Atomic Scale Origin of the OER Activity–Stability Trade-Off in NiFe Layered Double Hydroxides: Lattice-Site Oxygen Triggers Fe Leaching

Herein, using density functional theory calculations and constant-potential ab initio molecular dynamics simulations, we provide an atomic-scale understanding linking high OER activity to the origin of Fe leaching.

We reveal that the OER on the reconstructed active NiFeOOH phase preferentially follows an adsorbate-site/lattice-site oxygen coupling (ALOC) mechanism, achieving a theoretical overpotential as low as 0.29 V. Notably, the coupled structure that enables this high OER activity also drives the accumulation of oxygen vacancies. We identify the reconstructed double-oxygen-vacancy structure, formed through solvation-assisted interfacial reconstruction, as the precursor for Fe leaching.