Bimetallic Mn/Cu Single-Atom Catalysts Derived from Natural Wood for High-Performance Rechargeable Zinc-Air Batteries

The escalating global energy demand has spurred advancements in zinc-air batteries (ZABs); however, their commercialization is still impeded by sluggish oxygen reaction kinetics and the expensive nature of precious metal catalysts. In this study, we report a simple approach for preparing bimetallic Mn/Cu single-atom catalysts anchored on nitrogen-doped carbon (MnCu–N–C), using natural wood as the precursor. The unique porous structure of wood-derived carbon supplies plentiful active sites and facilitates mass transport, and the synergistic interaction between Mn and Cu atoms boosts catalytic activity. The optimized MnCu–N–C demonstrates outstanding ORR performance, achieving a half-wave potential of 0.87 V, along with remarkable OER activity characterized by an overpotential of 1.44 V at a current density of 10 mA/cm2. When applied as a zinc-air battery cathode, it achieved an open-circuit voltage of 1.53 V, a peak power density of 168.1 mW/cm2, a specific capacity of 720.5 mA·h·g–1, and exceptional cycling durability exceeding 187.3 h, surpassing the performance of commercial Pt/C + RuO2 catalysts. This work demonstrates an effective approach for developing high-performance bifunctional oxygen electrocatalysts from sustainable biomass resources and provides new insights into the design of bimetallic single-atom catalysts.