An oxidation catalyst for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a first washcoat region comprising platinum (Pt), manganese (Mn) and a first support material; a second washcoat region comprising a platinum group metal (PGM) and a second support material; and a substrate having an inlet end and an outlet end; wherein the second washcoat region is arranged to contact the exhaust gas at the outlet end of the substrate and after contact of the exhaust gas with the first washcoat region.

The present disclosure is directed to a method for treating a gaseous exhaust stream containing nitrogen oxides (NO.sub.x) from a diesel or lean-burn gasoline engine following a cold-start of the engine The method involves contact of the gaseous exhaust stream with at least a low temperature NO.sub.x adsorber (LT-NA) component. The LT-NA component includes a rare earth metal component, a platinum group metal (PGM) component, and a dopant. The present disclosure is also directed to a method of modulating a NO.sub.x adsorption/desorption profile of an LT-NA composition, a NO.sub.x desorption temperature range of an LT-NA composition, or both.

The present disclosure relates to gallium-based dehydrogenation catalysts that further include additional metal components, and to methods for dehydrogenating hydrocarbons using such catalysts. One aspect of the disclosure provides a calcined dehydrogenation catalyst that includes a gallium species, a cerium species, a platinum promoter, and a silica-alumina support. Optionally, the composition can include a promoter selected from the alkali metals and alkaline earth metals.

An oxidation catalyst for treating an exhaust gas from a diesel engine comprises: a first washcoat region for oxidising carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material, and wherein the first washcoat region does not comprise manganese or an oxide thereof; a second washcoat region for oxidising nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material comprising a refractory metal oxide, which is silica-alumina or alumina doped with silica in a total amount of 0.5 to 45% by weight of the alumina, wherein the platinum (Pt) is disposed or supported on the second support material and the manganese (Mn) is disposed or supported on the second support material; and a substrate having an inlet end and an outlet end, and wherein the first washcoat region is a first washcoat layer and the second washcoat region is a second washcoat layer, and the second washcoat layer is disposed on the first washcoat layer; and wherein when the oxidation catalyst comprises a hydrocarbon adsorbent, which is a zeolite, then the first washcoat region further comprises the hydrocarbon adsorbent.

A catalyst includes a carbon black support and active metal particles. A surface of the carbon black support has a relative atomic percentage of oxygen atoms ranged from 2 atom % to 12 atom %. The active metal particles are distributed on the carbon black support. Each of the active metal particles includes rhodium metal and rhodium oxide. A method for manufacturing the catalyst and a method for hydrogenating an aromatic epoxy compound are also provided herein.

A three-way catalyst device (TWC) includes a first catalytic brick (FCB) and a second catalytic brick (SCB) downstream from the FCB. The FCB has a first washcoat applied to a first support body including ceramic and/or metal oxide particles, Pd particles, and Rh particles, and has at most 35 g/ft.sup.3 Pd and at most 7.5 g/ft.sup.3 Rh. The SCB has a second washcoat applied to a second support body including ceramic and/or metal oxide particles, Pt particles, and Rh particles, and has a Pt loading of at most 35 g/ft.sup.3 Pt and a Rh loading of at most 7.0 g/ft.sup.3 Rh. The FCB can have 25 g/ft.sup.3 to 35 g/ft.sup.3 Pd and 5.5 g/ft.sup.3 to 7.5 g/ft.sup.3 Rh and the SCB can have 25 g/ft.sup.3 to 35 g/ft.sup.3 Pt and 5.0 g/ft.sup.3 to 7.0 g/ft.sup.3 Rh. The TWC can receive exhaust gas from an internal combustion engine powering a vehicle.

The disclosure relates to a three-way conversion catalyst for the treatment of an exhaust gas comprising nitrogen monoxide, carbon monoxide, and hydrocarbon, wherein the catalyst comprises: (i) a substrate; (ii) a first coating comprising rhodium supported on a first oxidic component; (iii) a second coating comprising palladium supported on a non-zeolitic oxidic material, wherein the non-zeolitic oxidic material comprises manganese and a second oxidic component, wherein the second coating consists of 0 weight-% to 0.001 weight-% of platinum; wherein the first coating is disposed on the substrate over x % of the axial length, with x ranging from 80 to 100; wherein the second coating extends over y % of the axial length from the inlet end to the outlet end and is disposed on the first coating, with y ranging from 20 to x.

Disclosed herein are emission treatment systems comprising an oxidation catalyst composition in fluid communication with an exhaust gas stream emitted from an engine that combusts both hydrocarbon fuel and hydrogen; and optionally, at least one selective catalytic reduction (SCR) composition and/or at least one three-way conversion (TWC) catalyst composition, combustion systems comprising the same, and method of treating an exhaust gas stream, such as, e.g., an exhaust gas produced by combusting hydrogen fuel during a cold-start period, using the same.

The present disclosure is directed to a low temperature carbon monoxide (LT-CO) oxidation catalyst composition for abatement of exhaust gas emissions from a lean burn engine. The LT-CO oxidation catalyst composition includes an oxygen storage component (OSC), a first platinum group metal (PGM) component, and a promoter metal, wherein the OSC is impregnated with the first PGM component and the promoter metal and the LT-CO oxidation catalyst composition is effective for oxidizing carbon monoxide (CO) and hydrocarbons (HC) under cold start conditions. Further provided are catalytic articles including the LT-CO oxidation catalyst composition, which may optionally further include a diesel oxidation catalyst (DOC) composition (giving an LT-CO/DOC article). Further provided is an exhaust gas treatment system including such catalytic articles, and methods for reducing a HC or CO level in an exhaust gas stream using such catalytic articles.

The present disclosure is directed to a low temperature carbon monoxide (LT-CO) oxidation catalyst composition for abatement of exhaust gas emissions from a lean burn engine. The LT-CO oxidation catalyst composition includes an oxygen storage component (OSC), a first platinum group metal (PGM) component, and a promoter metal, wherein the OSC is impregnated with the first PGM component and the promoter metal and the LT-CO oxidation catalyst composition is effective for oxidizing carbon monoxide (CO) and hydrocarbons (HC) under cold start conditions. Further provided are catalytic articles including the LT-CO oxidation catalyst composition, which may optionally further include a diesel oxidation catalyst (DOC) composition (giving an LT-CO/DOC article). Further provided is an exhaust gas treatment system including such catalytic articles, and methods for reducing a HC or CO level in an exhaust gas stream using such catalytic articles.