Directly Coated Iridium Nickel Oxide on Porous‐Transport Layer as Anode for High‐Performance Proton‐Exchange Membrane Water Electrolyzers
Sun Young Kang, Ji Eun Park, Ga Young Jang, Changsoon Choi, Yong‐Hun Cho, Yung‐Eun Sung
Abstract
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 higher with the Ir 0.5 Ni 0.5 O x electrode than that with the sprayed electrode with commercial IrO 2 nanoparticles. This enhancement is attributed to the high electrochemical surface area caused by introducing Ni in IrO x . Additionally, the performance of the directly coated Ir 0.5 Ni 0.5 O x PEMWE is the highest reported in the literature.