Single-atom catalysts (SACs) have recently attracted broad research interest as they combine the merits of both homogeneous and heterogeneous catalysts. Rational design and synthesis of SACs are of immense significance but have so far been plagued by the lack of a definitive correlation between structure and catalytic properties. Here, we report a general approach to a series of monodispersed atomic transition metals (for example, Fe, Co, Ni) embedded in nitrogen-doped graphene with a common MN₄C₄ moiety, identified by systematic X-ray absorption fine structure analyses and direct transmission electron microscopy imaging. The unambiguous structure determination allows density functional theoretical prediction of MN₄C₄ moieties as efficient oxygen evolution catalysts with activities following the trend Ni > Co > Fe, which is confirmed by electrochemical measurements. Determination of atomistic structure and its correlation with catalytic properties represents a critical step towards the rational design and synthesis of precious or nonprecious SACs with exceptional atom utilization efficiency and catalytic activities.

单原子催化剂（SAC）最近结合了均相和非均相催化剂的优点，引起了广泛的研究兴趣。SAC的合理设计和合成意义重大，但迄今为止，由于结构和催化性能之间缺乏明确的相关性而困扰。在这里，我们报告了一种通过系统性X射线吸收精细结构分析确定的，嵌入具有常见MN ₄ C ₄部分的氮掺杂石墨烯中的一系列单分散原子过渡金属（例如，Fe，Co，Ni）的一般方法。和直接透射电子显微镜成像。明确的结构确定可实现MN ₄ C _4的密度泛函理论预测作为有效氧释放催化剂的部分，其活性遵循趋势Ni> Co> Fe，这已通过电化学测量得到证实。原子结构的确定及其与催化性能的关系代表了合理设计和合成具有卓越原子利用效率和催化活性的贵金属或非贵金属SAC的关键步骤。