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

ACS Appl Mater Interfaces. 2021 Nov 17;13(45):53892-53903. doi: 10.1021/acsami.1c15661. Epub 2021 Nov 5.

Abstract

On the premise of cleanliness and stability, improving the catalytic efficiency for the oxygen reduction reaction in the electrode reaction of fuel cells and metal-air batteries is of vital importance. Studies have shown that heteroatom doping and structural optimization are efficient strategies. Herein, a single-atom-like B-N3 configuration in carbon is designed for efficient oxygen reduction reaction catalysis inspired by the extensively studied transition metal M-Nx sites, which is supported on the ordered macroporous carbon prepared by utilizing a hydrogen-bonded organic framework as carbon and nitrogen sources and SiO2 spheres as a template. The co-doping of B/N and ordered macroporous structures promote the metal-free material high oxygen reduction catalytic performance in alkaline media. DFT calculations reveal that the B-N3 structure played a key role in enhancing the oxygen reduction activity by providing rich favorable *OOH and *OH adsorption sites on the B center. The promoted formation of *OH/*OOH intermediates accelerated the electrocatalyst reaction. This study provides new insights into the design of single-atom-like nonmetallic ORR electrocatalysts and synthesis of ordered macroporous carbons based on hydrogen-bonded organic frameworks.

Keywords: heteroatom doping; hydrogen-bonded organic framework; metal-free electrocatalyst; ordered macroporous carbon; oxygen reduction reaction.