Study of the interaction between Desoot and DeNOx activity over Ba- and K-based LNT catalysts

Regarding automotive emissions, the new stringent regulation limits (EURO6) are forcing to develop innovative catalytic systems that combine denitrification catalysts with catalytic filters. The DPNR (Diesel Particulate NOx Reduction) system, which involves the use of LNT catalysts, is the first commercialized example of such a technology. In previous works of our group the capability of model DPNR catalysts (e.g. Pt-Ba/Al2O3 and Pt-K/Al2O3) to simultaneously remove soot and NOx has been investigated. It has been found that an interplay exists between the NOx storage-reduction function of the catalyst and the soot oxidation. Accordingly aim of this work is to provide new insights on the interaction between soot and the stored NOx species; for this purpose temperature programmed methods were used.