The present invention is directed to selective catalytic reduction catalysts that combine SCR activity with NOx absorber activity. In particular, the disclosed catalytic article includes a substrate having a first and a second material disposed thereon, wherein the first material includes a selective catalytic reduction (SCR) catalyst composition and the second material includes a nitrogen oxides (NOx) absorber composition, wherein the NOx absorber composition does not substantially oxidize ammonia, and wherein the catalytic article is effective to abate NOx from an engine exhaust gas stream. Emission treatment systems for treating an exhaust gas including a catalytic article of the invention are provided, particularly systems that include an injector adapted for the addition of ammonia to the exhaust gas stream located upstream of the catalytic article.

A passive NOx absorber for treating an exhaust gas from a diesel engine is described. The passive NOx absorber comprises a first washcoat region comprising a zeolite catalyst, the zeolite catalyst comprising a noble metal and a zeolite having a SAR of 2-15.

A method for operating an internal combustion engine includes combusting a fuel and air mixture within a combustion chamber of an internal combustion engine, thereby forming an exhaust gas, passing the exhaust gas out of the combustion chamber, performing a startup procedure, the startup procedure including passing the exhaust gas from the combustion chamber to a storage unit, capturing criteria pollutants of the exhaust gas with the storage unit, passing the exhaust gas from the storage unit to an aftertreatment system, heating the aftertreatment system to an activation temperature with the exhaust gas from the storage unit, and subsequent to heating the aftertreatment system to the activation temperature, performing a secondary procedure, the secondary procedure including passing the exhaust gas from the combustion chamber to the aftertreatment system thereby forming a treated exhaust gas, and passing the treated exhaust gas to the storage unit.

A cold start catalyst is disclosed. The cold start catalyst is effective to adsorb NO.sub.x and hydrocarbons (HC) at or below a low temperature and to covert and release the adsorbed NO.sub.x and HC at temperatures above the low temperature. The cold start catalyst comprises a molecular sieve catalyst and a supported platinum group metal catalyst. The molecular sieve catalyst consists essentially of a noble metal and a molecular sieve. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst, and a method for treating exhaust gas from an internal combustion engine utilizing the cold start catalyst.

Provided is an exhaust gas purification catalyst system comprising, in the following order, from the upstream side of an exhaust gas flow: a first exhaust gas purification catalyst apparatus 100 including a metal honeycomb substrate 110 and a first catalyst coat layer 120 on the metal honeycomb substrate 110; a heater 300; and a second exhaust purification catalyst apparatus 200 including a cordierite honeycomb substrate 210 and a second catalyst coat layer 220 on the cordierite honeycomb substrate 210, wherein the first catalyst coat layer 120 contains an adsorbent 130 that can adsorb one or two or more among NOx, HC and CO, and the second catalyst coat layer 220 contains inorganic oxide particles 230 and catalyst precious metal particles 240 supported on the inorganic oxide particles 230.

The present invention relates to a VOC reduction system and a VOC reduction method that applies pulse type thermal energy to a catalyst to activate the catalyst and oxidizes and removes the VOC.

A system includes a catalyst for receiving and treating exhaust gas generated by an engine, a passive NOx adsorber (PNA) positioned upstream of the catalyst, a bypass valve positioned upstream of the catalyst and the PNA, and a controller. The controller is configured to, determine that the catalyst is operating under cold start conditions, control the bypass valve to direct exhaust gas to the PNA, determine that the catalyst is no longer operating under cold start conditions and continue to control the bypass valve to direct exhaust gas to the PNA for a predetermined duration, and after the elapse of the predetermined duration, control the bypass valve to direct exhaust gas to the catalyst bypassing the PNA. The controller is also configured to detect a high transient torque demand while the exhaust gas is provided to the PNA, and split the torque demand between the engine and an electric motor.

A NOx adsorber catalyst for treating an exhaust gas from a diesel engine. The NOx adsorber catalyst comprises a first region comprising a NOx adsorber material comprising a first molecular sieve catalyst. The first molecular sieve catalyst comprises a first noble metal and a first molecular sieve, and the first molecular sieve contains the noble metal. The first molecular sieve has an STI Framework Type.

The present disclosure is directed to Low Temperature NOx-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 catalyst article. In particular, the LT-NA compositions include a zeolite containing a first metal component including palladium and a second metal component which is an alkaline earth metal component, an oxide of an alkaline earth metal component, a rare earth metal component, an oxide of a rare earth metal component, or a combination thereof. The LT-NA compositions exhibit increased low temperature NO.sub.x adsorption capacity and enhanced hydrothermal stability.

The present disclosure is directed to a mixed oxide composition comprising manganese, aluminum and/or magnesium, and a rare earth element; a method of making the mixed oxide composition; a NOx adsorber comprising the mixed oxide composition; an exhaust system for internal combustion engines comprising the NOx adsorber; and a method for reducing NOx in an exhaust gas that employs the NOx adsorber.