Highly efficient Fe-N-C oxygen reduction electrocatalyst engineered by sintering atmosphere

Fe-N and pyridinic-N generally are considered the active sites of Fe-N-C catalyst. In this featured work, small uniform Fe/N-rich polymer spheres are selected to prepare the Fe-N-C catalyst and study how the sintering atmosphere (NH 3 , Ar, and H 2 ) to engineer their products. The findings reveal that the sintering atmosphere greatly affected not only the composition , aggregate state, and morphology of Fe, but also the graphitization degree and pore structure of carbon. In addition, XPS results suggest that Fe-N-C-NH 3 possesses the highest Fe-N and pyridinic-N content. Combining its abundant pores, high graphitization, and large specific surface area, the catalyst obtained in NH 3 atmosphere delivers best ORR catalytic performance (E 0  = 0.97 V, E 1/2  = 0.85 V vs RHE), which is even comparable to commercial Pt/C (E 0  = 0.97 V, E 1/2  = 0.83V vs RHE). Moreover, the catalyst exhibits greater stability and methanol resistance than those of Pt/C.