Ligand‐Engineered MOF Catalyst Enabled Energy‐Efficient Urea‐Assisted Hydrogen Generation

ABSTRACT Urea‐assisted electrochemical water splitting offers an energy‐efficient pathway for hydrogen production; however, the inherently sluggish six‐electron reaction requires highly active electrocatalysts. Herein, a linker‐engineering strategy is introduced by partially substituting the benzene dicarboxylate (BDC) linker in NiCo‐BDC metal–organic framework (MOF) with a redox‐active dicarboxylferrocene (DFc) ligand to construct NiCo‐MOF‐DFc. The strongly coordinated DFc linker induces coordination asymmetry and effectively modulates the electronic structure with enriched Ni 3+ species and abundant oxygen vacancies, thereby enhancing urea oxidation activity. The NiCo‐MOF‐DFc delivers 100 mA cm −2 at a low potential of 1.32 V and exhibits excellent durability. Operando analyses show that DFc promotes faster electron transfer, accelerates rapid reconstruction into active metal (oxy)hydroxides, and stabilizes the active sites. Density functional theory calculations further support that DFc weakens CO 2 adsorption and lowers the energy barrier of the rate‐limiting desorption step. A urea‐assisted anion exchange membrane water electrolyzer using the NiCo‐MOF‐DFc as the anodic catalyst delivers 1000 mA cm −2 at a low cell voltage of 1.83 V and maintains stable operation for 500 h. The system consumes only 48.6 kWh to produce 1 kg of H 2 , more than 10% lower energy consumption than oxygen evolution‐based electrolysis, demonstrating its strong potential for energy‐efficient H 2 production.