Fe, N-doped carbon spheres prepared by electrospinning method as high efficiency oxygen reduction catalyst.

Electrocatalysts for the oxygen reduction reaction (ORR) are crucial in metal-air batteries, fuel cells and other electrochemical devices. In this study, iron and nitrogen co-doped carbon sphere electrocatalysts were synthesized by electrospinning and thermal treatment. According to the results, the catalyst marked as Fe-N/MCS-181 (Fe, N-doped mesoporous carbon spheres, iron nitrate nonahydrate as the iron source) has not only the highest iron content, which reaches up to 0.13%, but also a spherical shape. And its pore sizes are 11 and 35 nm. For the electrochemical performance, the onset potential (E onset) of Fe-N/MCS-181 is -0.018 V, while the half-wave potential (E 1/2) of Fe-N/MCS-181 is -0.145 V, which is better than the commercial Pt/C catalyst (E 1/2 is -0.18 V). The durability of the Fe-N/MCS-181 catalyst is better than commercial Pt/C. After 10 000 s, the retention ratio of current density is 86.4%, while that of the commercial Pt/C catalyst is 84.2%. At the same time, the methanol tolerance of the Fe-N/MCS-181 catalyst is also excellent. After adding methanol, the current density of the Fe-N/MCS-181 catalyst has no obvious change. This study provides an easy method to fabricate a highly efficient and durable Fe, N-doped carbon catalyst for the oxygen reduction reaction.