Low-temperature iron-modified cobalt oxide system Part 2. Catalytic oxidation of phenol in aqueous phase

Liquid-phase oxidation using a solid catalyst provides a potential method for removal of dissolved toxic organic pollutants from waste waters. Low-temperature heterogeneous oxidation of phenol on a cobalt oxide system modified with Fe has been studied. The conversion of phenol into nontoxic compounds occurs in air-equilibrated aqueous media. The major hydroxylated aromatic intermediates have been identified by UV-VIS spectroscopy and HPLC: catechol, hydroquinone and hydroxyhydroquinone. An oxidation mechanism has been proposed based on the results of the kinetic investigations and on the data obtained by IR and UV spectroscopic studies of the sample. The results obtained show that the Co-Fe-oxide system is a promising catalyst for practical application. (C) 2001 Elsevier Science B.V. All rights reserved.