Collect. Czech. Chem. Commun. 1990, 55, 1928-1934

Oxidation of carbon monoxide by oxygen over pure and platinum-doped LaMnO3 perovskites

Jaroslav Bartoň and Vladimír Pour

Institute of Inorganic Chemistry, Czechoslovak Academy of Sciences, 160 00 Prague 6


The properties of pure and platinum-doped LaMnO3 perovskites, including their catalytic activities for the reaction of CO with oxygen, have been determined. Perovskite samples were prepared by decomposition of lanthanum and manganese citrates. The surface areas were 12.2 m2/g for pure LaMnO3 and 9.8 m2/g for the platinum-doped sample. The doping with a small amount of platinum markedly enhances the catalytic activity of LaMnO3 perovskite. The (CO + O2) reaction starts at 200 °C over LaMnO3 and at temperatures below 100 °C over a sample doped with Pt. The reaction kinetics for both the pure and platinum-doped LaMnO3 can be described by empirical equation (4). When Pt-doped perovskite is used, an increase in the apparent activation energy occurs at about 150 °C. This fact is attributed to a change in the mechanism of CO oxidation.