Abstract: Reasonable condition for electrolytic oxidation of Mn²⁺ to Mn³⁺ in a diaphragmless electrolytic cell using anodic and cathodic electrodes of Pb-Sb alloy are:5:1 area ratio of anode to cathode,5 mol/L of sulfuric acid,80 (mA/cm²) of anodic current density,1 mol/L of Mn²⁺,25-35℃ of temperature,1.20 of Coulomb ratio.Current (efficiency) is about 60%,and electrolytic yield is over 70% under the above condition.When the ratio of Mn³⁺ to (p-cymene) is about 4:1(molar ratio),selectivity of cuminaldehyde in the oxidized products is relatively high.Yields of main oxidized products,namely p-methyl acetophenone and cuminaldehyde are 55.19% and 31.64%,respectively.Suitable condition for oxidation of toluene by Mn³⁺ is that the ratio of Mn³⁺ to toluene is about 1:6(molar ratio).Yield of benzaldehyde is 73.67%.The electrolytic liquor can be repeatedly used over 8 times by regeneration after (extraction) by n-hexane and adsorption by activated carbon.

Key words: p-cymene, toluene, indirect electrolytic oxidation