(57) [summary] NO fewer combustible component conditions and stoichiometric or combustible component of many conditions are contained in the exhaust gas stream flowing out of the engine to operate as it appears to periodically alternately contact trap zone suitable to undergo conversion to _x is equipped with multiple. The contact trap comprises a first zone, one or more intermediate zone located between said first zone and the second zone by a second zone and the case. The zone comprises a contact-trapping material, each covering the top of the refractory carrier member. Contact trapping material in the first zone have comprise a refractory metal oxide support in an amount of about 300 g / ft palladium catalytic component from about 30 thereon, platinum catalytic component is 0 to about 100g / amount and rhodium catalytic component of cubic feet from 0 to about 10g / ft amount and NO _x adsorbent (which one or more basic oxygenated compounds of one or more alkaline earth metals and optionally one comprising one or more basic oxygenated compounds of more alkali metal) are dispersed. Contact trapping material in the second zone optionally comprise a refractory metal oxide support in an amount of about 50 g / ft palladium catalytic component is from 0 thereon platinum catalytic component is from about 10 to about 100g / cubic foot of volume and rhodium catalytic component is from about 5 to about 20 g / ft amount and NO _x adsorbent (this is one of the one or more metals selected from the group consisting of alkali metals and alkaline earth metals comprising or more basic oxygenated compounds) is dispersed. Contact trapping material of any zone within one or two or more optionally comprise a refractory metal oxide support in an amount of about 75 g / ft palladium catalytic component about 25 thereon, platinum catalytic component There about 5 amount and the rhodium catalytic component of about 30 g / ft from 0 to about 10g / cubic foot of volume and NO _x adsorbent (which one or more selected from the group consisting of alkali metals and alkaline earth metals comprising one or more basic oxygenated compound of a metal) are dispersed.