Catalyst systemas for the oxidation of phenol in water

Abstract

The oxidation of phenol solutions (5 g/L) has been studied in a semibatch autoclave reactor. Activity screening experiments were performed over two commercial catalysts: CuO+ZnO (Topsoe) and CuO+NiO (Engelhard), and CuO/Al2O3 prepared in our laboratory. Isothermal runs between 393 and 423 K were carried out under an oxygen pressure of 7 bar. Phenol conversion as well as pH and Chemical Oxygen Demand (COD) measurements were recorded. Almost complete phenol conversion was obtained for all catalysts. However, conversion to CO2 was only partial. Laboratory prepared catalysts gave the best performance in terms of activity and selectivity with the lowest induction period. Stability tests showed that catalysts remained moderately active after 60 h of operation. A simple kinetic model fits experimental results.