Cu,N-doped biomass carbon catalyst enhanced oxygen reduction reaction and zinc-air battery performance

The oxygen reduction reaction (ORR) is a fundamental electrochemical process that plays a crucial role in fuel cells and zinc-air batteries. Currently, platinum (Pt) based materials are the most commonly used ORR catalysts; however, the scarcity and high cost of Pt significantly limits the large-scale commercialization of fuel cells. In recent years, biomass-derived catalysts have emerged as promising candidates. In this study, Cu- and N-doped layered biomass-derived carbon materials (Cu–N–C) were synthesized through a hydrothermal method followed by high-temperature pyrolysis. Three types of biomass-derived carbon catalysts (Cu–N–C-x) were prepared by varying the amount of Cu precursor. Among these, the Cu–N–C-0.8 catalyst exhibited the highest onset potential (0.886 V) and half-wave potential (0.786 V) in alkaline solution. The calculated electron transfer number of 3.96 indicates a dominant four-electron ORR pathway. Furthermore, the catalyst demonstrated excellent stability and strong methanol tolerance. When employed as the cathode in a zinc-air battery, the Cu–N–C-0.8 catalyst achieved a maximum power density of 254.5 mW m −2 . The superior ORR activity and zinc-air cell performance of the Cu–N–C-0.8 catalyst can be attributed to the synergistic effect of Cu and N co-doping and the unique folded layered surface structure. This synthesis strategy not only enables scalable production but also offers a sustainable approach to utilizing biomass waste, thereby reducing environmental pollution.