The implementation of low-cost transition-metal complexes in CO₂ reduction reaction (CO₂RR) is hampered by poor mechanistic understanding. Herein, a carbon-supported copper bis-(terpyridine) complex enabling facile kilogram-scale production of the catalyst is developed. We directly observe an intriguing baton-relay-like mechanism of active sites transfer by employing a widely accessible operando Raman/Fourier-transform infrared spectroscopy analysis coupled with density functional theory computations. Our analyses reveal that the first protonation step involves Cu-N bond breakage before the *COOH intermediate forms exclusively at the central N site, followed by an N-to-Cu active site transfer. This unique active site transfer features energetically favorable *CO formation on Cu sites, low-barrier CO desorption and reversible catalyst regeneration, endowing the catalyst with a CO selectively of 99.5 %, 80 h stability, and a turn-over efficiency of 9.4 s⁻¹ at −0.6 V vs. the reversible hydrogen electrode in an H-type cell configuration. We expect that the approach and findings presented here may accelerate future mechanistic studies of next-generation CO₂RR electrocatalysts.

低成本过渡金属配合物在CO ₂还原反应（CO ₂RR) 受到机械理解不足的阻碍。在此，我们开发了一种碳负载的双（三联吡啶）铜络合物，能够轻松地进行公斤级催化剂的生产。我们通过采用可广泛使用的操作拉曼/傅里叶变换红外光谱分析结合密度泛函理论计算，直接观察到一种有趣的类似接力棒的活性位点转移机制。我们的分析表明，第一个质子化步骤涉及在 *COOH 中间体仅在中心 N 位点形成之前的 Cu-N 键断裂，然后是 N 到 Cu 的活性位点转移。这种独特的活性位点转移具有在 Cu 位点上形成有利的*CO、低阻隔 CO 解吸和可逆催化剂再生的特点，使催化剂具有 99.5% 的 CO 选择性和 80 小时稳定性，^{-0.6 V 时的-1}与 H 型电池配置中的可逆氢电极。我们期望这里介绍的方法和发现可能会加速下一代 CO ₂ RR 电催化剂的未来机理研究。