A method of forming a bismuth-based catalyst can include mixing an inorganic alkali compound, a bismuth source compound, a transition metal precursor, and a reducing agent in an aqueous solution to form a bismuth precursor liquid. The bismuth precursor liquid can be hydrothermally reacted at a conversion temperature for a conversion time to produce the bismuth-based catalyst.

Described are compositions and catalytic articles comprising both a first molecular sieve promoted with copper and a second molecular sieve promoted with iron, the first and second molecular sieves having a d6r unit and the first molecular sieves having cubic shaped crystals with an average crystal size of about 0.5 to about 2 microns. The weight ratio of the copper-promoted molecular sieve to the iron-promoted molecular sieve can be about 1:1 to about 4:1. The catalytic articles are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

Proposed inventions are a recipe of denitrification-oxidation complex catalyst containing an SCR catalyst and an oxidation catalyst to simultaneously remove nitrogen oxides, carbon monoxide, hydrocarbons, and ammonia, a manufacturing method thereof, an exhaust gas treatment method using the denitrification-oxidation complex catalyst, and an SCR denitrification system including the denitrification-oxidation complex catalyst. The denitrification-oxidation complex catalyst simultaneously removes nitrogen oxides, carbon monoxide, hydrocarbons, and ammonia and exhibits an increased catalytic effect compared to the cases where the denitrification catalyst used alone and the denitrification and the oxidation catalyst ratios are and not properly balanced. When the denitrification-oxidation complex catalyst is applied to an SCR denitrification system, the structure is simplified, space is saved, cost is reduced, and catalyst maintenance is easy.

A catalyst composition comprising—a support comprising TiO.sub.2,—a composite oxide containing vanadium and antimony, which has a rutile-type structure different from VSbO.sub.4 and V.sub.0.92Sb.sub.0.92O.sub.4 as determined by X-ray diffraction (XRD) analysis with CuKα radiation, and—optionally, one or more selected from the group consisting of oxides of silicon, oxides of vanadium and oxides of antimony, for selective catalytic reduction of nitrogen oxides; to a process for preparing the catalyst composition, to the catalyst composition obtained/obtainable by the process and to use of the same for selective catalytic reduction of nitrogen oxides.

The present invention pertains to a catalyst for use in the selective catalytic reduction (SCR) of nitrogen oxides comprising a monolithic substrate and a coating A, which comprises an oxidic metal carrier comprising an oxide of titanium and a catalytic metal oxide which comprises an oxide of vanadium wherein the mass ratio vanadium/titanium is 0.07 to 0.26.

Provided is a system for treating a flowing exhaust gas comprising a lean NOx trap, a catalyzed soot filter, an ammonia or an ammonia precursor metering system for metering ammonia or an ammonia precursor into the flowing exhaust gas; and an SCR catalyst, wherein the SCR catalyst is disposed downstream of the lean NOx trap and comprises copper and/or iron supported on a small pore molecular sieve.

A method for processing an edge of a catalyst-supporting honeycomb structure in an exhaust gas denitration apparatus, in which an exhaust gas denitration apparatus equipped with a denitration catalyst-supporting honeycomb structure in which a corrugated plate-like inorganic fiber sheet and a flat plate-like inorganic fiber sheet, each supporting thereon a denitration catalyst containing a silica sol, titania particles, and ammonium metavanadate as a whole primary denitration catalyst layer, are alternately laminated, the edge of gas inlet side of the denitration catalyst-supporting honeycomb structure having the whole primary denitration catalyst layer is dipped in a denitration catalyst-containing slurry for edge processing composed of a silica sol, titania particles or kaolin particles, and ammonium metatungstate to form a coating layer of the denitration catalyst-containing slurry in the edge of the honeycomb structure, and this is dried and then calcinated to form an edge secondary denitration catalyst layer.

Described are catalyst materials and catalytic articles comprising a metal exchanged SAPO material comprising a plurality of substitutional sites consisting essentially of Si(4Al) sites and substantially free of Si(0Al) sites. The materials and catalytic articles are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

Disclosed are a catalyst for synergistic control of oxynitride and mercury and a method for preparing the same. The catalyst includes the following components by mass percentage: a carrier: TiO2 72%-98.6%, active components: V2O5 0.1%-5%, WO3 1%-10%, Cr2O3 0.1%-5% and Nb2O5 0.1%-5%, and a co-catalyst of 0.1%-3%. The present invention can be used for reducing the oxynitrides in a flue gas, meanwhile oxidizing zero-valent mercury into bivalent mercury and then controlling the reactions, has relatively high denitration performance and also has high mercury oxidation performance; compared with current commercial SCR catalysts, the mercury oxidation rate of the catalyst is improved to a great extent, which can adapt to the requirements for mercury removal in China's coal-fired power plants, the conversion rate of SO2/SO3 is relatively low, and the catalyst has a better anti-poisoning ability, and is a new catalyst with a low cost and high performance.

A method for production of vanadium catalysts, including steps of 1) providing a mixture comprising a TiO.sub.2-based support and a composite oxide containing vanadium and antimony; 2) preparing a slurry containing the mixture obtained from step 1), and additive comprising at least one species selected from the group consisting of Si, Al, Zr, Ti, W and Mo, and a solvent; and 3) applying the slurry onto a substrate or processing the slurry into shaped bodies. The vanadium catalysts obtained/obtainable from the method, and use thereof for abatement of nitrogen oxides (NOx).