Claims
- 1- A hybrid mesoporous silica composition comprising a framework structure defining the mesopores which is in one domain lamellar or hexagonal and in another domain with wormhole pores and wherein the domains are intergrown together.
- 2- A composition which is a hybrid wormhole and lamellar or hexagonal framework molecular sieve silica prepared by a neutralizing reaction in an aqueous solution of amine surfactant; a reactive silica species of pH between 5.0 and 10.5; aging of the solution to precipitate the silica and removing of the silica from the solution.
- 3- A composition which is a hybrid wormhole and lamellar or hexagonal molecular sieve silica prepared by a process which comprises:
(a) acidifying an aqueous solution of an amine surfactant as a structure director with an acid selected from the group consisting of organic, mineral and oxy acids; (b) preparing a reactive silica species in the aqueous solution by neutralization of a basic soluble silicate solution by mixing with the acidified amine surfactant aqueous solution of step (a) reaching a final pH of about 5 to 10.5; (c) aging the reactive silica species from step (b) at a temperature greater than −20° C.; (d) recovering a solid product from the aqueous solution by removal of the solution; and (e) removing the surfactant from the solid by calcination at 600° C. in air for not less than 30 minutes, by solvent extraction, or by treatment with a stoichiometric amount of aqueous acid solution and washing with water, to produce the molecular sieve silica, wherein silica possesses framework-confined mesopores with pore diameters ranging from 1.0 to 12.0 nm, the framework-confined channel structure comprises a hybrid wormhole and lamellar or hexagonal framework morphology has at least one resolved powder x-ray reflection corresponding to a pore-pore correlation spacing of 1.5 to 15.0 nm, inorganic oxide wall thickness of greater than 0.5 nm, specific surface areas of 400 to 1400 m2/g and framework pore volumes of 0.1 to 3 cc/g N2.
- 4- The composition of claim 3 wherein the silica in step (b) is sodium silicate “water glass” with a SiO2/Na2O=1.5 to 4.0.
- 5- The composition of claim 3 wherein silica in step (b) is colloidal silica or fumed silica.
- 6- The composition of claim 5 wherein soluble silica solution is prepared with addition of an alkali, or organic base to dissolve silica at a high pH greater than 12.
- 7- The composition of claim 3 wherein said acid is selected from the group consisting of:
HX where X=Cl, Br, I; HxY where Y=NO3−, SO4−2, PO4−3, CO3−2 and x equals the charge on Y; and HZ, where Z=an organic carboxylate, phenolate, citrate, glycolate.
- 8- The composition of claim 1 wherein the silica is defined in anhydrous form by the formula:
- 9- The composition of claim 8 having at least one resolved X-ray reflection and an X-ray diffraction pattern selected from the group consisting of FIGS. 1, 4 and 5.
- 10- The composition of claim 8 having a N2 adsorption-desorption isotherm selected from the group consisting of FIGS. 2 and 6.
- 11- The composition of claim 8 having a BET surface area between 400 and 1400 m2/g.
- 12- The composition of claim 8 having a textural mesopore volume from 0.01 to 3 cc/g.
- 13- The composition of claim 8 having TEM micrograph selected from the group consisting of FIGS. 3A, 7A and 8A.
- 14- The composition of claim 8 wherein the silica contains a hexagonal framework structure.
- 15- The composition of claim 1 wherein said oxide has a composition as follows:
- 16- The composition of claim 15 having a X-ray diffraction pattern selected from the group consisting of FIG. 4 wherein the main diffraction peak corresponds to a basal spacing between 2.0 and 15 nm.
- 17- The composition of claim 15 in which the surfactant has been removed from the silica matrix by calcination in air at 600° C.
- 18- The composition of claim 17 having a N2 adsorption-desorption isotherm, the shape of which is as in FIG. 2.
- 19- The composition of claim 15 having a TEM micrograph selected from the group consisting of FIGS. 3A, 7A and 8A.
- 20- The composition of claim 15 in which the surfactant has been removed from silica by solvent extraction or by extraction with an acid.
- 21- The composition of claim 1 wherein said silica has a composition as follows:
- 22- The composition of claim 21 having a X-ray diffraction pattern as in FIG. 1 or FIG. 5.
- 23- The composition of claim 21 in which the surfactant has been removed from the silica by calcination in air.
