The present invention relates to diesel oxidation catalyst compositions and catalyst articles, wherein the compositions and articles include a plurality of platinum group nanoparticles substantially in fully reduced form, wherein the nanoparticles have an average particle size of about 1 to about 10 nm and at least about 90% of the nanoparticles have a particle size of +/− about 2 nm of the average particle size. Such compositions can further include a refractory metal oxide material, wherein the nanoparticles and refractory metal oxide material can be combined within the same coating on a substrate or can be applied sequentially on a substrate. The nanoparticles can advantageously be substantially free of halides, alkali metals, alkaline earth metals, sulfur compounds, and boron compounds. Methods of preparing and using such compositions and catalyst articles (e.g., for the treatment of diesel exhaust gas streams) are also provided herein.

A manufacturing method thereof, and the catalyst for removing the nitrogen oxide includes a powdery gamma alumina support on which at least one selected from a group of titanium (Ti), lanthanum (La), or zirconium (Zr) is supported, wherein the support may be further supported with iridium (Ir) and ruthenium (Ru).

A nitrous oxide (N.sub.2O) removal catalyst composition for treating an exhaust stream of an internal combustion engine is provided, containing a platinum group metal (PGM) component on a metal oxide-based support, wherein the N.sub.2O removal catalyst composition is in a substantially reduced form, such that it has an oxygen deficiency of about 0.05 mmol oxygen atoms/g or greater, and wherein the N.sub.2O removal catalyst composition provides effective removal of at least a portion of N.sub.2O from the exhaust stream under lean conditions at a temperature of about 350 C. or lower. N.sub.2O removal catalytic articles, systems, and methods are also provided for removing at least a portion of N.sub.2O from an exhaust stream under lean, low temperature conditions.

An after treatment method for a lean-burn engine is disclosed. The after treatment method is configured to control an after treatment system sequentially equipped with an ammonia production catalyst module, a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows and which is connected to a lean-burn engine. In the after treatment method, a rich air/fuel ratio (AFR) is controlled in multiple phases in response to detecting that conversion to the rich AFR is desired.

A catalyst article including a substrate with an inlet side and an outlet side, a first zone and a second zone, where the first zone includes an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes a catalyst selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); and where the first zone is located upstream of the second zone. The first zone may include a bottom layer with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer comprising a second SCR catalyst, the top layer located over the bottom layer.

An after treatment method for a lean-burn engine is disclosed. The after treatment method is configured to control an after treatment system sequentially equipped with an ammonia production catalyst module, a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows and which is connected to a lean-burn engine. In the after treatment method, a rich air/fuel ratio (AFR) is controlled in multiple phases in response to detecting that conversion to the rich AFR is desired.

Installation and method for treating a flow comprising hydrogen sulfide The invention relates to an installation and a method for treating hydrogen sulphide. In particular, the invention relates to an installation and a method comprising at least one system for oxidizing hydrogen sulfide to sulfur (S) and water (H.sub.2O) with a solid reagent and at least one oxidizing system with an agent for oxidizing the solid reagent present in the reduced state, wherein the system of oxidizing the hydrogen sulfide to sulfur and the system for oxidizing the solid reagent, are so arranged that the hydrogen sulfide is not brought into contact with the agent oxidizing the solid reagent.

The present application relates to a multifunctional filter medium and a method of manufacturing the same. The multifunctional filter medium of the present application is capable of significantly reducing fine dust, harmful microorganisms, and toxic gases and reducing a pressure decrease during filtration due to exclusion of high-density nanofiber, thereby minimizing energy required for filtration and exhibiting sufficient filtration performance as a single filter medium.

A nitrous oxide (N.sub.2O) removal catalyst composition for treating an exhaust stream of an internal combustion engine is provided, containing a platinum group metal (PGM) component on a metal oxide-based support, wherein the N.sub.2O removal catalyst composition is in a substantially reduced form, such that it has an oxygen deficiency of about 0.05 mmol oxygen atoms/g or greater, and wherein the N.sub.2O removal catalyst composition provides effective removal of at least a portion of N.sub.2O from the exhaust stream under lean conditions at a temperature of about 350 C. or lower. N.sub.2O removal catalytic articles, systems, and methods are also provided for removing at least a portion of N.sub.2O from an exhaust stream under lean, low temperature conditions.

An exhaust gas post processing apparatus of a gasoline vehicle may include a housing mounted on the exhaust pipe to receive the exhaust gas discharged from the engine and to exhaust the exhaust gas passed through rearward thereof, a front end honeycomb catalyst unit embedded in the housing to primarily purify the exhaust gas introduced into the housing through a front end portion of the housing, and a rear end honeycomb catalyst unit embedded in the housing to secondarily purify the exhaust gas via the front end honeycomb catalyst unit before flowing out to a rear end portion of the housing, wherein the front end honeycomb catalyst unit includes a powder type catalyst in which an iridium-ruthenium alloy is supported on an aluminum oxide support powder, and the rear end honeycomb catalyst unit includes three-way catalyst powder which is configured to remove carbon monoxide, nitrogen oxides, and hydrocarbons simultaneously.