Effect of temperature on the catalytic oxidation of CO over nano-sized iron oxide

Nanocrystallite iron oxide powders were prepared by co-precipitation method using highly purified FeCl3 and NH4OH solution. The prepared powders were tested for the catalytic oxidation of CO to CO2. The effect of oxidation temperature on the catalytic reaction was isothermally investigated using advanced quadrpole mass gas analyzer system. The mechanism of the catalytic oxidation reaction was estimated from the experimental data. Fe2O3 nanocrystallite of 78 nm shows a good response towards catalytic CO oxidation at the temperature range 200-500 degrees C. The catalytic oxidation efficiency reached 98% at 400-500 degrees C. The reaction was found to be first order with respect to CO. The average activation energy of the reaction was found to be 26.3 kJ/mol which is smaller than the values reported in the literatures. The mechanism of CO catalytic oxidation was investigated by comparing the CO catalytic oxidation data in the absence and presence of oxygen. It was found that the catalytic oxidation of CO over Fe2O3 nanocrystallite proceeded by adsorption mechanism. Based on the experimental results, Fe2O3 nanocrystallite powders can be recommended as a promising catalyst for CO oxidation. (c) 2006 Elsevier B.V. All rights reserved.