Co,N-doped carbon sheets prepared by a facile method as high-efficiency oxygen reduction catalysts

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Transition metal and nitrogen codoped carbon materials are leading replacements for noble metal catalysts in oxygen reduction reactions (ORR).
• Developing high-efficiency, stable, and cost-effective metal-nitrogen-carbon catalysts remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize novel cobalt and nitrogen codoped carbon sheet catalysts.
• To evaluate the electrocatalytic performance of these catalysts for the oxygen reduction reaction (ORR) in alkaline media.
• To compare their efficiency and stability against commercial platinum-based catalysts.

Main Methods:

• Preparation of cobalt and nitrogen codoped carbon sheet catalysts using a self-injected vapor phase growth and template method.
• Characterization of the catalysts' physical properties, including pore structure and specific surface area.
• Electrochemical evaluation of the oxygen reduction reaction (ORR) activity, onset potential, half-wave potential, durability, and methanol tolerance.

Main Results:

• The synthesized Co-N-C-43.8 catalyst exhibited a multilevel pore structure and large specific surface area.
• The catalyst demonstrated superior ORR performance with onset and half-wave potentials 31 mV and 3 mV higher than commercial Pt/C in alkaline media.
• The Co-N-C-43.8 catalyst showed excellent durability, retaining 93% current density after 10,000 s, and exhibited good methanol tolerance compared to Pt/C.

Conclusions:

• Cobalt and nitrogen codoped carbon sheets are highly promising electrocatalysts for the oxygen reduction reaction.
• The developed Co-N-C-43.8 catalyst offers a cost-effective and high-performance alternative to noble metal catalysts.
• The unique structural characteristics contribute to the enhanced catalytic activity and stability.