Role of Pt-precursor on the performance of Pt/BaCO3/Al2O3·NOx storage catalysts

Monolith Pt/BaCO3/Al2O3 NOx storage catalysts were prepared using one of the following platinum precursors for each catalyst: (i) hexachloroplatinic acid [H2Pt(Cl)6], (ii) tetraammineplatinum hydroxide [Pt(NH3)4(OH)2], (iii) diammineplatinum nitrite [Pt(NH3)2(NO2)2] and (iv) platinum nitrate [Pt(NO3)2]. The Pt dispersion is strongly affected by the interaction between the Pt complex and the BaCO3/γ-Al2O3 surface during the Pt impregnation.