Monolithic filters based on sepiolite for the post-treatment of diesel engine exhausts

FERNANDO E. TULER; C. FERNANDEZ CABALLERO; R. PORTELA; P. AVILA; EDUARDO E. MIRÓ; V. G. MILT

San Sebastián

Congreso; ICOSCAR5; 2016

Most commercialized wall-flow monolithic filters are made of silicon carbide or cordierite andpresent high porosity, but low surface area. Alternatively, wall-flow monoliths with high surface areacan be employed as support for catalytically active phases. This approach is used in the present workwith the aim of developing catalytic ceramic filters to trap soot particles and remove NOx from dieselengine exhausts. Catalytic diesel particulate wall-flow filters force the exhaust gases to flow throughthe monolith walls, so that soot particles are trapped and in contact with the catalyst, they are burnt(passive regeneration) [1]. Sepiolite was used as catalytic support to prepare the structured catalyticfilter based on Co-Ba-K. The active elements were employed for the passive regeneration of the filterand the Pore Generating Agent (PGA) was added to tune the volume and size of macro-pores to allowexhaust gases to flow through the wall. The channel ends of the honeycomb monoliths obtained byextrusion were alternatively plugged, using different materials for this purpose, to obtain wall-flowfilters.