Diatomic Nitrogen‐Coordinated Metal‐Doping Carbon for Oxygen Reduction: A Focus on Structure and Active Site

Abstract Diatomic nitrogen‐coordinated metal‐doping carbon (M‐NC) electrocatalysts are marked by rearranged electronic structures and modified active sites, which are a hot frontier of oxygen reduction reaction (ORR). However, precisely prefabricating stable structures and revealing catalytic centers of diatomic M‐NC are arduous tasks. In this review, a series of synthetic strategies are outlined, including MOFs and coordination carbon precursors. The significance of metal precursors is also clarified based on controlling a well‐defined structure. Subsequently, various structural characterization methods to confirm diatomic dispersion and fine structure are elaborated, emphasizing on aberration‐corrected electron microscope technique and X‐ray absorption spectroscopy (XAFS) analysis. The poisoning experiments and in situ testing techniques with dynamic monitoring to reveal catalytic active center are discussed. Finally, a summary and several reflections in the development of diatomic M‐NC are addressed. This review aims to provide valuable guidance for the preliminary exploration of enhanced diatomic catalysts.