Study of IrxRu1−xO2 oxides as anodic electrocatalysts for solid polymer electrolyte water electrolysis

Electrocatalysts of the general formula IrxRu1−xO2 were prepared using Adams’ fusion method. The crystallite characterization was examined via XRD, and the electrochemical properties were examined via cyclic voltammetry (CV) in, linear sweep voltammetry (LSV) and chronopotentiometry measurements in 0.5 M H2SO4. The electrocatalysts were applied to a membrane electrode assembly (MEA) and studied in situ in an electrolysis cell through electrochemical impedance spectroscopy (EIS) and stationary current density–potential relations were investigated. The IrxRu1−xO2 (x = 0.2, 0.4, 0.6) compounds were found to be more active than pure IrO2 and more stable than pure RuO2. The most active electrocatalyst obtained had a composition of Ir0.2Ru0.8O2. With an Ir0.2Ru0.8O2 anode, a 28.4% Pt/C cathode and the total noble metal loading of 1.7 mg cm−2, the potential of water electrolysis was 1.622 V at 1 A cm−2 and 80 °C.