Photocatalytic Device With Mixed Photocatalyst/Silica Structure

• US 20110027138A1
• Filed: 08/04/2010
• Published: 02/03/2011
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Kryzman, Michael A., Vanderspurt, Thomas Henry, Hugener-Campbell, Treese, Hay, Stephen O., Ollis, David F., Obee, Timothy N., Schmidt, Wayde R.
• Granted Patent: US 8,617,478 B2
• Time in Patent Office: Days
• US Class Current: 422/186.3
• CPC Class Codes: B01D 2255/20707 Titanium
• CPC Class Codes: B01D 2255/30 Silica
• CPC Class Codes: B01D 2255/802 Photocatalytic
• CPC Class Codes: B01D 2255/902 Multilayered catalyst
• CPC Class Codes: B01D 2255/9202 Linear dimensions
• CPC Class Codes: B01D 2257/708 Volatile organic compounds V.O.C.'s
• CPC Class Codes: B01D 2259/804 UV light
• CPC Class Codes: B01D 53/8687 Organic components
• CPC Class Codes: B01D 53/885 Devices in general for catalytic purification of waste gases
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 21/08 Silica
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/393 Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: B01J 35/647 2-50 nm
• CPC Class Codes: B01J 37/04 Mixing B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: F24F 13/0209 characterised by their connecting means, e.g. flanges

Abstract

A catalytic device comprises a mixed structure of photocatalyst and silica. The mixed structure may be comprised of alternating layers of photocatalyst and silica, a layer having a uniform mixture of photocatalyst particles and silica particles, or a layer having a graded mixture of photocatalyst particles and silica particles.

Claims

1. A photocatalytic device comprising:

a substrate; and

a mixed structure of photocatalyst and silica particles supported by the substrate.

2. The photocatalytic device of claim 1 wherein the mixed structure comprises alternating layers of photocatalyst particles and silica particles.

3. The photocatalytic device of claim 2 wherein the layers of silica particles have a thickness of less than about 60 nm.

4. The photocatalytic device of claim 1 wherein the mixed structure comprises a layer of a mixture of photocatalyst particles and silica particles.

5. The photocatalytic device of claim 4 wherein the mixed structure contains about 5% to about 50% by volume silica particles.

6. The photocatalytic device of claim 5 wherein the mixed structure contains about 50% or less by volume porosity.

7. The photocatalytic device of claim 4 wherein the silica particles have a surface area of about 350 to about 400 m²/gm.

8. The photocatalytic device of claim 4 wherein the layer has a graded mixture of photocatalyst particles and silica particles.

9. The photocatalytic device of claim 8 wherein the silica particles have a particle size between about 7 nm and about 40 nm.

10. The photocatalytic device of claim 4 wherein a silica particles to photocatalyst particles ratio is uniform through the layer.

11. An air purification system comprising:

an inlet;

an outlet;

a photocatalyst device for reacting with organic compounds, the photocatalyst device having a mixed structure of photocatalyst particles and silica particles supported on a substrate; and

a UV source for providing UV illumination of the photocatalytic device.

12. The system of claim 11 wherein the mixed structure comprises alternating layers of photocatalyst particles and silica particles.

13. The system of claim 12 wherein the layers of silica particles have a thickness of less than about 60 nm.

14. The system of claim 11 wherein the mixed structure comprises a layer of a mixture of photocatalyst particles and silica particles.

15. The system of claim 14 wherein the mixture contains between about 5% to about 50% by volume silica particles.

16. The system of claim 15 wherein the mixture contains about 50% or less by volume porosity.

17. The system of claim 14 wherein the silica particles have a surface area of about 350 to about 400 m²/gm.

18. The system of claim 14 wherein the layer has a graded mixture of photocatalyst particles and silica particles.

19. The system of claim 18 wherein the layer has a greater silica concentration at a surface opposite the substrate than at a surface adjacent to the substrate.

20. A photocatalytic device comprising:

a substrate; and

a mixed structure of photocatalyst particles and silica particles supported by the substrate, wherein the photocatalyst particles have pores of a diameter of about 4 nm or greater, and wherein the silica particles have a particle size of about 7 nm to about 40 nm.