Deep-Eutectic Solvents Derived Nitrogen-Doped Graphitic Carbon as a Superior Electrocatalyst for Oxygen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalyst performance for oxygen reduction reaction (ORR) is crucial for energy devices.
• Structural and compositional properties significantly influence electrocatalyst activity and stability.

Purpose of the Study:

• To develop a facile method for preparing nitrogen-doped graphitic carbon (NGC) from deep-eutectic solvents (DESs).
• To investigate the effect of pyrolysis temperature on the ORR catalytic properties of NGCs.
• To evaluate NGCs as potential electrocatalysts for ORR in alkaline media.

Main Methods:

• Pyrolysis of deep-eutectic solvents (DESs) to synthesize nitrogen-doped graphitic carbon (NGC).
• Systematic variation of pyrolysis temperatures to optimize catalyst properties.
• Electrochemical characterization of ORR performance, including onset potential, half-wave potential, and stability tests.

Main Results:

• NGCs synthesized via DES pyrolysis exhibit high surface areas, rich nitrogen content, and favorable graphitization.
• The NGC material pyrolyzed at 900 °C (NGC900) demonstrated superior ORR activity.
• NGC900 achieved an onset potential of 0.97 V and a half-wave potential of 0.84 V, outperforming commercial Pt/C in stability.

Conclusions:

• The optimized NGC material, NGC900, is a highly efficient and stable electrocatalyst for ORR.
• The excellent performance is attributed to the synergistic effects of high surface area, pyridinic nitrogen content, and defect engineering.
• This low-cost synthesis route using DESs provides a promising pathway for developing advanced electrocatalysts for practical energy applications.