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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.

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.

One of the first alternative fuels have been fossil crude oil based containing a small amount of biomass derived compounds (bioethanol or biodiesel). Biofuels usually contain oxygenated hydrocarbons such as alcohols or esters. The increasing use of alternative fuels will occur at the same time when various after-treatment systems (oxidation catalysts, filters, SCR catalysts) will be commercialized world-widely between 2010 and 2020. The effects of biofuels on emissions and emission catalysts were reviewed widely in this study. The change in raw emissions has effects on the selection, performance and durability of catalytic systems. Bioethanol has been used widely with emission catalysts since 1990's in Brazil. The results with three-way catalysts (TWC) were analyzed in those conditions. PtRh catalysts showed the better performance and durability than Pd containing TWCs.

The emission regulations for mobile applications will become stricter in Euro 4 - 6 levels and require the use of active aftertreatment methods (deNOx and DPF) in addition to passively operating diesel oxidation catalysts (DOC). Vanadium-SCR (V-Selective Catalytic Reduction) catalysts based on stabilized TiO₂-WO₃ raw materials and tailored preparation methods were first evaluated by the laboratory experiments. Conventional V-SCR catalysts were durable up to about 600°C but the developed catalyst stand hydrothermal ageing up to 700°C without losses of activity. Simultaneously, the performance at 250 - 450°C was about the same as with the traditional V-SCR catalyst and the SCR selectivity at 450 - 600°C was high with a low NH₃ oxidation tendency. Coated V₂O₅/TiO₂-WO₃ catalysts (ceramic and metallic substrates) were evaluated with a 4.9 L engine by engine bench experiments.

Diesel engines are very popular in European passenger cars and their technology has been developed to have cleaner raw emissions and lower fuel consumption. Therefore the exhaust temperatures are extremely low in urban driving conditions. The current diesel European driving cycle (EDC) and diesel catalyst ageing in different positions (Preturbo, CC and UF) were simulated successfully according to diesel light-duty exhaust gas conditions with laboratory equipment. A small mixer type EcoXcell structure was used in Preturbo position with high Pt loading to enhance in particular CO and hydrocarbon oxidations. The small metal substrated pre and larger main catalyst with active, zeolite containing washcoat were developed to decrease emissions. Both experimental and calculation simulations gave a prediction for grams per kilometer emissions for a single or combined catalyst system. The reaction and ageing rate based design can be used to optimize the diesel aftertreatment system.