An oxidation catalyst for treating an exhaust gas produced by a diesel engine comprises a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: bismuth (Bi) or an oxide thereof; a Group 8 metal or an oxide thereof; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which comprises alumina, silica, a mixed oxide of alumina and a refractory oxide, a mixed oxide of silica and a refractory oxide, a composite oxide of alumina and a refractory oxide, a composite oxide of silica and a refractory oxide, alumina doped with a refractory oxide or silica doped with a refractory oxide.

A fuel tank inerting system is disclosed. In addition to a fuel tank, the system includes a catalytic reactor with an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from the fuel tank and air from an air source, and to react the fuel and air along the reactive flow path to generate an inert gas. The system also includes an inert gas flow path from the catalytic reactor to the fuel tank. The system also includes (a) an air distributor in the catalytic reactor arranged to distribute air along the reactive flow path, or (b) non-uniform catalyst loading or non-uniform catalyst composition along the reactive flow path, or both (a) and (b).

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 invention provides an automotive catalyst composite that includes a catalytic material on a carrier, the catalytic material including a plurality of core-shell support particles including a core and a shell surrounding the core, wherein the core includes a plurality of particles having a primary particle size distribution d.sub.90 of up to about 5 ?m, wherein the core particles include particles of one or more molecular sieves and optionally particles of one or more refractory metal oxides; and wherein the shell comprises nanoparticles of one or more refractory metal oxides, wherein the nanoparticles have a primary particle size distribution d.sub.90 in the range of about 5 nm to about 1000 nm (1 ?m); and optionally, one or more platinum group metals (PGMs) on the core-shell support. The invention also provides an exhaust gas treatment system and related method of treating exhaust gas utilizing the catalyst composite.

An oxidation catalyst device for exhaust gas purification, having a first catalyst coating layer on the exhaust gas flow's upstream side, second catalyst coating layer of an upper layer on exhaust gas flow's downstream side, and third catalyst coating layer of a lower layer on exhaust gas flow's downstream side, on a substrate, wherein the weight ratio of platinum to palladium in the first catalyst coating layer is 0.75 to 4.50, weight ratio of platinum to palladium in second catalyst coating layer is greater than 4.50 to 25.0, weight ratio of platinum to palladium in third catalyst coating layer is 0.12 or less, the length of first catalyst coating layer is 8% to 55% of the substrate's length, length of second catalyst coating layer is 45% to 95% of the substrate's length, and length of third catalyst coating layer is 45% to 95% of the substrate's length.

An oxidation catalyst for treating an exhaust gas produced by a compression ignition engine comprising: a substrate; a catalytic material disposed on the substrate, wherein the catalytic material comprises platinum (Pt); and a region comprising a capture material, wherein the region is arranged to contact the exhaust gas after the exhaust gas has contacted and/or passed through the catalytic material.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine, wherein the oxidation catalyst comprises: a substrate; a capture material for capturing at least one phosphorus containing impurity and/or at least one sulfur containing impurity in the exhaust gas produced by the diesel engine; and a catalytic region disposed on the substrate; wherein the catalytic region comprises a catalytic material comprising a platinum group metal (PGM) selected from the group consisting of platinum (Pt), palladium (Pd) and a combination of platinum (Pt) and palladium (Pd).

An exhaust system for a diesel engine comprises an oxidation catalyst for treating an exhaust gas from the diesel engine and an emissions control device, wherein the oxidation catalyst comprises: a first washcoat zone for oxidizing carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat zone comprises a first platinum group metal (PGM), which is a combination of platinum and palladium, a first support material and a hydrocarbon adsorbent material, which is a zeolite, and wherein the first washcoat zone does not comprise rhodium and is substantially free of manganese or an oxide thereof; a second washcoat zone for oxidizing nitric oxide (NO), wherein the second washcoat zone comprises platinum (Pt) and manganese (Mn) disposed or supported on a second support material, wherein the second support material comprises a refractory metal oxide, wherein the refractory metal oxide is silica-alumina or an alumina doped with silica in a total amount of 0.5 to 45% by weight of the alumina, and wherein the second washcoat zone does not comprise a hydrocarbon adsorbent material, which is a zeolite; and a substrate having and inlet end and an outlet end, and wherein the second washcoat zone is disposed at an outlet end of the substrate, and the first washcoat zone disposed at an inlet end of the substrate; and wherein the emissions control device is a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction filter catalyst, a diesel particulate filter (DPF), or a catalyzed soot filter (CSF).

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 and system for an internal combustion engine exhaust gas purification includes a first catalyst component region (a) having a catalyst component layer containing Rh at a concentration of 0.1 to 3.0 g/L at a length of 3 to 30 mm on an upstream side, a second catalyst component region (b) having a catalyst component layer containing Pd at a concentration of 1.0 to 20.0 g/L at a length of 10 to 100 mm on a downstream side, and a third catalyst region (c) containing rhodium at a concentration of 0.05 to 1.0 g/L and an oxygen storage material at a concentration of 30 to 150 g/L at a length of 25 to 150 mm on a monolithic support. The catalyst suppresses the formation and discharge of N.sub.2O from the exhaust gas with a small amount of a noble metal from the time of cold starting.