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.

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.

A method of synthesis for an aluminophosphate-based zeolite membrane includes a steps of preparing a mixed solution with a pH greater than or equal to 6 and less than or equal to 9 by mixing an acidic phosphorous source with an alkali source, a steps of preparing a starting material solution by adding and mixing an aluminum source to the prepared mixed solution, and a steps of synthesizing an aluminophosphate-based zeolite membrane by hydrothermally synthesizing the starting material solution.

A method for the preparation of a molecular sieve belonging to the ABC-6 framework family with disorder in the ABC stacking sequence essentially composed of double-six-ring periodic building units and having a mole ratio of silicon oxide to aluminum oxide from about 8 to about 60.

The present disclosure recognizes a correlation between zeolitic surface area (ZSA) of a catalyst composition and its catalytic activity. Particularly, the disclosure provides catalyst articles for diesel NO.sub.x abatement, including a substrate and a washcoat layer containing metal-promoted molecular sieves, wherein the zeolitic surface area (ZSA) of the catalyst article is about 100 m.sup.2/g or greater, the volumetric surface area is about 900 m.sup.2/in.sup.3 or greater, and/or the total zeolitic surface area (tZSA) is about 1200 m.sup.2 or greater. The disclosure further relates to methods for evaluating ZSA, volumetric ZSA, and tZSA, e.g., including the steps of coating a catalyst composition comprising metal-promoted molecular sieves onto a substrate; calcining and aging the catalyst composition; determining the ZSA (or volumetric ZSA or tZSA) thereof; and correlating the ZSA (or volumetric ZSA or tZSA) with catalyst composition NO.sub.x abatement activity to determine whether the catalyst composition is suitable for an intended use.

A catalyst and process for the production of methyl acetate by contacting dimethyl ether and carbon monoxide in the presence of a catalyst which is a zeolite of micropore volume of 0.01 ml/g or less.

A catalyst and process for the production of methyl acetate by contacting dimethyl ether and carbon monoxide in the presence of a catalyst which is a zeolite of micropore volume of 0.01 ml/g or less.

A method for removing acid gas from feed gas, comprising: alternating input of feed gas between beds of adsorbent particles that comprise zeolite SSZ-98 or SSZ-105; wherein gas contacts one of the beds during an adsorption and tail gas is vented from another bed by desorption; wherein a product gas containing no greater than about 2 Mol % carbon dioxide is produced, and methane and ethane are recovered. A method for removing acid gas, wherein the product gas contains 1 wppm H.sub.2S or less. A process for removing acid gas from feed gas, comprising adjusting selectivity of an adsorbent by changing a substitution of ERI phase with LEV phase in an intergrown molecular sieve. A process for removing acid gas from a feed gas, comprising: contacting a feed gas with adsorbent comprising a molecular sieve having a defined intergrowth of an ERI phase and a LEV phase.

A method for removing acid gas from feed gas, comprising: alternating input of feed gas between beds of adsorbent particles that comprise zeolite SSZ-98 or SSZ-105; wherein gas contacts one of the beds during an adsorption and tail gas is vented from another bed by desorption; wherein a product gas containing no greater than about 2 Mol % carbon dioxide is produced, and methane and ethane are recovered. A method for removing acid gas, wherein the product gas contains 1 wppm H.sub.2S or less. A process for removing acid gas from feed gas, comprising adjusting selectivity of an adsorbent by changing a substitution of ERI phase with LEV phase in an intergrown molecular sieve. A process for removing acid gas from a feed gas, comprising: contacting a feed gas with adsorbent comprising a molecular sieve having a defined intergrowth of an ERI phase and a LEV phase.

A method of synthesis for an aluminophosphate-based zeolite membrane includes a steps of preparing a mixed solution with a pH greater than or equal to 6 and less than or equal to 9 by mixing an acidic phosphorous source with an alkali source, a steps of preparing a starting material solution by adding and mixing an aluminum source to the prepared mixed solution, and a steps of synthesizing an aluminophosphate-based zeolite membrane by hydrothermally synthesizing the starting material solution.