Constructing crystalline-amorphous heterophase interfaces through Cr/Mo co-doping in RuO2 enables efficient acidic oxygen evolution reaction

The oxygen evolution reaction (OER), serving as the anode in water electrolysis, plays a pivotal role in various applications. Developing efficient non-iridium-based catalysts for acidic water splitting remains a significant challenge. This study employs a phase engineering strategy to synthesize defect-rich crystalline/amorphous Ru 0.6 Mo 0.2 Cr 0.2 O x solid solution catalysts through dual-metal doping. The catalyst exhibits superior acidic OER performance with an overpotential of 204 mV (@10 mA cm −2 ) and mass activity of 577.8 A g Ru −1 at 1.5 V vs RHE, outperforming all control samples. Furthermore, synergistic Cr/Mo doping effectively reduces the oxidation state of Ru in RuO 2 while enhancing structural stability, resulting in minimal activity decay during prolonged testing. Theoretical calculations reveal that dual-doping synergistically modulates charge distribution on Ru sites, lowering the energy barrier for *OOH formation in the thermodynamic limiting step. This work provides a facile strategy for developing high-performance acidic OER catalysts with dramatically reduced noble metal loading, demonstrating critical industrial relevance.