In situ investigation of hot-electron-induced Suzuki−Miyaura reaction by surface-enhanced Raman spectroscopy

The palladium-catalyzed Suzuki−Miyaura cross coupling reaction is one of the most useful methods for forming carbon—carbon bonds. In addition to traditional thermal activation, plasmonic photocatalysts can also promote this reaction under light illumination. However, it is still debated whether hot electron transfer or localized thermal heating is the main driving force of this reaction. Herein, we utilize in situ surface-enhanced Raman spectroscopy to characterize the Suzuki–Miyaura reaction on the surface of Au@Pd nanoparticles. We exclude the possibility that plasmon-induced heating drives the reaction, and we confirm the hot-electron mechanism by demonstrating a linear relationship between the reaction rate and laser power. Based on these results, we propose that the hot-electron transfer mechanism is the primary route for the plasmon-driven heterogeneous Suzuki−Miyaura cross coupling reaction. These results may help the rational design of photocatalysts.