Enhancing the Selective OH− Adsorption for Durable Alkaline Seawater Oxidation at Industrial Current Densities

The oxygen evolution reaction (OER) in seawater electrolysis is pivotal for sustainable hydrogen production, yet severe chloride ion (Cl⁻)-induced corrosion at the anode critically limits catalyst durability. Herein, we design a heterostructured catalyst comprising NiFe-layered double hydroxide and Ce(OH)CO₃ (denoted as NiFe-LDH/Ce(OH)CO₃) that exhibits remarkable OER stability in alkaline-simulated seawater. Experimental results and density functional theory calculations reveal that Ce(OH)CO₃ incorporation modulates interfacial charge redistribution and enhances the Lewis acidity of Ni and Fe sites, thereby tuning the adsorption energetics of Cl⁻ and OH⁻. Time-of-flight secondary ion mass spectrometry further confirms the preferential adsorption of OH⁻ over Cl⁻, effectively suppressing Cl⁻-induced corrosion. As a result, NiFe-LDH/Ce(OH)CO₃ demonstrates exceptional long-term stability, maintaining continuous operation for over 450 h at 1 A cm⁻² in alkaline seawater. When integrated into an anion exchange membrane electrolyzer, the catalyst achieves 1 A cm⁻² at a low cell voltage of 1.92 V and operates stably for over 60 h. The system delivers an impressive energy efficiency of 68.59% in alkaline-simulated seawater, corresponding to a hydrogen production cost as low as $0.97 per gasoline gallon equivalent at 500 mA cm⁻².