Ozone-activated nanoporous gold and methods of its use

Patent metadata

Field	Value
Publication number	US-10744488-B2
Application number	US-201716070943-A
Country	US
Kind code	B2
Filing date	Jan 20, 2017
Priority date	Jan 20, 2016
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

The invention relates to nanoporous gold nanoparticle catalysts formed by exposure of nanoporous gold to ozone at elevated temperatures, as well as methods for production of esters and other compounds.

First claim

What is claimed is:

1. A nanoporous gold catalyst produced by a method comprising the steps of:
providing nanoporous gold comprising 0.1 to 10% silver by atom; and
contacting the nanoporous gold with ozone at a temperature of 100° C. or greater for a time sufficient to form the activated nanoporous gold catalyst.

2. A nanoporous gold catalyst comprising from 0.1 to 10% silver by atom, wherein the catalyst is treated with ozone at a temperature of 100° C.-185° C., or wherein the catalyst is active for selective oxidation of alcohols and inactive for oxidation of CO, or wherein at least 80% of the surface silver is oxidized and at least 60% of the surface gold is oxidized.

3. The nanoporous gold catalyst of claim 2 , further treated with a mixture of dioxygen and a primary alcohol, or having a ligament width of 10-500 nm.

4. The catalyst of claim 2 , wherein the surface layer of the catalyst has a higher Ag/Au atomic ratio relative to the bulk material of the catalyst.

5. The nanoporous gold catalyst of claim 2 , wherein the catalyst comprises an oxygen species with a binding energy of 531.5 eV.

6. The nanoporous gold catalyst of claim 2 , wherein the catalyst is active for selective oxidation of alcohols and inactive for oxidation of CO.

7. The nanoporous gold catalyst of claim 2 , wherein the catalyst is treated with ozone at a temperature of 100° C.-185° C., and the ozone is present within a mixture comprising one or more gases at a concentration of from 10 to 50 g/Nm 3 .

8. The nanoporous gold catalyst of claim 2 , wherein at least 80% of the surface silver is oxidized and at least 60% of the surface gold is oxidized.

Assignees

• Harvard College
• L Livermore Nat Security Llc

Inventors

• Friend Cynthia M
• Madix Robert J
• Zugic Branko
• Wang Lucun
• Personick Michelle L
• Biener Juergen
• Biener Monika Margarete

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/505

  with a non-spherical or unspecified core-shell structure · CPC title

• B01J35/45

  Nanoparticles · CPC title