Ionic liquid as promotor to enhance the performance of oxygen reduction catalyst for fuel cell application

Patent metadata

Field	Value
Publication number	US-2018287165-A1
Application number	US-201715477967-A
Country	US
Kind code	A1
Filing date	Apr 3, 2017
Priority date	Apr 3, 2017
Publication date	Oct 4, 2018
Grant date	—

Abstract

A secondary ionomer that enhances activity and stability of a cathode catalyst in a polymer electrolyte membrane fuel cell includes the ionic liquid, 1-methyl-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,2-a]pyrimidin-9-ium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate ([MTBD][C 4 F 9 SO 3 ]). When contacting the catalyst, [MTBD][C 4 F 9 SO 3 ] enhances catalyst activity and stability more effectively than previously known ionomers, likely by preventing oxide formation and water adsorption at the catalyst surface. The disclosed secondary ionomer is thus most effective when completely coating the catalyst.

First claim

What is claimed is:

1 . An oxygen reduction reaction (ORR) catalyst comprising:
a solid catalyst; and a secondary ionomer contacting the solid catalyst, the secondary ionomer comprising 1-methyl-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,2-a]pyrimidin-9-ium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate ([MTBD][C 4 F 9 SO 3 ]).

2 . The ORR catalyst as recited in claim 1 , wherein the solid catalyst comprises platinum nanoparticles.

3 . The ORR catalyst as recited in claim 1 , wherein the solid catalyst comprises particles of platinum and carbon.

4 . The ORR catalyst as recited in claim 1 , wherein the [MTBD][C 4 F 9 SO 3 ] is present at a weight ratio relative to the solid catalyst within a range of 1.25:1 to 3.85:1.

5 . The ORR catalyst as recited in claim 1 , wherein the [MTBD][C 4 F 9 SO 3 ] is present at a weight ratio relative to the solid catalyst within a range of 2:1 to 3:1.

6 . The ORR catalyst as recited in claim 1 , wherein the [MTBD][C 4 F 9 SO 3 ] is present at a weight ratio relative to the solid catalyst within a range of 2.5:1 to 2.6:1.

7 . The ORR catalyst as recited in claim 1 , comprising a polymeric ionomer in contact with the solid catalyst.

8 . The ORR catalyst as recited in claim 1 , wherein the secondary ionomer completely coats the solid catalyst.

9 . The ORR catalyst as recited in claim 1 , wherein the secondary ionomer partially coats the solid catalyst.

10 . The ORR catalyst as recited in claim 1 , wherein the secondary ionomer comprises porous particles and the secondary ionomer is at least partially impregnated in the porous particles.

11 . A cathode for oxygen reduction, the cathode comprising:
a cathodic current collector; a solid catalyst; and a secondary ionomer contacting the solid catalyst, the secondary ionomer comprising 1-methyl-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,2-a]pyrimidin-9-ium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate ([MTBD][C 4 F 9 SO 3 ]).

12 . The cathode as recited in claim 11 , wherein the solid catalyst comprises platinum nanoparticles.

13 . The cathode as recited in claim 11 , wherein the solid catalyst comprises particles of platinum and carbon.

14 . The cathode as recited in claim 11 , wherein the [MTBD][C 4 F 9 SO 3 ] is present at a weight ratio relative to the solid catalyst within a range of 1.25:1 to 3.85:1.

15 . The cathode as recited in claim 11 , wherein the [MTBD][C 4 F 9 SO 3 ] is present at a weight ratio relative to the solid catalyst within a range of 2:1 to 3:1.

16 . The cathode as recited in claim 11 , wherein the [MTBD][C 4 F 9 SO 3 ] is present at a weight ratio relative to the solid catalyst within a range of 2.5:1 to 2.6:1.

17 . The cathode as recited in claim 11 , comprising a polymeric ionomer in contact with the solid catalyst.

18 . A polymer electrolyte fuel cell comprising the cathode of claim 11 .

Assignees

• Toyota Eng & Mfg North America
• The Univ Of Notre Dame
• Toyota Motor Co Ltd

Inventors

• Huang Kan
• Morales Collazo Oscar
• Brennecke Joan
• Jia Hongfei
• Kato Hisao

Classifications

• H01M4/926 Primary

  on carbon or graphite · CPC title

• H01M4/8663 Primary

  Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers · CPC title

• H01M4/92

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/86

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