Electrocatalytic Performance of Fe–N Encapsulated\nin Hollowly Mesoporous Carbon Microspheres for Oxygen Reduction Reaction\nand Zn–Air Battery

Abstract

Isolated\nsingle-atom catalysts have attracted tremendous attention\nfor their maximized atom utilization efficiency. However, the rational\ndesign of an economical and efficient single-atom catalyst is still\nconfronted with great challenges. In this work, hollow carbon microspheres\nwere constructed by an in situ template method to facilitate the anchoring\nof iron atoms and optimal porous structure with mesopores centered\nat around 2–10 nm. The catalyst with the single-atom Fe dispersed\non extremely stable hollow carbon microspheres exhibited a better <i>E</i>_on (0.98 V) and <i>E</i>_1/2 (0.86 V) than Pt/C in 0.1 M KOH. It also displayed superior long-term\ndurability and an outstanding methanol resistance compared with 20%\nPt/C. Meanwhile, the Zn–air battery using the as-obtained catalyst\nas an oxygen electrocatalyst on an air cathode exhibited superior\nperformance and prolonged operation durability than Pt/C. This design\nstrategy highlighted the tremendous potential of a Fe-based single-atom\ncatalyst for ORR and provided an alternative way for synthesizing\nother single-atom catalysts with excellent properties suitable for\na variety of applications.