Atomically Dispersed Metal-Nitrogen-Carbon Catalysts for Oxygen Reduction Reaction: From Heteroatom Coordination Engineering to Stability Enhancement Strategies

Abstract

Atomically dispersed metal−nitrogen−carbon (M−N−C) catalysts have emerged as promising alternatives to platinum-based catalysts for the oxygen reduction reaction (ORR). However, comprehensive and systematic reviews focusing on activity-enhancement engineering and stability-improvement strategies remain scarce, leading to an ambiguous understanding of the structure-activity-stability relationship. Therefore, this review systematically summarizes heteroatom doping engineering, and stability enhancement strategies, aiming to offering new insights to break the activity-stability trade-off. Firstly, the regulation mechanisms of heteroatom doping strategies on the electronic structure of active centers and ORR performance are discussed in depth. Specifically, this review encompasses the electronic modulation of the central metal via first coordination shell engineering, the structural optimization of the carbon support through second-shell doping, and the synergistic catalytic effects derived from multiheteroatom codoping. Then, the deactivation mechanisms of M–N–C catalysts are summarized, along with corresponding strategies for stability enhancement. Finally, future research directions for atomically dispersed M–N–C catalysts are proposed.