Kinetics study on catalytic wet air oxidation of phenol by several metal oxide catalysts.

Four metal oxide catalysts composed of copper (Cu), stannum(Sn), copper-stannum (Cu-Sn) and copper-cerium(Cu-Ce) respectively were prepared by the co-impregnation method, and gamma-alumina (gamma-Al2O3) is selected as support. A first-order kinetics model was established to study the catalytic wet air oxidation of phenol at different temperature when these catalysts were used. The model simulations are good agreement with present experimental data. Results showed that the reaction rate constants can be significantly increased when catalysts were used, and the catalyst of 6% Cu--10% Ce/gamma-Al2O3 showed the best catalytic activity. This is consistent with the result of catalytic wet air oxidation of phenol and the COD removal can be arrived at 98.2% at temperature 210 degrees C, oxygen partial pressure 3 MPa and reaction time 30 min. The activation energies of each reaction with different catalysts are nearly equal, which is found to beabout 42 kJ/mol and the reaction in this study is proved to be kinetics control.