W-Mediated Electron Accumulation in Ru-O-W Motifs Enables Ultra-Stable Oxygen Evolution Reaction in Acid

The development of efficient and durable oxygen evolution reaction (OER) catalysts is crucial for advancing proton exchange membrane water electrolysis (PEMWE) technology, especially in the pursuit of non-iridium alternatives. Herein, we report a Zn, W co-doped Ru₃Zn_0.85W_0.15O_x (RZW) ternary oxide catalyst that exhibits a low overpotential of 200 mV and remarkable stability for over 4000 hours at 10 mA cm^-2 in 0.1 M HClO₄. The incorporation of highly electronegative W facilitates the efficient capture of electrons released from the sacrificial Zn species during OER, and subsequently mediated to Ru sites. The observed enhancement in electron density within the stable Ru-O-W motifs substantially improves the anti-overoxidation properties of the Ru active sites. Our findings highlight the importance of strategic metal doping in modulating the electronic structure of OER catalysts during operation, thereby facilitating the development of practical and long-lasting water electrolysis technologies.