| 摘要 |
PURPOSE: To prevent the deterioration in NOx purification performance after Cong term duration by preventing the sulfur poisoning of a NOx absorbent while keeping initial NOx purifying rate. CONSTITUTION: This catalyst is made by carrying the NOx absorbent, selected from a Ti-Zr conjugate oxide, an alkali metal, an alkaline earth metal, a rare earth element, and a catalyst noble metal on an alumina carrier. The acidity of the alumina carrier itself is increased by carrying the Ti-Zr conjugate oxide and since it is considered that the adsorption of SOx to alumina is decreased with the increase of the acidity of the alumina carrier because of the acidity of SOx, the sulfur poisoning of the NOx absorbent due to the absorption of SOx is prevented. |
