A dual-bed lean deNO x catalyst system consisting of NO–H 2–O 2 reaction and subsequent N 2O decomposition

Abstract

The selective conversion of NO to N 2 in a stream of 0.08% NO, 0.28% H 2, 10% O 2, and He balance has been achieved for the first time using a serial dual-bed catalytic system. In the first bed at ⩽100 ° C , ca. 80–90% of NO was converted into N 2/N 2O by selective reduction with H 2, which could be catalyzed by Pt supported on TiO 2–ZrO 2 or HY zeolites. Almost all the N 2O thus formed in the first bed was successfully decomposed into N 2/O 2 over Pd/Al 2O 3 in the second bed at 400 °C. The combination with N 2O decomposition can broadly be applied to H 2–SCR in a strongly oxidizing atmosphere.