Modeled Single-Atomic-Site Pt Catalyst with Well-Defined Coordination Structure for Hydrosilylation Reaction

Single-atom-site (SAS) catalysts exhibit superior activity in catalytic reactions, and their isolated active sites are anticipated to serve as an ideal platform for mechanistic investigations. However, the coordination environment of SAS catalyst synthesized via pyrolysis is challenging to control, and the active sites are randomly distributed, posing challenges for structure-activity relationship studies. Therefore, the development of model catalysts featuring well-defined coordination structures remains highly desirable but challenging. Herein, a Pt₁C₄₈H₆₁P₂Cl SAS catalyst is synthesized by an in situ reduction-assembly strategy, serving as a modeled Pt-SAS catalyst with a precisely defined coordination structure. The structure is confirmed as Pt-P₂C₁Cl₁ by single-crystal X-ray diffraction and X-ray absorption spectroscopy. Under solvent-free conditions, this catalyst achieves 98% conversion and >99% selectivity in anti-Markovnikov alkene hydrosilylation within 1 h and can exhibit good recyclability. Density functional theory (DFT) calculations revealed that the synthesized Pt-SAS catalyst exhibits a significantly reduced free energy barrier for the hydrosilylation reaction compared to the traditional Pt (111) surface, which can be attributed to weaker interactions during the oxidative addition step, enabling easier product desorption.