Navigating Interfacial Water and Energy Band for Highly‐efficient Acidic Oxygen Evolution: Job‐sharing Asymmetric RuO 2

Abstract Developing RuO 2 electrocatalysts that simultaneously deliver high catalytic activity and long‐term durability for oxygen evolution reaction (OER) is crucial but remains a formidable challenge in proton exchange‐membrane water electrolyzer (PEMWE). This is primarily due to RuO 2 being over‐oxidized to soluble high‐valent RuO 4 2− , leading to irreversible surface dissolution. Herein, through structural tailoring of Ge‐RuO 2 catalyst, a valence‐segregated aggregate (a‐Ge‐RuO 2 ) is successfully achieved, with OER‐driven Ostwald ripening mediating nanoparticle to low‐index faceting bulks. Furthermore, the strategic reconfiguration achieves job‐sharing of interfacial water molecules and energy band structures. The covalent competition within the Ge‐O‐Ru motif induces an electron flux from Ge to Ru. It reduces Ru oxidation states and suppresses lattice oxygen involvement, ultimately impeding structural degradation. Concurrently, the restructured interfacial water with enhanced free water facilitates water dissociation and enhances the adsorption of oxygen‐containing intermediates, thereby boosting OER kinetics. The a‐Ge‐RuO 2 exhibited a low overpotential (205 mV) at 10 mA cm −2 and maintained the stability for > 500 h at 100 mA cm −2 . Remarkably, the assembled PEMWE device with a‐Ge‐RuO 2 as anode was fabricated at 0.2 A cm −2 with a 0.13 mV h −1 decay rate. The dynamic reconstruction‐driven strategy provides a catalytic design paradigm for OER.