A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst 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 first PGM support material, wherein the first catalytic region comprises up to 5 wt. % Sn.

A layered catalyst structure for purifying an exhaust gas stream includes a catalyst support and a rhodium catalyst layer including an atomic dispersion of rhodium ions and/or rhodium atoms adsorbed on an exterior surface of the catalyst support. The catalyst support includes an alumina substrate, a first ceria layer disposed on and extending substantially continuously over the alumina substrate, and a second colloidal ceria layer formed directly on the first ceria layer over the alumina substrate.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

A catalyst article is provided including a substrate including a plurality of passageways, and further including a first and a second oxidation region including a first and a second subset of said plurality of passageways. A first catalyst composition is coating at least a portion of each passageway of the first oxidation region and positioned as a sole PGM-containing catalyst layer, or a zoned portion thereof, or as a top PGM-containing catalyst layer, or a zoned portion thereof, in the first oxidation region. A second catalyst composition is coating at least a portion of each passageway of the second oxidation region and positioned as a sole PGM-containing catalyst layer, or a zoned portion thereof, or as a top PGM-containing catalyst layer, or a zoned portion thereof, in the second oxidation region. The Pt:Pd weight ratio is greater in the first catalyst composition than in the second catalyst composition.

The present invention relates to a catalyst which comprises a carrier substrate of length L, which extends between a first end face a and a second end face b, and catalytically active material zones A, B and C of different composition, wherein—material zone A comprises palladium or palladium and platinum with a weight ratio of Pd:Pt>1, and cerium oxide, —material zone B comprises platinum or platinum and palladium with a weight ratio of Pt:Pd>1, and cerium oxide and/or cerium/zirconium mixed oxide, and—material zone C comprises platinum or platinum and palladium with a weight ratio of Pt:Pd>1, and a carrier oxide, and wherein—material zone B is arranged above material zone A, and—material zone C is arranged above material zone B, and, starting from the second end face b of the carrier substrate, extends over a length of up to 60% of the length L. The invention also relates to a catalyst arrangement containing said catalyst.

The present disclosure is directed to a Low Temperature NOx-Absorber (LT-NA) catalyst composition which exhibits NOx adsorption in a broad temperature and space velocity range, and shifts NOx desorption to a desired temperature range. In particular, the LT-NA composition includes a large pore zeolite containing a palladium component and a small or medium pore zeolite containing a palladium component. Further provided is a catalyst article including the LT-NA catalyst composition, an emission treatment system for treating an exhaust gas including the catalyst article, and methods for reducing a NOx level in an exhaust gas stream using the catalyst article.

An exhaust gas purification catalyst is provided which can be more enhanced in NOx purification performance. An exhaust gas purification catalyst including a substrate, a NOx storage layer located over the substrate, an oxidation catalyst layer located over a part of the NOx storage layer, the part being located upstream in an exhaust gas flow direction, and a reduction catalyst layer located over a part of the NOx storage layer, the part being located downstream in an exhaust gas flow direction, wherein the NOx storage layer includes an oxidation catalyst including Pd or Pd and Pt, and a NOx storage material including at least one element selected from the group consisting of an alkali metal, an alkali earth metal and a rare-earth element, the oxidation catalyst layer includes an oxidation catalyst including Pt or Pt and Pd, the reduction catalyst layer includes a reduction catalyst including Rh, and a total content rate (mol %) of Pt and Pd based on a total content rate (100 mol %) of metal element(s) in the oxidation catalyst layer is higher than a total content rate (mol %) of Pt and Pd based on a total content rate (100 mol %) of metal elements in the NOx storage layer.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst 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 first oxygen storage capacity (OSC) material, wherein the first catalytic region has a washcoat porosity of less than 50%; and wherein the first OSC material has a pore: volume of at least 0.4 mL/g.

An exhaust gas purification device includes a substrate including an upstream end and a downstream end and having a length Ls; a first containing Pd particles, extending between the upstream end and a first position, and being in contact with the substrate; a second containing Rh particles, extending between the downstream end and a second position, and being in contact with the substrate; and a third catalyst layer containing Rh particles, extending between the upstream end and a third position, and being in contact with at least the first catalyst layer, wherein an average of a Rh particle size distribution is from 1.0 to 2.0 nm, and a standard deviation of the Rh particle size distribution is 0.8 nm or less in each of the second catalyst layer and the third catalyst layer.

A three-way catalyst article, and its use in an exhaust system for compressed natural gas engines, is disclosed. The catalyst article for treating exhaust gas from compressed natural gas (CNG) engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first PGM component; and a second catalytic region beginning at the inlet end, wherein the second catalytic region comprises a second PGM component; wherein the first PGM component comprises palladium, platinum, or a combination thereof; and wherein the second PGM component comprises rhodium.