- 24- The composition of claim 23 having a N2 adsorption-desorption isotherm shape as in FIG. 2 or FIG. 6.
- 25- The composition of claim 23 having a TEM micrograph image selected from the group consisting of FIGS. 3A, 7A and 8A.
- 26- The composition of claim 23 in which the surfactant has been removed from the silica matrix by solvent extraction or extraction with an acid.
- 27- The composition of claim 1 wherein said silica has a composition expressed in anhydrous form as follows:
- 28- The composition of claim 27 having a X-ray diffraction pattern selected from the group consisting of FIGS. 1 and 5.
- 29- The composition of claim 27 in which the surfactant has been removed from the silica by calcinations in air.
- 30- The composition of claim 29 having a N2 adsorption-desorption isotherm shape as in FIG. 6.
- 31- The composition of claim 29 having a TEM micrograph selected from the group consisting of FIGS. 3A, 7A and 8A.
- 32- The composition of claim 27 in which the surfactant has been removed from the silica by solvent extraction or by extraction with acid.
- 33- The composition of claim 27 having a N2 adsorption-desorption isotherm shape selected from the group consisting of FIG. 6.
- 34- The composition of claim 1 having a TEM micrograph of FIG. 8A showing ordered pore structures in a hexagonal unit cell within small particle materials and having a selected area electron diffraction pattern showing polycrystalline ordering in the silica as seen by multiple diffraction spots as shown in FIG. 8C.
- 35- A composition which is a hybrid molecular sieve silica prepared by a process that comprises:
(a) preparing an aqueous solution of a amine surfactant as an organic structure director; (b) adding a basic soluble silicate to the amine solution; (c) neutralizing the basic amine and silicate solution with an acid selected from the group consisting of organic, mineral and oxy acids to a final pH of about 5.0 to 10.5 to provide a reactive silica; (d) aging reactive silica from step (b) at temperatures greater than −20° C.; (e) recovering a solid product from the aqueous solution; and (f) removing the surfactant by removal of the solution to provide the molecular sieve silica, wherein the silica possesses framework-confined mesopores with pore diameters ranging from 1.0 to 12.0 nm, the framework-confined channel structure comprises the hybrid of a wormhole and lamellar or wormhole framework morphology, has one resolved powder X-ray reflection corresponding to a pore-pore correlation spacing of 1.5 to 15.0 nm, inorganic oxide wall thickness of greater than 0.5 nm, specific surface areas of 400 to 1400 m2/g and framework pore volumes of 0.2 to 3.0 cc/g N2.
- 36- A composition which is a hybrid molecular sieve silica prepared by a process which comprises:
(a) acidifying an aqueous solution of an amine surfactant containing an alkyl chain with 6 to 36 carbon atoms as the organic structure director with an acid selected from the group consisting of organic, mineral and oxy acids; (b) preparing a reactive silica species by addition of a soluble silicate to the acidified amine surfactant reaching a pH of less than 4; (c) titrating the reactive silica with a base to a final pH of about 5.0 to 10.5; (d) aging reactive silica from step (b) at temperatures greater than −20° C.; (e) recovering a solid product from the aqueous solution; and (f) removing the surfactant from the solid product to provide the molecular sieve silica, wherein the resulting inorganic oxide possesses framework-confined mesopores with pore diameters ranging from 10 to 12.0 nm, the framework-confined channel structure comprises the hybrid of a wormhole and lamellar or hexagonal framework morphology, has at least one resolved powder x-ray reflection corresponding to a pore-pore correlation spacing of 1.5 to 15.0 nm, inorganic oxide wall thickness of greater than 0.5 nm, specific surface areas of 400 to 1400 m2/g and framework pore volumes of 0.2 to 3.0 cc/g N2.
- 37- A process for the preparation of a hybrid wormhole and lamellar or hexagonal molecular sieve silica which comprises:
(a) reacting in an aqueous solution, an amine surfactant and a reactive silica species of pH between 5.0 and 10.5; (b) aging the solution to precipitate the silica; and (c) removing the silica from the solution.
