Wood Carbon Based Single-Atom Catalyst for Rechargeable Zn–Air Batteries

Low-cost and efficient oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional electrocatalysts are vital for the applications of rechargeable Zn–air batteries (ZABs). Given the high catalytic activity of single-atom catalysts (SACs), preparing SACs on a large scale for ZABs is desirable but remains challenging. Herein, in situ formation of single-atom Fe–N–C catalysts on plate wood-based porous carbon is achieved via a facile Lewis acid pretreatment and carbonization process. Lewis acid FeCl₃ pretreatment on the cell wall of wood not only produces abundant microchannels but also successfully introduces atomically dispersed Fe–N active species into the hierarchical structure. Such uniformly dispersive SACs on the hierarchical structure enhance the ORR/OER performance and durability. A ZAB using the catalyst in the cathode shows a high power density (70.2 mW cm^–2, at quasi solid state) and long-term stability. This work provides a new path for the large-scale preparation of high-performance SACs.