Preparation and Characterization of Mixed Metal Oxides Coatings on Titanium Substrate

RuO2-IrO2-TiO2 and RuO2-IrO2-TaO2-TiO2 are the most common mixed metal oxide (MMO) coatings coated on Ti substrates. MMO-coated titanium substrates serve as anodes in brine electrolyzers, which employ highly concentrated brine (33% NaCl) to generate chlorine gas and sodium hydroxide. These MMO electrodes were deposited using precursors that included ruthenium trichloride trihydrate (RuCl3.3H2O), diammonium iridium hexachloride [(NH4)2IrCl6], tantalum pentachloride (TaCl5), and titanium trichloride (TiCl3). Highly effective RuO2-IrO2-TiO2 and RuO2-IrO2-TaO2-TiO2 MMO coatings with the appropriate chemical composition were achieved. Both electrodes performed efficiently and showed high stability in the accelerated stability test, while tantalum in the coating composition enhances the MMO coating's stability.