Plasmonic oxidation of glycerol using AuPd/TiO₂ catalysts

AuPd nanoparticles supported on P25 TiO₂ (AuPd/TiO₂) were prepared by a facile sol-immobilisation method and investigated for surface plasmon-assisted glycerol oxidation under base-free conditions. The AuPd/TiO₂ samples were characterized by UV-vis spectroscopy and transmission electron microscopy. The sol-immobilisation method readily permitted the Au : Pd molar ratio to be changed over a wide range whilst keeping the mean particle size of the AuPd nanoparticles at 3 nm. Visible light irradiation during the reaction has a beneficial effect on the conversion of glycerol with the most marked effect being observed with gold-rich catalysts and the increase of conversion on light irradiation increases linearly with the gold content of the nanoparticles. The reaction selectivity is also affected by the plasmon-assisted oxidation and glycolic acid, not observed during the dark reactions, was observed for all illuminated reactions due to the enhanced activity of these catalysts.