Unlocking Superior Stability in High-Salinity Oxygen Evolution Reaction: A Ru Stabilized NiFeOOH/Ni Anode with over 2000 h Durability

TL;DR

A new anode design using ruthenium improves stability in saline water electrolysis, lasting over 2000 hours under harsh conditions.

Contribution

Introducing a dual-function ruthenium stabilizer that enhances anode durability in chloride-rich environments.

Findings

Ru incorporation forms a protective surface layer and denser catalyst structure.

The RuSA-NiFeOOH/Ni anode lasts over 2000 hours at 0.5 A cm−2 in chloride-enriched conditions.

This dual stabilization strategy sets a new benchmark for saline water electrolysis performance.

Abstract

A dual-function stabilizing agent in NiFe-based anodes is proposed.Ru incorporation promotes the formation of a protective surface layer enriched with Ru atoms, along with a denser NiFeOOH catalyst structure.RuSA-NiFeOOH/Ni anode exhibits exceptional operational stability over 2000 h at an industrial current density of 0.5 A cm−2 in a chloride-enriched alkaline medium.

A dual-function stabilizing agent in NiFe-based anodes is proposed.

Ru incorporation promotes the formation of a protective surface layer enriched with Ru atoms, along with a denser NiFeOOH catalyst structure.

RuSA-NiFeOOH/Ni anode exhibits exceptional operational stability over 2000 h at an industrial current density of 0.5 A cm−2 in a chloride-enriched alkaline medium.

The online version contains supplementary material available at 10.1007/s40820-026-02072-4.

Saline water electrolysis presents a promising pathway for green hydrogen production by leveraging abundant saline water resources instead of scarce freshwater. However, the presence of highly corrosive chloride ions (Cl−) severely undermines anode durability. This instability arises from two main issues: (i) penetration of Cl− through catalyst layers to the underlying substrate and (ii) degradation of active catalytic sites due to Cl− attack. To tackle both issues simultaneously, we introduce ruthenium (Ru) ions as a dual-function stabilizing agent in NiFe-based anodes. Our results show that Ru incorporation promotes the formation of a protective surface layer enriched with Ru atoms, along with a denser NiFeOOH catalyst structure, which collectively inhibit Cl– infiltration. Moreover, atomically dispersed ruthenium (RuSA) within the NiFeOOH matrix effectively mitigates Cl–-induced corrosion of active sites. Thanks to this dual stabilization effect, the resulting RuSA-NiFeOOH/Ni anode exhibits exceptional operational stability—over 2000 h at an industrial current density of 0.5 A cm−2 in a chloride-enriched alkaline medium (1 M KOH + 2 M NaCl)—setting a new benchmark for performance under such aggressive conditions. This study establishes a robust dual stabilization strategy that significantly enhances anode stability in saline water electrolysis.

The online version contains supplementary material available at 10.1007/s40820-026-02072-4.

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