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Catalyst coated silicon carbide filters were developed and applied for light-duty and heavy-duty diesel applications. This catalyst coating is suitable also for industrial applications and to be used on cordierite or sintered metal filters. Development activities yield solgel type coating for particulate filters with properties allowing very thin coating, containing metal oxides interacting with active sites, e.g. precious metals (Pt, Pd). A tailored catalyst composition was developed for the catalytic activity and durability in oxidation and soot regeneration reactions. The combination of thermal and catalytic particulate oxidation by oxygen and NO2 was investigated using different regeneration strategies in engine exhaust and laboratory conditions. The passive regeneration by NO2 initiated around 310°C with CPF only. One of the main targets was to lengthen the intervals between active regeneration phases by catalyzed particulate filters which enhance passive regeneration properties.

As the Diesel Particulate Filter (DPF) technology is nowadays established, research is currently focusing on meeting the emission and durability requirements by proper system design. This paper focuses on the optimum combination between the catalytic coating and substrate structural properties using experimental and simulation methodologies. The application of these methodologies will be illustrated for the case of SiC substrates coated with innovative sol-gel coatings. Coated samples are characterized versus their uncoated counterparts. Multi-dimensional DOC and DPF simulation models are used to study several effects parametrically and increase our understanding on the governing phenomena. The comparative analysis of DOC/DPF systems covers filtration – pressure drop characteristics, CO/HC/NO oxidation performance, effect of washcoat amount and catalyst dispersion on oxidation activity and finally passive regeneration performance.

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.