LAUSR

High cost, low reserves and poor stability of the Pt-based catalysts have hindered their large-scale applications. To solve these problems, we develop an efficient method to fabricate a hybrid of Fe3C@N, S co-doped carbon nanotubes coated porous carbon as a superior catalyst towards ORR. The resulted Fe-N-S/C sample exhibits excellent performance in alkaline solution, with a half-wave potential of 0.89 V, which is 30 mV higher than that of commercial Pt/C. The electron transfer number is 3.9 at 0.4 V, indicating a direct four-electron (4e-) pathway towards ORR, and the kinetic current density Jk is 7.96 mA cm-2 at 0.88 V. After 5000 repeated potential cycling test, only 4 mV of down-shift in its half-wave potential was detected, which manifested the remarkable stability of Fe-N-S/C. The electrochemical performance is attributed to the ordered porous structure, high content of active N-species and the synergistic effect between Fe3C group and S dopants.