A composition can include a Rho zeolite with a RHO topology having a Si to B ratio or a Si to A1 ratio greater than or equal to 8. Making such a composition can include heating an aqueous reaction mixture having a molar ratio of atomic Si to atomic B of about 4 to about 50 or a molar ratio of atomic Si to atomic Al of about 4 to about 50 in the presence of a C.sub.4-C.sub.6 diquat of N,2-dimethylbenzimidazole structure directing agent to a temperature of at least 75° C. to produce a Rho zeolite.

The present disclosure relates to a method for forming a catalyst article comprising: (a) forming a slurry having a solids content of up to 50 wt % by mixing together at least the following components a crystalline molecular sieve in an H.sup.+ or NH.sub.4.sup.+ form, an insoluble active metal precursor and an aqueous solvent at a temperature in the range 10 to 35° C.; (b) coating a substrate with the slurry formed in step (a); and (c) calcining the coated substrate formed in step (b) to form a catalyst layer on the substrate. The present disclosure further relates to a catalyst article, particularly a catalyst article which is suitable for use in the selective catalytic reduction of nitrogen oxides, and to an exhaust system.

The present invention relates to a process for the preparation of a catalyst for selective catalytic reduction comprising • (i) preparing a mixture comprising a metal-organic framework material comprising an ion of a metal or metalloid selected from groups 2-5, groups 7-9, and groups 11-14 of the Periodic Table of the Elements, and at least one at least monodentate organic compound, a zeolitic material containing a metal as a non-framework element, optionally a solvent system, and optionally a pasting agent, • (ii) calcining of the mixture obtained in (i); and further relates to a catalyst per se comprising a composite material containing an amorphous mesoporous metal and/or metalloid oxide and a zeolitic material, wherein the zeolitic material contains a metal as non-framework element, as well as to the use of said catalyst.

A catalyst for the conversion of NO.sub.X and N.sub.2O comprising iron chabazite and iron beta zeolite. A method of simultaneously reducing the NO.sub.X and N.sub.2O concentration in a process gas stream comprising contacting the process gas stream with a catalyst comprising iron chabazite and iron beta zeolite under conversion conditions.

A method of preparing a mesoporous Fe—Cu—SSZ-13 molecular sieve includes activating an aluminum source, a silicon source, an iron source and a copper source respectively; mixing the activated minerals with sodium hydroxide, water and a seed crystal at 25-90° C., while controlling feeding amounts of respective raw materials so that molar ratios of respective materials in a synthesis system are as follows: SiO.sub.2/Al.sub.2O.sub.3=10-100, SiO.sub.2/Fe.sub.2O.sub.3=30-3000, SiO.sub.2/CuO=1-100, Na.sub.2O/SiO.sub.2=0.1-0.5, H.sub.2O/SiO.sub.2=10-50, template/SiO.sub.2=0.01-0.5; adding an acid source to adjust pH of the system for first aging; and adding the acid source again to adjust the pH of the system for second aging to obtain aged gel; pouring an aged mixture into a kettle; cooling a crystallized product and filtering to remove a liquor; washing a filter cake; drying to obtain a solid; performing ion exchange; and filtering, washing and drying the solid to obtain powder; and placing the powder in a muffle furnace.

Provided is a catalyst with a more satisfactory denitration efficiency at low temperatures during a selective catalytic reduction reaction having ammonia as the reductant, compared to prior art techniques.

This denitration catalyst contains vanadium oxide. The denitration catalyst has a carbon content of 0.05% by weight or more, and has a deficiency site wherein oxygen deficiency occurs within the crystal structure.

Provided is a catalyst having better denitration efficiency at low temperatures compared to the prior art, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent. This denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which oxygen deficiency occurs in a crystal structure of the vanadium pentoxide.

The present invention pertains to a catalyst for use in the selective catalytic reduction (SCR) of nitrogen oxides cornprising: —a ceramic candle filter substrate and—a coating 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 0.03 to 0.27, —wherein the mass ratio is calculated based on the mass of vanadium metal and titanium metal, and—wherein the catalyst comprises from about 1 to about 10% by weight of the catalytically active material, and—wherein the catalytic metal oxide is adsorbed onto the surface of the oxidic metal carrier.

A method comprising treating combustion exhaust gas containing nitrogen oxides in the presence of a denitration catalyst to remove nitrogen oxides from the combustion exhaust gas, wherein the denitration catalyst is composed of a shaped product comprising a catalyst component, the shaped product has micro cracks in a mesh pattern or a bipectinate pattern on the surface of the shaped product, and the micro cracks have a 95% crack width of 100 μm or less and a crack area ratio variation coefficient of 0.7 or less.

Provided is a combustion system in which a catalyst having superior denitration efficiency at a low temperature compared with those used in the conventional techniques is used in a selective catalytic reduction reaction using ammonia as a reducing agent. A combustion system equipped with: a denitration device which is arranged in the exhaust passage and can remove a nitrogen oxide from the exhaust gas with a denitration catalyst. In the combustion system, the denitration device is arranged on the downstream side of the dust collection device in the exhaust passage, and the denitration catalyst is one which contains vanadium oxide as the main component and in which the content of a second metal in terms of oxide content is 1 to 40 wt % inclusive, wherein the second metal comprises at least one metal element selected from the group consisting of Co, W, Mo, Nb, Ce, Sn, Ni, Fe, Cu, Zn and Mn.