| abstract |
The present invention provides a nitrogen oxide storage material, which has Mg 1-y Al 2 O 4-y (in the formula, y represents a number of 0≤y≤0.2) and is supported on the Mg 1-y Al 2 O 4-y noble metal, metal oxides other than the noble metal supported on the Mg 1 -y Al 2 O 4 -y , and nitrogen oxide storage material of the barium compound supported on the Mg 1-y Al 2 O 4-y , as the metal oxide, including at least one compound of zirconium oxide, praseodymium oxide, niobium oxide and iron oxide. |