Highly active thermally stable nanoporous gold catalyst

Patent metadata

Field	Value
Publication number	US-10406507-B2
Application number	US-201615331712-A
Country	US
Kind code	B2
Filing date	Oct 21, 2016
Priority date	Jun 15, 2012
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

In one embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles. In another embodiment, a system includes a nanoporous gold structure comprising a plurality of ligaments, and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase.

First claim

What is claimed is:

1. A method, comprising:
depositing oxide nanoparticles on a nanoporous gold support to form an active structure; and
functionalizing the deposited oxide nanoparticles.

2. The method as recited in claim 1 , the depositing comprising one or more of atomic layer deposition, liquid phase deposition, and wet chemical impregnation.

3. The method as recited in claim 1 , the functionalizing comprising annealing the active structure at a temperature effective to cause crystallization of the oxide nanoparticles.

4. The method as recited in claim 3 , wherein the temperature is greater than 500 C, wherein a duration of time to cause crystallization of the oxide nanoparticles is greater than 20 min.

5. The method as recited in claim 1 , further comprising etching a gold alloy to form the nanoporous gold support, the nanoporous gold support comprising at least 99% at % gold and having a porosity of at least 50%.

6. The method as recited in claim 5 , wherein the etching comprises: submersing the gold alloy in a solution of concentrated nitric acid for at least 24 hours, wherein a concentration of the concentrated nitric acid is greater than about 70 weight percent of the solution.

7. The method as recited in claim 6 , further comprising applying an electric potential to the gold alloy during the etching.

8. The method as recited in claim 1 , wherein oxide nanoparticles comprise at least one metal oxide and/or precursor thereof.

9. The method as recited in claim 8 , wherein the at least one metal oxide is selected from the group consisting of: a titanium oxide, a precursor of titanium oxide, titanium isopropoxide (TTIP), a cerium oxide, a praseodymium oxide, Pr(NO 3 ) 3 , and an iron oxide.

10. The method as recited in claim 9 , wherein the at least one metal oxide includes titanium oxide, wherein the titanium oxide comprises at least 90% anatase crystalline phase.

11. The method as recited in claim 9 , wherein the at least one metal oxide includes cerium oxide, wherein the cerium oxide comprises at least 90% fluoride crystalline phase having oxygen vacancies.

12. The method as recited in claim 9 , wherein the at least one metal oxide includes praseodymium oxide, wherein the praseodymium oxide comprises at least 90% fluoride crystalline phase having oxygen vacancies.

13. The method as recited in claim 9 , wherein the at least one metal oxide includes iron oxide, wherein the iron oxide comprises at least 90% hematite crystalline phase.

Assignees

• L Livermore Nat Security Llc

Inventors

• Biener Juergen
• Wittstock Arne
• Biener Monika M
• Bagge-Hansen Michael
• Baeumer Marcus
• Wichmann Andre
• Neuman Bjoern

Classifications

• B01D2255/20707

  Titanium · CPC title

• B01J23/52 Primary

  Gold · CPC title

• B01D2255/106

  Gold · CPC title

• B01D2255/2065

  Cerium · CPC title

• B01D2255/802

  Photocatalytic · CPC title