A RuO2IrO2 electrocatalyst with an optimal composition and novel microstructure for oxygen evolving in the single cell

Abstract

A highly active RuO2IrO2 electrocatalyst was developed via dip-coating/calcination method for oxygen evolution reaction (OER). The catalyst on Ti substrate with a 7/3 molar ratio between Ru and Ir showed the highest electrocatalytic activity for OER among composite samples in different molar ratios. Moreover, the properties of RuO2IrO2 grown on carbon paper were evaluated by proton exchange membrane water electrolysis single cell. Compared with the micron-particle structure of RuO2IrO2 catalyst on the Ti substrate, the catalyst grown on the carbon paper showed a novel nano dendrite shape and can be used directly as the gas diffusion electrode. Owing to the large surface area of the catalyst, the nano dendrite-shaped RuO2IrO2 catalyst exhibits excellent OER performance in the single cell. Furthermore, a cell voltage of 2.50 V is achieved under 200 mA cm(-2) at 30 degrees C by using the optimal composition RuO2IrO2 (Ru: Ir=7/3) and the commercial 20% Pt/C as anode and cathode, respectively.