- 38- A process for the preparation of a hybrid molecular sieve silica which comprises:
(a) providing a protonated amine surfactant solution with a pH below 7.0; (b) reacting the protonated amine surfactant solution with a mixture of a base and a soluble silicate solution to produce a reactive silica species at a final pH between about 5.0 and 10.5; (c) aging the reactive silica species in the solution of step (b) at a temperature greater than −20° C. to form a precipitated product which is the silica in the solution; and (d) recovering the precipitated product from the solution.
- 39- The process of claim 38 wherein the surfactant is removed from the precipitated product.
- 40- A process for the preparation of a hybrid molecular sieve silica which comprises:
(a) acidifying surfactant solution of a neutral amine surfactant with an acid thereof to produce a pH below 7.0; (b) forming a reactive silica species by neutralization of a soluble silicate solution with the surfactant solution of step (a) to provide a final pH of about 5.0 to 10.5; (c) aging the reactive silica species in the solution of step (b) at a temperature greater than −20° C. to form a precipitated product which is the silica composition in the solution; and (d) recovering the precipitated product from the solution.
- 41- The process of claim 40 wherein soluble silica solution is a sodium silicate with SiO2/OH− ratio of between 0.7 and 2.
- 42- The process of claim 40 wherein the acid is an organic acid.
- 43- The process of claim 42 wherein the acid is selected from the group consisting of acetic, glycolic, formic and citric acid.
- 44- The process of claim 40 wherein the surfactant is removed by calcination, solvent extraction or acid washing.
- 45- The process of claim 40 with the additional step (d) of removing the surfactant and by calcination of the precipitated product in air for not less than 30 minutes.
- 46- A process for the preparation of a hybrid molecular sieve silica which comprises:
(a) providing an aqueous solution of a water soluble silicate at a pH greater than 9; (b) combining the aqueous solution with a neutral amine surfactant and an acid to produce a resulting mixture wherein the pH of the mixture is between about 5.0 and 10.5; (c) aging the resulting mixture at a temperature between −20° and 100° C. until the hybrid molecular sieve silica is formed; and (d) removing at least the aqueous solution to produce the hybrid molecular sieve silica.
- 47- A process for the preparation of a hybrid molecular sieve aluminosilicate which comprises:
(a) providing an aqueous solution of a water soluble aluminate and silicate in a molar ratio of aluminate to silicate of between about 0.01 and 1.0 at a pH greater than 9; (b) combining the aqueous solution with a neutral amine surfactant and an acid in aqueous solution to produce a resulting mixture wherein the pH of the mixture to be between about 5.0 and 10.5; (c) aging the resulting mixture at a temperature between −20° and 100° C. until the hybrid molecular sieve aluminosilicate is formed; and (d) removing at least the aqueous solution to produce the hybrid molecular sieve aluminosilicate.
- 48- A process for the preparation of a hybrid molecular sieve aluminosilicate which comprises:
(a) providing an aqueous solution of a water soluble silicate at a pH greater than 9; (b) combining the aqueous solution with a neutral amine surfactant, an aluminum salt and an acid in aqueous solution to produce a resulting mixture wherein the aluminum to silicon molar ratio is between 0.01 and 1.0 and the pH of the mixture to be between about 5.0 and 10.5; (c) aging the resulting mixture at a temperature between −20° and 100° C. until the hybrid molecular sieve aluminosilicate is formed; and (d) removing at least the aqueous solution to produce the hybrid molecular sieve aluminosilicate.
- 49- The process of claim 48 wherein in step (d) the surfactant and water are removed from the aluminosilicate so that aluminosilicate is dry.
- 50- The process of claim 48 wherein the aluminosilicate is calcined.
- 51- The process of claim 48 wherein the aluminum salt is selected from the group consisting of aluminum nitrate, aluminum chloride, aluminum sulfate and a cationic aluminum oligomer.
- 52- The composition of claim 1 derived from a mixture of a neutral amine, basic silicate and acid in an aqueous solution to produce a pH between about 5 to 10.5.
- 53- The composition of claim 1 derived from a mixture of a protonated amine and a basic silicate in an aqueous solution to produce a pH between about 5.0 and 10.5.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application relies for priority on application Ser. No. 60/197,033, filed Apr. 13, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was sponsored by NSF grant CHE 96-33798 and 99-03706. The government has certain rights in this invention.
Provisional Applications (1)
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Number |
Date |
Country |
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60197033 |
Apr 2000 |
US |