Highly Active Ni–Fe Based Oxide Oxygen Evolution Reaction Electrocatalysts for Alkaline Anion Exchange Membrane Electrolyser

Oxygen evolution reaction (OER) electrocatalysts are pivotal for sustainable hydrogen production through anion exchange membrane electrolysis. Cost-effective transition metals such as nickel and iron-based oxides (Ni–Fe–Ox) have been recognized as viable catalysts for the oxygen evolution process in alkaline media. In this work, we study the electrochemical characterization and stability of the Ni–Fe–Ox to find the suitability for AEM electrolysis. The results indicate that Ni–Fe–Ox has 5 times higher activity than pure Ni. The Ni–Fe–Ox electrodes exhibit an exceptionally high catalytic activity of 22 mA cm−2 at 1.55 V vs. RHE, and a Tafel value as low as 97 dec−1, for OER to occur. These findings imply that OER occurs at similar places along the Ni–Fe–Ox interface and that the Ni—Fe2O3 contact plays a significant role as the OER active site. Furthermore, it is also worth noting that the presence of metallic Ni allows for fast electron transit within the interface, which is necessary for successful electrocatalysis. Aside from the excellent OER performance, the exfoliated Ni–Fe–Ox demonstrated great stability with almost constant potential after 10 h of electrolysis at a current density of 10 mA cm−2. This work confirms Ni–Fe–Ox is a promising, highly efficient and cost-effective OER catalyst for AEM electrolysis.This research was funded by Foundation of Korea (NRF) grant number 2019H1D3A2A02102994. And the APC was funded by 2019R1I1A3A030504411