Two-in-one strategy to construct bifunctional oxygen electrocatalysts for rechargeable Zn-air battery

Integrating two different catalytic active sites into one composite is a useful 2-in-1 strategy for de-signing high-efficient bifunctional catalysts, which can easily tailor the activity of each reaction. Hence, we adopt the 2-in-1 strategy to design the metal oxyhydroxide supported on N-doped po-rous carbons (PA-CoFe@NPC) as the oxygen bifunctional catalyst, where NPC provides the activity for oxygen reduction reaction (ORR) while the metal oxyhydroxide is responsible for oxygen evolu-tion reaction (OER). Results demonstrate that the PA-CoFe@NPC indeed exhibits both super ORR and OER activities. Impressively, using bifunctional PA-CoFe@NPC as the oxygen electrode, the resulting Zn-air battery exhibits outstanding charge and discharge performance with the peak power density of 156.3 mW cm-2, and also exhibits a long-term cycle stability with continuous cyclic charge and discharge of 170 hours that is obviously better than the 20% Pt/C+IrO2based one. The 2-in-1 strategy in this work can be efficiently extended to design other bi-or multi-functional elec-trocatalysts.(c) 2022, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

Integrating two different catalytic active sites into one composite is an effective approach to design efficient bifunctional catalysts. In this study, the 2-in-1 strategy was adopted to design the PA-CoFe@NPC catalyst, which exhibited superior oxygen reduction and oxygen evolution activities. The resulting Zn-air battery showed outstanding charge and discharge performance and long-term cycle stability.