A continuous process for preparing a zeolitic material comprising (i) preparing a mixture comprising a source of YO.sub.2, optionally a source of X.sub.2O.sub.3, and a liquid solvent system; (ii) continuously feeding the mixture prepared in (i) into a continuous flow reactor at a liquid hourly space velocity in the range of from 0.3 to 20 h.sup.−1 for a duration of at least 1 h; and (iii) crystallizing the zeolitic material from the mixture in the continuous flow reactor, wherein the mixture is heated to a temperature in the range of from 100 to 300° C.; wherein the volume of the continuous flow reactor is in the range of from 150 cm.sup.3 to 75 m.sup.3, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.

An exhaust gas purification catalyst device includes a honeycomb base material and an inlet-side coat layer, wherein: the honeycomb base material includes a plurality of cells partitioned by porous partition walls, the plurality of cells including inlet-side cells and outlet-side cells and being configured such that exhaust gas that has flowed into the inlet-side cells passes through the partition walls and is exhausted from the outlet-side cells; and the inlet-side coat layer is present on the surface sides of the partition walls of the inlet-side cells, with the proportion of 4-9 μm through-pores in the through-pore diameter distribution of the partition walls being at least 80 vol %, and the peak pore diameter measured using a mercury porosimeter being at least 3.0 μm greater than the peak through-pore diameter measured using a perm porometer.

The invention provides a method of synthesizing a zeolite having the CHA crystalline framework, the method including forming a reaction mixture comprising an alumina source comprising a zeolite having an FAU crystalline framework, a silica source, and an organic structure directing agent, the reaction mixture—having a combined molar ratio of M/Si+R/Si higher than the molar ratio OH/Si, wherein M is moles of alkali metal and R is moles of organic structure directing agent; and crystallizing the reaction mixture to form a product zeolite having the CHA crystalline framework, wherein the product zeolite has a mesopore surface area (MSA) of less than about 25 m.sup.2/g. The invention also includes catalyst articles made using the product zeolite, exhaust gas treatment systems including the catalyst articles, and methods of treating exhaust gas using the catalyst articles.

A microporous crystalline material having a molar silica to alumina ratio (SAR) ranging from 10 to 15 and a fraction of Al in the zeolite framework of 0.63 or greater is disclosed. A method of selective catalytic reduction of nitrogen oxides in exhaust gas that comprises contacting exhaust gases, typically in the presence of ammonia, urea, an ammonia generating compound, or a hydrocarbon compound, with an article comprising the disclosed microporous crystalline is also disclosed. Further, a method of making the disclosed microporous crystalline material is disclosed.

A method of producing hydrothermally stable chabazite (CHA) zeolites is disclosed. The disclosed method is based on the use of reaction mixtures that (1) are essentially void of alkali metal cations and (2) contain the N,N,N-trimethyl-1-adamantyl ammonium (TMAda+) organic as the sole OSDA. The disclosed method results in a higher crystalline CHA zeolite that exhibits hydrothermal stability. There is also disclosed a zeolite material having a CHA-type framework structure made by the disclosed method. A method of selective catalytic reduction of NOx in exhaust gas using the material described herein is also disclosed.

A process for dehydrating methanol to dimethyl ether using a Brønsted acid catalyst which is a 1-dimensional or a 3-dimensional aluminosilicate zeolite or a heteropolyacid, and a promoter of Formula I C.sub.nH.sub.(2n+1)CO.sub.2CH.sub.3 wherein n=1 to 11 or Formula II C.sub.mH.sub.2m(CO.sub.2CH.sub.3).sub.2 wherein m=2 to 7 and the molar ratio of promoter to methanol is maintained at less than 1.

Disclosed herein are compositions including aluminosilicate zeolite crystals with an 8 ring pore size having a depth dependent silica to alumina molar ratio and processes of making aluminosilicate zeolite crystals with an 8 ring pore size having a depth dependent silica to alumina molar ratio.

An as-synthesized microporous material having a CHA structure and containing at least one organic structure directing agent that has the following general structure of the quaternary ammonium cation is disclosed: ##STR00001##
A microporous crystalline material made from the as-synthesized material is also disclosed. A method of making microporous crystalline material using one or more organic structure directing agents is also disclosed. A method of selective catalytic reduction of nitrogen oxides in exhaust gas that comprises contacting exhaust gases, typically in the presence of ammonia, urea, an ammonia generating compound, or a hydrocarbon compound, with an article comprising the disclosed microporous crystalline is also disclosed.

Processes are provided for the removal of hydrogen from a mixture. The process can be performed by contacting a mixture comprising hydrogen, oxygen, and one or more organic compounds with a synthetic zeolite to produce water or steam. The synthetic zeolite can include Si and Al and has a SiO.sub.2:Al.sub.2O.sub.3 molar ratio of greater than 4:1, an 8-membered ring zeolite having a framework type of AEI, AFT, AFX, CHA, CDO, DDR, EDI, ERI, IHW, ITE, ITW, KFI, MER, MTF, MWF, LEV, LTA, PAU, PWN, RHO, SFW or UFI, a degree of crystallinity of at least 80% as measured by ASTM D535-197, and at least 0.01 wt % of at least one catalytic metal, based on a weight of the synthetic zeolite, where the at least one catalytic metal can include Ru, Rh, Pd, Ag, Os, Ir, Pt, Au, Mo, W, Re, Co, Ni, Zn, Cr, Mn, Ce, Ga, alloys thereof, or mixtures thereof. At least 95% of the catalytic metal can be disposed within a plurality of pores of the synthetic zeolite.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.