Electrochemical properties of sol–gel processed Ti_0.6Ir_0.4O₂ and Ti_0.6Ru_0.3Ir_0.1O₂ coatings on titanium substrate were investigated using cyclic voltammetry, polarization measurements and electrochemical impedance spectroscopy and compared to the properties of Ti_0.6Ru_0.4O₂ coating. The role of iridium oxide in the improvement of the electrocatalytic, capacitive and stability properties of titanium anodes activated by a RuO₂–TiO₂ coating is discussed. The oxide sols were prepared by forced hydrolysis of the metal chlorides. The characterization by dynamic light scattering and X-ray diffraction showed that polydisperse oxide sols were obtained with the particles tending to form agglomerates. The presence of IrO₂ causes a suppression of the X-ray diffraction peaks of TiO₂ and RuO₂ in the sol–gel prepared Ti_0.6Ir_0.4O₂ and Ti_0.6Ru_0.3Ir_0.1O₂ coatings. The IrO₂-containing coatings had an enhanced charge storage ability and activity for the oxygen evolution reaction (OER) in comparison to Ti_0.6Ru_0.4O₂ coating. The voltammogram of the Ti_0.6Ir_0.4O₂/Ti electrode showed well-resolved peaks related to Ir redox transitions, which are responsible for the enhanced charge storage ability of IrO₂-containing coatings. Redox transitions of Ir were also registered in the high-frequency domain of the ac impedance spectra of the coatings as a semicircle with characteristics insensitive to the electrolyte composition and to the electrode potential prior to OER. However, the semicircle characteristics were different for the two IrO₂-containing coatings, as well as at potentials outside the OER in comparison to those at which the OER occurs.