Cheap carbon black-based high-performance electrocatalysts for oxygen reduction reaction.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Oxygen reduction reaction (ORR) is crucial for energy conversion devices.
• Developing cost-effective and high-performance ORR electrocatalysts is essential.
• Traditional platinum-based catalysts are expensive and face durability issues.

Purpose of the Study:

• To synthesize and characterize a series of inexpensive Fe-Nx/C electrocatalysts.
• To evaluate their performance for the oxygen reduction reaction.
• To elucidate the structure-activity relationship of different active sites in Fe-Nx/C catalysts.

Main Methods:

• Synthesis of Fe-Nx/C electrocatalysts using carbon black as a support.
• Characterization of the synthesized materials.
• Electrochemical evaluation of ORR activity using rotating disk electrode (RDE) voltammetry.

Main Results:

• A family of Fe-Nx/C electrocatalysts with varying Fe and N content was successfully synthesized.
• The optimal catalyst composition (10 wt% Fe, 1.57 wt% N) exhibited superhigh performance for ORR.
• The activity order of active sites was determined as Fe-N4/2-C > Fe4-N-C > N-C ≫ Fe4-C ≈ C.

Conclusions:

• Fe-Nx/C electrocatalysts offer a cost-effective alternative to platinum for ORR.
• The Fe-N4/2-C site is the most active species for ORR in these catalysts.
• This study provides valuable insights into designing efficient non-precious metal electrocatalysts for energy applications.