Silica doped aluminous particulate materials

Patent metadata

Field	Value
Publication number	US-9017811-B2
Application number	US-201213536754-A
Country	US
Kind code	B2
Filing date	Jun 28, 2012
Priority date	Jun 29, 2011
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

A particulate material includes an aluminous material and a silica dopant. The particulate material includes crystallite particles with a crystallite particle size of less than about 10 nm. The crystallite particles are stacked together to form primary particles with a primary particle size of less than about 500 nm. The primary particles are agglomerated together to form secondary particles with a secondary particle size of greater than about 1 μm. The particulate material has a mean pore diameter of not less than 8 nm.

First claim

What is claimed is:

1. A particulate material comprising:
an aluminous material; and
a silica dopant in an amount of 1.5 wt % to 10 wt % based on the total weight of the particulate material,
wherein the particulate material includes crystallite particles with a crystallite particle size of less than about 10 nm, wherein the crystallite particles are stacked together to form primary particles with a primary particle size of less than about 500 nm, wherein the primary particles are agglomerated together to form secondary particles with a secondary particle size from about 1 μm to about 8 μm, and wherein the particulate material has a mean pore diameter of not less than 8 nm and a total pore volume of not less than 0.5 ml/g.

2. The particulate material of claim 1 , wherein the primary particles include rod-shaped particles.

3. The particulate material of claim 2 , wherein the rod-shaped particles have a primary aspect ratio of greater than about 2:1.

4. The particulate material of claim 1 , wherein the aluminous material comprises hydrated alumina.

5. The particulate material of claim 1 , wherein the aluminous material comprises non-hydrated alumina.

6. The particulate material of claim 1 , wherein an average particle size of the silica dopant is less than about 20 nm.

7. The particulate material of claim 1 , wherein a ratio of the aluminous material to the silica dopant is greater than about 93:7 by weight.

8. The particulate material of claim 1 , wherein the particulate material has a Hydrothermal Stability Index of not more than 25 percent, wherein the Hydrothermal Stability Index represents a change in a specific surface area of the particulate material after calcining at a temperature of about 650° C. for a time period of 3 hours and performing a hydrothermal heat treatment at a temperature of about 220° C. for a time period of 16 hours.

9. The particulate material of claim 1 , wherein the particulate material has an Acid Resistance Index of less than 15 ppm/m 2 , wherein the Acid Resistance Index represents alumina that is dissolved after calcining at a temperature of about 650° C. for a time period of 3 hours and performing an acid treatment on the particulate material at a pH of about 2 for 25 hours.

10. A method comprising:
providing a precursor material, seeds, and a silica dopant in a suspension; and
forming a particulate material that includes an aluminous material and the silica dopant, the silica dopant being present in an amount of 1.5 wt % to 10 wt % based on the total weight of the particulate material,
wherein forming the particulate material includes hydrothermal treating of the suspension, wherein the particulate material includes crystallite particles with a crystallite particle size of less than about 10 nm, wherein the crystallite particles are stacked together to form primary particles with a primary particle size of less than about 500 nm, and wherein the primary particles are agglomerated together to form secondary particles with a secondary particle size from about 1 μm to about 8 μm, and wherein the particulate material has a mean pore diameter of not less than 8 nm and a total pore volume of not less than 0.5 ml/g.

11. The method of claim 10 , wherein forming the particulate material further comprises:
drying the suspension after heat treating the suspension to form a dried gel; and
crushing the dried gel.

12. The method of claim 10 , wherein the aluminous material comprises boehmite.

13. The method of claim 10 , wherein the aluminous material comprises gamma alumina.

14. The particulate material of claim 6 , wherein an average particle size of the silica dopant is less than about 12 nm.

15. The particulate material of claim 1 , wherein the particulate material has a specific surface area of not less than 150 m 2 /g.

16. The particulate material of claim 1 , wherein at least 90% of a total pore volume of the particulate material is between 10 nm and 50 nm.

17. The particulate material of claim 4 , wherein the hydrated alumina comprises boehmite.

18. The particulate material of claim 5 , wherein the non-hydrated alumina comprises gamma alumina.

19. The particulate material of claim 2 , wherein the rod-shaped particles are arranged in form of spherical grains.

Assignees

• Te Mure
• Yener Doruk O
• Saint Gobain Ceramics

Inventors

• Te Mure
• Yener Doruk O

Classifications

• B01J35/55

  Cylinders or rings · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/77

  Compounds characterised by their crystallite size · CPC title

• B01J35/51

  Spheres · CPC title

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title