Selective alcohol oxidation to aldehydes and ketones over base-promoted gold–palladium clusters as recyclable quasihomogeneous and heterogeneous metal catalysts

Bimetallic gold–palladium clusters, with an average size of 1.9 nm and composed of 80 mol% gold, proved to be highly active and selective metal catalysts for the organic phase oxidation with O2 of aliphatic, allylic and benzylic alcohols to the corresponding carbonyl products. Polyvinylpyrrolidone stabilized gold–palladium clusters dispersed in N,N-dimethylformamide emerged as promising quasihomogeneous metal catalysts for the oxidation of benzyl alcohol to benzaldehyde with full selectivity; they could be efficiently recycled with unaffected catalytic performance by solvent-resistant nanofiltration. Highly active and durable heterogeneous catalysts for the amide phase or solvent-free alcohol oxidation were prepared by the quantitative immobilization of the optimized gold–palladium clusters on the high surface area basic BaAl2O4 spinel support with preservation of the bimetallic clusters’ nanodispersion.

Bimetallic gold–palladium clusters, with an average size of 1.9 nm and composed of 80 mol% gold, proved to be active, selective and durable metal catalysts for the oxidation with O2 of aliphatic, allylic and benzylic alcohols to the corresponding aldehydes and ketones, both as such as quasihomogeneous catalysts applied in DMF and as heterogeneous catalysts after immobilization on a basic high surface area BaAl2O4 spinel support for use in solvent-free conditions.Figure optionsDownload as PowerPoint slide