Density effect of Re1 electronic promoter on the activity of Pt1-catalyzed hydrosilylation

The development of noble-metal single atom catalysts (SACs) with low valence is highly required for many important chemical reactions such as alkene hydrosilylation, but proves to be very challenging. Herein, we report a facile strategy for the precise construction of low-valent Pt SACs by preparing 0.1Pt 1 x Re 1 /NiO with varying Re density and find that the activity of Pt-catalyzed hydrosilylation is strongly dependent on the density of Re promoters. Spectroscopic characterizations reveal the electron transfer process from Re promoters to Pt sites is facilitated by denser Re atoms, forming Pt species with less electron deficiency. During alkene hydrosilylation, Pt species modified by adjacent Re single atoms can lower energy barrier of key reduction elimination step. As a result, the 0.1Pt 1 5Re 1 /NiO SAC exhibits a TOF of 2.38 × 10 5 h -1 , a 12-fold improvement over that of pristine 0.1Pt 1 /NiO.