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The LEV II and EURO V legislation in 2007/2008 require a high conversion level for nitrogen oxides to meet the emission levels for diesel SUVs and trucks. Therefore, U.S. and European truck manufacturers are considering the introduction of urea SCR systems no later than model year 2005. The current SCR catalysts are based mainly on systems derived from stationary power plant applications. Therefore, improved washcoat based monolith catalysts were developed using standard types of formulations. These catalysts achieved high conversion levels similar to extruded systems in passenger car and truck test cycles. However, to meet further tightening of standards, a new class of catalysts was developed. These advanced type of catalytic coatings proved to be equivalent or even better than standard washcoat formulations. Results will be shown from ESC, MVEG and US-FTP 75 tests to illustrate the progress in catalyst design for urea SCR.

It is well known that the catalytic efficiency and durability of an automotive catalytic converter can be significantly affected by its design. This paper demonstrates the potential for further improvement in both the durability and efficiency by using a novel catalytic converter concept based on a large frontal area, high cell density substrate. This concept requires that attention be paid to optimization of the flow as well as of the mounting system. The converter design is determined with a computational fluid dynamic (CFD) simulation and the effect of this design on the temperature distribution in the substrate is calculated and measured. Due to this novel converter concept the maximum substrate temperature is reduced, which results in a better aging behavior. This improvement allows a reduction in precious metal content without a loss in efficiency.

This paper will discuss a number of different matters relating to the regeneration of catalyst coated diesel particulate filters such as: impact of the catalyst on the soot ignition temperature, soot combustion rate and NO2 generation. If catalytic coatings prove to be sufficient compared to certain fuel additives they could be used in second generation diesel particulate aftertreatment systems. Examples will be shown on how catalytic diesel particulate filters (“DPF”) can operate on a common rail passenger car diesel engine. Furthermore, an outlook is given on the future combination of particulate - and NOx - emission control for diesel passenger cars.