Disclosed are a ZSM-5 molecular sieve and a preparation method and use thereof. In this disclosure, a silicon source, an aluminum source, sodium hydroxide, a template and water are mixed in a rotating micro liquid membrane reactor, and then subjected to a hydrothermal crystallization to obtain the ZSM-5 molecular sieve.

Disclosed is a method for preparing a catalyst for a gasoline reaction of dimethyl ether that includes reacting a silica source, an aluminum source, and a structural derivative to synthesize a zeolite sol, mixing an alcohol with an organic template to form an emulsion phase, and adding a zeolite sol to the emulsion phase to perform a reaction.

Disclosed is a method for preparing a catalyst for a gasoline reaction of dimethyl ether that includes reacting a silica source, an aluminum source, and a structural derivative to synthesize a zeolite sol, mixing an alcohol with an organic template to form an emulsion phase, and adding a zeolite sol to the emulsion phase to perform a reaction.

A desilicated crystalline material having an MFI (ZSM-5) framework type, a molar silica to alumina ratio (SAR) of 15 or more, and mean crystal size of about 200 nm or less, is disclosed. The disclosed crystalline material has a mesopore volume of at least 0.40 cm.sup.3/g and a micropore volume of at least 0.10 cm.sup.3/g. A method of preparing a desilicated crystalline material is also disclosed. The method comprises mixing a starting ZSM-5 material having a mean crystal size of 200 nm or less in a base solution, collecting the solids by filtration or other separation methods, drying, and optionally calcining the solids.

A ZSM-5/β core-shell molecular sieve has a core composed of at least two crystal grains of ZSM-5 molecular sieve and a shell composed of a plurality of crystal grains of β molecular sieve. The ZSM-5 molecular sieve grains has an average grain size of 0.05-15 μm. The core-shell molecular sieve has a shell coverage of 50-100%, a shell thickness of 10-2000 nm, and an average grain size of the β molecular sieve grains in the shell of 10-500 nm. A ratio of a height of a diffraction peak at 2θ=22.4° to a height of a diffraction peak at 2θ=23.1° in an X-ray diffraction pattern of the ZSM-5/β core-shell molecular sieve is 0.1-10:1.

A ZSM-5/β core-shell molecular sieve has a core composed of at least two crystal grains of ZSM-5 molecular sieve and a shell composed of a plurality of crystal grains of β molecular sieve. The ZSM-5 molecular sieve grains has an average grain size of 0.05-15 μm. The core-shell molecular sieve has a shell coverage of 50-100%, a shell thickness of 10-2000 nm, and an average grain size of the β molecular sieve grains in the shell of 10-500 nm. A ratio of a height of a diffraction peak at 2θ=22.4° to a height of a diffraction peak at 2θ=23.1° in an X-ray diffraction pattern of the ZSM-5/β core-shell molecular sieve is 0.1-10:1.

According to the subject matter of the present disclosure, a method of producing an aromatization catalyst may comprise producing a plurality of uncalcined ZSM-5 nanoparticles via a dry-gel method, directly mixing the plurality of uncalcined ZSM-5 nanoparticles with large pore alumina and a binder to form a ZSM-5/alumina mixture, and calcining the ZSM-5/alumina mixture to form the aromatization catalyst. The plurality of uncalcined ZSM-5 nanoparticles may have an average diameter of less than 80 nm.

Provided are a zeolite with increased hydrothermal durability and a method of manufacturing the same. One aspect of the present invention provides a method of producing the zeolite, comprising the steps of: preparing a raw material zeolite (excluding FAU-type zeolite material) containing at least Si but not Al in the framework or having a Si/Al atomic ratio of 50 or more, and bringing the zeolite material into contact with a solution containing fluoride ions or with hot water at a temperature of 50° C. or more and 250° C. or less.

Modified crystalline zeolite materials have a zeolite framework with both tetra-coordinate Lewis aluminum single sites and Brønsted aluminum sites. The tetra-coordinate Lewis aluminum single sites include aluminum atoms covalently bonded to a variable group and to two oxygen atoms and further coordinated to a third oxygen atom. The variable group may be alkyl, hydride, or hydroxyl. Methods for incorporating tetra-coordinate Lewis aluminum single sites into a crystalline zeolite material include contacting the crystalline zeolite material with a dialkylaluminum hydride R.sub.2AlH, where each R is alkyl, to react the dialkylaluminum hydride with the zeolite framework and form tetra-coordinate alkyl aluminum single sites. Heating the alkyl-aluminum zeolite induces β-hydride elimination of the alkyl groups, whereby tetra-coordinate aluminum hydride single sites are formed. By oxidizing the hydride-aluminum zeolite, at least a portion of the tetra-coordinate aluminum hydride single sites are converted to tetra-coordinate aluminum hydroxide single sites.

Modified crystalline zeolite materials have a zeolite framework with both tetra-coordinate Lewis aluminum single sites and Brønsted aluminum sites. The tetra-coordinate Lewis aluminum single sites include aluminum atoms covalently bonded to a variable group and to two oxygen atoms and further coordinated to a third oxygen atom. The variable group may be alkyl, hydride, or hydroxyl. Methods for incorporating tetra-coordinate Lewis aluminum single sites into a crystalline zeolite material include contacting the crystalline zeolite material with a dialkylaluminum hydride R.sub.2AlH, where each R is alkyl, to react the dialkylaluminum hydride with the zeolite framework and form tetra-coordinate alkyl aluminum single sites. Heating the alkyl-aluminum zeolite induces β-hydride elimination of the alkyl groups, whereby tetra-coordinate aluminum hydride single sites are formed. By oxidizing the hydride-aluminum zeolite, at least a portion of the tetra-coordinate aluminum hydride single sites are converted to tetra-coordinate aluminum hydroxide single sites.