Synergizing Single-Atom and Carbon-Encapsulated Nanoparticles of Fe for Efficient Oxygen Reduction and Durable Zn–Air Batteries
Wuyi Zhang, Chuangwei Liu, Anthony Kucernak, Hui Liu, Jun Wu, Song Li
Abstract
Overcoming the sluggish kinetics of the oxygen reduction reaction (ORR) remains a critical challenge for Zn–air batteries. Fe–N/C catalysts have emerged as promising alternatives to precious Pt-based materials. Herein, we report the design and synthesis of carbon-encapsulated Fe nanoparticles decorated Fe–N/C (denoted as Fe NPs @Fe–N/C) via controlled pyrolysis. The Fe NPs @Fe–N/C catalyst exhibits excellent ORR performance in alkaline media with a half-wave potential ( E 1/2 ) of 0.893 V RHE . The strategic integration of carbon-encapsulated Fe nanoparticles substantially improves the catalytic activity of Fe–N/C catalysts. The Fe NPs @Fe–N/C as the Zn–air battery cathode delivers an impressive peak power density of 175.7 mW cm –2 and excellent stability over 500 h, surpassing the Pt/C benchmarks. Density functional theory calculations reveal that the carbon-encapsulated Fe nanoparticles facilitate electron transfer to the catalytic site by modulating the d-band center, thereby boosting the ORR activity. This research paves the way for future design strategies integrating nanoparticles and single atoms for efficient electrocatalysis.