Simultaneous Removal of Soot and NOx over Precious Metal Catalysts O2-Rich Atmospheres and in the Presence of H2O and SO2

The activities of ZrO2-supported precious metal catalysts for simultaneous removal of soot and NOx in the presence of rich O2and H2O as well as SO2 have been studied by keeping loose contact between catalyst and soot.The results show that only Ru,Ir and Rh have catalytic activity for simultaneous removal of soot and NOx and the order of catalytic activity is Ru > Ir > Rh.Pt has the catalytic activity only for the removal of soot,and Ag,Pd,and Au have hardly any catalytic activities for the removal of soot and NOx.The relationships between catalytic activity of precious metal catalysts and various reaction conditions were discussed.