Phosphoryl-Engineered MOFs Promote Interfacial Reconstruction for Efficient Seawater Ethanol Electrooxidation

The hydrogen production efficiency of hybrid seawater electrolysis devices hinges on high-performance catalytic materials with superior activity and chlorine corrosion resistance under the alkaline seawater conditions. However, the controllable modulation of catalyst structures to construct an effective anti-chlorine protective layer, one that simultaneously enhances both Cl corrosion resistance and anodic oxidation reaction activity, remains a formidable challenge. Herein, we report a phosphonyl-ligand engineering strategy that promotes the transformation of metal-organic frameworks (MOFs) into metal oxyhydroxides containing oxygen-anions during alkaline seawater ethanol oxidation reaction (EOR) with enhanced activity and Cl^- corrosion resistance. Leveraging the tunable nature of organic ligands in MOFs provides a versatile platform for the in situ formation of oxygen anion layers with robust chlorine corrosion resistance. A phosphorus-containing MOF (P_a-Ni-TPA) was synthesized by partially substituting terephthalic acid (TPA) with 4-phosphonobenzoic acid (P_a). In contrast to the conventional MOF (Ni-TPA), the in situ generated metal oxyhydroxide from P_a-Ni-TPA incorporates PO₄ ^3-. PO₄ ^3- promotes the adsorption of ethanol and its intermediates onto nickel centers while inhibiting Cl adsorption, thereby significantly boosting both EOR activity and Cl corrosion resistance. These findings establish a detailed structure-performance correlation between MOF structural evolution and both catalytic activity toward alkaline seawater EOR and resistance to chlorine corrosion.