Described herein is a layered catalytic article which includes a) a top layer including a front zone and a rear zone, where the front zone includes a palladium component and a rhodium component, supported individually or together on a support, and the rear zone includes a platinum component, a rhodium component and optionally a palladium component, supported individually or together on a support; b) a bottom layer including a platinum component and a palladium component supported individually or together on a support; and c) a substrate. Also described herein are an exhaust treatment system including the layered catalytic article and a method of using the layered catalytic article for abatement of hydrocarbons, carbon monoxide and nitrogen oxides in an exhaust stream.

The present disclosure provides msect-4 molecular sieves with OFF and ERI topologies, a preparation method therefor, and applications thereof. An eight-membered ring small pore molecular sieve used as a raw material is dispersed in an aqueous phase. Following that, caustic potash, an aluminum source, and an organic structure-directing agent (OSDA) are added. The pH value is then adjusted to be greater than 10, and a silicon source is introduced to attain the desired silicon-aluminum ratio, followed by stirring reaction, aging, crystallization, filtration, washing, ammonia exchange reaction, drying, and calcination. The msect-4 molecular sieves with OFF and ERI topologies, the preparation method therefor, and applications exhibit excellent hydrothermal stability, a plurality of adsorption sites exposed by a regular bone-like structure, and a large specific surface area. Consequently, this molecular sieves find applicability across various technical fields including selective catalytic reduction, passive adsorption, and catalytic cracking, and has broad application prospects.

Catalyst materials comprising iron and palladium are described. Also described are methods for preparing such materials. In addition, methods for remediating materials such as sediments and groundwater using the catalyst materials are described.

The disclosure describes a method of depositing a plurality Ft metal containing nanodots on a catalyst carbon support structure by forming a vapor of Pt(PF3)4, exposing a surface of the catalyst support to the vapor of Pt(PF3)4, purging the surface of the catalyst support with a purge gas to remove the vapor of Pt(PF3)4, exposing the surface of the catalyst support to a second reactant in gaseous form, purging the surface of the catalyst support with a purge gas to remove the second reactant, and repeating these steps to form a plurality of the Pt metal containing nanodots.

An iron-free supported catalyst for the selective conversion of hydrocarbons to carbon nanotubes may include cobalt and vanadium as active catalytic metals in any oxidation state on a catalyst support comprising aluminum oxide hydroxide. The mass ratio of cobalt to vanadium is between 2 and 15; the mass ratio of cobalt to aluminum is between 5.8 10.sup.−2 and 5.8 10.sup.−1; and the mass ratio vanadium to aluminum is between 5.8 10.sup.−3 and 8.7 10.sup.−2. The present disclosure is further related to a method for the production of this iron-free supported catalyst and to a method for the production of carbon nanotubes using the iron-free supported catalyst.

A compression ignition internal combustion engine (30) for a heavy-duty diesel vehicle comprising an exhaust system (32) comprising a composite oxidation catalyst (12, 42) and a soot filter substrate (44, 50) disposed downstream from the composite oxidation catalyst comprising: a substrate (5), preferably a honeycomb flow-through substrate monolith, 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 catalyst washcoat zones (1, 2) arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L.sub.1 and comprising a first catalyst washcoat layer (9), wherein L.sub.1<L, is defined at one end by the first substrate end (I) and at a second end by a first end (15) of a second catalyst washcoat zone (2) having a length L.sub.2 and comprising a second catalyst washcoat layer (11), wherein L.sub.2<L, wherein the second catalyst washcoat zone (2) is defined at a second end thereof by the second substrate end (O), and wherein the first substrate end (I) of the composite oxidation catalyst (12, 42) is oriented to an upstream side and wherein the first catalyst washcoat zone (1) comprises a first refractory metal oxide support material and two or more platinum group metal components supported thereon comprising both platinum and palladium at a weight ratio of platinum to palladium of <1; and the second catalyst washcoat zone (2) 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 (I) comprising a particulate metal oxide having a loading of >48.8 g/l (>0.8 g/in.sup.3), 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 greater than a total platinum group metal loading in the second catalyst washcoat zone (2) and wherein the first catalyst washcoat zone (1) comprises one or more first alkaline earth metal components, preferably barium, supported on the first refractory metal oxide support material.

Tungstated zirconium catalysts for paraffin isomerization may comprise: a mixed metal oxide that is at least partially crystalline and comprises tungsten, zirconium, and a variable oxidation state metal selected from Fe, Mn, Co, Cu, Ce, Ni, and any combination thereof. The mixed metal oxide comprises about 5 wt. % to about 25 wt. % tungsten, about 40 wt. % to about 70 wt. % zirconium, and about 0.01 wt. % to about 5 wt. % variable oxidation state metal, each based on a total mass of the mixed metal oxide. The mixed metal oxide has a total surface area of about 50 m.sup.2/g or greater as measured according to ISO 9277, and at least one of the following: an ammonia uptake of about 0.05 to about 0.3 mmol/g as measured by temperature programmed adsorption/desorption, or a collidine uptake of about 100 μmol/g or greater as measured gravimetrically.

To provide a structured catalyst for catalytic cracking or hydrodesulfurization that suppresses decline in catalytic activity, achieves efficient catalytic cracking, and allows simple and stable obtaining of a substance to be modified. The structured catalyst for catalytic cracking or hydrodesulfurization (1) includes a support (10) of a porous structure composed of a zeolite-type compound and at least one type of metal oxide nanoparticles (20) present in the support (10), in which the support (10) has channels (11) that connect with each other, the metal oxide nanoparticles (20) are present at least in the channels (11) of the support (10), and the metal oxide nanoparticles (20) are composed of a material containing any one or two more of the oxides of Fe, Al, Zn, Zr, Cu, Co, Ni, Ce, Nb, Ti, Mo, V, Cr, Pd, and Ru.

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 photocatalyst, a photocatalytic filter for air purification, and an air purification device that includes the photocatalytic filter. The composite photocatalyst includes: a first metal oxide particle; and second metal oxide particles arranged on a surface of the first metal oxide particle, wherein specific surface area of the second metal oxide particles is greater than specific surface area of the first metal oxide particle, and bandgap energy of the second metal oxide particles is greater than bandgap energy of the first metal oxide particle. The composite photocatalyst structure may degrade and remove gaseous pollutants under room temperature and atmospheric pressure conditions. The composite photocatalyst may be applied to various indoor and outdoor air purification systems in the form of a photocatalytic filter.