Uranyl-based heterogeneous catalyst for the selective oxidation of benzylic alcohols to form corresponding carbonyl compounds

Uranyl ions (OUO)2+ immobilized in mesoporous MCM-41 are found to serve as highly active heterogeneous catalyst for the formation of benzaldehyde in liquid-solid-phase oxidation of benzylic alcohols, using tert-butyl hydrogen peroxide (t-BuOOH) as an oxidant. The benzoic acid was formed on subsequent oxidation of benzaldehyde and therefore its yield increased with the increasing contact time. The solvent employed as a reaction medium influenced the catalyst activity considerably, and the best results were obtained using ethyl acetoacetate as the solvent. In the repeated cycles of activity measurements, fairly reproducible results were achieved after an initial decrease in the activity because of the partial leaching of uranyl ions.