The mechanism study on the catalytic synthesis of 2,6-dimethylphenol from KA-oil and methanol over magnesium oxide catalysts

Catalytic synthesis of 2,6-dimethylphenol from KA-oil (a mixture of cyclohe xanol and cyclohexanone) and methanol was achieved by using magnesium oxide -supported chromium oxide catalysts in one step. At higher conversion (> 90 %), dimethylphenol was formed in high yield (> 60 %). The activity of Cr/MgO catalysts depended on the concentration of chromium. The yield of 2,6-dimethylphenol was also affected by the composition of th e ratio of cyclohexanol to cyclohexanone in KA-oil. Cyclohexanol and cycloh exanone reacting with methanol under the same conditions indicated that pur e cyclohexanol or cyclohexanone is less reactive than their mixture, KA-oil . The adsorption properties of cyclohexanol and cyclohexanone on the surfac e of Cr/MgO determined by FT-IR spectroscopy suggest that cyclohexanone is easily reduced to cyclohexanol by the hydrogen which formed in the reaction , and then further reacted with methanol to form 2,6-dimethylphenol.