Electron-Withdrawing Ligands Regulated the Reconstruction of Metal–Organic Frameworks via Enhanced π–π Stacking for Water Oxidation

Developing alkaline-stable metal–organic framework (MOF) precatalysts is a significant challenge for the oxygen evolution reaction (OER) in anion exchange membrane water electrolysis (AEM-WE) due to their structural reconstruction and ligand leaching. Herein, we report an electron-withdrawing ligand strategy to modulate the electrocatalytic behavior of NiFe-MOFs. The as-prepared fluorinated NiFe-BDC-BDC(F)4 nanosheet array directly serves as an anode, which demonstrates outstanding OER activity with an overpotential of 245 mV at 100 mA cm–2. When integrated into an AEM-WE, the catalyst delivers an industrial current density of 500 mA cm–2 at 1.65 V. Crucially, the NiFe-BDC-BDC(F)4 anode demonstrates a 75% reduction in the voltage decay rate compared to its pristine counterpart during continuous operation. Experimental and theoretical analyses reveal that the electron-withdrawing ligands enhance π–π stacking, which effectively suppresses excessive structural transformation and leads to the formation of a hybrid active phase (NiFeOOH/NiFe-BDC-BDC(F)4) with preserved proton transfer pathways. This work not only provides mechanistic guidance for designing stable MOF-based precatalysts but also demonstrates a practical strategy with balanced activity and durability for industrial water electrolysis.