Construction of highly dispersed Pt single sites and high-efficiency-heterocatalysis silylation of alcohols with silanes

The construction of silicon–oxygen bonds has been highlighted as an exciting achievement in organosilicon and green chemistry, but their synthetic efficiency has great improvement potential, so it is crucial to explore and achieve an effective approach for synthesizing such compounds. In this study, we successfully prepared the highly dispersed platinum single-atom catalyst (Pt SAC/N-C) through a coordination-assisted strategy with a mixture of ligands (H₂bpdc and H₂bpydc), which were used for the O-silylation of alcohols with silanes. The strong coordination between Pt²⁺ and the Pyridine N at the skeleton of UiO-67 plays a critical role in accessing the atomically isolated dispersion of Pt sites. Without the assistance of the H₂bpydc ligands, the Pt/ UiO-67-bpdc precursor is prone to aggregation during the pyrolysis process, resulting in the formation of Pt nanoparticles. Aided by advanced characterization techniques of high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption fine structure (XAFS) spectroscopy, it has been demonstrated that atomically dispersed Pt was formed on the UiO-67 through a local structure of four-coordinated Pt-N₄, exhibiting a high actual Pt loading content (0.6962 wt.%). In the oxidation of silanes, the Pt SAC/N-C catalyst showed a high turnover frequency (TOF) value (up to 9,920 h⁻¹) when the catalyst loading decreased to 0.005%. Excellent performance was maintained during recycling experiments, indicating high stability of the catalyst.