Ruthenium And Silver Synergetic Regulation NiFe LDH Boosting Long-Duration Industrial Seawater Electrolysis

The chloride ions in seawater result in corrosion, low catalytic efficiency, and poor stability of the electrocatalysts in direct seawater electrolysis, which limits the use of large-scale seawater electrolysis technology. Herein, a corrosion-resistant Ag/NiFeRu layered double hydroxide (LDH) electrocatalyst for seawater electrolysis at industrial current density, in which Ru and Ag species in the catalyst can have a corrosion-resistance of chloride ions from the anode surface and enhance its robustness in seawater is designed. The catalyst requires the overpotentials of 256 and 287 mV to obtain a current density of 1 A cm-2 in 1 m KOH and 1 m KOH + seawater, respectively. More importantly, it works stably for over 1000 h at 1 A cm-2 in alkaline seawater. Further quasi-industrial conditions measurement (6 m KOH + seawater, 60 degrees C) shows a markedly low overpotential of 174 mV at 1 A cm-2 on Ag/NiFeRu LDH, obtaining over 140 h under harsh industrial conditions. Theoretical calculations demonstrate that the Ru species can effectively regulate the local electronic structure of NiFe LDH, and enhance the intrinsic activity of NiFe LDH. The transformation of Ag2O from Ag during OER stabilizes the Fe site in NiFe LDH, which improves the overall stability of the electrocatalyst. Ru and Ag synergetic regulation NiFe LDH exhibits excellent activity and stability in industrial seawater electrolysis. This catalyst requires a low overpotential of 287 mV to obtain a current density of 1 A cm-2 in 1 m KOH + seawater with a long-term operation of 1000 h. image