Accelerating Green Hydrogen Generation Strategies for High‐Efficiency Auxiliary Hydrogen Production Under High Current Density

Overall water splitting (OWS) for hydrogen production has attracted considerable interest as a promising route to generate green hydrogen and reduce dependence on conventional fossil fuels. However, the electrolysis efficiency of OWS is limited by the sluggish kinetics of the anodic oxygen evolution reaction (OER), a demanding four-electron transfer process, hindering large-scale implementation. This review first introduces the mechanism of water electrolysis, the various components of water electrolyzers, and optimization strategies under high-current-density conditions. Subsequently, it focuses on optimization strategies for working electrodes, elucidates the reaction mechanisms of various alternative anodic oxidation reactions (including urea, hydrazine, 5-hydroxymethylfurfural, alcohols, and aldehydes, among others), explores novel high-current-density hydrogen production systems coupled with water electrolysis, and examines the impact of external factors on electrolyzer operation-all aimed at achieving enhanced hydrogen production efficiency. Finally, the challenges, application prospects, and potential of these advanced electrolysis systems are emphasized, aiming to provide novel and efficient approaches for advancing the development of green hydrogen energy. This review aims to provide systematic guidance for advancing water electrolysis technology, facilitating the industrialization of efficient hydrogen production.