Nonthermal Charge Carriers Control Selectivity in Plasmon-Induced Suzuki–Miyaura Cross-Coupling Reaction on Spiked Au/Pd Nanowires

High Resolution Image Download MS PowerPoint Slide Palladium (Pd)-catalyzed reactions, such as the Suzuki–Miyaura cross-coupling, have demonstrated significant enhancement when facilitated by hybrid Au/Pd nanostructures. However, the role of gold, through charge transfer or localized heating, remains debated. Moreover, the impact of plasmon excitation on reaction selectivity remains largely unexplored. Herein, we report a facile, two-step, room-temperature synthesis of spiked Au/Pd nanowires for visible-light-driven Suzuki–Miyaura cross-coupling under ambient conditions. The reaction was monitored in situ using liquid-state surface-enhanced Raman spectroscopy (SERS) and ex situ using gas chromatography-mass spectrometry (GC-MS). We systematically studied the cross-coupling of 4-iodothiophenol with phenyl boronic acid under varying excitation wavelengths, laser intensities, external heating, and charge carrier scavengers, revealing the distinct role of non-thermal charge carriers in selectively promoting formation of the biaryl product. In the dark, a temperature of 85 °C was required to initiate the reaction, while thiophenol was observed as a major by-product. To further validate the plasmon-induced selectivity, we performed the reaction with 4-iodotoluene entirely in solution and monitored the products using GC-MS. Under light irradiation, cross-coupling was favored over the thermally driven reactions in the dark. This highlights the role of non-thermal charge carriers in enhancing the selectivity of Suzuki cross-coupling under plasmonic excitation.