Pt_1.8Pd_0.2CuGa Intermetallic Nanocatalysts with Enhanced Methanol Oxidation Performance for Efficient Hybrid Seawater Electrolysis

Abstract Seawater electrolysis is a potentially cost‐effective approach to green hydrogen production, but it currently faces substantial challenges for its high energy consumption and the interference of chlorine evolution reaction (ClER). Replacing the energy‐demanding oxygen evolution reaction with methanol oxidation reaction (MOR) represents a promising alternative, as MOR occurs at a significantly low anodic potential, which cannot only reduce the voltage needed for electrolysis but also completely circumvents ClER. To this end, developing high‐performance MOR catalysts is a key. Herein, a novel quaternary Pt_1.8Pd_0.2CuGa/C intermetallic nanoparticle (i‐NP) catalyst is reported, which shows a high mass activity (11.13 A mg_PGM⁻¹), a large specific activity (18.13 mA cm_PGM⁻²), and outstanding stability toward alkaline MOR. Advanced characterization and density functional theory calculations reveal that the introduction of atomically distributed Pd in Pt₂CuGa intermetallic markedly promotes the oxidation of key reaction intermediates by enriching electron concentration around Pt sites, resulting in weak adsorption of carbon‐containing intermediates and favorable adsorption of synergistic OH⁻ groups near Pd sites. MOR‐assisted seawater electrolysis is demonstrated, which continuously operates under 1.23 V for 240 h in simulated seawater and 120 h in natural seawater without notable degradation.