Iron atom-cluster interactions increase activity and improve durability in Fe-N-C fuel cells

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Achieving simultaneous increases in activity and stability of single-atom active sites in M-N-C catalysts is a significant challenge.
• Fe-N-C catalysts are crucial for oxygen reduction reactions (ORR) in acidic fuel cells.

Purpose of the Study:

• To develop an Fe-N-C catalyst with enhanced activity and stability for ORR.
• To investigate the role of electronic interactions between iron clusters and Fe-N4 active sites.

Main Methods:

• Fabrication of a novel Fe-N-C catalyst featuring nitrogen-coordinated iron clusters and Fe-N4 active sites.
• Characterization of electronic interactions between iron clusters and Fe-N4 sites.
• Evaluation of catalyst performance in oxygen reduction reactions under acidic conditions.

Main Results:

• A strong electronic interaction was established between iron clusters and satellite Fe-N4 sites.
• The iron clusters modulated the adsorption of ORR intermediates and reduced Fe-N4 bond vibrations.
• Catalyst activity (turnover frequency) and stability (demetalation resistance) of Fe-N4 sites were improved by approximately 60%.

Conclusions:

• Strong electronic interactions between multiphase metal species offer a promising strategy for single-atom catalyst improvement.
• The developed Fe-N-C catalyst demonstrates significant potential for efficient and durable oxygen reduction reactions in fuel cells.