Synthesis of bimetallic structures for use as catalysts

Patent metadata

Field	Value
Publication number	US-12030035-B2
Application number	US-202318227154-A
Country	US
Kind code	B2
Filing date	Jul 27, 2023
Priority date	Mar 16, 2022
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

Aspects described herein generally relate to bimetallic structures, syntheses thereof, and uses thereof. In an embodiment, a process for forming a bimetallic nanoframe is provided. The process includes forming a first bimetallic structure by reacting a first precursor comprising platinum (Pt) and a second precursor comprising a Group 8-11 metal (M 2 ), wherein M 2 is free of Pt; reacting a third precursor comprising Pt with the first bimetallic structure to form a second bimetallic structure, the second bimetallic structure having a higher molar ratio of Pt to Group 8-11 metal than the first bimetallic structure; and introducing the second bimetallic structure with an acid to form the bimetallic nanoframe, the bimetallic nanoframe having a higher molar ratio of Pt to Group 8-11 metal than that of the second bimetallic structure, the bimetallic nanoframe having the formula: (Pt) a (M 2 ) b , wherein: a is the amount of Pt; b is the amount of M 2 .

First claim

What is claimed is:

1. A catalyst composition, comprising:
a bimetallic polyhedral nanoframe, comprising:
an interior that is at least partially hollow; and
a plurality of facets encapsulating the interior, each facet of the plurality of facets comprising metal atoms, wherein the bimetallic polyhedral nanoframe has the formula:
(M 1 ) a (M 2 ) b ,

wherein:
M 1 is Pt;
M 2 is a Group 8-11 metal comprising Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Cu, Ag, Au, or combinations thereof;
a molar ratio of a:b is from about 99:1 to about 25:75; and
an X-ray diffraction pattern of the bimetallic polyhedral nanoframe has a peak located at {111} split into two sets of diffraction patterns.

2. The catalyst composition of claim 1 , further comprising a support.

3. The catalyst composition of claim 1 , wherein the Group 8-11 metal of the bimetallic polyhedral nanoframe comprises Ni, Co, Pd, Au, Ag, or combinations thereof.

4. The catalyst composition of claim 1 , wherein the bimetallic polyhedral nanoframe, when supported on carbon, has a mass activity of greater than about 0.44 A/mg(Pt) at 0.9 V with a reference to a reversible hydrogen electrode (V RHE ).

5. The catalyst composition of claim 1 , wherein the bimetallic polyhedral nanoframe comprises a face-centered cubic nanoframe, a cubic nanoframe, a tetrahedral nanoframe, an octahedral nanoframe, a rhombic dodecahedral nanoframe, a decahedral nanoframe, an icosahedral nanoframe, a triangular prism nanoframe, a hexagonal prism nanoframe, a cuboctahedral nanoframe, a rod-shaped nanoframe, a bar-shaped nanoframe, a wire-shaped (or tube-like) nanoframe, or combinations thereof, as determined by X-ray diffraction.

6. The catalyst composition of claim 1 , wherein about 70% or more of the metal atoms of the bimetallic polyhedral nanoframe are Pt packed in a face-centered cubic structure.

7. The catalyst composition of claim 1 , wherein the Group 8-11 metal is selected from the group consisting of Ni, Fe, Co, Pd, Au, Ag, and combinations thereof.

8. The catalyst composition of claim 1 , wherein the Group 8-11 metal is selected from the group consisting of Ni, Fe, Co, and combinations thereof.

9. The catalyst composition of claim 1 , wherein M 2 comprises Ni.

10. The catalyst composition of claim 1 , wherein about 70% or more of the metal atoms are Pt.

11. The catalyst composition of claim 1 , wherein about 85% or more of the metal atoms are Pt.

12. A process for forming a conversion product, comprising:
introducing a reactant to a bimetallic polyhedral nanoframe to form the conversion product, the bimetallic polyhedral nanoframe comprising:
an interior that is at least partially hollow; and
a plurality of facets encapsulating the interior, each facet of the plurality of facets comprising metal atoms, the bimetallic polyhedral nanoframe having the formula:
(M 1 ) a (M 2 ) b ,

wherein:
M 1 is Pt;
M 2 is a Group 8-11 metal comprising Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Cu, Ag, Au, or combinations thereof;
a molar ratio of a:b is from about 99:1 to about 25:75; and
an X-ray diffraction pattern of the bimetallic polyhedral nanoframe has a peak located at {111} split into two sets of diffraction patterns.

13. The process of claim 12 , wherein the bimetallic polyhedral nanoframe, when supported on carbon, has a loss in mass activity, after 30,000 cycles, that is less than about 40% of its initial mass activity.

14. The process of claim 12 , wherein the bimetallic polyhedral nanoframe, when supported on carbon, has a mass activity of greater than about 0.44 A/mg(Pt) at 0.9 V with a reference to a reversible hydrogen electrode (V RHE ).

15. The process of claim 12 , wherein the Group 14-9 metal is selected from the group consisting of Ni, Fe, Co, Pd, Au, Ag, and combinations thereof.

16. The process of claim 12 , wherein the Group 14-9 metal is selected from the group consisting of Ni, Fe, Co, and combinations thereof.

17. The process of claim 12 , wherein M 2 comprises Ni.

18. The process of claim 12 , wherein about 70% or more of the metal atoms are Pt.

19. The process of claim 12 , wherein about 85% or more of the metal atoms are Pt.

20. The catalyst composition of claim 1 , wherein the bimetallic polyhedral nanoframe, when supported on carbon, has a loss in mass activity, after 30,000 cycles, that is less than about 40% of its initial mass activity.

Assignees

• Honda Motor Co Ltd

Inventors

• Chen Shutang
• Chen Gugang

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

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/54

  Bars or plates · CPC title

• B01J35/55

  Cylinders or rings · CPC title

• B01J2235/15

  X-ray diffraction · CPC title