Single-atomic Fe sites decorated N-doped carbon toward oxygen reduction in MFCs†
Abstract
An atomically dispersed Fe–N–C catalyst has been synthesized and enables high power-out performance in microbial fuel cells (MFCs). The influence of Fe doping on the electronic properties of N-doped carbon was investigated, proving that single-atomic Fe sites embedded into N-doped carbon play a significant role in enhancing oxygen reduction reaction (ORR) performance in challenging neutral electrolyte. Density functional theory (DFT) studies indicate that a lower energy barrier for the limiting-potential step (*OH desorption) on Fe–N4 sites is favorable for the ORR process. This work offers new insights into the nature of Fe–N4 sites for the construction of highly active electrocatalysts for use in diverse energy conversion applications.