Trimetallic La/Ce-CoFe Layered Double Hydroxide Electrocatalysts with a Tailored Electronic Structure for Seawater Oxidation

Direct seawater electrolysis is fundamentally constrained by the slow kinetics of the oxygen evolution reaction (OER) and the presence of chloride ions. This work addresses these challenges through the strategic engineering of La/Ce-CoFe layered double hydroxide (La/Ce-CoFe LDH) nanosheets. The optimized Ce-CoFe LDH reaches industrial-grade current densities of 500 mA cm–2. In simulated alkaline seawater, it has an overpotential of 335 mV, which is 92 mV lower than the overpotential of CoFe LDH at the same current density. In real alkaline seawater, Ce-CoFe LDH maintains favorable OER performance (377 mV at 500 mA cm–2). Crucially, it demonstrates exceptional chloride tolerance, retaining activity after 110 h of continuous operation at 500 mA cm–2 in simulated alkaline seawater─a critical advance over La-CoFe LDH and CoFe LDH under comparable conditions. The enhanced performance is likely attributed to the lattice distortion induced by La/Ce doping and the optimized d-band center. Additionally, the unique electron pairs of Ce promote robust electronic interactions within the LDH matrix. The findings underscore the considerable promise of La/Ce-CoFe LDH as an advanced platform for the design of highly active and stable electrocatalysts, thereby facilitating efficient and sustainable seawater electrolysis.