Selective oxidation of alcohols to aldehydes/ketones over copper oxide-supported gold catalysts

Selective oxidation of alcohols to aldehydes/ketones with O2 over a series of supported gold catalysts was studied. The catalytic performance depends strongly on the support. It is also strongly influenced by the preparation method and the pH value and stirring rate during the co-precipitation process as a result of their effect on the structure of the support and the particle size and electronic state of gold. The Au/CuO co-precipitated at pH 10 and stirring rate 100 rpm showed high activity, selectivity, and stability. The reaction might occur via oxidative dehydroxylation of alcohols to aldehydes/ketones by direct β-CH elimination, as indicated by the IR result. The oxidation of different cycloalcohols showed that the activity increased with an increase in their methyl groups. Both conversion and ketone selectivity higher than 99% were achieved for cyclooctanol and cyclododecanol.

Selective oxidation of alcohols with O2 to aldehydes or ketones on supported Au catalyst was studied. The Au/CuO with appropriate-sized gold nanoparticles and cationic gold species shows high activity, selectivity and stability for a range of cyclic, benzylic, and unsaturated alcohols. The reaction probably occurred via an integrated oxidation mechanism.Figure optionsDownload high-quality image (179 K)Download as PowerPoint slideHighlights
► Au/CuO shows high activity, selectivity, and stability for the oxidation of alcohols with O2.
► Support structure and catalyst preparation process greatly influence the catalytic properties.
► Introduction of base or use of toluene solvent significantly increases the catalyst stability.
► The reaction occurs via an integrated oxidation mechanism involving lattice oxygen of CuO.