Enhanced activity promoted by amorphous metal oxyhydroxides on CeO₂ for alkaline oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for energy conversion technologies.
• Developing efficient and stable OER catalysts is essential for renewable energy applications.
• Amorphous metal oxyhydroxides (AMO) show promise as OER catalysts but often suffer from poor conductivity and stability.

Purpose of the Study:

• To develop a novel amorphous metal oxyhydroxide (AMO) catalyst directly grown on a cerium dioxide (CeO2) substrate.
• To investigate the synergistic effects between AMO and CeO2 for enhanced oxygen evolution reaction (OER) performance.
• To evaluate the catalytic activity and stability of the as-prepared AMO@CeO2 catalyst on nickel foam (NF).

Main Methods:

• Galvanic replacement mechanism was employed for the direct growth of AMO on CeO2.
• The AMO@CeO2 composite was supported on nickel foam (NF) to create the AMO@CeO2/NF electrode.
• Electrochemical characterization was performed in 1.0 M KOH solution to assess OER performance.

Main Results:

• The CeO2 substrate provided high surface area and conductivity, facilitating AMO formation and electron transfer.
• The AMO@CeO2 composite exhibited abundant active sites for the OER.
• The AMO@CeO2/NF electrode demonstrated excellent OER performance, including a low overpotential (261 mV at 10 mA cm-2) and high turnover frequency (0.07 s-1 at 20 mA cm-2).
• Superior stability was observed in 1.0 M KOH.

Conclusions:

• The direct growth of AMO on CeO2 via galvanic replacement is an effective strategy for fabricating advanced OER catalysts.
• The synergistic integration of AMO and CeO2 significantly enhances OER activity and stability.
• The AMO@CeO2/NF catalyst represents a promising candidate for efficient oxygen evolution in alkaline media.