摘要:
The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.
摘要:
The present invention provides a titanium-silicalite molecular sieve and a method for preparing the same. The method includes the steps of preparing a mixture of a titanium source, a silicon source, a transition metal source, a template agent and water; heating the mixture to form a gel mixture; heating the gel mixture in a water bath; and calcining the gel mixture after the gel mixture in the water bath to form the titanium-silicalite molecular sieve. The present invention further provides a method for preparing cyclohexanone oxime by using the titanium-silicalite molecular sieve as the catalyst which results in high conversion rate, high selectivity and high usage efficiency of hydrogen peroxide.
摘要:
There is provided a gallium-containing MCM-22 zeolite. There are also provided methods for making this zeolite and processes for using this zeolite as a catalyst for the conversion of organic molecules. Particular conversions are reforming and the dehydrogenation of methylcyclohexane to form toluene.
摘要:
There is described a process for the preparation of novel crystalline molecular sieves, characterized by a distinctive x-ray diffraction pattern and a chemical composition in terms of mole ratios of oxides in the anhydrous state by the formula aX.sub.2 O:bM.sub.2 O.sub.3 :cSiO.sub.2 where X is a mixture of monovalent cation selected from the group consisting of alkali metal, ammonium and hydrogen, M is selected from Al, B, Fe, Ga, Cr or mixtures thereof and a=0.0 to 1.0, b=0.0 to 1.0 and c=20 or above. The process includes (i) mixing a source of silicon with (a) a source of alkali metal, (b) an organic compound containing nitrogen selected from the group consisting of hexamethylene bis trialkyl ammonium, salts of hexamethylene bis trialkyl ammonium and mixtures thereof, and (c) optionally, a source of Al, Fe, Ga, B, Cr, or mixtures thereof to form a gel, (ii) heating the resultant gel to form a crystalline material, (iii) quenching the resultant crystalline material in water, filtering, and washing with deionized water thoroughly, (iv) drying, and (v) calcining to obtain a composite catalyst.
摘要:
This disclosure relates to a ferrosilicate molecular sieve of MTW framework topology, its synthesis and use. Ferrosilicate MTW may be directly prepared using 1,3-diisobutylimidazolium cations as a structure directing agent. Ferrosilicate MTW may be used in organic compounds conversion and absorptive processes.
摘要:
This disclosure relates to new crystalline microporous solids (including silicate- and aluminosilicate-based solids), the compositions comprising 8 and 10 membered inorganic rings, particularly those having RTH topologies having a range of Si:Al ratios, methods of preparing these and known crystalline microporous solids using certain quaternized imidazolium cation structuring agents.
摘要:
This disclosure relates to new crystalline microporous solids (including silicate- and aluminosilicate-based solids), the compositions comprising 8 and 10 membered inorganic rings, particularly those having HEU topologies having a range of Si:Al ratios, methods of preparing these and known crystalline microporous solids using certain quaternized imidazolium cation structuring agents.
摘要:
This disclosure relates to new crystalline microporous solids (including silicate- and aluminosilicate-based solids), the compositions comprising 8 and 10 membered inorganic rings, particularly those having RTH topologies having a range of Si:Al ratios, methods of preparing these and known crystalline microporous solids using certain quaternized imidazolium cation structuring agents.
摘要:
This invention relates to novel compositions of zeolites or microporous metallosilicates characterized by a continuous spatial distribution of the metal and silicon in the crystals and characterized by a crystal surface enriched in silicon relative to the internal part of the same crystals. This invention also relates to a synthesis method of producing these metallosilicates with spatial distribution of the constituting elements. These novel zeolitic compositions can be used in various hydrocarbon conversion reactions. The crystalline metallosilicates can be selected from the group consisting of aluminosilicates, gallosilicates, ferrosilicates, titanosilicates and borosilicates.
摘要:
A Zn—Si or Fe—Si zeolite having an MWW framework may be formed by treating a gel solution with a hydrothermal treatment. The gel solution includes water, a silicon source, a zinc or iron source, and an MWW-templating agent. The hydrothermal treatment may include dissolving the source materials in the gel solution, and heating the gel solution with the dissolved sources to induce hydrothermal crystallization in the gel solution. The zeolite can be substantially free of aluminum, and can be used in a catalyst, or in a separation or purification device.