Beitrag zur Entwicklung eines Niedertemperatur-Oxidationskatalysators für die Anwendung in Industriegasen mit LaCoO3 als Aktivphase

In this thesis the supported catalyst LaCoO3/ZrO2 is evaluated for CO Oxidation in industrial flue gases at low temperatures below 250 °C. Initially, the catalytic material is in powder form. Application oriented investigations require an immobilization of this ceramic powder. Therefore, various techniques are presented in princi-ple, out of which the washcoating technique is used to test coating porous TiO2 honeycombs. Possible deactivation mechanisms are discussed as well. Especially, a generally valid model for the capillary condensation of sulfuric acid solutions is developed. The model is based on the Kelvin equation and indicates a hindered condensation in pores smaller 2 µm due to the capillary curvature induced undercut of the vapor pressure. Additionally, thermogravimetric analyses and tests in a tube reactor are performed. They show partially a deactivation of LaCoO3 by SO2. Finally, based on the gained knowledge, suggestions for future research are presented.