A Reversed‐Active Sites Strategy to Boost the Activity and Durability of Perovskite for Seawater Electrolysis

Seawater electrolysis has attracted considerable attention in hydrogen production. However, the chloride ions (Cl − ) in seawater can corrode metal sites and decrease the lifespans of the oxygen evolution reaction (OER). Herein, we report a reversed‐active sites strategy, converting Cl − ‐affinitive metal sites to Cl − ‐repellent oxygen sites, for OER in alkaline seawater electrolysis. First, ex/in situ experiments confirm the effectiveness of such a strategy using typical perovskites following the adsorbate evolution mechanism (AEM) or lattice oxygen‐mediated mechanism (LOM). Furthermore, the origins of the superior activity and durability of as‐prepared La 0.3 SrCo 0.5 Fe 0.5 O x (La0.3) can be ascribed to higher participation of lattice oxygen in OER, rapid bulk oxygen diffusion, and excellent OH − adsorption kinetics. Hence, an alkaline seawater electrolytic cell with La0.3 as the anode produces 10 mA cm −2 at just 1.57 V and maintains near‐constant activity over 150 hours. This work introduces novel concepts for the production of superactive and steady electrocatalysts for the electrolysis of seawater.