One challenge for realizing high-efficiency electrocatalysts for CO₂ electroreduction is lacking in comprehensive understanding of potential-driven chemical state and dynamic atomic-configuration evolutions. Herein, by using a complementary combination of in situ/operando methods and employing copper single-atom electrocatalyst as a model system, we provide evidence on how the complex interplay among dynamic atomic-configuration, chemical state change and surface coulombic charging determines the resulting product profiles. We further demonstrate an informative indicator of atomic surface charge (φ_e) for evaluating the CO₂RR performance, and validate potential-driven dynamic low-coordinated Cu centers for performing significantly high selectivity and activity toward CO product over the well-known four N-coordinated counterparts. It indicates that the structural reconstruction only involved the dynamic breaking of Cu–N bond is partially reversible, whereas Cu–Cu bond formation is clearly irreversible. For all single-atom electrocatalysts (Cu, Fe and Co), the φ_e value for efficient CO production has been revealed closely correlated with the configuration transformation to generate dynamic low-coordinated configuration. A universal explication can be concluded that the dynamic low-coordinated configuration is the active form to efficiently catalyze CO₂-to-CO conversion.

_{实现CO 2}电还原高效电催化剂的一大挑战是缺乏对电势驱动的化学态和动态原子构型演化的全面理解。在此，通过使用原位/操作方法的互补组合并采用铜单原子电催化剂作为模型系统，我们提供了动态原子构型、化学状态变化和表面库仑充电之间复杂相互作用如何决定所得产物的证据配置文件。我们进一步展示了用于评估 CO _{2 RR 性能的原子表面电荷 (} φ _e )的信息指标，并验证了电势驱动的动态低配位 Cu 中心，与众所周知的四个 N 相比，对 CO 产物具有显着高的选择性和活性。 ——协调一致。这表明仅涉及Cu-N键动态断裂的结构重构是部分可逆的，而Cu-Cu键的形成显然是不可逆的。对于所有单原子电催化剂（Cu、Fe 和 Co），有效产生 CO 的φ _e值已被证明与生成动态低配位构型的构型转换密切相关。普遍的解释是动态低配位构型是有效催化CO ₂转化为CO的活性形式。