Aerobic oxidation of alcohols using ruthenium supported on DD3 kaolin.

Supported ruthenium nanoparticles were prepared through the chemical reduction of aqueous Ru(III) species previously loaded (1 or 5 wt%) onto DD3 kaolin through an ion-exchanged pathway. Resulting nanoporous materials were characterized by XRF, XRD, TEM, EDX, and N2 sorption measurements, and then used as catalysts in the liquid phase aerobic oxidation of benzyl alcohol. Benzaldehyde was obtained as the main product with a 97% yield at 100% alcohol conversion at 100 °C in the presence of Ru-DD3 (5%) using 10 mL/min O2 flow and 10 mol% of tert-butyl hydroperoxide with respect to the substrate. Oxidation tests were more efficient in the case of Ru-DD3 (5%) than with other Ru-based solids such as Ru-HZSM-5 (5%). It was also shown that, in the presence of Ru-DD3 (5%), the aerobic oxidation of benylalcohol in the presence of an amine (aniline) gives rise to the imine instead of the aldehyde through a one-pot oxidation and condensation process. [ABSTRACT FROM AUTHOR]