Described is a selective catalytic reduction material comprising a spherical particle including an agglomeration of crystals of a molecular sieve. The catalyst is a crystalline material that is effective to catalyze the selective catalytic reduction of nitrogen oxides in the presence of a reductant at temperatures between 200° C. and 600° C. A method for selectively reducing nitrogen oxides and an exhaust gas treatment system are also described.

Provided is a method for producing an inexpensive, high-performance AEI type zeolite and an AEI type zeolite having a Si/Al ratio of 6.5 or less by using neither an expensive Y type zeolite as a raw material nor dangerous hydrofluoric acid. The method for producing an AEI type zeolite having a Si/Al ratio of 50 or less includes: preparing a mixture including a silicon atom material, an aluminum atom material, an alkali metal atom material, an organic structure-directing agent, and water; and performing hydrothermal synthesis of the obtained mixture, in which a compound having a Si content of 20% by weight or less and containing aluminum is used as the aluminum atom material; and the mixture includes a zeolite having a framework density of 14 T/1000 Å.sup.3 or more in an amount of 0.1% by weight or more with respect to SiO.sub.2 assuming that all Si atoms in the mixture are formed in SiO.sub.2.

An exhaust gas purification system of the present disclosure includes a first exhaust gas purification device that purifies exhaust gas discharged from an internal combustion engine and a second exhaust gas purification device that additionally purifies the exhaust gas purified by the first exhaust gas purification device, wherein the exhaust gas is exhaust gas with a gaseous composition in which an amount of reducing agents is in excess compared to a stoichiometric gaseous composition and a gaseous composition in which an amount of oxidants is in excess compared to the stoichiometric gaseous composition are alternately switched between, the first exhaust gas purification device includes a three-way catalyst, and the second exhaust gas purification device includes an exhaust gas purification catalyst containing spinel-type MgAl.sub.xFe.sub.2.00−xO.sub.4.00 supporting particles on which Rh is supported, where 0.00<×≤1.50.

The present invention relates generally to the field of exhaust treatment systems for purifying exhaust gas discharged from a lean burn engine. The exhaust treatment system comprises a Diesel Oxidation Catalyst (DOC), a Catalyzed Soot Filter (CSF), a reductant injector, an AEI zeolite based Selective Catalyzed Reduction (SCR) catalyst and an Ammonia Oxidation Catalyst (AMOX) downstream to the AEI zeolite based SCR catalyst.

Disclosed in certain embodiments are catalyst-adsorbent compositions that include a metal oxide catalyst adapted for converting gaseous pollutants into chemically-benign species, and an adsorbent adapted for adsorbing the chemically-benign species together with other gaseous species and volatile organic compounds.

A selective catalytic reduction catalyst for the treatment of an exhaust gas stream of a passive ignition engine, the catalyst comprising a porous wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length (w) extending between the inlet end and the outlet end, and a plurality of passages defined by porous internal walls of the porous wall flow filter substrate; wherein the catalyst further comprises a first coating, said first coating extending over x % of the substrate axial length from the inlet end toward the outlet end of the substrate, x being in the range of from 10 to 100, wherein the first coating comprises copper and an 8-membered ring pore zeolitic material; wherein the catalyst further comprises a second coating, the second coating extending over y % of the substrate axial length from the outlet end toward the inlet end of the substrate, y being in the range of from 20 to 90, wherein the second coating comprises copper, and optionally an 8-membered ring pore zeolitic material; wherein the catalyst optionally further comprises a third coating; wherein x+y is at least 90; wherein y % of w from the outlet end toward the inlet end of the substrate define the outlet zone of the coated substrate and (100−y) % of w from the inlet end toward the outlet end of the substrate define the inlet zone of the coated substrate; wherein the ratio of the loading of copper in the inlet zone, Cu(in), calculated as CuO, relative to the loading of copper in the outlet zone, Cu(out), calculated as CuO, Cu(in):Cu(out), is less than 1:1.

It is an object to provide a catalyst that can effectively purify exhaust gas, in particular, carbon monoxide (CO) in exhaust gas, emitted from a diesel engine, a production method therefor, and an exhaust gas purification method using the same. A diesel engine exhaust gas purification catalyst for purifying exhaust gas emitted from a diesel engine of the present invention comprises a precious metal and alumina and/or zeolite supported on a three-dimensional structure, and has peaks for not less than three different pore sizes in a pore size distribution measured by the mercury intrusion method, wherein one of the peaks is a peak 2 at a pore size of not less than 0.3 μm and less than 1.0 μm, and the pore volume of the peak 2 being greater than 3.1% of the total pore volume.

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 method for making a catalyst for ozone decomposition includes: adding a reducing agent into a water solution of a permanganate salt to obtain a first reaction liquid, and heating the first reaction liquid under continuous stirring to form a birnessite-type manganese dioxide; and adding the birnessite-type manganese dioxide into a water solution of an ammonium salt to obtain a second reaction liquid, and heating the second reaction liquid under continuous stirring to form the catalyst.

The present disclosure is directed to compositions for use in oxygen capture applications, for example in three-way catalysts (TWC) systems. In some embodiments, the compositions comprise composites of aggregated and/or fused primary particles, the aggregated and/or fused primary particles collectively having the formulae [MnO.sub.x]:.sub.y:[La.sub.zMnO.sub.3].sub.1-y; wherein x is in a range from about 1 to 2.5; y is in a range from about 1 to about 30 wt %, or from about 1 to about 20 wt % or from about 2-10 wt % or from about 2 to about 5 wt %; and z is about 0.7 to about 1.1; and the La.sub.zMnO.sub.3 is a crystalline perovskite phase; the aggregated and/or fused primary particles of the composite having a mean surface area in a range of from about 25 to about 60 m.sup.2/g, preferably from about 27 to about 45 m.sup.2/g. In preferred embodiments, these compositions further comprise low levels of at least one platinum group metal (PGM), preferably Pd.