Atomically Precise Dinuclear Site Active toward Electrocatalytic CO2 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-2(dppm)(2)Cl-3 dinuclear-cluster-derived strategy to a uniform atomically precise Ni-2 site, consisting of two Ni-1-N-4 moieties shared with two nitrogen atoms, anchored on a N-doped carbon. By using operando synchrotron X-ray absorption spectroscopy, we identify the dynamically catalytic dinuclear Ni-2 structure under electrochemical CO2 reduction reaction, revealing an oxygen-bridge adsorption on the Ni-2-N-6 site to form an O-Ni-2-N-6 structure with enhanced Ni-Ni interaction. Theoretical simulations demonstrate that the key O-Ni-2-N-6 structure can significantly lower the energy barrier for CO2 activation. As a result, the dinuclear Ni2 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.

Automated summary

The study reports a novel strategy to develop atomically precise Ni-2 sites and demonstrates their efficient catalytic performance in the electrochemical CO2 reduction reaction. The key O-Ni-2-N-6 structure significantly lowers the energy barrier for CO2 activation, leading to enhanced CO production with >94% Faradaic efficiency. The findings provide insights into the synergy mechanism of dinuclear catalysts and offer a bottom-up synthesis approach for efficient catalytic reactions.