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Stricter emission limitations for NOx and particulates in mobile diesel applications will require the combinations of active aftertreatment methods like Diesel Particulate Filters (DPF), Selective Catalytic Reduction (SCR) with urea and Lean NOx Trap (LNT) in the 2010's. A new concept is the combination of LNT+SCR, which enables on-board synthesis of ammonia (LNT), which is then removed on the SCR catalyst. The main application for this kind system will be light-duty vehicles, where LNTs are already used and the low temperature deNOx is a main target. That combinatory system was investigated by developing and selecting PtRh/LNT and SCR catalysts for that particulate application, where the maximum temperature may reach 800°C and SCR should proceed without NO2 assistance. Pt-rich, PtRh/LNT with reasonable high loadings above 80g/cft resulted in a high NOx efficiency in the experimental laboratory conditions which created also on LNTs a higher NH3 concentration for the SCR unit.

The use of biofuels in internal combustion engines changes the composition of the engine exhaust gas. When burning a biofuel blend, significant amounts of oxygenated hydrocarbons such as alcohols, ethers and aldehydes are present in the exhaust gas. It is known, that these compounds influence catalytic processes in exhaust gas converters. In this work we propose a global kinetic model for ethanol and acetaldehyde oxidation on commonly used Pt, PtPd and Pd-based catalytic oxidation converters of automobile exhaust gases. The mechanism is based on two steps: (i) partial oxidation of ethanol to acetaldehyde, and (ii) complete oxidation of acetaldehyde to CO₂ and H₂O. Kinetic parameters of ethanol and acetaldehyde reactions are evaluated on the basis of laboratory light-off experiments with several catalytic monolith samples (noble metal loading 9-140 g/cft; Pt, Pd, and PtPd; at space velocity 30 000-240 000 h-₁).

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.