Porous Co@NC Materials Obtained by Pyrolyzing Metal-Organic Framework-Supported Multinuclear Metal Clusters for the...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for oxygen reduction reactions (ORR) in energy conversion devices like fuel cells and metal-air batteries.
• Single-atom catalysts offer maximum atomic utilization and tunable properties, making them highly sought after for ORR applications.

Purpose of the Study:

• To design and synthesize novel electrocatalysts for ORR using multinuclear metal clusters as precursors.
• To investigate the performance of cobalt nanoparticles and single-atomic cobalt sites supported on nitrogen-doped carbon (Co@NC) for ORR.

Main Methods:

• Preparation of Co-based metal clusters (Co4O4) and zinc-based zeolitic imidazolate frameworks (ZIF-8).
• Pyrolysis of ZIF-8-Co4O4 hybrids to form porous nitrogen-doped carbon supports with embedded cobalt species (Co@NC).
• Characterization of the material's structure, including the presence of Co nanoparticles and single-atomic Co-N4 sites.

Main Results:

• Successful synthesis of Co@NC materials featuring both cobalt nanoparticles and single-atomic Co-N4 sites on porous nitrogen-doped carbon supports.
• The porous structure resulted from the high-temperature departure of Zn and O during pyrolysis.
• The Co@NC catalyst achieved a high half-wave potential of 0.86 V (vs. RHE) for the ORR in 0.1 M KOH.

Conclusions:

• Multinuclear metal clusters can serve as effective precursors for constructing advanced single-atom catalysts.
• The developed Co@NC catalyst demonstrates excellent electrocatalytic activity for ORR, offering a new strategy for catalyst design.
• This approach provides a promising pathway for developing high-performance electrocatalysts for clean energy technologies.