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XP-SiC is an innovative type of a porous substrate material on the basis of a reaction formed SiC for DPF applications. The high porosity, large pore size inside the cell wall and low specific weight are the special characteristics of this substrate. The aim of the current paper is to present an investigation based on the experimental and modeling approaches to evaluate the back pressure, filtration efficiency and the thermal durability. The latter one was assessed by measuring and predicting the temperature field, as well as calculating the thermal stresses. For this purpose the filter was modeled in the commercial computational code axitrap as a stand-alone tool, in which the conservation equations of mass continuity, momentum, energy and species were solved. The soot filtrations, loading as well as the regeneration by fuel-borne catalyst were modeled.

Diesel particulate filters (DPF) are now a mandatory part in diesel exhaust aftertreatment systems in order to achieve compliance with current emission legislations. However future demands for further NOx and CO₂ reductions combined with a maximum amount of allowed particle numbers per ccm lead to special requirements for the DPF substrate material. On the one hand high filtration efficiency of soot particles in the nanometer scale has to be reached and on the other hand high porosities and large pore sizes have to be realized to support catalytic coating. In order to have a base material composition which can easily be modified to meet current and future demands a new SiC substrate, called XP-SiC, was developed. The technology of the XP-SiC is based on a reaction forming process of coextruded silicon and carbon particles to SiC. This new manufacturing process leads to a unique microstructure with a sponge-like appearance and a high porosity in the range of 50% - 70%.

The environmental impact of heavy-duty vehicles powered by natural gas is considered to be less harmful compared to Diesel vehicles. Consequently, the share of vehicles using either compressed natural gas (CNG) or liquified natural gas (LNG) is expected to increase in the coming years. Since most Euro VI compliant engines operate with stoichiometric air-fuel ratio, the aftertreatment system (ATS) requires efficient three-way catalyst. With ever increasing prices on platinum group metals (PGM) over the past few years, three-way catalysts products have been exposed to wild fluctuations in cost that have had great impact on their affordability. Given that stoichiometric operation is the most widely used calibration of heavy-duty natural gas engines, the trade-off between efficiency, calibration and PGM cost must be constantly reset.

The integration of DeNOx functionality into wall flow filters for the after treatment of diesel engine exhaust gases is a field of technology to which many publications in the recent years have drawn their attention. To integrate the needed amount of catalyst, high porous substrate materials have been developed. A drawback of the high porosity levels of 60% and higher is a significant reduction in mechanical strength. The aim of this work is to provide a new solution based on a high porous SiC material which is treated by a dual layer coating. The first layer is a nanoparticle coating which enhances the mechanical strength of the substrate. It can also be used to improve the catalytic performance and to finally decrease the loading of the second coating layer which is the active catalyst for selective catalytic reduction (SCR) of NOx with ammonia.