Molecular sieve CIT-6
AssigneeCalifornia Institute of Technology
InventorsTakahiko Takewaki, Mark E. Davis
Life of this patent
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Abstract
The present invention relates to new crystalline, molecular sieve CIT-6 that has the topology of zeolite beta. CIT-6 can be in an all-silica form, in a form wherein zinc is in the crystal framework, or a form containing silicon oxide and non-silicon oxides. In a preferred embodiment, CIT-6 has a crystal size of less than one micron and a water adsorption capacity of less than 0.05 g/g.
Claims80
A molecular sieve comprising an oxide of silicon and an oxide of zinc and having the framework topology of zeolite beta, wherein the molecular sieve contains zinc in its crystal framework.
A molecular sieve having the topology of zeolite beta, and having a composition, as synthesized and in the anhydrous state, in terms of mole ratios as follows:
- 8 SiO2/ZnO 10-100 M/SiO2 0.01-0.1 Q/SiO2 0.07-0.14
- wherein M is lithium or a mixture of lithium and another alkali metal;
- and Q comprises a tetraethylammonium cation, wherein the molecular sieve contains zinc in its crystal framework.
A molecular sieve comprising silicon oxide, zinc oxide, and an oxide selected from aluminum oxide, boron oxide, gallium oxide, iron oxide, titanium oxide, vanadium oxide, zirconium oxide, tin oxide or mixtures thereof and having the framework topology of zeolite beta, wherein the molecular sieve contains zinc in its crystal framework.
A molecular sieve having the topology of zeolite beta, and having a composition, as synthesized and in the anhydrous state, in terms of mole ratios as follows:
- 9 SiO2/ZnO 10-100 SiO2/W 30-250 M/SiO2 0.01-0.1 Q/SiO2 0.07-0.14
- wherein W is an oxide of aluminum, boron, gallium, vanadium, iron, titanium or mixtures thereof, M is lithium or a mixture of lithium and another alkali metal;
- and Q comprises a tetraethylammonium cation, wherein the molecular sieve contains zinc in its crystal framework.
A method of preparing a crystalline material comprising an oxide of silicon and an oxide of zinc and having the framework topology of zeolite beta, wherein the molecular sieve contains zinc in its crystal framework, said method comprising contacting in admixture under crystallization conditions sources of said oxides, a source of lithium or a mixture of lithium and another alkali metal and a templating agent comprising a tetraethylammonium cation.
A method of preparing a crystalline material comprising an oxide of silicon, an oxide of zinc and an oxide selected from aluminum oxide, boron oxide, gallium oxide, vanadium oxide, iron oxide, titanium oxide or mixtures thereof and having the framework topology of zeolite beta, wherein the molecular sieve contains zinc in its crystal framework, said method comprising contacting in admixture under crystallization conditions sources of said oxides, a source of lithium or a mixture of lithium and another alkali metal and a templating agent comprising a tetraethylammonium cation.
A method of removing a tetraethylammonium organic template from the pores of a molecular sieve, said method comprising contacting the molecular sieve with acetic acid or a mixture of acetic acid and pyridine at elevated temperature for a time sufficient to remove essentially all of the tetraethylammonium organic template from the molecular sieve.
A method of removing an organic template from the pores of a molecular sieve and at the same time removing zinc atoms from the framework of the molecular sieve, wherein the molecular sieve comprises an oxide of silicon, an oxide of zinc and, optionally, an oxide selected from aluminum oxide, boron oxide, gallium oxide, vanadium oxide, iron oxide, titanium oxide and mixtures thereof, and having the framework topology of zeolite beta, said method comprising contacting the molecular sieve with acetic acid or a mixture of acetic acid and pyridine at elevated temperature for a time sufficient to remove essentially all of the organic template and zinc from the molecular sieve.
A method of making a crystalline material comprising (1) contacting in admixture under crystallization conditions a source of silicon oxide, a source of zinc oxide, a source of lithium or a mixture of lithium and another alkali metal and a templating agent comprising a tetraethylammonium cation until a crystalline material comprised of oxides of silicon and zinc and having the topology of zeolite beta are formed, (2) contacting the crystals with acetic acid or a mixture of acetic acid and pyridine at an elevated temperature of about 60° C. or less for a time sufficient to-remove essentially all of the organic template and zinc from the crystals, and (3) contacting the crystals with a solution containing a source of aluminum, boron, gallium, iron, titanium, vanadium, zirconium, tin or mixtures thereof.
A crystalline molecular sieve having the topology of zeolite beta, a crystal size of less than one micron and a water adsorption capacity of less than 0.05 g/g of molecular sieve.
A crystalline silicate molecular sieve having the topology of zeolite beta, a crystal size of less than one micron and a water adsorption capacity of less than 0.05 g/g of molecular sieve.
A method of preparing a crystalline material having the topology of zeolite beta comprising impregnating a silica-containing mesoporous material with an aqueous solution of tetraethylammonium cation in an amount sufficient to form a crystalline product having the topology of zeolite beta, and wherein the water to mesoporous material molar ratio is from about 0.5 to about 2, and subjecting the impregnated mesoporous material to crystallizing conditions of heat and pressure for a time sufficient to form crystals of a material having the topology of zeolite beta.
A process for converting hydrocarbons comprising contacting a hydrocarbonaceous feed at hydrocarbon converting conditions with a catalyst comprising a molecular sieve comprising an silicon oxide, zinc oxide, and an oxide selected from aluminum oxide, boron oxide, gallium oxide, iron oxide, vanadium oxide, zirconium oxide, tin oxide or mixtures thereof and having the framework topology of zeolite beta.
The process of claim 43 wherein the molecular sieve is predominantly in the hydrogen form.
A process for converting lower alcohols and other oxygenated hydrocarbons comprising contacting said lower alcohol or other oxygenated hydrocarbon under conditions to produce liquid products with a catalyst comprising a molecular sieve comprising silicon oxide, zinc oxide, and an oxide selected from aluminum oxide, boron oxide, gallium oxide, iron oxide or mixtures thereof and having the framework topology of zeolite beta.
In a process for the reduction of oxides of nitrogen contained in a gas stream in the presence of oxygen wherein said process comprises contacting the gas stream with a molecular sieve, the improvement comprising using as the molecular sieve a molecular sieve comprising silicon oxide, zinc oxide, and an oxide selected from aluminum oxide, boron oxide, gallium oxide, iron oxide, vanadium oxide, zirconium oxide, tin oxide or mixtures thereof and having the framework topology of zeolite beta, wherein the molecular sieve contains zinc in its crystal framework.
A method of removing liquid organic compounds from a mixture of liquid organic compounds and water, comprising contacting the mixture with an all-silica molecular sieve having the framework topology of zeolite beta, a crystal size less than one micron and a water adsorption capacity of less than 0.05 g/g of molecular sieve.
A method of removing liquid organic compounds from a mixture of liquid organic compounds and water, comprising contacting the mixture with a molecular sieve comprising an oxide of silicon, an oxide of zinc and, optionally, an oxide selected from aluminum oxide, boron oxide, gallium oxide, iron oxide and mixtures thereof, and having the framework topology of zeolite beta, wherein the molecular sieve contains zinc in its crystal framework.
Dependencies are inferred from the claim text.