Partial Oxidation of Toluene in CH3COOH by H2O2 in the Presence of VO (acac)2 Catalyst

The partial oxidation of toluene by hydrogen peroxide with catalytic amount of bis (acetylacetonato) oxovanadium (VO(acac)2) in acetic acid is studied in detail. Benzaldehyde is found to be the main product in the reaction, and V51NMR and ESI-MS are used to detect the possible intermediate species. The effect of reaction parameters, such as the amounts of catalyst and hydrogen peroxide used, the reaction temperature, and reaction time on the reaction are investigated. The mechanism of toluene partial oxidation is also studied, and the hydroxyl radical is found to be the key active species. The solvent acetic acid coordinates with vanadium atom, and the toluene partial oxidation passes through cage reaction to form the C6H5CH·(OOH) radical, which promptly decomposes to benzaldehyde and hydroxyl radical. C6H6CH2OOCH2C6H6 is also found to be one possible intermediate.