IMPROVED DURABILITY OF IRIDIUM OXIDE-COATED TITANIUM ANODE WITH INTERLAYERS FOR OXYGEN EVOLUTION AT HIGH-CURRENT DENSITIES

The development of a non-consumable coated anode which has high performance is important for the electrogalvanization of sheet steel from the viewpoint of economy and product quality. MODE-H, which is one of the metal oxide dispersed electrodes being used for electroplating of copper and tin at a current density lower than 50 A dm(-2), was tested as the anode for electrolysis at high current densities in a sulfate solution. A part of the oxide layer of MODE-H was detached, and the titanium substrate was corroded. The utilization of the coated layer on MODE-H was only 25%. Thus MODE-J has been developed, which had a modified interlayer to prevent the substrate from corrosion and active mass to ensure low oxygen overvoltage at high current density. The service life of MODE-J was more than twice that of MODE-H-six months at several locations. MODE-J worked actively until the active mass was lost by about 40%.