Construction of Highly Active Metal‐Containing Nanoparticles and FeCo‐N₄ Composite Sites for the Acidic Oxygen Reduction Reaction

Abstract

Metal-containing nanoparticles (M-NPs) in metal/nitrogen-doped carbon (M-N-C) catalysts have been considered hostile to the acidic oxygen reduction reaction (ORR). The relation between M-NPs and the active sites of metal coordinated with nitrogen (MN_x ) is hard to establish in acid medium owing to the poor stability of M-NPs. Herein, we develop a strategy to successfully construct a new FeCo-N-C catalyst containing highly active M-NPs and MN₄ composite sites (M/FeCo-SAs-N-C). Enhanced catalytic activity and stability of M/FeCo-SAs-N-C is shown experimentally. Calculations reveal that there is a strong interaction between M-NPs and FeN₄ sites, which can favor ORR by activating the O-O bond, thus facilitating a direct 4 e^- process. Those findings firstly shed light on the highly active M-NPs and FeN₄ composite sites for catalyzing acid oxygen reduction reaction, and the relevant reaction mechanism is suggested.