Operando Reconstructed Molecule Fence to Stabilize NiFe-Based Oxygen Evolution Catalysts

Economical NiFe-based oxygen evolution reaction catalysts have recently gained attention for their potential to accelerate green hydrogen production through water electrolysis. However, their practical application is limited by durability issues caused by the leaching of Fe sites during operation. Here an operando reconstructed molecule fence, that is, sulfate-anchored aromatic ring molecule, is proposed to inhibit the leaching of Fe atoms and improve the durability of NiFe-based catalysts. With this design, the sulfate not only immobilizes the aromatic ring as the protective layer to ensure long-term service but also leaves space for beneficial site exposure and mass penetration. Molecule fence-protected NiFe-based catalysts exhibit excellent stability to withstand continuous high current densities of 100 mA cm(-2) for over 2200 h and frequent current fluctuations and under start-up/shut-down events for over 200 h. Furthermore, the implementation of optimized catalysts in industrial water electrolysis equipment operates steadily for over 100 h with an energy consumption of & AP;4.18 kWh m(-3) H-2.

Automated summary

Economical NiFe-based catalysts that can accelerate green hydrogen production through water electrolysis have gained attention. However, the leaching of Fe atoms during operation limits their practical application. In this study, an operando reconstructed molecule fence, with sulfate-anchored aromatic ring molecules, is proposed to inhibit Fe leaching and improve catalyst durability. The protected catalysts show excellent stability under high current densities and frequent fluctuations, as well as in industrial water electrolysis equipment with low energy consumption.