High performance Fe-N-C oxygen reduction electrocatalysts by solid-phase preparation of metal-organic frameworks

Abstract

Iron-nitrogen-carbon (Fe-N-C) compounds have been regarded as efficient and non-precious metal electrocatalysts for oxygen reduction reaction (ORR). The environmentally friendly preparation of Fe-N-C electrocatalysts is desirable but still challenging. Here, several Fe-N-C catalysts incorporated by ZIF-8 has been simply prepared by solid state reaction method. Fe-N-C containing 2% mole percentage Fe electrocatalysts fired at 900 °C exhibited superior intrinsic activities in oxygen saturated-0.1 M KOH for ORR with half wave potential of 0.831 V (versus RHE), comparable with Pt/C from JM (0.838 V). It also exhibited higher stability than those of Pt-C in alkaline condition. The higher intrinsic ORR activity and remarkable stability can be due to the more dispersed Fe-Nx active sites, which indicate that Fe-N-C by 2% mole percentage Fe electrocatalyst is an excellent alternative electrocatalyst for energy applications.