Mixed metallic oxides as scavengers for fluorinated ion exchange polymers

Patent metadata

Field	Value
Publication number	US-9819041-B2
Application number	US-201314414321-A
Country	US
Kind code	B2
Filing date	Jul 9, 2013
Priority date	Jul 11, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A mixed oxide of Si and at least one metal M comprising inorganic groups —SO 3 H. The addition of the mixed oxide to fluorinated polymers containing sulfonic acid functional groups increases their stability towards radical degradation when used in fuel cell applications.

First claim

The invention claimed is:

1. A mixed oxide of Si and at least one metal M, said oxide comprising inorganic groups —SO 3 H, wherein the inorganic groups —SO 3 H are not bound to any moiety containing at least one carbon atom.

2. The mixed oxide according to claim 1 wherein the inorganic groups —SO 3 H are bound via the sulphur atom to at least one Si, metal M or oxygen atom of the mixed oxide.

3. The mixed oxide according to claim 1 wherein the weight ratio Si/M is at least 1 and it does not exceed 40.

4. The mixed oxide according to claim 1 wherein the inorganic groups —SO 3 H are at least 0.2% with respect to the total amount of atoms of metal M in the mixed oxide.

5. The mixed oxide of claim 1 wherein the at least one metal M is selected from the group consisting of the elements of Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11 of the periodic table, Zn, Al, La and Ce.

6. The mixed oxide of claim 1 wherein the at least one metal M is selected from the group consisting of Ce, Co, Cr, Mn.

7. A process for the preparation of the mixed oxide of claim 1 comprising:
reacting an aqueous suspension comprising SiO 2 , at least one water soluble salt of metal M and at least one source of inorganic groups —SO 3 H at a temperature between 30 and 100° C. to form a gel; and
heat treating the gel at a first temperature between 30 and 180° C. and subsequently at a second temperature between 180 and 350° C. to obtain the mixed oxide in solid form.

8. A composition comprising at least one fluorinated polymer comprising —SO 2 X functional groups, wherein X is selected from X′ or from OZ and wherein X′ is selected from the group consisting of F, Cl, Br, I and Z is selected from the group consisting of H, alkaline metals, NH 4 , and at least one mixed oxide of claim 1 .

9. The composition according to claim 8 wherein the at least one mixed oxide is present in an amount of at least 0.1% and not exceeding 20% moles of metal M/moles of —SO 2 X functional groups in the fluorinated polymer.

10. A liquid composition comprising the composition of claim 8 dispersed in a liquid medium.

11. The liquid composition of claim 10 wherein in the fluorinated polymer X═OZ and Z═H.

12. A process for the preparation of a composition according to claim 8 comprising blending the at least one mixed oxide and the at least one fluorinated polymer comprising —SO 2 X functional groups in solid form or in a solution.

13. An article comprising the composition of claim 8 .

14. The article according to claim 13 which is a proton exchange membrane, an electrocatalytic layer or a membrane electrode assembly.

15. A process for the preparation of the article of claim 13 comprising impregnating, casting or coating a liquid composition, wherein the liquid composition comprises at least one fluorinated polymer comprising —SO 2 X functional groups and at least one mixed oxide of Si and at least one metal M, said oxide comprising inorganic groups —SO 3 H dispersed in a liquid medium, and wherein X is selected from X′ or from OZ and wherein X′ is selected from the group consisting of F, Cl, Br, I and Z is selected from the group consisting of H, alkaline metals, NH 4 .

16. A fuel cell comprising the article of claim 13 .

Assignees

• Solvay Specialty Polymers It

Inventors

• Oldani Claudio
• Merlo Luca
• Arico Antonio Salvatore
• D'Urso Claudia
• Baglio Vincenzo

Classifications

• H01M8/1039

  halogenated, e.g. sulfonated polyvinylidene fluorides · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M8/1055 Primary

  Inorganic layers on the polymer electrolytes, e.g. inorganic coatings · CPC title

• H01M8/1048

  Ion-conducting additives, e.g. ion-conducting particles, heteropolyacids, metal phosphate or polybenzimidazole with phosphoric acid · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title