Method for the synthesis of high efficiency PT branched nanocatalysts

Patent metadata

Field	Value
Publication number	US-12080895-B2
Application number	US-202217883912-A
Country	US
Kind code	B2
Filing date	Aug 9, 2022
Priority date	Aug 9, 2022
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A method for making a branched metal nanocatalyst including providing a first metal precursor solution having a first metal precursor, wherein providing the first metal precursor solution includes combining a first metal ion source and a first alkylamine, and providing a second metal precursor solution, wherein providing the second metal precursor solution includes combining a second metal ion source and a second alkylamine, heating the second metal precursor solution, combining the first metal precursor solution with the second metal precursor solution to provide a reaction solution, and holding the reaction solution at an elevated temperature for a reaction time to provide a branched metal nanocatalyst. Also described are nanocatalysts prepared according to the method.

First claim

What is claimed is:

1. A method for making a branched metal nanocatalyst, comprising:
providing a first metal precursor solution comprising a first metal precursor, wherein providing the first metal precursor solution comprises combining a first metal ion source and a first alkylamine, and
providing a second metal precursor solution, wherein providing the second metal precursor solution comprises combining a second metal ion source and a second alkylamine,
heating the second metal precursor solution;
combining the first metal precursor solution with the second metal precursor solution to provide a reaction solution; and
holding the reaction solution at an elevated temperature for a reaction time to provide a branched metal nanocatalyst.

2. The method of claim 1 , wherein the first metal ion source is selected from a group consisting of sodium hexachloroplatinate hexahydrate, chloroplatinic acid hexahydrate, platinum chloride, platinum acetylacetonate, hydrates thereof, and combinations thereof.

3. The method according to claim 1 , wherein the first alkylamine is selected from a group consisting of oleylamine, hexadectylamine, dodecylamine, octadecylamine, tetradecylamine, and combinations thereof.

4. The method of claim 1 , wherein the first metal precursor is selected from a group consisting of Pt-OLA, Pt-HDA, Pt-DD, Pt-ODA, and Pt-TDA.

5. The method of claim 1 , wherein the second metal ion source is selected from a group consisting of sodium hexachloroplatinate hexahydrate, chloroplatinic acid hexahydrate, platinum chloride, platinum acetylacetonate, hydrates thereof, and combinations thereof.

6. The method according to claim 1 , wherein the second alkylamine is selected from a group consisting of oleylamine, hexadectylamine, dodecylamine, octadecylamine, tetradecylamine, and combinations thereof.

7. The method of claim 1 , wherein the elevated temperature is between about 100 and 300° C.

8. The method of claim 1 , wherein the elevated temperature is between about 100 and 200° C.

9. The method of claim 1 , wherein the branched metal nanocatalyst comprises platinum.

10. The method of claim 9 , wherein branched metal nanocatalyst is enclosed by high-index facets.

11. The method according to claim 9 , wherein the branched metal nanocatalyst has a mass activity of at least 0.44 A/mg Pt at 0.9 V with <40% loss in initial activity after 100,000 cycles in a proton exchange membrane fuel cell.

12. The method of claim 1 , wherein a concentration of the first metal precursor provided to the reaction solution is between about 1 and 200 mg/mL.

13. The method of claim 1 , wherein an atomic molar ratio of the first metal ion source to the first alkylamine combined to provide the first metal precursor solution is from about 1:1 to 1:200.

14. The method of claim 13 , wherein the atomic molar ratio of the first metal ion source to the first alkylamine combined to provide the first metal precursor solution is from about 1:10 to 1:160.

15. The method of claim 1 , wherein an atomic molar ratio of the second metal ion source to the second alkylamine combined to provide the first metal precursor solution is from about 1:1 to 1:500.

16. The method of claim 15 , wherein the atomic molar ratio of the second metal ion source to the second alkylamine combined to provide the first metal precursor solution is from about 1:10 to 1:360.

17. A branched metal nanocatalyst prepared by the method according to claim 1 , wherein the branched metal nanocatalyst comprises platinum, and wherein branched metal nanocatalyst is enclosed by high-index facets.

Assignees

• Honda Motor Co Ltd

Inventors

• Chen Shutang

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/921

  Alloys or mixtures with metallic elements · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• H01M4/86

  Inert electrodes with catalytic activity, e.g. for fuel cells · CPC title