The influence of xMnyCe/γ-Al2O3 on NOx catalysts on the properties of NOx storage and reduction over Pt-Ce-Ba/γ-Al2O3 catalysts

The aim of the study was to investigate the influence of Diesel Oxidation Catalysts (DOC) xMnyCe/gamma-Al2O3 catalysts on the properties of NOx storage and reduction (NSR) under the treatment of Pt-Ce-Ba/gamma-Al2O3 catalysts. The physicochemical properties of DOC and NSR were determined with XRD, TEM and XPS. The results showed that Pt-CeO2 interaction had a great impact on the dispersion of the NSR catalyst. Furthermore, the performance of NO oxidation by DOC and NO, desorption by DOC/NSR combined system were evaluated based on the simulation experiments. Moreover, optimal operation of the single NSR catalyst and the DOC/NSR combined system were attained at 400 degrees C, while the durations of the lean and rich periods were t(L) = 240 s and t(R) = 30 s/45 s/60 s, respectively. The single NSR catalyst showed that the highest NO, conversion and maximum NO, adsorption conversion were 58.0% and 74.8%. The DOC/NSR combined system allowed Pt10 Ce15Ba/gamma-Al2O3 catalyst storing the NO2 oxidized on the 6MnlOCe/gamma-Al2O3 catalyst, favoring the NOx storage process during the lean phase. And it also allowed the stored NO, species of NSR catalysts desorbing due to H-2 oxidation by the 6Mn10Ce/gamma-Al2O3 catalyst, favoring the NOx desorption process during the rich phase. (C) 2017 Published by Elsevier B.V.