Visible-Light-Driven Photocatalytic Carbon–Carbon Coupling Reaction under Atmospheric Temperature and Pressure Conditions Using Hybrid Cu₂O–Pd Nanostructures

Metal-catalyzed carbon-carbon (C-C) coupling reactions are important in the chemical industry. These reactions are conventionally carried out through fossil-fuel-derived heat-driven high-temperature catalytic processes. In this contribution, we report that Pd nanoclusters decorated on the surface of quasi-spherical Cu₂O (i.e., Cu₂O-Pd) nanoparticles can successfully photocatalyze the C-C coupling reaction under ambient temperature and pressure conditions. Oxidative C-C homocoupling of phenylacetylene into diphenyl diacetylene is used as the probe reaction. Based on our results from transient reflection, density functional theory calculations, and photoreactor studies, we propose that the photocatalytic mechanism involves photon-excited electron transfer from Cu₂O into Pd nanoclusters and the subsequent activation of the phenylacetylene molecules by these excited electrons in the Pd nanoclusters. The visible-light-driven photocatalytic C-C coupling approach demonstrated herein can decarbonize C-C coupling processes in the chemical industry since the visible light input can be supplied from renewable energy resources.