Provided is a combustion system using a catalyst having better denitration efficiency at low temperatures, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent. This combustion system comprises: a combustion device that combusts fuel; an exhaust path through which flows exhaust gas generated from the combustion of fuel in the combustion device; a dust collection device that is arranged on the exhaust path and collects ash dust/dust in the exhaust gas; and a denitration device that is arranged on the exhaust path and removes nitrogen oxides from the exhaust gas by means of a denitration catalyst, wherein the denitration device is arranged downstream of the dust collection device on the exhaust path, and the denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which an oxygen atom is deficient in a crystal structure of the vanadium pentoxide.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion, wherein the partition wall defining inflow cells includes partition wall parts making up sides of polygon that is sectional shape of each cell, the partition wall parts each having a surface that is a face defining the inflow cell, the partition wall part is either a first partition wall part loaded with the exhaust-gas purifying catalyst on the surface so that a percentage of the area loaded therewith exceeds 10%, or a second partition wall part loaded with the exhaust-gas purifying catalyst so that a percentage of the area loaded therewith is 10% or less, and the partition wall is configured to include one or more the first partition wall parts and one or more the second partition wall parts as the partition wall parts.

Disclosed herein is a particulate filter, in particular a catalyzed particulate filter, for use in an emission treatment system of an internal combustion engine. Provided are catalyzed particulate filters, emission treatment systems with catalyzed particulate filters, methods for manufacturing catalyzed particulate filters, and methods for controlling emissions in exhaust gas from internal combustion engines with catalyzed particulate filters.

The disclosure provides a catalyst composition that includes a catalytic material and a magnetic ferrite compound. The magnetic ferrite compound can be pretreated, for example, by heating prior to incorporation within the catalyst composition. The magnetic ferrite compound may include iron, and one or more additional metals including zinc, cobalt, nickel, yttrium, manganese, copper, barium, strontium, scandium, and lanthanum. The disclosure also includes a system and method for heating the catalyst composition, which employs a conductor for receiving current and generating an alternating magnetic field in response thereto.

Disclosed herein are emission treatment systems, articles, and methods for selectively reducing NOx compounds. The systems include a hydrogen generator, a hydrogen selective catalytic reduction (H.sub.2-SCR) article, and one or more of a diesel oxidation catalyst (DOC) and/or a lean NOx trap (LNT) and/or a low temperature NOx adsorber (LTNA). Certain articles may comprise a zone coated substrate and/or a layered coated substrate and/or an intermingled coated substrate of one or more of the H.sub.2-SCR and/or DOC and/or LNT and/or LTNA catalytic compositions.

A layered catalyst structure for purifying an exhaust gas stream includes a catalyst support and a rhodium catalyst layer including an atomic dispersion of rhodium ions and/or rhodium atoms adsorbed on an exterior surface of the catalyst support. The catalyst support includes an alumina substrate, a first ceria layer disposed on and extending substantially continuously over the alumina substrate, and a second colloidal ceria layer formed directly on the first ceria layer over the alumina substrate.

The invention relates to a catalytic article comprising a substrate having an inlet and an outlet; a first coating comprising a blend of: (1) platinum on a support, and (2) a first SCR catalyst comprising a Cu- and Mn-exchanged molecular sieve; and a second coating comprising a second SCR catalyst; wherein the support comprises at least one of a zeolite or a SiO.sub.2-Al.sub.2O.sub.3 mixed oxide. The platinum may be fixed on the support in solution.

Disclosed is a method of preparing a high-performance zeolite catalyst for reducing nitrogen oxide emissions, and more particularly a technique for preparing a zeolite catalyst, suitable for use in effectively removing nitrogen oxide (NOx), among exhaust gases emitted from vehicle internal combustion engines through selective catalytic reduction (SCR), thereby exhibiting high efficiency, high chemical stability and high thermal durability upon SCR using the prepared catalyst.

A wall-flow honeycomb catalyst for dust removal and low-temperature denitrification of flue gas, and a preparation process thereof are provided. The catalyst is prepared from the following raw materials in parts by weight: calcined titanium dioxide: 30 to 60 parts; crude titanium dioxide: 30 to 50 parts; boehmite: 3 to 5 parts; fused silica powder: 2 to 4 parts; binder: 0.5 to 2 parts; lubricant: 0.5 to 2 parts; vanadium-molybdenum composite oxide: 5 to 10 parts; and water: 150 to 200 parts; and the vanadium-molybdenum composite oxide is obtained by dissolving ammonium metavanadate and ammonium molybdate in an oxalic acid solution and spray-drying a resulting solution. The preparation process of the catalyst of the present disclosure is simple and low in cost.

Disclosed is a method of preparing a high-performance zeolite catalyst for reducing nitrogen oxide emissions, and more particularly a technique for preparing a zeolite catalyst, suitable for use in effectively removing nitrogen oxide (NOx), among exhaust gases emitted from vehicle internal combustion engines through selective catalytic reduction (SCR), thereby exhibiting high efficiency, high chemical stability and high thermal durability upon SCR using the prepared catalyst.