Micropore-induced high-performance Fe–Nx/C electrocatalysts towards the oxygen reduction reaction†
Abstract
Fe–Nx moieties modified carbons (Fe–Nx/C) have been considered to be a promising substitute for Pt/C to electrocatalyze the oxygen reduction reaction (ORR). Alongside directly tuning the Fe–Nx active sites, developing carbon supports is one of the efficient ways to improve the ORR activity and stability by increasing the number of sites and ameliorating the site environment. In this work, a Fe–Nx modified microporous carbon (Fe–N–MC) has been successfully synthesized by low-temperature thermal treatment of microporous carbon (MC) adsorbed Fe phthalocyanine. Owing to a high defect exposure and numerous micropores, MC provides an appropriate environment for the favorable incorporation of Fe–Nx moieties into carbon matrixes, resulting in a superior ORR activity of Fe–N–MC (onset potential of 0.97 V and half-wave potential of 0.90 V) to commercial Pt/C and the Fe–Nx modified commercial nanocarbons (carbon black and carbon nanotubes). Moreover, the good electrochemical performance of Fe–N–MC in scale-up production also ensures practical and economic feasibility for further commercial applications.