Synthesis of N/Fe/S-Codoped Cathode Catalysts on Gasification Residue Carbon for Zinc–Air Batteries

The gasification fine slag (GFS) contains a large amount of residual carbon (RC). The RC has a large specific surface area, a well-developed pore structure, and a wide pore size distribution. Therefore, oxygen reduction reaction (ORR) catalysts can be prepared using the RC and can be applied in zinc–air batteries. In this work, ORR catalysts were prepared by using the RC as precursors with N/Fe/S codoping. The codoping effect between different heteroatoms was investigated by combining physicochemical and electrochemical characterization. The results demonstrate that the N/Fe/S-codoped catalyst CKN6FeS has a high onset potential and average electron transfer number. In alkaline conditions, CKN6FeS exhibits catalytic activity comparable to that of commercial Pt/C and shows better methanol tolerance than that of Pt/C. It shows good catalytic ability in zinc–air batteries with good cycling stability and durability, achieving high power density and specific capacity.