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).

A particulate filter having a porous ceramic honeycomb structure with a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels. Filtration material deposits are disposed on one or more of the wall surfaces of the honeycomb body. The highly porous deposits provide durable high clean filtration efficiency with small impact on pressure drop through the filter.

The present invention relates to a catalyst comprising a carrier substrate of length L and at least two washcoat layers A and B wherein washcoat layer A comprises alumina; ceria; an alkaline earth compound and/or an alkali compound; platinum, palladium or platinum and palladium; washcoat layer B comprises a zeolite and palladium, wherein the palladium is present as palladium cation in the zeolite structure or is wholly or partially present as palladium metal and/or as palladium oxide in the zeolite structure and/or on the surface of the zeolite structure; and
wherein washcoat layer A is arranged below washcoat layer B.

An ozone purification catalyst, and a preparation method therefor and an application thereof are provided. The catalyst coating uses macroporous, high specific surface and CeO.sub.2 and/or La.sub.2O.sub.3 modified Al.sub.2O.sub.3 as the carrier material, and Mn and/or Pd as the active component. The preparation method is to prepare the Al.sub.2O.sub.3-based material by a sol-gel method, and then to load the active components on the carrier material, and to dry, calcinate and solidify to obtain the ozone purification catalyst. The catalysts as prepared shows a fast and efficient purification of ozone. The complete conversion temperature covers a wide range of temperature. The catalyst has excellent texture performance, high specific surface area and large pore volume, which is beneficial to ozone purification when the car is running at high speed. The particle sizes and colors of the catalyst can be modified according to various requirements. According to the actual application, it can be coated on the radiator fins of automobile water tanks, and any place where coating is allowed in public areas such as urban bus stations, stop signs, kiosks, roadside guardrails, or exterior walls of buildings that is in contact with outdoor air.

A substrate (11) of an exhaust gas purification catalyst (10) includes inflow-side cells (21), outflow-side cells (22), and porous partition walls (23), each separating the inflow-side cell and the outflow-side cell. Catalyst portions (14, 15) are provided on the surfaces of the partition walls that each face the inflow-side cell and/or the surfaces of the partition walls that each face the outflow-side cell. In a cross section vertical to an exhaust gas flow direction, the percentage of the total area of voids, each void satisfying the expression L/{2(πS).sup.1/2}≤1.1 (wherein L is the perimeter of the void in the cross section, and S is the area of the void in the cross section), is greater than 10% to 30% or less based on the apparent area of the catalyst portion present on the partition wall. The content of zirconium element in terms of oxide (amount of ZrO2) in the catalyst portions is from 35 mass % to 85 mass %.

Embodiments of the present invention include a filter element for decomposing contaminants including a substrate, and a photocatalytic composition comprising at least a photocatalyst and a co-catalyst. The embodiments of the present invention also includes a system for decomposing contaminants including a substrate, and a photocatalytic composition comprising at least a photocatalyst and a co-catalyst; and a method using the system.

An exhaust gas purification device has a metal substrate and a catalyst layer on the metal substrate, wherein the metal substrate is a wound body of one or a plurality of metal foils, at least one of the one or a plurality of metal foils is a perforated metal foil having holes, the catalyst layer contains noble metal catalyst particles and a carrier for carrying the noble metal catalyst particles, and more noble metal catalyst particles are present in the catalyst layer on side surfaces of holes, which face an upstream side of an exhaust gas flow, than in the catalyst layer on side surfaces of holes, which face a downstream side of the exhaust gas flow.

The exhaust gas purification catalyst device includes an upper layer which includes first carrier particles and rhodium, and a lower layer which includes second carrier particles, and the upper layer includes a rhodium enriched area in the range a, from the upstream end in the exhaust gas flow to 50% of the upper layer length, and a range b from the upper layer top surface to 18 μm in the depth direction. The rhodium enriched area contains at least 50% and less than 100% of all the rhodium in the upper layer.

There is provided an exhaust gas purification device that shows a high HC removal performance under a condition in which a rich air-fuel mixture is introduced. The exhaust gas purification device includes a substrate, a first catalyst layer, and a second catalyst layer. The substrate includes an upstream end and a downstream end. The first catalyst layer is disposed on a surface of the partition wall in an upstream region including the upstream end of the substrate. The second catalyst layer is disposed inside the partition wall in a downstream region including the downstream end of the substrate. The first catalyst layer contains a first metal catalyst and alumina-zirconia composite oxide. The second catalyst layer contains a second metal catalyst.

The present invention relates to a diesel oxidation catalyst comprising a carrier body having a length L extending between a first end face and a second end face, and differently composed material zones A and B arranged on the carrier body, wherein material zone A comprises platinum and palladium applied to a cerium-titanium mixed oxide, and material zone B comprises platinum and palladium applied to a carrier oxide B.