Zirconium Oxide Modification of the Structure and Catalytic Properties of MnOxв€’Al2O3 in the Oxidation of CO
T. N. AFONASENKO1, O. A. BULAVCHENKO2,3, E. A. ANOSHKINA1, T. I. GULYAEVA1, I. G. TSYRULNIKOV1
1Institute of Hydrocarbons Processing, Siberian Branch of the Russian Academy of Sciences, Ul. Neftezаvodskаya 54, Omsk 644040 (Russia)
2Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Prospekt Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia)
3Novosibirsk State University, Ul. Pirogova 2, Novosibrisk 630090 (Russia)
Keywords: катализаторы MnO
-ZrO
-Al
O
, MnO
-Al
O
, окисление СО, catalysts MnO
-ZrO
-Al
O
, MnO
-Al
O
, oxidation of СО
Abstract
Effect of the addition of zirconium oxide on the structural and catalytic properties of MnOx−Al2O3 in CO oxidation was studied. It was established that the addition of zirconium oxide (5 and 10 mol. % calculated for the metal) into MnOx−Al2O3 stabilizes the structure of γ-Al2O3, preventing its transformation into corundum with an increase in annealing temperature, and promotes the formation of spinel Mn3-xAlxO4, which is not typical for the system MnOx−Al2O3 annealed in the air. At the same time, the tetragonal modification of ZrO2 gets stabilized at high Al2O3 content, which is characteristic of binary systems. Two maximal are observed on the curve of the dependence of catalytic activity of the system MnOx−ZrO2−Al2O3 on the temperature of preliminary annealing; these maxima are likely to be connected with structural transformations in the system with an increase in annealing temperature. The mutual effect of ZrO2 and Al2O3 in the system MnOx−ZrO2−Al2O3 leads to the shift of the maxima of catalytic activity to higher temperature region with respect to binary systems MnOx−ZrO2 and MnOx−Al2O3.
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