abstracts - Институт катализа им. Г.К. Борескова

PL-4KINETICS AND MECHANISM OF SELECTIVE CATALYTIC REDUCTION OFNO x WITH HYDROCARBONS UNDER LEAN CONDITIONSMurzin D.Yu.Åbo Akademi University, Turku/Åbo, FinlandE-mail: dmurzin@abo.fiLean-burn gasoline and direct injected common rail turbo charged diesel engines havesignificant fuel economy benefits compared to stoichiometric gasoline engines. However, the fullworldwide expansion of such engines is hindered by the difficulties in effective NO x andparticulate removal. In exhaust gas cleaning, the catalyst has to operate under highly transientconditions. A wide temperature range (100-600°C), presence of high amount of water (12 %), aneed for almost zero pressure drop simultaneously with extremely high flow rates (GHSV up to200 000 h -1 ) and ability to catalyse oxidation reactions and reduction of NO x under highlyoxidising conditions at the same time, are challenges hardly met in any other field of catalysis.Three major catalytic techniques are widely proposed and used for removal of NO xemissions from lean-burn and diesel operated vehicles: NO x -storage, urea- and hydrocarbons(HC) selective catalytic reduction (SCR). Each of these techniques have significantdisadvantages such as sulphur sensitiveness and regeneration requirements of NO x -storagematerials, infrastructure issues and formation of ammonium nitrate (at low temperatures) forurea-SCR and low temperature activity of HC-SCR catalysts. The presentation will focus onHC-SCR over Ag/alumina, which has been proven to be the most active and stable catalyst. Inparticular catalyst preparation, characterization, reaction mechanism and kinetics, importanceof gas-phase reactions as well as beneficial effect of hydrogen will be addressed [1-9]. Thegathered knowledge led to a cascade concept of exhaust pipes, which was confirmed in a fullscale vehicle verification test.References:1 K. Arve, K. Svennerberg, F. Klingstedt, K. Eränen, L. R Wallenberg, J.-O. Bovin,L. Čapek, D. Yu. Murzin, Journal of Physical Chemistry B (in press).2 K. Arve, F. Klingstedt, K. Eränen, L.-E.Lindfors, D.Yu. Murzin, Catalysis Letters, 2005,105, 133.3 K. Arve, F.Klingstedt, K.Eränen, J.Wärnå, L.-E.Lindfors, D.Yu.Murzin, ChemicalEngineering Journal, 2005, 107, 215.4 K. Arve, E.A.Popov, F. Klingstedt, K. Eränen, L.-E.Lindfors, J. Eloranta, D.Yu. Murzin,Catalysis Today, 2005, 100, 229.5 K. Arve, E.A.Popov, M. Rönnholm, F. Klingstedt, J. Eloranta, K. Eränen, D. Yu. Murzin,Chem. Eng. Science, 2004, 59, 5277.6 K. Eränen, L.-E.Lindfors, F. Klingstedt, D.Yu.Murzin, Journal of Catalysis, 2003, 219, 257 K. Arve, L. Capek, F. Klingstedt, K. Eränen. L.-E. Lindfors, D.Yu. Murzin, J. Dedecek,Z. Sobalik, B. Wichterlova, Topics in Catalysis , 2004, 30-31, 91.8 K. Eränen, F. Klingstedt, K. Arve, L.-E.Lindfors, D. Yu. Murzin, Journal of Catalysis,2004, 227, 328.9 L.-E. Lindfors, K. Eränen, F. Klingstedt, D.Yu. Murzin, Topics in Catalysis, 2004, 28, 185.14