An object of the present invention is to provide a porous support-zeolite membrane composite ensuring that at the time of separation or concentration with a zeolite membrane, both sufficient throughput and high separation performance are achieved in practice and the present invention relates to a porous support-zeolite membrane composite having a porous support and a zeolite membrane formed on the porous support, wherein part of the zeolite membrane penetrates into the inside of the porous support and the distance from the surface of the porous support to the inside into which the zeolite film penetrates is 5.0 μm or less on average.

A family of crystalline aluminosilicate zeolites has been synthesized that is a layered pentasil zeolite. These zeolites are represented by the empirical formula:

M.sub.m.sup.n+R.sub.r.sup.p+Al.sub.1-xE.sub.xSi.sub.yO.sub.z

where M is an alkali, alkaline earth, or rare earth metal such as sodium or strontium, R can be a mixture of organoammonium cations and E is a framework element such as gallium, iron, boron, or indium. These zeolites are characterized by unique x-ray diffraction patterns and compositions and have catalytic properties for carrying out various hydrocarbon conversion processes.

A family of crystalline aluminosilicate zeolites has been synthesized that is a layered pentasil zeolite. These zeolites are represented by the empirical formula:

M.sub.m.sup.n+R.sub.r.sup.p+Al.sub.1-xE.sub.xSi.sub.yO.sub.z

where M is an alkali, alkaline earth, or rare earth metal such as sodium or strontium, R can be a mixture of organoammonium cations and E is a framework element such as gallium, iron, boron, or indium. These zeolites are characterized by unique x-ray diffraction patterns and compositions and have catalytic properties for carrying out various hydrocarbon conversion processes.

Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.

Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.

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.

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 porous support-zeolite membrane composite comprising an inorganic porous support and a zeolite membrane provided on, wherein the zeolite membrane contains a zeolite having a microporous structure of 8-membered oxygen ring or less, and a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 in the zeolite membrane surface is larger by at least 20 than a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 in the zeolite membrane itself, or a water adsorption of the porous support-zeolite membrane composite at a relative pressure of 0.8, as determined from a water vapor adsorption isotherm of the porous support-zeolite membrane composite, is at least 82% of a water adsorption of the porous support-zeolite membrane composite under the same condition as above after one-week immersion of the porous support-zeolite membrane composite in an aqueous 90 mass % acetic acid solution at room temperature.

A porous support-zeolite membrane composite comprising an inorganic porous support and a zeolite membrane provided on, wherein the zeolite membrane contains a zeolite having a microporous structure of 8-membered oxygen ring or less, and a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 in the zeolite membrane surface is larger by at least 20 than a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 in the zeolite membrane itself, or a water adsorption of the porous support-zeolite membrane composite at a relative pressure of 0.8, as determined from a water vapor adsorption isotherm of the porous support-zeolite membrane composite, is at least 82% of a water adsorption of the porous support-zeolite membrane composite under the same condition as above after one-week immersion of the porous support-zeolite membrane composite in an aqueous 90 mass % acetic acid solution at room temperature.

Supported catalysts, methods of making and using are described herein. A supported catalyst can include a metal nanostructure, an oxide, or an alloy thereof, having a Lewis acid active site capable of catalyzing the formation of an alkyl aromatic compound from an aromatic hydrocarbon and an olefin, and an inert hollow zeolite support. The inert hollow zeolite support has a peripheral shell with an exterior surface and an interior surface that defines and encloses a hollow space within the interior of the shell, where the metal nanostructure, or an oxide or an alloy thereof is comprised in the hollow space.