Strengthening d-p Orbital Hybridization by Fluorine Modification for Efficient Oxygen Evolution Reaction
The sluggish kinetics and high onset potentials of the oxygen evolution reaction (OER) at the anode of alkaline water/seawater electrolyzers limit overall energy efficiency. Noble-metal oxides like RuO2 are active but suffer from high cost, agglomeration, and dissolution under oxidizing potentials, especially in chloride-rich electrolytes where competing chloride oxidation reaction (ClOR) occurs. Here, we report a mild two-step dry-wet milling strategy to achieve throughout lattice doping of F− into MnO2 (F-MnO2) and subsequent anchoring of atomically dispersed Ru via Ru–O/F hybrid bonds. The strengthened Mn 3d–O/F 2p hybridization and negative charge shielding of surface F− enhance OER activity/selectivity relative to ClOR and impart superior Cl− tolerance and corrosion resistance. The resulting F-Ru-MnO2-TH electrocatalyst exhibits overpotentials of 280 mV and 200 mV at 10 mA cm−2 in alkaline water and simulated seawater, respectively. It retains ~100% of initial activity after 200 h continuous operation in alkaline media and >95% after 300 h in simulated seawater, significantly outperforming Ru-MnO2 and commercial RuO2. This work provides a scalable route to durable, high-performance OER catalysts for seawater electrolysis.