A dual-bed lean deNOx catalyst system consisting of NO–H2–O2 reaction and subsequent N2O decomposition

Abstract The selective conversion of NO to N2 in a stream of 0.08% NO, 0.28% H2, 10% O2, 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 N2/N2O by selective reduction with H2, which could be catalyzed by Pt supported on TiO2–ZrO2 or HY zeolites. Almost all the N2O thus formed in the first bed was successfully decomposed into N2/O2 over Pd/Al2O3 in the second bed at 400 °C. The combination with N2O decomposition can broadly be applied to H2–SCR in a strongly oxidizing atmosphere.