Synthesis of RuxIr1-xO2 Anode Electrocatalysts for Proton Exchange Membrane Water Electrolysis

Abstract

Ru and Ir based materials were prepared by the thermal decomposition of polymeric precursor's method. The anode catalysts free from carbon substrate were obtained by tailoring the reaction process to avoid occurrence of CO2 formation during water electrolysis. Various Ir contents were added in the Ru catalytic compositions for improving the oxidation-resistance of RuO2 which was the best metallic oxide in H2O splitting. Their physical characterizations revealed the presence of agglomerates due probably to the heat treatment process consisting in the removal of organic carbon at 400 ºC. The prevalent existence of RuO2 and IrO2 in the anode materials was confirmed by XPS experiments and the electrochemical measurements enabled to show that RuxIr1-xO2 materials were more active towards water oxidation than IrO2 catalyst. The O2 evolution process started at 1.45 V with Ru0.9Ir0.1O2 in the anodic compartment of a 25 cm2 Proton Exchange Membrane Water Electrolyzer at 60ºC.