| 摘要 |
PURPOSE: To improve NOX cleaning performance in a lean atmosphere, and clean NOX contained in an exhaust gas efficiently even in a wide range of temperature from low to high, and at the time of low HC concentration. CONSTITUTION: A HC adsorbent expressed by formula Yf /zeolite (in the formula, Y is at least, one element selected from among phosphorus, copper, silver, gallium, indium, alkali metal and alkaline earth metal; f represents weight % of a carried element Y; and f=0, 1 to 10) is added to a multicomponent compound oxide containing copper, nickel and aluminum expressed by formula, Cua Nib Ald Og (in the formula, a, b and d represents the atomic ratio of each element, when d=2.0, a=0.01 to 0.3, b=0.2 to 0.8, g = the number of atoms of oxygen required for satisfying the valence of each component). |
