Site-specific synergy by heteronuclear microenvironment atomic editing for oxygen reduction reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Iron-nitrogen-carbon catalysts show promise for oxygen reduction reactions (ORR).
• Achieving high activity and long-term stability in ORR catalysts is challenging.
• Precise control over the active site microenvironment is crucial for catalyst design.

Purpose of the Study:

• To develop a microenvironment atomic editing strategy for designing advanced ORR catalysts.
• To investigate the performance of heteronuclear triatomic Fe and Co sites (Fe1Co2/NC) for ORR.
• To explore the application of the developed catalyst in rechargeable zinc-air batteries.

Main Methods:

• Synthesis of a nitrogen-doped carbon matrix supported Fe1Co2N7O1 catalyst.
• Characterization of the catalyst's atomic structure and electronic properties.
• Electrochemical evaluation of the catalyst's activity and stability in ORR (alkaline and acid conditions).
• Fabrication and testing of quasi-solid-state zinc-air batteries using the catalyst.

Main Results:

• The Fe1Co2/NC catalyst exhibited enhanced ORR activity with half-wave potentials of 0.94 V (alkaline) and 0.88 V (acidic).
• Orbital hybridization between Fe and Co atoms optimized d band centers, improving activity and stability.
• The catalyst demonstrated excellent performance in quasi-solid-state zinc-air batteries, achieving high power densities (282.7 mW cm-2) and operational stability.
• Optimized metal-adsorbate interactions and strengthened metal-N bonding contributed to competitive activity and stability.

Conclusions:

• The microenvironment atomic editing strategy is effective for designing low-nuclearity catalysts.
• The Fe1Co2N7O1 catalyst offers a promising alternative to commercial catalysts for energy-efficient batteries.
• Atomic-level control over catalyst active sites is key to advancing ORR catalysis and energy storage solutions.