Single-atom catalysts serve as a promising candidate to realize noble-metal-free electrocatalytic oxygen reduction in acid media. However, their poor stability under working conditions strictly restrains their practical applications. Therefore, regeneration of their electrocatalytic activity is of great significance. Herein, the regeneration of a Fe–N–C single-atom catalyst is demonstrated to be feasible by a facile annealing regeneration strategy. The activity after regeneration recovers to that of the pristine electrocatalyst and surpasses the deactivated electrocatalyst. The regeneration mechanism is identified to be self-etching of the surface carbon layer and consequent exposure of the previously buried single-atom sites. Furthermore, the regeneration strategy is applicable to other single-atom catalysts. This work demonstrates the feasibility of regenerating oxygen reduction electrocatalysts and affords a pioneering approach to deal with rapid deactivation under working conditions.

单原子催化剂是在酸性介质中实现无贵金属电催化氧还原的有希望的候选者。然而，它们在工作条件下较差的稳定性严格限制了它们的实际应用。因此，对其电催化活性的再生具有重要意义。在此，通过简便的退火再生策略证明了 Fe-N-C 单原子催化剂的再生是可行的。再生后的活性恢复到原始电催化剂的活性并超过失活的电催化剂。再生机制被确定为表面碳层的自蚀刻和随后暴露的先前掩埋的单原子位点。此外，再生策略适用于其他单原子催化剂。