An after treatment system is disclosed. The after treatment system may include a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows. The CUC may include a zeolite in which Cu and Fe are ion-exchanged and CeO.sub.2 in which Pt is supported, wherein a weight ratio of the CeO.sub.2 to a total weight of the CUC is 30-70 wt % such that the CUC purifies NH.sub.3 at a lean air/fuel ratio and purifies NH.sub.3 during a delay time at a rich air/fuel ratio.

Described are three-way conversion (TWC) catalytic articles effective to abate hydrocarbons (HCs), carbon monoxide (CO), and nitrogen oxides (NO.sub.x) from an engine exhaust gas containing phosphorous impurities. The disclosed catalytic article has a layered catalytic material, wherein the first layer of the catalytic material is disposed directly on the substrate and a second layer is disposed on top of the first layer. The second layer includes phosphorus resistant materials that prevent catalytic poisoning of the catalytic article by the phosphorous impurities. In particular, the second layer includes a phosphorus trap material having an alkaline earth metal component and a rhodium component impregnated on a phosphorus-resistant support material.

One object is to provide an aldehyde decomposition catalyst, and an exhaust gas treatment apparatus and an exhaust gas treatment method using the aldehyde decomposition catalyst that achieve low cost and sufficient aldehyde decomposition performance with a small amount of the catalyst. An aldehyde decomposition catalyst of the present invention is made of a zeolite in a cation form NH.sub.4 having a structure selected from MFI and BEA and carrying at least one metal selected from the group consisting of Cu, Mn, Ce, Zn, Fe, and Zr.

The present disclosure discloses a dry desulfurizing and denitrificating agent and its preparation method and applications. The desulfurizing and denitrificating agent is made of raw materials comprising the following components based on 100 parts by weight of the desulfurizing and denitrificating agent: 30-60 parts by weight of TiO.sub.2, 10-30 parts by weight of ZrO.sub.2, 2-10 parts by weight of V.sub.2O.sub.5, 2-10 parts by weight of CoO, 1-8 parts by weight of Co.sub.2O.sub.3, 2-10 parts by weight of Fe.sub.2O.sub.3, 5-15 parts by weight of MnO.sub.2, and 2-10 parts by weight of KMnO.sub.4. The desulfurizing and denitrificating agent of the present disclosure has a good catalytic oxidation performance on sulfur dioxide and nitrogen oxides of flue gas, and a high rate of desulfurization and denitrification.

The present invention discloses a preparation method of a catalyst with white carbon black modified by ZrNdO and use thereof, and belongs to the field of catalyst technologies. In the present invention, an organic solvent evaporation induced self-assembly method is used to load ZrNdO onto white carbon black to obtain a mesoporous ZrNdO/white carbon black catalyst. The mesoporous ZrNdO/white carbon black catalyst in the present invention has high catalytic activity, contains uniformly distributed mesopores with a relatively large average aperture, and has a simple preparation process, etc.

An exhaust purification system includes an LAF sensor provided in an exhaust pipe and generates a signal corresponding to an air-fuel ratio of exhaust gas. An upstream catalytic converter is downstream of the LAF sensor and has a catalyst to purify the exhaust gas. An O2 sensor is downstream of the upstream catalytic converter, and generates a signal corresponding to the air-fuel ratio of the exhaust gas. A GPF is downstream of a the O2 sensor and purifies the exhaust gas. An ECU controls an air-fuel mixture in an engine using output signal KACT of the LAF sensor and an output signal VO2 of the O2 sensor such that the air-fuel ratio of exhaust gas flowing into the GPF converges to a target value near the stoichiometric ratio. The GPF has a filter substrate and a downstream TWC supported by a partition of the filter substrate.

An inorganic oxide material doped with nano-rare earth oxide particles that is capable of trapping one or more of NO.sub.x or SO.sub.x at a temperature that is less than 400 C. The nano-rare earth oxide particles have a particle size that is less than 10 nanometers. The catalyst support can trap at least 0.5% NO.sub.2 at a temperature less than 350 C. and/or at least 0.4% SO.sub.2 at a temperature less than 325 C. The catalyst support can trap at least 0.5% NO.sub.2 and/or at least 0.2% SO.sub.2 at a temperature that is less than 250 C. after being aged at 800 C. for 16 hours in a 10% steam environment. The catalyst support exhibits at least a 25% increase in capacity for at least one of NO.sub.x or SO.sub.x trapping at a temperature that is less than 400 C. when compared to a conventional rare earth doped support in a 10% steam environment.

The present invention relates to a catalyst for decomposition of nitrous oxide and also to its method of preparation and use.

The present invention relates to a mixed oxide with enhanced resistance and NO.sub.x storage capacity. The mixed oxide may be used as a component of a NO.sub.x trap material in an exhaust system of an internal combustion engine. The invention also relates to a method for treating an exhaust gas from an internal combustion engine using the mixed oxide.

A catalysed substrate monolith 12 for use in treating exhaust gas emitted from a lean-burn internal combustion engine, which catalysed substrate monolith 12 comprising a first washcoat coating 16 and a second washcoat coating 18, wherein the first washcoat coating comprises a catalyst composition comprising at least one platinum group metal (PGM) and at least one support material for the at least one PGM, wherein at least one PGM in the first washcoat coating is liable to volatilise when the first washcoat coating is exposed to relatively extreme conditions including relatively high temperatures, wherein the second washcoat coating comprises at least one metal oxide for trapping volatilised PGM and wherein the second washcoat coating is oriented to contact exhaust gas that has contacted the first washcoat coating.