Photoinduced reactivity of Au–H intermediates in alcohol oxidation by gold nanoparticles supported on ceria

Abstract

H-Au-np/CeO₂ species, that are important intermediates in the alcohol oxidation by gold nanoparticles, show a photoinduced reactivity. UV-visible photoexcitation in deaerated conditions causes a hydride transfer from gold to the spin trap DMPO. The photoassisted breaking of the Au–H bond restores the catalyst in its active form. As a consequence, photochemical excitation has a positive effect on the catalytic oxidation of 2-pentanol under anaerobic conditions, demonstrating that light can be used in place of oxygen. This new photocatalytic activity of H-Au-np/CeO₂ species is of general interest in the field of catalysis with gold nanoparticles, since the photoinduced hydride shift from gold surface to organic substrates opens up exciting possibilities to use alcohols for hydrogenation reactions.