RuO2, RuO2–TiO2 and RuO2–TiO2–IrO2 nanoparticles supported on Ni mesh as mixed metal oxide electrodes for oxygen reduction reaction

The oxygen depolarized cathode (ODC) has been fabricated for energy saving modification of chlor-alkali membrane cells. In this work, a series of metal oxide sol-gels (RuO2, TiO2 and IrO2) are prepared and coated on Ni mesh (RuO2/Ni, RuO2–TiO2/Ni and RuO2–TiO2–IrO2/Ni) as ODCs. The surface morphologies and compositions of electrodes are determined by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction techniques. The results indicate that the cathodes contain mud-crack structures and flat areas. The performance of cathodes towards the oxygen reduction reaction (ORR) is studied using the cyclic voltammetry, polarization, electrochemical impedance spectroscopy, and chronoamperometry methods. The higher cathodic current and more positive ORR potential is obtained for RuO2–TiO2–IrO2/Ni electrode. It is because of the RuO2 and IrO2 synergistic effect. According to the EIS results, the quicker dissolution of Ru from the RuO2/Ni is happening in the correlation of other electrodes.