Incorporation of catalytic compounds in the porosity of SiC wall flow filters 4 Way Catalyst and Deno{sub}x application

摘要

International standards, for exhaust gas composition produced by diesel engines, are becoming more and more severe. For European car industry, the Euro V standard, effective in September 2009 will result in dividing by 5 the present norm for the carbon particles (PM) level (from 25 to 5 mg/km) and by 2012, the NO{sub}x level will have to be divided by 4. So, it will be necessary to obtain a system that will combine oxidizing hydrocarbons and carbon monoxide, reducing NO{sub}x and particles. This challenge can be sorted out by impregnation of the particles filter with a catalyst. It must be taken into account that the system must be efficient and especially design for not using more diesel fuel. That means a product that must have the slightest counter-pressure. Different impregnation technologies have been approached (SC CO{sub}2 media, sol gel method, forced slurry…). CTI and IFP are working since years on several catalysts formulations and on efficient methods of impregnation in the heart of the particles filter. Impregnation examples with two DENO{sub}x catalysts and results obtained on motor bench with industrial sized particles filters will be explained.