P-Block Atomically Dispersed Antimony Catalyst for Highly Efficient Oxygen Reduction Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Main-group metals are typically inactive catalysts due to their electronic structure.
• Developing efficient and stable catalysts for the oxygen reduction reaction (ORR) is crucial for energy technologies.

Purpose of the Study:

• To synthesize and characterize a p-block antimony single-atom catalyst (Sb SAC) for ORR.
• To evaluate the catalytic performance and stability of the Sb SAC in ORR and Zn-air batteries.

Main Methods:

• Synthesis of antimony single-atom catalyst with Sb-N4 configuration.
• Electrochemical testing for oxygen reduction reaction (ORR) activity and stability.
• Zn-air battery performance evaluation.
• Theoretical calculations (Density of States - DOS) to elucidate catalytic mechanisms.

Main Results:

• The Sb SAC achieved a high half-wave potential of 0.86 V for ORR, surpassing transition-metal catalysts and commercial Pt/C.
• Demonstrated excellent stability and high power density (184.6 mW cm⁻²) and specific capacity (803.5 mAh g⁻¹) in Zn-air batteries.
• Experimental and theoretical studies identified positively charged Sb-N4 sites as active centers, with synergistic electronic interactions between Sb p-orbitals and O2 facilitating catalysis.

Conclusions:

• P-block antimony single-atom catalysts are highly effective for ORR, challenging the notion of main-group metal inactivity.
• The Sb SAC offers a promising alternative for clean energy applications, including fuel cells and batteries.
• Provides a blueprint for designing novel main-group metal single-atom catalysts for various catalytic processes.