NOx removal efficiency and ammonia selectivity during the NOx storage-reduction process over Pt/BaO(Fe, Mn, Ce)/Al2O3 model catalysts. Part II: Influence of Ce and Mn-Ce addition

作者：Le Phuc N; Courtois X^*; Can F; Royer S; Marecot P; Duprez D

来源：Applied Catalysis B: Environmental , 2011, 102(3-4): 362-371.

DOI：10.1016/j.apcatb.2010.12.043

• NOx storage
• NOx reduction
• Ammonia
• Barium
• Lean/rich cycles
• Manganese
• Ceria

It was previously demonstrated in the first part of this work that NOx storage-reduction process over Pt/BaO/Al2O3 model catalyst is limited by the reduction step, with ammonia emission since H-2 is not fully consumed. The stored NOx reacts preferentially with the introduced H-2 giving NH3, than with NH3 in order to produce N-2. Mn addition favors the NOx reduction with ammonia leading to better conversion and selectivity, but only at 400 degrees C. In Part II, a special attention was focused on the role of Ce and Mn-Ce addition in regard to the NOx conversion and the ammonia emission in the 200-400 degrees C temperature range. With ceria modified Pt/20Ba/Al catalyst, significant improvements are obtained from 300 degrees C. In addition to the enhancement of the NOx + NH3 reaction, the ammonia selectivity is maintained at a lower level compared with Pt/Ba(Mn)/Al catalysts, even in the case of a large H-2 excess. It is attributed to the ammonia oxidation into N-2 via the available oxygen at the catalyst surface. A synergetic effect is observed between Mn and Ce when they are added simultaneously in Pt/Ba/Al catalyst.

• 出版日期2011-2-22