Dual engine drive: The synergy of Mn and Ti 4 O 7 achieves highperformance acidic water oxidation

The development of electrocatalysts that simultaneously exhibit high activity and robust stability for the oxygen evolution reaction (OER) is critical to advancing proton exchange membrane water electrolysis (PEMWE). In this work, Mn-doped RuO2 is composited with acid-resistant and highly conductive Ti4O7 via a simple molten salt method, yielding a Mn-RuO2/Ti4O7 hybrid electrocatalyst. Electrochemical measurements reveal that Mn-RuO2/Ti4O7 achieves a low overpotential of 194 mV at 10 mA cm⁻² and maintains stable operation for over 220 h at this current density. In situ spectroscopic analysis and computational studies further indicate that Mn doping modulates the electronic interplay between RuO2 and Ti4O7, which not only suppresses over-oxidation of Ru at high potentials but also promotes the deprotonation kinetics of reaction intermediates, thereby significantly enhancing the overall catalytic performance. This work offers an effective strategy for balancing activity and stability in acidic OER electrocatalys.