RuO2-IrO2 electrodes, prepared by thermal decomposition of RuCl3 + (NH4)2IrCl6 on Ti substrate, were studied by means of XPS and electrochem. techniques. The surface of RuO2-IrO2 electrode is homogeneous in composition, and a common p* conduction band is formed by the t2g orbitals of Ru and Ir. As the Ir content of coating increases, the position of p* band shifts to higher binding energy, indicating that the further oxidation of RuO2 is more difficult. As a result, the electrode becomes more stable and its electrocatalytic activation for O evolution in acid solution becomes lower.

Key words: METAL ELECTRODE, CALCIUM OXIDE, X-RAY PHOTOELECTRON SPECTROMETRY, ELECTROCHEMICAL ANALYSIS, THERMAL DECOMPOSITION, ELECTRODE LIFE TIME, IRIDIUM OXIDE