Synthesis of mesoporous catalytic materials

• US 5,538,710 A
• Filed: 12/14/1994
• Issued: 07/23/1996
• Est. Priority Date: 12/14/1994
• Status: Expired due to Term

• Current Assignee: Her Majesty The Queen In Right of Canada As Represented By The Minister of National Defence
• Original Assignee: Energy Mines and Resources Canada
• Inventors: Guo, Chang-Jiey, Charland, Jean-Pierre, Fairbridge, Craig W.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US08/355,899
• Time in Patent Office: 587 Days
• Field of Search: 423/701, 423/704, 423/705, 423/716, 423/713, 502/60
• US Class Current: 423/701
• CPC Class Codes: B01J 29/0308 Mesoporous materials not having base exchange properties, e.g. Si-MCM-41
• CPC Class Codes: B01J 29/041 Mesoporous materials having base exchange properties, e.g. Si/Al-MCM-41
• CPC Class Codes: B01J 29/06 Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
• CPC Class Codes: B01J 29/88 Ferrosilicates; Ferroaluminosilicates B01J29/005 takes precedence
• CPC Class Codes: B01J 29/89 Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium B01J29/005 takes precedence
• CPC Class Codes: B01J 35/69 bimodal
• CPC Class Codes: C01B 37/02 Crystalline silica-polymorphs, e.g. silicalites dealuminated aluminosilicate zeolites
• CPC Class Codes: C01B 39/00 Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination treatment to modify the sorption properties, e.g. shaping using a binder, B01J20/10; treatment to modify the catalytic properties, e.g. combination of treatments to make the zeolites appropriate to their use as a catalyst, B01J29/04; treatment to improve the ion-exchange properties B01J39/14

Abstract

A novel siliceous molecular sieve material is described for use as catalyst, along with a process for its production. The sieve material is unique in having a bimodal pore size distribution with micropores having diameters in the range from 5 to 12 Å and uniformly sized mesopores having diameters in the range from 20 to 80 Å. It is prepared by first preparing two reaction solutions, the first solution containing a source of silica and the second solution containing a quaternary ammonium surfactant having a hydrophilic ammonium group and a linear hydrophobic hydrocarbon chain. The two solutions are combined and the solid product obtained at room temperature is subjected to a two-stage heat treatment.

Claims

1. A process for synthesizing a molecular sieve material comprising an inorganic porous material having, after calcination, a bimodal pore size distribution comprising an arrangement of uniformly-sized mesopores having diameters of at least about 20 Å

and an arrangement of micropores having diameters in the range of about 5 to 12 Å

, an internal area greater than 200 m² /g and a thermal stability up to 800°

C.,

which comprises preparing two reaction solutions, the first solution containing a source of silica and the second solution containing a quaternary ammonium surfactant having a hydrophilic ammonium group and a linear hydrophobic hydrocarbon chain, combining the first and second solutions and mixing the combination at a pH in the range of 8 to 13, stopping the mixing and forming the mixture into a solid product with the mixing and solid product formation being carried out at a temperature in the range of 0°

-25°

C., separating the solid product and subjecting the product to a two-stage heat treatment comprising the steps of raising the temperature of the solid product to about 100°

to 150°

C., holding the product at this temperature for a time of 0.5 to 24 hours, then raising the temperature of the product to a temperature of about 300°

to 600°

C. and holding the product at this higher temperature for about 1 to 24 hours.

2. A process according to claim 1 wherein the molecular sieve material has an internal area greater than 800 m² /g.

3. A process according to claim 2 wherein the molecular sieve material has both an arrangement of micropores having diameters in the range from 6 to 8 Å

and an arrangement of uniformly sized mesopores having diameters in the range from 20 to 80 Å

.

4. A process according to claim 1 wherein the second solution also contains an alumina source.

5. A process according to claim 1 wherein the second solution contains a metal salt of a metal selected from the group consisting of iron sulphate, cobaltous sulphate, cupric sulphate, magnesium sulphate and titanium sulphate.

6. A process according to claim 1 wherein the mixing and formation of the solid product is carried out within a period of about 5 minutes to 4 hours.

7. A process according to claim 6 wherein the two-stage heat treatment comprises raising the temperature of the product at a rate of about 3°

C. per minute from the solid forming temperature of 0°

-25°

C. to about 120°

C. and holding at that temperature for about 2 to 5 hours, then again raising the temperature of the product at a rate of about 5°

C. per hour to about 540°

C. and holding at that temperature for about 2 to 5 hours.

8. A siliceous molecular sieve material having after calcination, an arrangement of micropores having diameters in the range from 5 to 12 Å

and also an arrangement of uniformly sized mesopores having diameters in the range from 20 to 80 Å

, said sieve material having an internal area greater than 200 m² /g and a thermal stability of up to 800°

C.

9. A molecular sieve material according to claim 8 having an internal area creater than 800 m² /g.

10. A molecular sieve material according to claim 9 comprising an aluminosilicate.