Research progress on metallic Ni-based catalysts for electrolytic oxygen evolution reaction

As a pivotal renewable energy carrier, hydrogen has emerged as a clean and sustainable alternative to fossil fuels, offering significant potential for industrial development, agricultural modernization, and daily life applications. Among various hydrogen production technologies, proton exchange membrane (PEM) water electrolysis stands out as one of the most promising approaches for green hydrogen generation. However, the practical implementation of this technology faces substantial challenges due to the inherently sluggish kinetics of the anodic oxygen evolution reaction (OER), resulting in compromised hydrogen production efficiency and accelerated catalyst degradation. These limitations highlight the urgent need to develop cost-effective OER electrocatalysts with enhanced activity and long-term durability. This review first introduces the two reaction pathways of OER mechanisms: the conventional adsorbate evolution mechanism (AEM) and the lattice oxygen-mediated mechanism (LOM). It then summarizes and discusses recent advances in non-precious metal Ni-based electrocatalysts for the OER, which have demonstrated remarkable potential for practical applications. We comprehensively analyze various strategies for catalyst optimization, including morphological control, heterostructure, alloying, heteroatom doping, composite strategies, single-atom catalyst engineering, and other strategies. Finally, we present a forward-looking perspective on the challenges and opportunities in developing next-generation Ni-based OER electrocatalysts.