Metal oxide nanorod arrays on monolithic substrates

• US 9,855,549 B2
• Filed: 09/28/2012
• Issued: 01/02/2018
• Est. Priority Date: 09/28/2011
• Status: Active Grant

• Current Assignee: University of Connecticut (State of Connecticut)
• Original Assignee: University of Connecticut (State of Connecticut)
• Inventors: Gao, Pu-Xian, Guo, Yanbing, Ren, Zheng
• Primary Examiner(s): Zimmer, Anthony J
• Application Number:
  US14/347,850
• Publication Number:
  US 20140256534A1
• Time in Patent Office: 1,922 Days
• CPC Class Codes: B01D 2255/10 Noble metals or compounds thereof
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/34 Manganese
• CPC Class Codes: B01J 23/42 Platinum
• CPC Class Codes: B01J 23/44 Palladium
• CPC Class Codes: B01J 23/462 Ruthenium
• CPC Class Codes: B01J 23/464 Rhodium
• CPC Class Codes: B01J 23/60 with zinc, cadmium or mercury
• CPC Class Codes: B01J 23/63 with rare earths or actinides
• CPC Class Codes: B01J 23/66 Silver or gold
• CPC Class Codes: B01J 23/83 with rare earths or actinides
• CPC Class Codes: B01J 23/8913 Cobalt and noble metals
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/393 Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/56 Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 35/612 less than 10 m2/g
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: B01J 37/031 : Precipitation
• CPC Class Codes: B01J 37/038 : to form slurries or suspensions, e.g. a washcoat
• CPC Class Codes: Y10T 428/24612 : Composite web or sheet

Abstract

A metal oxide nanorod array structure according to embodiments disclosed herein includes a monolithic substrate having a surface and multiple channels, an interface layer bonded to the surface of the substrate, and a metal oxide nanorod array coupled to the substrate surface via the interface layer. The metal oxide can include ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide. The substrate can include a glass substrate, a plastic substrate, a silicon substrate, a ceramic monolith, and a stainless steel monolith. The ceramic can include cordierite, alumina, tin oxide, and titania. The nanorod array structure can include a perovskite shell, such as a lanthanum-based transition metal oxide, or a metal oxide shell, such as ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide, or a coating of metal particles, such as platinum, gold, palladium, rhodium, and ruthenium, over each metal oxide nanorod. Structures can be bonded to the surface of a substrate and resist erosion if exposed to high velocity flow rates.

Claims

1. A metal oxide nanorod array structure comprising:

a honeycomb monolithic substrate having a surface and multiple channels;

an interface layer bonded to the surface of the substrate; and

a metal oxide nanorod array coupled to the substrate surface via the interface layer, wherein the metal oxide nanorod is formed of TiO₂, CeO₂, ZnO, SnO₂, Al₂O₃, ZrO₂, Co₃O₄, or Ga₂O₃.

2. The nanorod array structure of claim 1, wherein the metal oxide nanorod array is vertically aligned relative to the surface of the substrate.

3. The nanorod array structure of claim 2, wherein the metal oxide nanorod is formed of titania (TiO₂).

4. The nanorod array structure of claim 3, wherein the titania is brookite titania.

5. The nanorod array structure of claim 1, wherein the substrate is formed of plastic, silicon, ceramic or stainless steel.

6. The nanorod array structure of claim 4, wherein the substrate is formed of ceramic.

7. The nanorod array structure of claim 6, wherein the ceramic includes one of the following:

cordierite, alumina, tin oxide, and titania.

8. The nanorod array structure of claim 1, wherein the metal oxide nanorod includes one of the following:

ceria (CeO₂), zinc oxide (ZnO), tin oxide (SnO2), alumina (Al₂O₃), zirconia (ZrO₂), cobalt oxide (Co₃O₄), and gallium oxide (Ga₂O₃).

9. The nanorod array structure of claim 1, further including a perovskite ABO₃ (A=La, Ba, Sr, and/or Pb, B=Co, Cr, Fe, Mn, or Ni) shell over each metal oxide nanorod.

10. The nanorod array structure of claim 9, wherein the perovskite is a lanthanum-based transition metal oxide, LaMO₃ (M=Co, Cr, Fe, Mn, and Ni).

11. The nanorod array structure of claim 10, wherein the lanthanum-based transition metal oxide is lanthanum strontium cobaltate.

12. The nanorod array structure of claim 10, wherein the lanthanum-based transition metal oxide is lanthanum strontium manganate.

13. The nanorod array structure of claim 1, further including a metal oxide shell over each metal oxide nanorod.

14. The nanorod array structure of claim 13, wherein the shell includes one of the following metal oxides:

ceria (CeO₂), zinc oxide (ZnO), tin oxide (SnO₂), alumina (Al₂O₃), zirconia (ZrO₂), cobalt oxide (CO₃O₄), and gallium oxide (Ga₂O₃).

15. The nanorod array structure of claim 1, further including an alkaline oxide shell over each metal oxide nanorod.

16. The nanorod array structure of claim 15, wherein the alkaline oxide shell includes at least one of the following oxides:

barium oxide and potassium oxide.

17. The nanorod array structure of claim 1, further including a coating of metal particles over each metal oxide nanorod, the metal including at least one of the following:

platinum, gold, palladium, rhodium, and ruthenium.

18. The nanorod array structure of claim 9, further including a coating of metal particles over each metal oxide nanorod, the metal including at least one of the following:

platinum, gold, palladium, rhodium, and ruthenium.