SAE International Deactivation of Cu/Zeolite SCR Catalyst Due To Reductive Hydrothermal Aging 2008-01-1021

Temperature programmed reduction by CO, H 2 , and propylene (C 3 H 6 ), as well as hydrothermal aging in the presence of mixture of NO, HC, CO, H 2 and O 2 were used to study the deactivation of Cu/zeolite SCR catalysts. The presence of CO had no detrimental effect on catalyst activity. Carbonaceous deposit on the catalyst surface from propylene (C 3 H 6 ) reduction suppressed the catalyst activity and burn off of carbonaceous deposit recovered activity, the presence of O 2 suppressed carbonaceous deposit formation. The presence of H 2 under lean conditions had much less effect on catalyst activity than H 2 presence under rich conditions. Rich conditions with O 2 presence represented the most detrimental effect on catalyst activity.