The efficient liquid‐phase oxidation of aromatic hydrocarbons by molecular oxygen in the presence of MnCO3

BACKGROUND: The liquid‐phase catalytic oxidation of aromatic hydrocarbons by molecular oxygen is a commercially important process. We consider the MnCO3‐promoted oxidation of toluene to produce benzaldehyde and benzoic acid. In this investigation, toluene was oxidized with 25.0% conversion and 80.8% selectivity with respect to benzoic acid in the presence of MnCO3 under 1.0 MPa of oxygen at 190 °C for 2 h. RESULTS: Moreover, the oxidation of other aromatic hydrocarbons, such as ethylbenzene, p‐xylene, m‐xylene, o‐xylene, and p‐chlorotoluene, were also efficiently promoted by MnCO3. CONCLUSION: It is concluded that an efficient oxidation of aromatic hydrocarbons can be achieved in the presence of MnCO3 under solvent‐free conditions. The catalytically active species are high‐valence Mn generated via the action of MnCO3 with oxygen.