Aerobic oxidation of benzyl alcohol on zinc oxide-supported gold nanostructures

Abstract This study focuses on the development of efficient catalysts for the selective oxidation of alcohols to high-value intermediates, including aldehydes, ketones, and carboxylic acids, which are key components in pharmaceuticals and fragrances. Gold nanoparticles (Au), especially when supported on ZnO, have shown exceptional catalytic performance in the aerobic oxidation of benzyl alcohol. Au/ZnO catalysts were synthesized via co-precipitation with Au loadings ranging from 0.1 to 7.0 wt%. Advanced characterization techniques, including x-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), reveals that smaller Au particles significantly enhance the Au/ZnO interactions, leading to superior catalytic activity. When optimized at 150 °C for 20 h, the catalyst achieved a remarkable benzaldehyde selectivity of 47.99% with single Au atoms, while larger particles decreased the selectivity. In addition, the performance and stability of ZnO were investigated in comparison to alternative supports such as CeO 2 and g-C 3 N 4 . This work provides novel insights into the critical role of particle size and interactions with the support and furthers the development of highly efficient oxidation catalysts.