An air purification device including a flow passage through which air circulates; an electrical precipitator unit that is disposed in the flow passage and that includes a discharge electrode having a body unit and a corona discharge unit for corona discharge which protrudes from the body unit, and a collecting electrode disposed opposing the discharge electrode; an ozone removal unit that is disposed in the flow passage, and that is capable of removing ozone included in the circulating air, and a control unit that switches between a first mode in which air from which ozone has been removed is supplied from a downstream section of the flow passage to the outside, and a second mode in which air including ozone is supplied from the downstream section of the flow passage to the outside.

The present invention relates to a particulate filter which comprises a wall flow filter of length L and two different catalytically active coatings Y and Z, wherein the wall flow filter comprises channels E and A that extend in parallel between a first and a second end of the wall flow filter and are separated by porous walls which form the surfaces O.sub.E and O.sub.A, respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end. The invention is characterized in that the coating Y is located in the channels E on the surfaces O.sub.E and the coating Z is located in the channels A on the surfaces O.sub.A.

The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.

A pillar shaped honeycomb structure includes: an outer peripheral wall; and porous partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells penetrating from one end face to other end face to form a flow path, wherein at least one cell of the cells has a magnetic substance coated with glass.

The present disclosure provides SCR catalyst compositions capable of reducing nitrogen oxide (NO.sub.x) emissions in engine exhaust. The catalyst compositions include a reducible metal oxide support containing ceria, one or more transition metal oxides as a redox promotor; and an oxide of niobium, tungsten, silicon, molybdenum, or a combination thereof as an acidic promotor. The redox promotor and the acid promotor are both supported on the reducible metal oxide support. Further provided are SCR catalyst articles coated with such compositions, processes for preparing such catalyst compositions and articles, an exhaust gas treatment system including such catalyst articles, and methods for reducing NO.sub.x in an exhaust gas stream using such catalyst articles and systems.

The invention provides a catalyst composition, including a mixture of catalytically active particles and a magnetic material, such as superparamagnetic iron oxide nanoparticles, capable of inductive heating in response to an applied alternating electromagnetic field. The catalytically active particles will typically include a base metal, platinum group metal, oxide of base metal or platinum group metal, or combination thereof, and will be adapted for use in various catalytic systems, such as diesel oxidation catalysts, catalyzed soot filters, lean NOx traps, selective catalytic reduction catalysts, ammonia oxidation catalysts, or three-way catalysts. The invention also includes a system and method for heating a catalyst material, which includes a catalyst article that includes the catalyst composition and a conductor for receiving current and generating an alternating electromagnetic field in response thereto, the conductor positioned such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material.

An object of the present invention is to provide a composition for forming an undercoat layer capable of forming an undercoat layer that does not easily peel off from the substrate, an undercoat layer formed by the composition, as well as an exhaust gas purification catalyst and an exhaust gas purification apparatus each including the undercoat layer, and, to achieve the object, the present invention provides a composition for forming an undercoat layer, the composition containing tin oxide microparticles and tin oxide nanoparticles, wherein a content of the tin oxide nanoparticles is 8% by mass or more and 30% by mass or less, with respect to a total content of the tin oxide microparticles and the tin oxide nanoparticles, an undercoat layer formed by the composition, as well as an exhaust gas purification catalyst and an exhaust gas purification apparatus each including the undercoat layer.

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 TWC2 is greater than the OSC of the GPF, 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.

The structured catalyst for oxidation for exhaust gas purification includes a support having a porous structure constituted by a zeolite-type compound, and at least one type of oxidation catalyst that is present in the support and selected from the group consisting of metal and metal oxide, the support having channels that communicate with each other, and the oxidation catalyst being present in at least the channels of the support.

A composite, zone-coated, dual-use ammonia (AMOX) and nitric oxide oxidation catalyst (12) comprises: a substrate (5) having a total length L and a longitudinal axis and having a substrate surface extending axially between a first substrate end (I) and a second substrate end (O); two or more catalyst washcoat zones (1; 2) comprised of a first catalyst washcoat layer (9) comprising a refractory metal oxide support material and one or more platinum group metal components supported thereon and a second catalyst washcoat layer (11) different from the first catalyst washcoat layer (9) and comprising a refractory metal oxide support material and one or more platinum group metal components supported thereon, which two or more catalyst washcoat zones (1; 2) being arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L.sub.1, wherein L.sub.1<L, is defined at one end by the first substrate end (I) and at a second end (13) by a first end (15) of a second catalyst washcoat zone (2) having a length L.sub.2, wherein L.sub.2<L, wherein the first catalyst washcoat zone (1) comprises a first refractory metal oxide support material and one or more platinum group metal components supported thereon; and the second catalyst washcoat zone comprises a second refractory metal oxide support material and one or more platinum group metal components supported thereon; and a washcoat overlayer (G) extending axially from the first substrate end for up to 200% of the axial length of the underlying first catalyst washcoat layer, which washcoat overlayer comprising a particulate metal oxide loading of >48.8 g/l (>0.8 g/in.sup.3), wherein the particulate metal oxide is an aluminosilicate zeolite including at least one of copper, iron and manganese, wherein a total platinum group metal loading in the first catalyst washcoat zone (1) defined in grams of platinum group metal per litre of substrate volume (g/l) is different from the total platinum group metal loading in the second catalyst washcoat zone (2).