Abstrait

Removal of NOx in the presence of oxygen over Mn/BaO/Al2O3 catalysts.

Nguyen Le-Phuc*

In this study, the influence of Mn content on the NOx decomposition in the presence of oxygen over xMn/BaO/Al2O3 catalysts (x is molar ratio of Mn/Ba) was investigated. Samples were characterized by N2 adsorption, XRD and SEM-EDX. The Mn loading, the dispersion of Ba on the surface and the BET surface area are the key factors affecting the NOx removal activity of the catalysts. The maximum conversion of NOx was obtained with 0.5 MnBa/Al sample. Lower and higher Mn loading resulted in a significant loss of the overall efficiency of NOx conversion. The lower NOx conversion at lower Mn loading (x=0.1) demonstrated that oxide manganese is the catalyst active site. The loss in efficiency observed at higher Mn loading is attributed to the lower dispersion of Ba on the surface, which could decrease the NOx storage ability, and the lower BET surface. There is no NOx conversion on support γ-Al2O3 or Ba/γ-Al2O3.