecular layer of material on a substrate utilizing cathodic polarization of short duration, and (b) oxidizing the electrodeposit and the substrate utilizing anodic polarization, also of short duration is described. The deposited material preferably is a metal or metal oxide having useful catalytic and/or electrical properties, e.g., platinum or gold. The substrate preferably is a metal or metal oxide such as tantalum oxide, tungsten oxide, or a sodium tungsten bronze, NaxWO3. The substrate is treated in an electrolyte containing a very dilute solution of the material to be deposited and/or in the presence of a counterelectrode containing this material. Several repetitions of these method steps, i.e., reversing the polarity such that the deposition and oxidation steps alternate, results in the complete or partial integration of minute portions of electrodeposited material in the substrate material. This method is useful for providing or improving catalytic activity in a substrate. The products produced by the method are useful in electrochemical devices. |