Electrocatalysis for Urea Evolution and Oxidation Through Confining Atomic Ni Into In₂O₃ Nanosheet Catalysts

Abstract Urea, a highly sought‐after fertilizer, is conventionally manufactured through the energy‐intensive Haber–Bosch process but is frequently encountered as a pollutant in wastewater. Thus, achieving sustainable urea production under ambient conditions and the potential to recycle urea from wastewater represent significant eco‐economic advancements. In this study, a novel Ni‐confined In₂O₃ (Ni‐In₂O₃) electrocatalyst demonstrating outstanding capabilities in both the urea evolution reaction (UER) from nitrate and carbon dioxide and the highly efficient urea oxidation reaction (UOR) for waste urea utilization is introduced. Computational data and in situ X‐ray absorption spectroscopy (XAS) analysis demonstrate that the unique Ni‐oxygen vacancy (Ni‐Vo) local structure effectively modulates the electronic configuration of neighboring In and Ni atoms. This structural refinement results in a significantly reduced energy barrier for the potential‐determining steps (PDS) in both UER (*COOHNH₂ → *CONH₂) and UOR (*CO(NH₂)₂ → *CONHNH₂). Consequently, the optimized catalysts achieve a urea evolution faradic efficiency of 19.6%, accompanied by remarkable UOR performance, attaining a 100 mA cm⁻² anodic current density at a potential of 1.35 V. This work not only offers a sustainable route to urea production but also highlights the potential for efficient urea oxidation, contributing to a greener and more economically viable future for the nitrogen cycle.