Surface-rough Fe-N/C composite wrapped on carbon nanotubes as efficient electrocatalyst for oxygen reduction reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Iron-nitrogen/carbon (Fe-N/C) composites are promising non-precious metal electrocatalysts for oxygen reduction reaction (ORR).
• Developing efficient and durable ORR catalysts is crucial for various electrochemical energy conversion devices.

Purpose of the Study:

• To fabricate a novel and efficient carbon nanotube (CNT)-supported Fe-N/C composite catalyst.
• To evaluate the electrocatalytic performance of the synthesized catalyst for ORR in alkaline media.

Main Methods:

• Fabrication involved surface-self-polymerization of polydopamine on CNTs, followed by Fe species incorporation and pyrolysis.
• Electrocatalytic performance was assessed using techniques such as cyclic voltammetry and rotating disk electrode measurements in 0.1 M KOH.

Main Results:

• The Fe-N/C catalyst demonstrated excellent ORR electrocatalytic activity with an onset potential of 0.95 V (vs. RHE) and a half-wave potential of 0.82 V (vs. RHE).
• The catalyst achieved a limiting current density of 5.39 mA cm⁻².
• Compared to commercial Pt/C, the Fe-N/C catalyst showed a more positive half-wave potential, higher limiting current density, superior durability, and better methanol tolerance.

Conclusions:

• The developed CNT-supported Fe-N/C catalyst is a highly efficient and durable alternative to precious metal catalysts for ORR.
• The synthesis strategy offers a promising route for designing advanced non-precious metal electrocatalysts for energy applications.