Simple-Cubic Carbon Frameworks with Atomically Dispersed Iron Dopants toward High-Efficiency Oxygen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Iron and nitrogen codoped carbons (Fe-N-C) are promising electrocatalysts for the oxygen reduction reaction (ORR).
• Achieving highly dispersed and accessible active sites is crucial for enhancing ORR performance.
• Existing Fe-N-C catalysts face challenges in optimizing active site distribution and accessibility.

Purpose of the Study:

• To develop a novel graphitic Fe-N-C catalyst with uniformly dispersed single iron atoms.
• To investigate the ORR activity and electrochemical performance of the new catalyst.
• To evaluate the potential of the Fe-N-C catalyst in zinc-air batteries.

Main Methods:

• Synthesis of Fe-N-C catalysts using self-assembled Fe3O4 nanocube superlattices.
• In situ ligand carbonization, acid etching, and ammonia activation.
• Electrochemical characterization for oxygen reduction reaction (ORR) and zinc-air battery testing.

Main Results:

• A unique 3D simple-cubic carbon framework with anchored Fe single atoms was successfully synthesized.
• The developed Fe-N-C catalyst demonstrated superior ORR activity compared to commercial Pt/C and other reported Fe-N-C catalysts.
• The catalyst exhibited excellent performance in zinc-air batteries, with current and power densities rivaling state-of-the-art Pt/C.

Conclusions:

• The novel Fe-N-C catalyst offers highly accessible and uniformly dispersed active sites, leading to enhanced ORR electrocatalysis.
• The catalyst's unique structure and properties make it a competitive alternative to platinum-based catalysts for energy applications.
• This work provides a new strategy for designing advanced Fe-N-C electrocatalysts with improved performance.