Direct Seawater Electrolysis with Stabilized High‐Performance NiCr Anodes

Abstract Hydrogen (H2) production through direct seawater electrolysis faces significant challenges due to the complex composition of seawater that induces undesirable reactions competing with the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Such competition ultimately has a considerable impact on both the efficiency and sustainability of this process. Indeed, Cl⁻ and Br⁻ anions in seawater contribute to corrosion, lower the catalytic efficiency, and compromise the stability of conventional electrocatalysts, thereby restricting the feasibility of large‐scale direct seawater electrolysis at high pH through alkaline seawater electrolysis (ASE). In this work, it is shown that the use of an alloyed NiCr foam (NiCrF) anode, exhibiting enhanced durability compared to conventional Ni foam (NiF), is compatible with the ASE process if coated with an efficient and robust electrocatalyst. This is reported here by using a highly active NiFe‐layered double hydroxide (NiFeLDH) deposited on the NiCr foam. It is demonstrated that this assembly shows high corrosion resistance during ASE, minimal Cr leaching in the electrolyte, and long‐term efficiency. An ASE electrolyzer comprising the so‐prepared anode and a cathode derivatized with NiMoO4 is stable in operation at 50 °C for 270 h at a current density of 100 mA cm−2 and an iR‐corrected voltage of 1.6 V.