Atomically Precise Dinuclear Site Active toward Electrocatalytic CO Reduction.

The development of atomically precise dinuclear heterogeneous catalysts is promising to achieve efficient catalytic performance and is also helpful to the atomic-level understanding on the synergy mechanism under reaction conditions. Here, we report a Ni(dppm)Cl dinuclear-cluster-derived strategy to a uniform atomically precise Ni site, consisting of two Ni-N moieties shared with two nitrogen atoms, anchored on a N-doped carbon. By using synchrotron X-ray absorption spectroscopy, we identify the dynamically catalytic dinuclear Ni structure under electrochemical CO reduction reaction, revealing an oxygen-bridge adsorption on the Ni-N site to form an O-Ni-N structure with enhanced Ni-Ni interaction. Theoretical simulations demonstrate that the key O-Ni-N structure can significantly lower the energy barrier for CO activation. As a result, the dinuclear Ni catalyst exhibits >94% Faradaic efficiency for efficient carbon monoxide production. This work provides bottom-up target synthesis approaches and evidences the identity of dinuclear sites active toward catalytic reactions.