From Ni Sites to System Synergy: Decoding Structural‐Mechanism‐Performance Relationships in Urea Electrooxidation Catalysts

Abstract The urea oxidation reaction (UOR) has emerged as a pivotal research frontier in the interdisciplinary field of energy and environment, offering a dual benefit for energy‐efficient hydrogen (H 2 ) production and urea‐rich wastewater purification. However, the practical implementation of UOR faces fundamental challenges stemming from its intrinsically sluggish six‐electron transfer kinetics, necessitating advanced electrocatalysts design. Due to the dynamic reconstruction behavior, tunable electronic configuration and cost‐effectiveness advantages, Ni‐based materials have garnered significant attention as the most promising UOR electrocatalysts. This comprehensive review systematically examines recent mechanistic and material advances in UOR, with particular emphasis on rational design strategies for enhancing UOR performance of Ni‐based electrocatalysts. The reaction pathways and emerging in situ characterization technologies for UOR are also discussed. Furthermore, aiming at the electrochemical energy and environmental applications about UOR, this work introduces the urea‐assisted electrolytic cell, direct urea fuel cell (DUFC), and electrochemical wastewater purification systems. The review concludes by identifying persistent scientific challenges and future research priorities, ultimately framing UOR as an enabling technology for synergistic advancement of sustainable H 2 economies and closed‐loop nitrogen management.