Defect-Promoted Reductive Regeneration on Cobalt Catalysts Enables Efficient Dual-Pathway Hydrazine Electrooxidation

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Hydrazine oxidation reaction (HzOR) is a key pathway for sustainable hydrogen production.
• Mechanistic understanding and catalyst stability are critical challenges for HzOR implementation.

Purpose of the Study:

• To elucidate the dual-pathway mechanism of HzOR on cobalt-based catalysts.
• To design and synthesize a highly efficient and stable cobalt catalyst for HzOR.

Main Methods:

• Electrochemical analysis
• Density Functional Theory (DFT) calculations
• One-step electrodeposition for catalyst synthesis.

Main Results:

• Identified a dual-pathway mechanism involving direct electrooxidation and mediated oxidation via a Co redox cycle.
• Developed a defect-rich cobalt catalyst exhibiting superior HzOR performance (100 mA cm⁻² at -79 mV vs RHE) and long-term stability.
• Demonstrated that defect engineering enhances the dual-pathway HzOR on cobalt catalysts.

Conclusions:

• Mechanistic insights into HzOR on cobalt catalysts were achieved.
• Defect-rich cobalt catalysts offer a promising strategy for efficient and durable non-noble metal electrocatalysts for HzOR.
• This work advances the understanding and design of catalysts for sustainable hydrogen production.