Preparation of phenol from benzene by one-step reaction

The direct gas-phase oxidation of benzene to phenol with a mixture of oxygen-ammonia-water vapors was studied over mixed calcium-copper-hydroxyapatite catalysts. The effect of various reaction parameters on the transformation of benzene to phenol was tested. About 3% conversion of benzene and 97% phenol selectivity was achieved at atmospheric pressure and the temperature of 450 degreesC in the first 3 h of reaction, when deactivation of the catalyst was not so significant. However, after this period the deactivation of the catalyst was pronounced and probably caused by destruction of an active hydroxyapatite structure of the catalyst. (C) 2003 Elsevier B.V. All rights reserved.