Fe-Co heteronuclear atom pairs as catalytic sites for efficient oxygen electroreduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Single-site Fe-N-C catalysts are promising alternatives to platinum-group catalysts for the oxygen reduction reaction (ORR).
• Challenges include low activity, poor stability, and high production costs.
• Synergistic effects between metals can enhance catalytic performance.

Purpose of the Study:

• To enhance the catalytic activity and stability of Fe-N-C catalysts for the oxygen reduction reaction (ORR).
• To investigate the synergistic effect of incorporating cobalt into Fe-N-C catalysts.
• To evaluate the performance of the developed catalysts in zinc-air batteries and anion-exchange membrane fuel cells (AEMFCs).

Main Methods:

• Synthesized Fe-N-C catalysts with introduced cobalt atoms and phenanthroline ligand.
• Characterized the catalyst structure and composition.
• Evaluated catalytic activity and stability for the oxygen reduction reaction (ORR) in alkaline media.
• Tested catalyst performance in constructed zinc-air batteries and AEMFCs.

Main Results:

• The FeCo-N-C catalyst exhibited a high half-wave potential of 0.892 V for ORR with good stability.
• The developed catalyst enabled a zinc-air battery with high power density (247.93 mW cm⁻²) and capacity (768.59 mA h gZn⁻¹).
• An anion-exchange membrane fuel cell (AEMFC) using the FeCo-N-C cathode achieved a high open-circuit voltage (0.95 V) and rated power density (444.7 mW cm⁻²).

Conclusions:

• Cobalt incorporation into Fe-N-C catalysts effectively enhances ORR activity via synergistic Fe-Co effects.
• The FeCo-N-C catalyst demonstrates excellent performance in both zinc-air batteries and AEMFCs.
• This non-precious metal catalyst strategy shows significant practical applicability for energy conversion devices.