IMPROVED PRECIOUS METAL NANOPARTICLES

• US 20190308155A1
• Filed: 11/29/2017
• Published: 10/10/2019
• Est. Priority Date: 11/30/2016
• Status: Active Application

• Current Assignee: Heraeus Deutschland GmbH & Co. KG (Heraeus Holding GMBH)
• Original Assignee: Sebastian Kunz
• Inventors: KUNZ, Sebastian, ARENZ, Matthias, QUINSON, Jonathan, KACENAUSKAITE, Laura
• Application Number:
  US16/464,773
• Publication Number:
  US 20190308155A1
• Time in Patent Office: Days
• CPC Class Codes: B01J 13/0013 from a precipitate
• CPC Class Codes: B01J 13/0043 containing elemental metal for medical or diagnostical purposes A61K, G01N
• 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 23/468 Iridium
• CPC Class Codes: B01J 35/23 in a colloidal state
• 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 37/0211 using a colloidal suspension
• CPC Class Codes: B01J 37/16 Reducing
• CPC Class Codes: B22F 1/0545 Dispersions or suspensions of nanosized particles
• CPC Class Codes: B22F 2301/25 Noble metals, i.e. Ag Au, Ir, Os, Pd, Pt, Rh, Ru
• CPC Class Codes: B22F 9/24 starting from liquid metal compounds, e.g. solutions

Abstract

A method for preparing a colloidal dispersion of precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol, the colloidal dispersion of the precious metal nanoparticles obtained by the method according to the invention, solid and re-dispersed precious metal nanoparticles and products comprising colloidally dispersed or solid precious metal nanoparticles.

Claims

1. A method for preparing a colloidal dispersion of precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol, the method comprising:

a) providing at least one inorganic precursor for the precious metal nanoparticles, a mono-alcoholic solvent system comprising at least one mono-alcohol, and a base, wherein the at least one inorganic precursor comprises a precious metal selected from the group consisting of Pt, Pd, Ir, Ru, and combinations thereof, and the mono-alcohol of the mono-alcoholic solvent system is methanol, ethanol, propanol, or a combination thereof,

b) mixing the at least one inorganic precursor, the mono-alcoholic solvent system and the base in the absence of polymers, ligands, capping agents and surfactants, thereby obtaining a reaction mixture, so as to reduce the at least one inorganic precursor with the mono-alcoholic solvent system, and

c) obtaining the colloidal dispersion of precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol.

2. The method according to claim 1, wherein in step a) the at least one inorganic precursor comprises a first inorganic precursor for the precious metal nanoparticles and a second inorganic precursor for the precious metal nanoparticle, and the first inorganic precursor comprises a first metal selected from the group consisting of Pt, Pd, Ir, Ru, and combinations thereof, wherein the first metal in the first inorganic precursor differs from a second metal in the second inorganic precursor, so as to obtain a colloidal dispersion of bi-metallic precious metal nanoparticles.

3. The method according to claim 1, wherein the base is selected from lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH) or a mixture thereof.

4. The method according to claim 1, wherein the mono-alcoholic solvent system comprises a mixture of the at least one mono-alcohol and water.

5. The method according to claim 4, wherein the ratio (volume:

volume) of the at least one mono-alcohol to the water in the mono-alcoholic solvent system is 100;

0 to 5;

95.

6. The method according to claim 1, wherein in step a) a support is further provided and step b) is conducted in the presence of the support, so as to obtain in step c) supported precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol.

7. The method according to claim 1, wherein in step c) centrifugation and/or distillation is carried out so as to obtain solid precious metal nanoparticles.

8. A colloidal dispersion of precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol, wherein the colloidal dispersion of precious metal nanoparticles is obtainable by the method according to claim 1.

9. Solid precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol, wherein the precious metal nanoparticles are obtainable by the method according to claim 7.

10. The solid precious metal nanoparticles according to claim 9, wherein the solid precious nanoparticles are dried.

11. Re-dispersed precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol, prepared by re-dispersing the solid precious metal nanoparticles according to claim 9.

12. The re-dispersed precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol according to claim 11, wherein the precious metal nanoparticles are re-dispersed in organic solvents or aqueous media.

13. A product comprising colloidally dispersed or solid precious metal nanoparticles obtainable by the method according to claim 1.

14. The product comprising precious metal nanoparticles according to claim 13, wherein the product is selected from catalysts, sensing devices, energy devices, supported catalysts, means for bio and medical applications, membranes, supports, electric devices, and magnetic devices.

15. The re-dispersed precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol according to claim 12, wherein the precious metal nanoparticles are re-dispersed in water, an aqueous buffer, or an aqueous saline solution, each with a pH of from 2.5 to 12.5.

16. A composition comprising a colloidal dispersion of precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol.

17. The colloidal dispersion according to claim 16, wherein the colloidal dispersion is incorporated into a product selected from the group consisting of catalysts, sensing devices, energy devices, supported catalysts, means for bio and medical applications, membranes, supports, electric devices, and magnetic devices