Directly Coated Iridium Nickel Oxide on Porous‐Transport Layer as Anode for High‐Performance Proton‐Exchange Membrane Water Electrolyzers

Abstract Developing a high‐performance anode design is important for a low‐cost proton‐exchange membrane water electrolyzer (PEMWE). In this study, an iridium nickel oxide directly coated anode (IrNiO x electrode) for high‐efficient PEMWE is reported. Five IrNiO x electrodes with different Ir‐to‐Ni ratios are developed using co‐electrodeposition. The resulting electrodes contain a thin IrNiO x layer on the carbon substrate. To develop the PEMWE incorporating IrNiO x electrode, the effect of fabrication methods, catalyst compositions, and porous transport layer are investigated. Consequently, the IrNiO x electrode prepared with 7:3 precursor solution (Ir 0.5 Ni 0.5 O x ) exhibits higher oxygen evolution reaction activity with a smaller overpotential than the electrode prepared with 10:0 precursor solution (IrO x ) and the commercial IrO 2 . Furthermore, the performance of the PEMWE is hig…