Tailoring Oxygen‐Bridged Asymmetric Active Sites for Oxygen Reduction Reaction in Seawater

ABSTRACT Seawater electrocatalysis is essential for energy conversion systems, particularly metal‐air batteries that utilize seawater as the electrolyte. However, developing durable oxygen reduction catalysts for direct seawater operation remains challenging due to severe chloride corrosion and scale deposition. Here, a Pt–Lu ₂ O ₃ /KB catalyst is rapidly synthesized via a microwave‐assisted method, which constructs an asymmetric Pt–O–Lu interface in which the Lewis‐acidic Lu ₂ O ₃ regulates the interfacial chemistry by selectively anchoring cathodically generated OH ⁻ , thereby suppressing their diffusion and preventing the formation of Ca ²⁺ and Mg ²⁺ precipitates. Meanwhile, the local enrichment of OH ⁻ at the interface generates electrostatic repulsion with Cl ⁻ , effectively inhibiting Cl ⁻ adsorption, thereby mitigating site poisoning and enhancing structural stability. As a result, Pt–Lu ₂ O ₃ /KB exhibits remarkable ORR activity and durability, with a half‐wave potential of 0.88 V (vs. RHE) in alkaline seawater. It demonstrates exceptional ORR performance in zinc–air batteries, with stable operation for 280 h in alkaline seawater and sustained discharge for over 200 h in natural seawater.