초록 |
Various supported Pt catalysts (Pt/WO3/CeO2/ZrO2; Pt/ZrO2, Pt/CeO2, Pt/CeZrO, Pt/WO3/ZrO2, and Pt/WO3/CeZrO) were prepared and characterized, and their characteristics of catalytic reductions of NO by CO with or without oxygen were investigated. For NO CO reaction without oxygen, the easily reducible catalysts (Pt/CeO2 and Pt/CeZrO) exhibited better catalytic performances. With excess oxygen, however, Pt/WO3/CeZrO and Pt/WO3/ZrO2 catalysts exhibited higher NO conversions to N2 and N2O especially at a low temperature. The acidity in Pt/WO3/CeO2/ZrO2 catalysts should play an important role on their NO conversion only in the presence of excess oxygen. |