Electrocatalytic behavior of thin Co–Te–O films in oxygen evolution and reduction reactions

Co–Te–O catalytic films, obtain by vacuum co-evaporation of Co and TeO2 are investigated as electrocatalysts for oxygen reactions in alkaline media. Bifunctional gas-diffusion oxygen electrodes (gde) are prepared by direct deposition of catalyst films on gas-diffusion membranes (gdm) consisting of hydrophobized carbon blacks or hydrophobized “Ebonex” (suboxides of titanium dioxide). Thus obtained electrodes with different atomic ratio RCo/Te of the catalyst, treated at different temperatures were electrochemically tested by means of cyclic voltammetry and steady-state voltammetry. It is shown that the electrodes exhibit high catalytic activity toward oxygen evolution and reduction reaction despite very low catalyst loading of about 0.05–0.5 mg cm−2.