Overview

• Researchers at the Fritz Haber Institute report a bias-dependent transition potential where OER activity shifts from charge buildup limitation to a highly active regime.
• Operando X-ray spectroscopy captured concurrent structural and chemical adaptations on oxide catalyst surfaces at this transition.
• Temperature-dependent electrochemistry implicates interfacial ion solvation as the key step governing intrinsic activity at the catalyst–electrolyte interface.
• The transition potential did not vary with catalyst loading or surface area, indicating an intrinsic interphase phenomenon rather than a surface-area effect.
• The peer-reviewed study, published September 3 in Nature Chemistry, outlines mechanistic insights that could guide more efficient catalysts for green hydrogen production.