Since May 2000, PSA Peugeot Citroën has commercialized a wide range of diesel vehicles of different sizes (Peugeot 807, 607, 406 and 307; Citroën C8 and C5) equipped with a Diesel Particulate Filter (DPF) system using a Ceria-based Fuel-Borne Catalyst (FBC). More than 250000 vehicles have been sold in Europe. Based on extensive in-service feedback, an opportunity to further improve and optimize the technology was identified which will facilitate its extension to smaller passenger vehicles.
The use of a more active FBC was identified as one of the key areas for improvement: with increased catalytic activity the FBC dosing rate is reduced and thus the rate of ash-build up in the DPF is limited. This could significantly extend the DPF interval maintenance.
A new Ceria-based FBC (Ce-FBC) has been developed which demonstrates enhanced catalytic activity with limited exothermal peaks during DPF regeneration. This property is essential in preventing mechanical failure of the DPF. Furthermore the application of this new Ce-FBC did not imply any significant modification of the existing DPF system.
This paper describes the development of the new Ce-FBC and the associated DPF system from the initial R&D phase through to European certifications with particular emphasis on: adaptation of the DPF management system to the higher activity Ce-FBC; European certification of the Ce-FBC in association with the SiC-based DPF (VERT Filter Test, VERT Secondary Emission Test); ash accumulation over 90000km; raw engine-out emissions analysis (both regulated and unregulated) over the European MVEG cycle.
The improved performance of the DPF system clearly demonstrates the attractiveness of fuel-borne catalyst technology for DPF regeneration in series applications.