Energy-efficient anodic reactions for sustainable hydrogen production via water electrolysis
Wenxian Liu, Xinxin Niu, Jiawei Tang, Qian Liu, Jun Luo, Xijun Liu, Yingtang Zhou
Abstract
Overall water splitting is considered as an effective technique for hydrogen (H2) production; however, it usually requires large operating voltage mainly due to the high equilibrium potential of the anodic oxygen evolution reaction (OER). Replacing OER with energy-saving anode reactions not only reduces the operating voltage for H2 production but also generates high-value-added chemicals or purifies wastewater. This review article provides an overview of the fundamental reaction principles of overall water splitting and typical energy-saving alternative anode reactions, including methanol oxidation, hydrazine oxidation, and urea oxidation reactions. Then, the preparation methods, regulation strategies, and composition/structure-performance relations of advanced catalysts for these energy-efficient H2 generation technologies are discussed. Finally, we propose the underlying challenges and perspectives for this promising field.