Heterojunction-Guided Reconstruction Toward Ru-Co Bridged Dual Sites for Efficient Oxide-Path Water Electrolysis.

Abstract

The oxide path mechanism (OPM) offers a compelling route to bypass the activity-stability trade-off of conventional oxygen evolution catalysis. However, its deliberate activation has largely relied on doping strategies to create heterometallic dual sites, which suffer from limited electronic tunability. Here, we demonstrate a fundamentally different approach that combines heterojunction engineering with guided in situ reconstruction. By integrating ruthenium oxide with a cobalt-nickel telluride heterostructure, we exploit the pronounced surface reconstruction of tellurides under anodic potentials to in situ generate a metastable CoO₂ phase featuring high-valent cobalt. This reconstructed phase intimately couples with neighboring RuO₂ to form well-defined Co-O-Ru bridged dual sites, which are proposed as the pivotal centers for OPM-enabled O─O coupling. The telluride framework further acts as an electronic modulator, stabilizing ruthenium while promoting high-valent cobalt formation. This synergy yields a catalyst with an overpotential of 213 mV at 100 mA cm^-2 and a mass activity 103 times that of commercial RuO₂. When deployed in an anion-exchange membrane electrolyzer, it operates at 1 A cm^-2 with a cell voltage of 1.78 V for over 800 h. Our work establishes heterojunction-induced reconstruction as a powerful strategy to unlock OPM catalysis, moving beyond conventional doping toward dynamically assembled active interfaces.