An Investigation on the Electrochemical Characteristics of Ta 2 O 5 -IrO 2 Anodes for the Application of Electrolysis Process

The electrochemical characteristics of Ta2O5-IrO2 electrodes prepared from different chemical compositions and coating methods were observed by using cyclic voltammetry, potentiostatic polarization, galvanostatic polarization and scanning electron microscopy. The efficiency for chloride oxidation and oxygen evolution processes was not only influenced by the chemical composition but also by the surface morphology of the oxide electrode which was susceptible to the ratio of the two components and the coating method. Ta2O5(50)-IrO2(50) electrodes revealed the highest catalytic activity for the chloride ion oxidation and oxygen evolution reaction because they had the largest effective surface area. The durability of the oxide electrodes in the accelerated life tests was improved as the thickness of the oxide layer increased and the ratio of [IrO2] to [Ta2O5] approached 80/20.