Durability of a thermally decomposed iridium(IV) oxide–tantalum(V) oxide coated titanium anode in aqueous ammonium citrate

Abstract Ti/IrO 2 –Ta 2 O 5 coated anodes were widely used in the production process of aluminum foil that is vital raw material for high-performance electronic components, exhibits excellent service durability in sulfuric acid medium, but its lifespan is significantly reduced when used in ammonium citrate neutral electrolyte. The evolution of constant current accelerated lifetime process of Ti/IrO 2 –Ta 2 O 5 anodes in 100 g/L ammonium citrate aqueous solution was systematically studied. The corrosion mechanism was revealed by physical characterization and electrochemical measurements. During electrolysis, IrO 2 was gradually dissolved due to the interaction of IrO 2 coating and the electrolyte. Consequently, the corrosion mechanism of the compact IrO 2 –Ta 2 O 5 coating is the effect of substantial dissolution of the active components.