Melamine-assisted synthesis of atomically dispersed Fe sites anchored on crumple-rich carbon nanospheres as highly efficient electrocatalysts for oxygen reduction reaction

Fabrication of an advanced electrocatalyst for oxygen reduction reaction (ORR) is important for the commercialization of fuel cells. Herein, we report an ORR electrocatalyst with Fe atoms evenly distributed on crumple-rich nitrogen-doped carbon (N–C) nanospheres via a simple melamine-assisted pyrolysis strategy, where crumple-rich N–C nanospheres are prepared by a dual soft template approach. The as-obtained Fe–N-C-M electrocatalyst shows a better onset potential (1.02 V vs. RHE) and half-wave potential (0.883 V vs. RHE) in alkaline solution, superior to the commercial Pt/C (0.97 and 0.860 V vs. RHE, respectively). Moreover, the Fe–N-C-M also displays outstanding stability with 80.4% of relative current remained after a 10-h stability test at 0.8 V vs. RHE and remarkable methanol tolerance with 79.2% of relative current sustained after adding 3 M methanol, outperforming the commercial Pt/C (49.4% and 48.5%, respectively). All of these excellent properties are contributed to the unique crumple-rich structure, large specific surface area, and high content of Fe-Nx and pyridinic-N active centers.