STUDY ON HYDROXYLATION OF PHENOL FOR PRODUCTION OF DIHYDRIC PHENOL

The direct hydroxylation of phenol on catalyst by hydrogen peroxide to produce diphenol is a very competitively clean technology. In this paper, the hydroxylation of phenol on complex oxide catalyst was studied. The effects such as temperature, decomposition of hydrogen peroxide, feeding amount and feeding rate of hydrogen peroxide etc. on the reaction results were studied experimentally. The results showed that it is a rapid and strongly exothermal reaction and the reaction rate is controlled by the feeding rate of hydrogen peroxide. Hydrogen peroxide should be dropped during the reaction, and the optimal mass ratio of hydrogen peroxide to phenol is 0.35. The variation of temperature from 50℃ to 80℃ had no effect on the reaction. The catalyst had a induced reaction. The induction period could be reduced by initial addition of diphenol to the system.