Polymer-supported electrodes containing multi-atomic clusters and methods of making and using same

Patent metadata

Field	Value
Publication number	US-10026969-B2
Application number	US-201414483268-A
Country	US
Kind code	B2
Filing date	Sep 11, 2014
Priority date	Dec 13, 2011
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

Atomic mixed metal electrodes, including electrodes containing a conductive polymer-mixed metal complex, as well as methods of making and using the same, are disclosed. In some embodiments, the atomic mixed metal electrode can be described as a conductive polymer-coated electrode having mixed metal clusters complexed to the conductive polymer at levels of between 2 and 10 metal atoms. A method for preparing the conductive polymer-mixed metal complexes is disclosed that can deposit metal atoms one at a time into a complex with the conductive polymer, allowing for highly tailored atomic clusters. A method of oxidizing alcohols, and the application to devices such as fuel cells are also disclosed.

First claim

What is claimed is:

1. A method of making an atomic metal with a desired catalytic activity comprising:
coating a substrate with a conductive polymer film;
preconditioning the conductive film by oxidizing the conductive polymer film;
forming from one metal a conductive polymer-metal-X n − complex;
reducing the conductive polymer-metal-X n − complex to form an atomic metal-conductive polymer complex; and
sequentially repeating the steps of forming and reducing (N−1) number of times to create a conductive polymer-(metal) N complex;
wherein N is 2 to 10;
wherein at least two different metals are used; and
wherein the order of selection of the single metal-X n − complex used in each step of forming and reducing is determined based upon a desired catalytic activity of the atomic metal.

2. The method of claim 1 wherein:
the substrate comprises an electrode;
the metals are noble metals;
the step of forming the conductive polymer-metal-X n − complex comprises forming a conductive polymer-noble metal-X n − complex;
the step of reducing the conductive polymer-metal-X n − complex to form an atomic metal-conductive polymer complex comprises reducing the conductive polymer-noble metal-X 4 − complex to form an atomic noble metal-conductive polymer complex; and
repeating the steps of forming and reducing (N−1) number of times creates a conductive polymer-noble metal N complex.

3. The method of claim 2 , wherein the coating step comprises treating at least a portion of the electrode with a conductive polymer solution at positive potential.

4. The method of claim 3 , wherein the conductive polymer is selected from the group consisting of polyaniline (PANI), polypyrrole, and polypyridine.

5. The method of claim 3 , wherein the conductive polymer is PANI.

6. The method of claim 2 , wherein the preconditioning step comprises cycling a potential from −0.2V to +0.7V, then holding the potential at least about +0.8V for at least 30 minutes.

7. The method of claim 2 , wherein the forming step comprises:
holding the conductive polymer at about 0.7 V; and
exposing the conductive polymer to noble metal-X 4 − in an acidic medium.

8. The method of claim 2 , wherein the reducing step comprises sweeping the potential to −0.2V.

9. The method of claim 2 , wherein the noble metals are gold and palladium.

10. The method of claim 1 , wherein N is at least 3.

11. The method of claim 2 , wherein the forming step comprises:
holding the conductive polymer at about 0.7 V; and
exposing the conductive polymer to noble metal-X n − in a buffer having a pH of approximately 7.

12. The method of claim 2 , wherein the forming step comprises:
holding the conductive polymer at about 0.7 V; and
exposing the conductive polymer to noble metal-X n − in a phosphate buffer having a pH of approximately 7.

13. The method of claim 1 , wherein the desired catalytic activity of the atomic metal is selected from the group consisting of a desired HOMO-LUMO gap energy, a desired reaction rate, a desired selectivity, and a desired lifetime.

14. The method of claim 13 , wherein the substrate comprises an electrode and the method forms an atomic metal electrode.

15. The method of claim 2 , wherein the noble metals are gold and palladium;
wherein N is 3; and
wherein palladium and gold are used in repeating the steps of forming and reducing to obtain a terminal arrangement of Pd—Au in the atomic noble metal electrode.

16. A method of making an atomic metal with a desired catalytic activity comprising:
coating a portion of a substrate with a conductive polymer film;
preconditioning a portion of the conductive film by oxidizing the conductive polymer film;
forming from one metal a conductive polymer-metal-X n − complex by:
holding the conductive polymer film at a positive potential; and
exposing the conductive polymer film to metal-X n − in a medium;

reducing the conductive polymer-metal-X n − complex to form an atomic metal-conductive polymer complex; and
sequentially repeating the steps of forming and reducing (N−1) number of times to create a conductive polymer-(metal) N complex;
wherein N is an integer greater than 1;
wherein at least two different metals are used; and
wherein the sequential order of forming and reducing the conductive polymer-one metal-X n − complex is determined based upon a desired catalytic activity of the atomic metal.

17. A method of making an atomic metal with a desired catalytic activity comprising:
coating at least a portion of a substrate with a polymer film;
preconditioning at least a portion of the polymer film by oxidizing a portion of the polymer film;
forming from one metal a polymer-metal-X n − complex;
reducing the polymer-metal-X n − complex to form an atomic metal-polymer complex; and
sequentially repeating the steps of forming and reducing (N−1) number of times to create a polymer-metal N complex;
wherein N is an integer greater than 1;
wherein (M) number of different metal-X n − complexes are used;
wherein (M) is an integer from 2 to (N−1);
wherein the number of permutations of the atomic metal formed of (M) number of different metal-X n − complexes deposited (N) times is given by:

P
⁡

(

N
,
M

)

=

N
!

(

N
-
M

)

!

(
1
)

wherein the order of selection of the metal-X n − complex used in each step of forming and reducing is determined based upon a desired catalytic activity of the atomic metal.

18. The method of claim 17 , wherein the desired catalytic activity of the atomic metal comprises selecting a desired HOMO-LUMO gap energy from among the P(N,M) choices.

19. The method of claim 17 , wherein the desired catalytic activity of the atomic metal comprises selecting a desired reaction rate from among the P(N,M) choices.

20. The method of claim 17 , wherein the desired catalytic activity of the atomic metal comprises selecting a desired selectivity from among the P(N,M) choices.

21. The method of claim 17 , wherein the desired catalytic activity of the atomic metal comprises selecting a desired lifetime from among the P(N,M) choices.

22. The method of claim 17 further comprising controlling the oxidation potential of the conductive polymer film.

23. The method of claim 22 , wherein controlling the oxidation potential of t

Assignees

• Georgia Tech Res Inst

Inventors

• Jonke Alex P
• Josowicz Miroslawa A
• Janata Jiri

Classifications

• H01M4/8853

  Electrodeposition · CPC title

• H01M4/9008 Primary

  Organic or organo-metallic compounds · CPC title

• H01M8/1013

  Other direct alcohol fuel cells [DAFC] · CPC title

• C25D13/12

  characterised by the article coated · CPC title

• C25D3/48

  of gold · CPC title