Ceramics in Environmental Applications

ABSTUCT Environmental pollution by vehicles, turbines and aircrafts has enormously increased in the last decade. New generation lean-burn combustion engines which are more effective and q u i r e less fuel consumption will raise the emission of nitrogen oxides even more. Thus, especially in urban areas, more stringed environmental regulations are to release which can only be met by development of new catalytic materials and concepts. Rare earth oxide catalysts are reported to offer highly effective conversion of NO, by methane (Cfi) in the terms of selective catalytic reduction (HC-SCR). Especially La203 is reported to have a high NO reduction by CH, to N2, although its technid realhation as catalyst material has not yet reported and can be challenging due to the hydroscopic property of La103. Complex oxide compounds containing La203 however can be suitable alternatives and promising candidates for technical application aa catalysts. In this study, LaMnAlllOl9 is characterized in terms of HC-SCR with methane. Phase and morphological characterization of the powder synthesized by sol-gel route and coatings by electron-beam physical vapor deposition (EB-PVD) deposition was presented. LaMnAlliO19 crystallizes to the magnetoplumbite phase at about 1000°C and is then thermally stabile up to 1400°C. FTIR spectra of pressed sol-gel powder showed that NO is adsorbed superficially and oxidized by the surface. The addition of oxygen led to changes of the spectrum in the nitrite-nitrate region and the formation of NO' and NzO, species. The EB-PVD coated LaMnAlllOl~ layer was catalytically characterized at 200", 400" and 600 "C and showed catalytic activity towards NO depending on temperature.