Single-Atom-like\nB‑N₃ Sites in Ordered\nMacroporous Carbon for Efficient Oxygen Reduction Reaction

Abstract

On\nthe premise of cleanliness and stability, improving the catalytic\nefficiency for the oxygen reduction reaction in the electrode reaction\nof fuel cells and metal-air batteries is of vital importance. Studies\nhave shown that heteroatom doping and structural optimization are\nefficient strategies. Herein, a single-atom-like B-N₃ configuration\nin carbon is designed for efficient oxygen reduction reaction catalysis\ninspired by the extensively studied transition metal M-N_<i>x</i> sites, which is supported on the ordered macroporous\ncarbon prepared by utilizing a hydrogen-bonded organic framework as\ncarbon and nitrogen sources and SiO₂ spheres as a template.\nThe co-doping of B/N and ordered macroporous structures promote the\nmetal-free material high oxygen reduction catalytic performance in\nalkaline media. DFT calculations reveal that the B-N₃ structure\nplayed a key role in enhancing the oxygen reduction activity by providing\nrich favorable *OOH and *OH adsorption sites on the B center. The\npromoted formation of *OH/*OOH intermediates accelerated the electrocatalyst\nreaction. This study provides new insights into the design of single-atom-like\nnonmetallic ORR electrocatalysts and synthesis of ordered macroporous\ncarbons based on hydrogen-bonded organic frameworks.