Single-atom palladium anchored N-doped carbon towards oxygen electrocatalysis for rechargeable Zn-air batteries

Herein, an atomically dispersed palladium catalyst on a hierarchical porous structure of N-doped carbon (Pd-1/N-C) is prepared using a facile freeze-drying-assisted strategy. Freeze-drying methods not only suppress the aggregation of Pd atoms but also successfully produce abundant nanopores. HAADF-STEM confirms that Pd single atoms are uniformly anchored on the N-C surface. The Pd-1/N-C electrocatalyst enhances the ORR and OER activity and durability compared to N-C and Pd-NPs/N-C. Rechargeable Zn-air batteries (ZABs) based on novel Pd-1/N-C exhibit a peak power density of 113.7 mW cm(-2) and maintain a voltage efficiency of 64.0% after 495 cycles at a discharge current density of 5 mA cm(-2). Besides, two ZABs in series can supply an LED light for at least 170 h.

Automated summary

A catalytic material consisting of atomically dispersed palladium on a hierarchically porous structure of N-doped carbon has been prepared using a freeze-drying-assisted strategy. The material exhibits enhanced electrocatalytic activity for the oxygen reduction and oxygen evolution reactions, leading to improved performance in rechargeable zinc-air batteries.