COMPOSITE ELECTRODE FOR ELECTROLYTIC PROCESSES

摘要

A process is disclosed for producing a composite electrode for use in an electrolytic cell comprising a valve metal substrate and an outer surface layer comprising ruthenium dioxide. The improvement resides in the steps of providing a barrier layer comprising a platinum group metal. A composite electrode for use in an electrolytic cell comprising a valve metal substrate and an outer surface layer comprising ruthenium dioxide, the improvement comprises providing a barrier layer comprising a platinum group metal directly on the substrate, and providing, between the barrier layer and outer surface layer, an intermediate layer comprising a metallic electroplated deposit consisting of ruthenium and iridium, said intermediate layer containing at least a small but effective amount of iridium to reduce ruthenium dissolution during use in said cell, said intermediate layer being at least partially oxidized.