Single-Atom-like B-N₃ Sites in Ordered Macroporous Carbon for Efficient Oxygen Reduction Reaction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Improving catalytic efficiency for oxygen reduction reactions (ORR) is crucial for fuel cells and metal-air batteries.
• Heteroatom doping and structural optimization are effective strategies for enhancing ORR performance.
• Transition metal-nitrogen-carbon (M-N-C) sites are well-studied ORR catalysts.

Purpose of the Study:

• To design and synthesize a novel single-atom-like boron-nitrogen-3 (B-N3) configuration in carbon for efficient ORR catalysis.
• To investigate the ORR performance of this metal-free catalyst in alkaline media.
• To explore the role of ordered macroporous structures and B/N co-doping in enhancing catalytic activity.

Main Methods:

• Synthesis of ordered macroporous carbon using hydrogen-bonded organic frameworks and SiO2 spheres as a template.
• Fabrication of a single-atom-like B-N3 configuration within the carbon matrix.
• Electrochemical characterization of the catalyst for ORR performance in alkaline media.
• Density Functional Theory (DFT) calculations to elucidate the catalytic mechanism.

Main Results:

• The designed B-N3 configuration supported on ordered macroporous carbon exhibits high ORR catalytic performance in alkaline media.
• Co-doping of boron and nitrogen, along with the ordered macroporous structure, significantly enhances the metal-free catalyst's activity.
• DFT calculations confirm that the B-N3 site facilitates favorable adsorption of *OOH and *OH intermediates, accelerating the ORR.

Conclusions:

• The study successfully demonstrates a new strategy for designing efficient, single-atom-like nonmetallic ORR electrocatalysts.
• The developed ordered macroporous carbon synthesized from hydrogen-bonded organic frameworks provides a promising platform for advanced catalysts.
• The B-N3 active site is identified as a key factor in boosting oxygen reduction activity.