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NOx storage and reduction (NSR) catalysts are a widely investigated solution for lean gasoline applications. Open coating on metallic substrates gives a new opportunity to combine low and high temperature NSR catalysts into a converter by using differentiated chemistry on separate foils. A wide operation window for NOx conversion between 200-600°C was reached with alumina based NSR catalyst in appropriate conditions. Differentiation on separate foils can be made by NOx adsorption compounds, active metals (Pt, Rh), exhaust gas conditions or desulfation strategy. The desulfation, particularly from potassium-containing high temperature NSR catalysts, was decreased by 100°C by the addition of a small amount of TiO2. The combination of 3-way and NSR catalyst was designed by the size and lean-rich timings in laboratory and engine conditions. Low OSC PdRh (7:1) catalysts with higher loadings were used as 3-way catalysts.

The emission limitations for heavy-duty vehicles are coming stricter between 2005 - 2008 in Europe, Japan and United States. In addition to engine, fuel and control modifications, efficient exhaust gas after treatments like oxidation/deNOx catalysts and particulate filters are needed. In mobile truck applications the system should operate at low (<300°C) and stand high temperatures (500-650°C) in transient driving conditions. Coated V2O5/TiO2-WO3 based SCR catalysts on thin metal foil substrates have been studied here in laboratory and engine experiments. The open-coating method enables the high volumetric amount of SCR catalyst evenly coated on high cell density substrates (e.g. 600 cpsi). A new washcoat composition with platinum loading has been used in pre-oxidation catalyst to reach the NO2 concentrations, which initiate the SCR reaction clearly below 300°C.