Catalytic Reduction of NOx by CO and Hydrocarbons Over Different Catalysts in the Presence or Absence of O2

The performances of a non-noble metal (catalyst A), a non-noble metal catalyst containing a smaller amount of a noble metal (catalyst B) and noble metal (catalyst C) for NOx reduction at 400 - 600°C and space velocity of 16×10-1h-1 have been studied by means of a fixed-bed continuous flow system. In both the absence and presence of oxygen, the following activity orders of catalysts for the reduction of NOx to N2 by CO and C3H6(HC) can be given: C > B > A and B > A ≅ C, respectively. Meanwhile, there was CO formation in the reduction reactions of NOx by HC on the three catalysts. The amount of CO produced on catalyst C was the largest of the three catalysts.