The M–N–C catalysts are considered potential alternative to Pt-based catalysts for the oxygen reduction reaction (ORR) due to its low cost and promising electrocatalytic performance. However, the catalysts are yet to become truly applicable in terms of activity and stability, and addressing such issues necessitate for indepth understanding in the structure performance relationship, which is remain elusive to date. Herein, we summarize our research progress achieved on M–N–C catalysts in recent years. Firstly, we successfully synthesized atomically dispersed Fe–N–C catalysts and conducted a detailed in-situ spectroscopy study, where the high spin D₂ states of FeN₄ is found to be an active species. Subsequently, in order to address the catalyst utilization and the overall activity of the catalysts, we carried out studies in increasing the active site density through regulating the microstructure of the catalysts. Finally and most importantly, in order to address the intrinsic activity of the catalysts, we carried work in developing new active centers of the M–N–C catalysts, where the new single or dual center catalysts were developed. Some of these centers are able to increase the stability of the catalysts, where the Fenton reaction is largely alleviated, resulting in both enhanced catalytic activity and stability. We hope that as the research continues, commercially available high performance and high stability M–N–C catalysts may eventually be realized.

M-N-C 催化剂由于其低成本和良好的电催化性能而被认为是用于氧还原反应 (ORR) 的 Pt 基催化剂的潜在替代品。然而，这些催化剂在活性和稳定性方面还没有真正适用，解决这些问题需要深入理解结构性能关系，这迄今为止仍然难以捉摸。在此，我们总结了近年来我们在 M-N-C 催化剂上取得的研究进展。首先，我们成功合成了原子分散的 Fe-N-C 催化剂，并进行了详细的原位光谱研究，其中FeN ₄的高自旋 D ₂态被发现是一个活跃的物种。随后，为了解决催化剂的利用率和催化剂的整体活性，我们进行了通过调节催化剂的微观结构来增加活性位点密度的研究。最后也是最重要的是，为了解决催化剂的内在活性，我们致力于开发 M-N-C 催化剂的新活性中心，其中开发了新的单中心或双中心催化剂。这些中心中的一些能够提高催化剂的稳定性，其中芬顿反应大大减轻，从而提高了催化活性和稳定性。我们希望随着研究的继续，最终可以实现商用的高性能和高稳定性 M-N-C 催化剂。