Method for producing proton-conducting platinum particles with a large active surface area and surface-grafted with specific, proton-conducting polymers

Patent metadata

Field	Value
Publication number	US-10673076-B2
Application number	US-201716089240-A
Country	US
Kind code	B2
Filing date	Apr 3, 2017
Priority date	Apr 4, 2016
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A specific method for preparing platinum particles grafted with proton-conducting polymers and use of these particles as catalysts for oxygen reduction.

First claim

What is claimed is:

1. Method for preparing platinum particles bonded to a carbon material, said particles being grafted with grafts consisting of at least one polymer comprising at least one styrene repeating unit having at least one proton-conducting group, said method comprising:
a) a step of preparing said platinum particles bonded to a carbon material comprising an operation of heating under microwaves of a mixture comprising a platinum salt, said carbon material and at least one polyol compound, subject to which said particles are obtained;
b) a step of preparing at least one ethylene polymer by ATRP polymerisation of an ethylene monomer with an ATRP initiator having the following formula (I):

wherein:
the R 1 groups represent, independently of one another, an organic spacer group;
the Z groups represent, independently of one another, a single bond or an organic spacer group;
the R 2 groups represent, independently of one another, a halogen atom;

the resulting polymer having the following formula (II):

wherein Y corresponds to the styrene repeating unit having at least one proton-conducting group and n 1 to the repetition number of the repeating unit taken in parentheses, the R 1 , R 2 and Z being such as defined hereinabove;
c) a step of contacting particles obtained in a) with the polymer obtained in b), subject to which particles are obtained grafted with grafts having the following formula (III):

the brace indicating the location where the grafts are bonded, covalently, to the particles and the R 1 , R 2 , Z, Y and n 1 being such as defined hereinabove.

2. Method according to claim 1 , wherein the platinum salt is a platinum halide salt.

3. Method according to claim 1 , wherein the carbon material is graphite, carbon black, carbon fibres, carbon tubes or graphene.

4. Method as claimed in claim 1 , wherein the carbon material is carbon black.

5. Method as claimed in claim 1 , wherein the polyol compound is a hydrocarbon compound comprising at least two carbon atoms each having at least one —OH group.

6. Method as claimed in claim 1 , wherein the polyol compound is ethylene glycol.

7. Method as claimed in claim 1 , wherein the step a) is carried out at a basic pH.

8. Method as claimed in claim 1 , wherein R 1 and Z represent, independently of one another, an alkylene group.

9. Method as claimed in claim 1 , wherein the —Z—R 2 groups are located in para position with respect to the —COO— groups.

10. Method as claimed in claim 1 , wherein the ATRP initiator is a compound having the following formula (IV):

11. Method as claimed in claim 1 , wherein the proton-conducting group is a sulphonic acid group —SO 3 H, a carboxylic acid group —CO 2 H or a phosphonic acid group —PO 3 H 2 , these groups being able to be present optionally in the form of salts.

12. Method as claimed in claim 1 , wherein the styrene monomer is a monomer having the following formula (V):

wherein:
Z 1 corresponds to a phenylene group; and
E corresponds to a proton-conducting group, optionally in the form of a salt.

13. Method as claimed in claim 1 , wherein the styrene monomer is a sodium styrene sulphonate monomer.

14. Platinum particles being able to be obtained by a method according to claim 1 , said platinum particles being bonded to a carbon material and being grafted with grafts having the following formula (III):

wherein R 1 , R 2 , Z, Y and n 1 have the same meaning as those given in claim 1 .

15. Particles according to claim 14 , wherein Y is a repeating unit coming from the repetition of a sodium styrene sulphonate monomer.

16. Electrode comprising particles such as defined according to claim 14 .

17. Fuel cell comprising at least one electrode-membrane-electrode assembly, wherein at least one of its electrodes is an electrode such as defined in claim 16 .

Assignees

• Commissariat Energie Atomique
• Centre Nat Rech Scient
• Commissariat A Lenergie Atomoique Et Aux Energies Alternatives

Inventors

• Buvat Pierrick
• Bigarré Janick
• Coutanceau Christophe
• Baranton Stève
• Dru Delphine

Classifications

• B01J23/42

  Platinum · CPC title

• B01J37/0213

  Preparation of the impregnating solution · CPC title

• B01J37/16

  Reducing · CPC title

• C08F12/30

  Sulfur · CPC title

• H01M4/926

  on carbon or graphite · CPC title