| 摘要 |
PROBLEM TO BE SOLVED: To obtain a catalyst which enables an efficient purification of HC, CO and NOx in a low to high temperature region, exhibiting particularly a high NOx-purification activity in the low temperature region. SOLUTION: Pd and an alkyline earth metal are carried on an oxide having an oxygen-occluding/releasing function. By carrying Pb and the alkaline earth metal, NOx-purification activity in a low temperature region is improved, although its reason therefore remains. If an alkali metal is carried, such an effect can not be attained. |
