Mn-BASED CATALYSTS FOR LOW TEMPERATURE SCR OF NOx IN MARINE DIESEL APPLICATION

MnO x -based catalysts supported at different loadings on TiO 2 (2-10 wt%) and H-ZM5 (2-20wt%) were tested for the NH 3 -SCR of NO in the temperature range 50-250°C. All catalysts showed enhanced activity at low temperature compared to traditional SCR catalyst. A detailed characterization of catalysts (ICP-MS, BET, H 2 -TPR, NH 3 - and O 2 -TPD) revealed the predominance of MnO 2 , with an enhanced dispersion when supported on TiO 2 . SCR activity correlated with a good oxygen lability which in turn increased for highly dispersed MnOx. The poisoning effects deriving from a hypothetical Sea Water Scrubber Desulphurization unit placed upstream of the SCR unit were investigated by ex-situ addition of KCl to the catalysts.