The present disclosure provides Low Temperature NO.sub.x-Absorber (LT-NA) catalyst compositions, catalyst articles, and an emission treatment system for treating an exhaust gas, each including the LT-NA catalyst compositions. Further provided are methods for reducing a NO.sub.x level in an exhaust gas stream using the LT-NA catalyst articles. In particular, the LT-NA catalyst compositions include a first zeolite, a first palladium component, and a plurality of platinum nanoparticles. The LT-NA catalyst compositions exhibit enhanced regeneration efficiency with respect to NO.sub.x adsorption capacity, even after hydrothermal aging.

The present invention relates to a catalyst comprising a carrier substrate of length L and at least two washcoat layers A and B wherein washcoat layer A comprises alumina; ceria; an alkaline earth compound and/or an alkali compound; platinum, palladium or platinum and palladium; washcoat layer B comprises a zeolite and palladium, wherein the palladium is present as palladium cation in the zeolite structure or is wholly or partially present as palladium metal and/or as palladium oxide in the zeolite structure and/or on the surface of the zeolite structure; and
wherein washcoat layer A is arranged below washcoat layer B.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

The present invention relates to a diesel oxidation catalyst comprising a carrier body having a length L extending between a first end face and a second end face, and differently composed material zones A and B arranged on the carrier body, wherein material zone A comprises platinum and palladium applied to a cerium-titanium mixed oxide, and material zone B comprises platinum and palladium applied to a carrier oxide B.

The present invention relates generally to the field of exhaust treatment systems for purifying exhaust gas discharged from a lean burn engine. The exhaust treatment system comprises a Diesel Oxidation Catalyst (DOC), a Catalyzed Soot Filter (CSF), a reductant injector, an AEI zeolite based Selective Catalyzed Reduction (SCR) catalyst and an Ammonia Oxidation Catalyst (AMOX) downstream to the AEI zeolite based SCR catalyst.

A process for coating substrates of motor vehicle exhaust gas catalysts is described, and includes steps of applying a suspension (e.g., washcoat) to a substrate, allowing a shear force to act on the applied washcoat, as in pressure transmitted by gas (e.g., air), and then sucking and/or pressing the washcoat into the substrate. The process in inclusive of providing the suspension (washcoat) containing the catalytic material from above in a metered charge process. An apparatus for carrying out the noted process steps is also featured.

The present disclosure generally relates to a process for coating a scaffold, and in particular a process for coating a scaffold of a static mixer using catalytic liquid suspensions. The present disclosure also generally relates to a process for preparing a catalytically coated scaffold comprising applying a catalytic liquid suspension to a surface of a scaffold to provide a coating containing catalytically reactive sites on the surface of the coated scaffold.

A passive NO.sub.x adsorber is disclosed. The passive NO.sub.x adsorber is effective to adsorb NO.sub.x at or below a low temperature and release the adsorbed NO.sub.x at temperatures above the low temperature. The passive NO.sub.x adsorber comprises a noble metal and a molecular sieve having an LTL Framework Type. The invention also includes an exhaust system comprising the passive NO.sub.x adsorber, and a method for treating exhaust gas from an internal combustion engine utilizing the passive NO.sub.x adsorber.

A catalytic article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; a first catalytic region comprising a first platinum group metal (PGM) component and a support; a second catalytic region comprising a second PGM component on a support with low ammonia storage and a first SCR catalyst; and wherein the first catalytic region is covered by at least another catalytic region.

A low-temperature NO.sub.x storage catalyst for automobile exhaust purification and a preparation method thereof. Loading a noble metal salt solution on molecular sieve by equal volume impregnation method, wherein the noble metal salt solution comprises palladium nitrate and platinum nitrate, and the molecular sieve comprises SSZ, SAPO and BETA, then drying at 60-120° C. for 2-6 h, roasting at 500-550° C. in air for 2-5 h, and further roasting at 750-850° C. in air for 2-5 h, and then mixing with aluminum sol, ball milling and pulping, and then coating the slurry on a carrier, wherein the loading on the coating is 100-250 g/L and the noble metal content is 10-150 g/ft.sup.3, drying at 60-120° C. for 2-6 h, then roasting at 500-550° C. in air for 2-5 h, and further continuing roasting at 750-850° C. in air for 2-5 h, to obtain the catalyst. Loading the noble metals Pt and Pd into a pore channel of a molecular sieve improves NO.sub.x storage capacity of a catalyst at low temperatures, and selecting a different type of molecular sieve as an NO.sub.x storage unit and increasing a roasting temperature of a molecular sieve material on which Pt and Pd are loaded significantly increases NO.sub.x storage capacity.