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.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

The present invention relates to a rare earth element containing zeolitic material having a framework structure selected from the group consisting of AEI, AFT, AFV, AFX, AVL, CHA, EMT, GME, KFI, LEV, LTN, and SFW, including mixtures of two or more thereof, the framework structure of the zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3, wherein X stands for a trivalent element, wherein the zeolitic material displays an SiO.sub.2:X.sub.2O molar ratio in the range of from 2 to 20, and wherein the zeolitic material contains one or more rare earth elements as counter-ions at the ion exchange sites of the framework structure. Furthermore, the present invention relates to a process for the production of the inventive rare earth element containing zeolitic material as well as to the use of the inventive rare earth element containing zeolitic material.

The present invention provides a method for preparing acrylic acid and methyl acrylate. The method comprises passing the feed gas containing dimethoxymethane and carbon monoxide through a solid acid catalyst to generate acrylic acid and methyl acrylate with a high conversion rate and selectivity at a reaction temperature in a range from 180 to 400 and a reaction pressure in a range from 0.1 MPa to 15.0 MPa, the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.05 h.sup.−1 to 10.0 h.sup.−1, and the volume percentage of dimethoxymethane in the feed gas is in a range from 0.1% to 95%.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

A catalyst for synthesizing aromatic hydrocarbons, a preparation method thereof and a method for synthesizing aromatic hydrocarbons by using the catalyst. The catalyst comprises acidic molecular sieve particles and zinc-aluminum composite oxide particles. The catalyst has relatively high selectivity to aromatic hydrocarbons, particularly BTX, stable performance, and a long single-pass life.

The present invention relates to a rare earth element containing zeolitic material having a framework structure selected from the group consisting of AEI, AFT, AFV, AFX, AVL, CHA, EMT, GME, KFI, LEV, LTN, and SFW, including mixtures of two or more thereof, the framework structure of the zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3, wherein X stands for a trivalent element, wherein the zeolitic material displays an SiO.sub.2:X.sub.2O.sub.3 molar ratio in the range of from 2 to 20, and wherein the zeolitic material contains one or more rare earth elements as counter-ions at the ion exchange sites of the framework structure. Furthermore, the present invention relates to a process for the production of the inventive rare earth element containing zeolitic material as well as to the use of the inventive rare earth element containing zeolitic material as such and as obtainable and/or obtained according to the inventive process.

The present invention provides a method for preparing acrylic acid and methyl acrylate. The method comprises passing the feed gas containing dimethoxymethane and carbon monoxide through a solid acid catalyst to generate acrylic acid and methyl acrylate with a high conversion rate and selectivity at a reaction temperature in a range from 180 to 400 and a reaction pressure in a range from 0.1 MPa to 15.0 MPa, the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.05 h.sup.−1 to 10.0 h.sup.−1, and the volume percentage of dimethoxymethane in the feed gas is in a range from 0.1% to 95%.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

Described is a selective catalytic reduction catalyst comprising a zeolitic framework material of silicon and aluminum atoms, wherein a fraction of the silicon atoms are isomorphously substituted with a tetravalent metal. The catalyst can include a promoter metal such that the catalyst effectively promotes the reaction of ammonia with nitrogen oxides to form nitrogen and H.sub.2O selectively over a temperature range of 150 to 650 C. In another aspect, described is a selective catalytic reduction composite comprising an SCR catalyst material and an ammonia storage material comprising a transition metal having an oxidation state of IV. The SCR catalyst material promotes the reaction of ammonia with nitrogen oxides to form nitrogen and H.sub.2O selectively over a temperature range of 150 C. to 600 C., and the SCR catalyst material is effective to store ammonia at temperatures of 400 C. and above. A method for selectively reducing nitrogen oxides, and a method for simultaneously selectively reducing nitrogen oxide and storing ammonia are also described. Additionally, an exhaust gas treatment system is also described.