Phenol synthesis by direct oxidation of benzene with molecular oxygen over supported metal salts

The direct oxidation of benzene to phenol over supported palladium (II) salt and rhodium (III) salt with various metal salts was investigated. The effective component as co-catalyst was VOCl2 for the PdCl2 or RhCl3 catalyst. The PdCl2-RhCl3 catalyst coupled VOCl2 resulted in a high selectivity to phenol, >97% and a high yield in acetic acid solvent under the condition of oxygen and carbon monoxide. An increase of acetic acid afforded a high activity, the oxidation rate depending on the concentration of acetic acid. The inspection of the molecular dynamics method reveals that the metal salt coordinated to Pd or Rh would modify the electric charge of Pd or Rh metal which is highly important for the catalytic activity.