Advances in Stability of NiFe-Based Anodes toward Oxygen Evolution Reaction for Alkaline Water Electrolysis

Abstract

Alkaline electrolysis plays a crucial role in sustainable energy solutions by utilizing electrolytic cells to produce hydrogen gas, providing a clean and efficient method for energy storage and conversion. Efficient, stable, and low-cost electrocatalysts for the oxygen evolution reaction (OER) are essential to facilitate alkaline water electrolysis on a commercial scale. Nickel-iron-based (NiFe-based) transition metal electrocatalysts are considered the most promising non-precious metal catalysts for alkaline OER due to their low cost, abundance, and tunable catalytic properties. Nevertheless, the majority of existing NiFe-based catalysts suffer from limited activity and poor stability, posing a significant challenge in meeting industrial applications. This also highlights a common situation where the emphasis on material activity receives significant attention, while the equally critical stability aspect is often underemphasized. Initiating with a comprehensive exploration of the stability of NiFe-based OER materials, this article first summarizes the debate surrounding the determination of active sites in NiFe-based OER electrocatalysts. Subsequently, the degradation mechanisms of recently reported NiFe-based electrocatalysts are outlined, encompassing assessments of both chemical and mechanical endurance, along with essential approaches for enhancing their stability. Finally, suggestions are put forth regarding the essential considerations for the design of NiFe-based OER electrocatalysts, with a focus on heightened stability.