Subject of the invention is an exhaust gas purification system for a gasoline engine, comprising in consecutive order the following devices: a first three-way-catalyst (TWC1), a gasoline particulate filter (GPF) and a second three-way-catalyst (TWC2), wherein the oxygen storage capacity (OSC) of the GPF is greater than the OSC of the TWC2, wherein the OSC is determined in mg/l of the volume of the device. The invention also relates to methods in which the system is used and uses of the system.

A cerium-zirconium oxide-based ionic conductor (CZOIC) material including zirconium oxide in an amount ranging from 5 wt. % up to 95 wt. %, cerium oxide in an amount ranging from 95 wt. % to 5 wt. %, and at least one oxide or a rare earth metal in an amount ranging from 30 wt. % or less, based on the overall mass of the CZOIC material. The CZOIC material exhibits a structure comprising one or more expanded unit cells and a plurality of crystallites having ordered nano-domains. The structure of the CZOIC material exhibits a crystal lattice defined by a d-value measured at multiple (hkl) locations using a SAED technique that exhibit distortions, such that the d-values for the same (hkl) location varies from about 2% to about 5% from the d-value measured for a reference cerium-zirconium material at the same (hkl) location.

The present invention provides an oxidation catalyst composition suitable for at least partial conversion of gaseous hydrocarbon emissions, e.g., methane. The oxidation catalyst composition includes at least one platinum group metal (PGM) component supported onto a porous zirconia-containing material that provides an effect on hydrocarbon conversion activity. The porous zirconia-containing material is at least 90% by weight in the monoclinic phase. Furthermore, the PGM component can comprise at least one platinum group metal in the form of colloidally deposited nanoparticles. The oxidation catalyst composition can be used in the treatment of emissions from lean compressed natural gas engines.

An exhaust gas purification system for a gasoline engine is described the system comprising in consecutive order the following devices: •a first three-way-catalyst (TWC1), a gasoline particulate filter (GPF) and a second three-way-catalyst (TWC2), •wherein the oxygen storage capacity (OSC) of the GPF is greater than the OSC of the TWC1, wherein the OSC is determined in mg/l of the volume of the device.

A method of selectively catalysing the reduction of oxides of nitrogen (NO.sub.x) including nitrogen monoxide in an exhaust gas of a stationary source of NO.sub.x emissions also containing oxides of sulfur (SO.sub.x) comprising the steps of passively oxidising nitrogen monoxide to nitrogen dioxide (NO.sub.2) over an oxidation catalyst comprising a platinum group metal so that a NO.sub.2/NO.sub.x content is from 40-60%; introducing a nitrogenous reductant into the exhaust gas; and contacting exhaust gas having the 40-60% NO.sub.2/NO.sub.x content and containing the nitrogenous reductant with a selective catalytic reduction (SCR) catalyst comprising an aluminosilicate zeolite promoted with copper.

A plasma filter for treating a gas flow therethrough. The filter has a dielectric barrier plasma electrode assembly including a plurality of electrodes having a dielectric barrier layer coated thereon. The dielectric barrier plasma electrode assembly is configured to produce an atmospheric pressure plasma, A filtration medium is disposed on or between the electrodes, and a photocatalytic material is formed on surfaces of the filtration medium. Upon operation of the plasma filter, the plasma infiltrates voids in the filtration medium, and the gas flow through the filtration medium a) is exposed to reactive species of the plasma, b) interacts with the catalytic material, and c) is exposed to light generated from the plasma.

Synergized platinum group metals (SPGM) with ultra-low PGM loadings employed as close-coupled (CC) three-way catalysts (TWC) systems with varied material compositions and configurations are disclosed. SPGM CC catalysts in which ZPGM compositions of binary or ternary spinel structures supported onto support oxides are coupled with commercialized PGM UF catalysts and tested under Federal Test Procedure FTP-75 within TGDI and PI engines. The performance of the TWC systems including SPGM CC (with ultra-low PGM loadings) catalyst and commercialized PGM UF catalyst is compared to the performance of commercialized PGM CC and PGM UF catalysts. The disclosed TWC systems indicate that SPGM CC TWC catalytic performance is comparable or even exceeds high PGM-based conventional TWC catalysts, with reduced tailpipe emissions.

Provided is an electrically heated catalytic converter including at least a conductive substrate and an electrode member that is fixed to the substrate, in which a protective film is formed on a surface of at least a portion of the electrode member. In the electrically heated catalytic converter, at least a portion of the protective film is formed of Al.sub.2O.sub.3, SiO.sub.2, a composite material of Al.sub.2O.sub.3 and SiO.sub.2, or a composite oxide including Al.sub.2O.sub.3, SiO.sub.2, or a composite material of Al.sub.2O.sub.3 and SiO.sub.2 as a major component, the protective film has an amorphous structure or a partially crystalline glass structure having a crystallization rate of 30 vol % or lower with respect to the entire portion of the protective film, and a thickness of the protective film is in a range of 100 nm to 2 μm.

Phosphorus tolerant or resistant three-way catalysts (TWC) are disclosed. The TWC may include a substrate defining a plurality of channels. It may include front and rear washcoat portions overlying the substrate and having respective first and second washcoat loadings, the first washcoat loading being at most 2.0 g/in.sup.3 and less than the second washcoat loading. The front washcoat portion may include a catalyst material supported on a support material comprising a cerium oxide, such as ceria or CZO, or a pre-phosphated material, such as AlPO.sub.4, or CePO.sub.4. In one embodiment, the support material may comprise at least 85 wt. % of a cerium oxide or at least 85 wt. % of a phosphate-containing material. The front portion and the underlying substrate may comprise from 3 to 25 vol. % of the three-way catalyst or the front portion may overly up to an initial 15% of an axial length of the substrate.

Composites of mixed metal oxides for an exhaust gas purifying catalyst comprise the following co-precipitated materials by weight of the composite: zirconia in an amount in the range of 55-99%; titania in an amount in the range of 1-25%; a promoter and/or a stabilizer in an amount in the range of 0-20%. These composites are effective as supports for platinum group metals (PGMs), in particular rhodium.