| 摘要 |
PURPOSE: To treat oxygen-rich exhaust gas from an internal combustion engine and to reduce the emission of NOx by using a catalyst containing a large amount of an oxide having a spinel structure of the formula ZnAl2 O4 . CONSTITUTION: The catalyst containing a layer amount of an oxide having a spinel structure of the formula ZnAl2 O4 is used for treating oxygen-rich exhaust gas from an internal combustion engine and reducing the emission of NOx . In other way, a catalyst containing an oxide having a normal or inverse spinel structure other than ZnAl2 O4 is used for treating oxygen-rich exhaust gas from an internal combustion engine and reducing the emission of NOx . The oxide having a normal or inverse spinel structure has the formula AB2 O4 (where A is at least one element selected from the groups IIa, Ib, IIb, IIIb, IVb and Vb elements of the Periodic Table or transition elements and B is at least one element selected from the groups IVa, VIa, VIIa, VIIIa and Ib-Vb elements of the Periodic Table. |
