Catalytic N-Formylation of CO₂ by Atomically Precise Au₈Pd₁(DPPF)₄ ²⁺ Clusters into a Two-Dimensional Metal-Organic...

By highly efficient ligand-exchange strategy, atomically precise Au₈Pd₁(PPh₃)₈ ²⁺ (PPh₃=triphenylphosphine) cluster can be transformed into a Au₈Pd₁(DPPF)₄ ²⁺ (DPPF=1,1'-bis(diphenylphosphino)ferrocene) cluster that can maintain the atomic-packing structure but overcome the lability of Au₈Pd₁(PPh₃)₈ ²⁺. Catalytic evaluation for the CO₂ hydrogenation coupled with o-phenylenediamine demonstrates that the Au₈Pd₁(DPPF)₄ ²⁺ catalyst can remarkably enhance both activity and stability compared to the Au₈Pd₁(PPh₃)₈ ²⁺ catalyst. More notably, the direct construction of a two-dimensional metal-organic framework (2D MOF) can be elaborately accomplished in the formylation process of o-phenylenediamine, CO₂ and H₂ with zinc nitrate enabled by the Au₈Pd₁(DPPF)₄ ²⁺ catalyst. The 2D MOF further enables the capture and transformation of CO₂ to combine in the organic synthesis with epoxides under mild conditions. This work provides opportunities for creating highly active cluster sites for the chemical recycling of CO₂.