Highly Efficient Hydrosilylation of Ethyne over Pt/ZrO₂ Catalysts with Size-Dependent Metal–Support Interactions

Abstract

Replacing homogeneous noble-metal catalysts with supported catalysts in hydrosilylation reactions can overcome the difficulties of catalyst recovery and regeneration. Here, we report the scalable synthesis of heterogeneous Pt/ZrO2 catalysts with 1–5 wt % Pt supported on commercial ZrO2 nanocrystals. Pt/ZrO2 can effectively catalyze the hydrosilylation of triethoxysilane (TES) with ethyne to high-value triethoxyvinylsilane, even superior to the common homogeneous catalyst (H2PtCl6). Intensive characterizations indicate that the coating of ZrO x on Pt greatly depends on the size of Pt, with more ZrO x overlayers on smaller Pt metal particles. Among all the catalysts, 2Pt/ZrO2 exhibits the highest activity, optimal selectivity, and reusability toward hydrosilylation of TES with ethyne. The unusual catalytic properties of 2Pt/ZrO2 can be attributed to its more abundant surface PtO x species and the electron transfer between Pt and ZrO2. This change in local electronic properties promotes catalytic activity, which is also supported by the corresponding theoretical calculation. This work advances the understanding of metal–support interactions and provides a powerful approach to designing environmentally friendly heterogeneous catalysts for the industrially important hydrosilylation process.

Thermodynamic Analysis of the Main Reactions Involved in the Synthesis of Organosilanes

“…Thermodynamics and kinetics are two main research aspects of chemical reactions. Regarding kinetics, the preparation and application of these organosilicon compounds have been intensively studied, with a focus on catalyst development. − The thermodynamic analysis of the system can determine the reaction equilibrium limits under various reaction conditions and how the reaction conditions affect the equilibrium, thus providing an important reference value for optimizing the reaction and developing the catalysts. However, there have been few studies on the thermodynamic analysis of organosilicon compounds.…”