| 摘要 |
A moisture adsorbing device 1 comprising a type Y zeolite, and an NO x adsorbing device 2 being put in place on an exhaust-gas downstream side of the moisture adsorbing device 1, and comprising a zeolite that includes a transition metal ion in the cation exchange sites are included. In NO x adsorbing apparatuses, since the less the moisture content in exhaust gases is the more the NO x adsorbing capability improves, the NO x adsorbing capability in low-temperature region is improved especially by means of the combination with a moisture adsorbing device that comprises a type Y zeolite whose Al 2 O 3 proportion is great and whose moisture adsorbing amount is great compared with the other zeolites. |
