摘要 |
A catalyst carrying a catalyst material containing an alkaline metal and/or an alkaline earth metal on a carrier and used as an NOx trap catalyst for purifying automobile exhaust gas and the like comprises alumina incorporated into the carrier and/or placed between the carrier and the catalyst material, thereby suppressing the deterioration of the carrier caused by the metals such as Li, Na, K and Ca to be used as an alkaline metal and/or an alkaline earth metal and enabling it to be used for a extended period of time. |