Synthesis of ZIF-8 derived high-efficiency Fe-N-C catalyst and its oxygen reduction reaction performance

Abstract

To promote the large-scale commercial application of fuel cells， efficient， stable， and low-cost oxygen reduction reaction （ORR） catalysts should be developed. In this study， a Fe-doped ZIF-8 is used as the precursor， and the Fe-N-C non-precious metal catalyst is obtained by ball milling， calcination under a high-temperature argon atmosphere， pickling， and secondary calcination under an ammonia atmosphere. The results of various characterization methods show that Fe atoms are uniformly dispersed on the nitrogen-doped carbon framework， thus forming abundant Fe-Nx active sites. The electrochemical performance test results show that the Fe-N-C-5% catalyst with optimized preparation process and metal contents exhibits excellent ORR activity in 0.1 mol/L HClO4 acidic solution， with a half-wave potential of 0.845 V. Meantime， it has good stability， and the half-wave potential does not drop significantly after 20000 cycles. These results provide an effective strategy for the rational design of precious metal-free ORR catalysts in the future.