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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.

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.