Dual-functional nickel cobalt disulfide electrocatalyst for nitrogen-containing small-molecule electrooxidation

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Oxygen evolution reaction (OER) byproducts limit green hydrogen production.
• Nitrogen-containing small molecule oxidation reactions (NOR) offer a more energy-efficient alternative.
• NOR facilitates environmental cleanup and valuable chemical synthesis.

Purpose of the Study:

• To develop a highly efficient bifunctional catalyst for NOR.
• To investigate the catalytic mechanism of NOR.
• To establish a scalable materials design for integrated hydrogen production and chemical upgrading.

Main Methods:

• Hydrothermal synthesis of a NiCo2S4 precursor on nickel foam (NF).
• Sulfidation strategy to create the bifunctional catalyst.
• In-situ Raman spectroscopy to elucidate reaction mechanisms.

Main Results:

• The NiCo2S4/NF catalyst achieved exceptional NOR performance in alkaline media.
• Urea oxidation reaction (UOR) reached 100 mA cm-2 at 1.35 V.
• Adiponitrile oxidation reaction (ADOR) reached 100 mA cm-2 at 1.40 V with 98% Faradaic efficiency for adiponitrile (ADN) production.
• The catalyst demonstrated high stability with <5% decay over 30 hours.

Conclusions:

• Sulfur leaching triggers the formation of the active Ni(Co)OOH phase.
• A closed-loop redox cycle involving urea chemisorption and reduction stabilizes the active NiCo-LDH interface.
• The developed catalyst offers a scalable pathway for integrated hydrogen production, environmental remediation, and resource upgrading.