(569ek) Ambient Photocatalysis: C-C Coupling of Terminal Alkynes with Hybrid Cu2O-Pd Nanostructures

Traditionally, Carbon-Carbon (C-C) coupling reactions relied on palladium (Pd) catalysts in homogeneous systems.^1,2 Now, attention shifts to heterogeneous photocatalysts featuring metal nanoparticles (e.g., Au, Ag, Cu) and their potent interaction with light, resulting in robust plasmonic field enhancement. However, plasmonic metal nanoparticles (PMNs) encounter challenges like thermal losses, limited charge carrier lifespan, and obstacles in large-scale production. In this context, we propose dielectric Mie resonator nanoparticles (MRNPs) like Cu₂O nanostructures as an alternative to PMNs.

In this study, we present hybridized Cu₂O photocatalysts integrated with catalytically active palladium (Pd) within Mie resonator nanoparticles (MRNPs), forming Cu₂O-Pd hybrids. We evaluated their efficacy through an oxidative homocoupling of phenylacetylene (PA) as the model reaction. Notably, we observed a ~22-fold increase in the reaction rate under visible light compared to dark conditions, conducted at ambient temperature and pressure in air. UV-Vis spectroscopy facilitated the characterization of reactants and products. Temperature measurements under light and dark conditions were employed to discern the influence of light on the reaction, excluding thermal-driven catalysis. We also elucidated the mechanistic pathways, aiming to develop a robust heterogeneous Cu-based photocatalyst for solar-chemical energy conversion. Furthermore, leveraging the optical properties of Cu₂O nanostructures, we aim to conduct photocatalytic coupling reactions under solar irradiation, fostering energy-efficient and environmentally sustainable flow processes. This comprehensive approach seeks to harness solar-chemical energy effectively and establish eco-friendly methodologies for catalytic transformations.

References

(1) Addanki Tirumala, R. T. et. al Green Chem. 2019, 21 (19), 5284–5290.

(2) F. Pary, F.; Tirumala, R. T. et.al. Catalysis Science & Technology 2021, 11 (7), 2414–2421.