A Super‐Chlorophobic Yet Weak‐Reconstructed Electrocatalyst by Fluorination Engineering toward Chlorine Oxidation‐Free and High‐Stability Seawater Electrolysis

Abstract Direct seawater electrolysis is key for achieving sustainable green‐hydrogen production and transitioning toward a decarbonized energy system. However, its performance is limited by significant challenges, mainly catalyst instability, which is caused by excessive reconstruction, low catalytic activity, and aggressive chlorine‐corrosion. Herein, high‐electronegativity F is introduced into NiFe layered double‐hydroxide (F‐NiFe‐LDH) through fluorination engineering to induce electron‐deficient regions around Ni, thus creating abundant intrinsic high‐valence Ni sites. Correspondingly, the features of weak reconstruction accompanied by high stability, chlorophobic surface, and high‐activity lattice oxygen are produced on the F‐NiFe‐LDH, confirmed detailedly by experiment and theory. Consequently, the F‐NiFe‐LDH exhibits a superior oxygen evolution reaction (OER) activity with low overpotentials of 306 and 375 mV to reach 500 mA cm −2 at alkaline simulated seawater and alkaline seawater, respectively. Also, it demonstrates a chlorine‐corrosion resistance, along with ultra‐stability seawater electrolysis for over 1000 h at 1000 mA cm −2 without performance degradation, structural collapse, or chlorine oxidation reaction. Furthermore, an anion exchange membrane electrolyzer assembled by the F‐NiFe‐LDH anode shows an energy consumption of only 4.87 kWh Nm −3 for hydrogen production. This work provides an inspiration for designing corrosion‐resistance electrocatalysts aimed at chlorine oxidation‐free seawater electrolysis, which simultaneously achieve high stability and OER activity.