Total Oxidation of Isopropanol in the Liquid Phase, under Atmospheric Pressure and Low Temperature, on Transition Metal Oxides Catalysts Cr2O3and Fe2O3

Abstract

Isopropanol oxidation in the liquid phase under atmospheric pressure and low temperature has been studied in the presence of transition metal oxides (Cr2O3 and Fe2O3) prepared by the precipitation method. These solids characterized by structural analyses (FTIR and XRD) and textural analysis (BET) have led to results in line with those reported in the literature. Chromium oxide has a much more developed texture, with a specific surface area and pore volume 5 times larger than iron oxide. Both of the solids show a good specific activity and led to acetone and carbon dioxide to be formed as the only oxidation products of isopropanol. However, chromium oxide is more active. The initial catalytic activity for the latter is varying between 4.87 ∗ 10-6 and 5.79 ∗ 10-6mol·g-1·s-1 with temperature range from 40 to 80°C. Kinetic study shows that the reaction follows a successive scheme: isopropanol → acetone → CO2 involving a redox mechanism. The low value of the activation apparent energy (Ea.(Cr2O3) = 2.87 kJ·mol-1 < Ea. (Fe2O3) = 5.37 kJ·mol-1) justifies the relatively higher activity observed for chromium oxide.