Ag Nanoparticle-Induced Surface Chloride Immobilization Strategy Enables Stable Seawater Electrolysis.

Although hydrogen gas (H 2 ) storage might enable offshore renewable energy to be stored at scale, the commercialization of technology for H 2 generation by seawater electrolysis depends upon the development of methods that avoid the severe corrosion of anodes by chloride (Cl - ) ions. Here, we reveal that the stability of an anode used for seawater splitting can be increased by more than an order of magnitude by loading Ag nanoparticles on the catalyst surface. In experiments, an optimized NiFe-layered double hydroxide (LDH)@Ag electrode displayed stable operation at 400 mA cm -2 in alkaline saline electrolyte and seawater for over 5000 and 2500 h, respectively. The impressive long-term durability was more than 20 times that of an unmodified NiFe-LDH anode. Meticulous characterization and simulation revealed that in the presence of an applied electric field, free Cl - ions reacted with oxidized Ag nanoparticles to form stable AgCl species, giving rise to the formation of a Cl - -free layer near the anode surface. Because of its simplicity and effectiveness, we anticipate that the proposed strategy to immobilize chloride ions on the surface of an anode has the potential to become a crucial technology to control corrosion during large-scale electrolysis of seawater to produce hydrogen. This article is protected by copyright. All rights reserved.