Environmental Reconstruction of Undercoordinated 2D MOF Based Nickel for Efficient Urea Oxygen Reaction

Abstract The sluggish kinetics of the six‐electron transfer process and the inevitable self‐oxidation reaction of Ni species (NSOR) during the urea oxygen reaction (UOR) necessitate the development of efficient urea oxidation electrocatalysts. This study introduces a mild chemical modulation strategy, which is used to trigger the occurrence of UOR before NSOR via an environmental reconstruction of the undercoordinated 2D CoNi‐MOF to CoNi‐MOF@CoNi(OH) ₂ . In situ spectroscopic characterization and density functional theory (DFT) calculations reveal that the formation of metal hydroxides and the introduction of abundant oxygen defects on the surface of the 2D CoNi‐MOF can optimize the electronic structure and significantly enhance the catalyst's adsorption capacity for urea molecules. The fabricated catalyst exhibits outstanding urea oxidation performance, achieving a remarkably low potential of 1.278 V at 10 mA cm ⁻² and an ultra‐low Tafel slope of 11.2 mV dec ⁻¹ , thus outperforming most reported metal oxides and hydroxides. These findings offer profound insights into the design and application of transition metal‐based catalysts, particularly for advancing electrochemical hydrogen production and the efficient treatment of urea‐rich wastewater.