SIMS Characterization of IrO2-Ta2O5 Thin Films: Effect of Relative Composition on Electrode Properties

IrO2 and Ta2O5 mixed oxide coatings were deposited on Ti supports in order to fabricate dimensionally stable electrodes used in chloro-alkali technology. Secondary ion mass spectrometry (SIMS) and electrochemical experiments were carried out in order to characterize these materials. Electrochemical tests found the highest electrocatalytic activity for 50% IrO2-50% Ta2O5 electrodes. SIMS analyses are in harmony with these results, and it is shown that IrO2 is more diluted on the surface for noble metal oxide concentrations higher than 50%. Finally, it was observed by SIMS that support material migration was favoured at the highest concentrations of Ta2O5 stabilizer.