CATALYST FOR SOLID POLYMER FUEL CELL AND METHOD FOR PRODUCING SAME

• US 20150125783A1
• Filed: 06/19/2013
• Published: 05/07/2015
• Est. Priority Date: 06/25/2012
• Status: Active Grant

• Current Assignee: Tanaka Kikinzoku Kogyo Kabushiki Kaisha (Tanaka Holdings Company Limited)
• Original Assignee: Tanaka Kikinzoku Kogyo Kabushiki Kaisha (Tanaka Holdings Company Limited)
• Inventors: Ishida, Minoru, Matsutani, Koichi
• Granted Patent: US 10,454,113 B2
• Time in Patent Office: Days
• US Class Current: 429/524
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 4/8642 Gradient in composition
• CPC Class Codes: H01M 4/8652 as mixture
• CPC Class Codes: H01M 4/8657 layered
• CPC Class Codes: H01M 4/8825 Methods for deposition of the catalytic active composition
• CPC Class Codes: H01M 4/8882 Heat treatment, e.g. drying, baking
• CPC Class Codes: H01M 4/9083 on carbon or graphite
• CPC Class Codes: H01M 4/921 Alloys or mixtures with metallic elements
• CPC Class Codes: H01M 4/926 on carbon or graphite
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The present invention is a catalyst for a solid polymer fuel cell including: catalyst particles of platinum, cobalt and manganese; and a carbon powder carrier supporting the catalyst particles, wherein the component ratio (molar ratio) of the platinum, cobalt and manganese of the catalyst particles is of Pt:Co:Mn=1:0.06 to 0.39:0.04 to 0.33, and wherein in an X-ray diffraction analysis of the catalyst particles, the peak intensity ratio of a Co—Mn alloy appearing around 2θ=27° is 0.15 or less on the basis of a main peak appearing around 2θ=40°. It is particularly preferred that the catalyst have a peak ratio of a peak of a CoPt₃ alloy and an MnPt₃ alloy appearing around 2θ=32° of 0.14 or more on the basis of a main peak.

Claims

1. A catalyst for a solid polymer fuel cell comprising:

catalyst particles of platinum, cobalt and manganese; and

a carbon powder carrier supporting the catalyst particles, wherein

a molar ratio of the platinum, cobalt and manganese of the catalyst particles is of Pt;

Co;

Mn=1;

0.06 to 0.39;

0.04 to 0.33, and

in an X-ray diffraction analysis of the catalyst particles, a peak intensity ratio of a Co—

Mn alloy appearing around 2θ

=27°

is 0.15 or less on the basis of a main peak appearing around 2θ

=40°

.

2. The catalyst for a solid polymer fuel cell according to claim 1, wherein in an X-ray diffraction analysis of the catalyst particles, a peak ratio of a peak of a CoPt₃ alloy and an MnPt₃ alloy appearing around 2θ

=32°

is 0.14 or more on the basis of a main peak appearing around 2θ

=40°

.

3. The catalyst for a solid polymer fuel cell according to claim 1, wherein the catalyst particles have a cobalt concentration and manganese concentration at a surface of the catalyst particles which is lower than a cobalt concentration and manganese concentration at a center of the particles.

4. The catalyst for a solid polymer fuel cell according to claim 1, wherein a supported density of the catalyst particles is from 30 to 70%.

5. A method for producing the catalyst for a solid polymer fuel cell according to claim 1, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

6. The method according to claim 5 for producing the catalyst for a solid polymer fuel cell, comprising the step of:

bringing the catalyst that has undergone the heat treatment into contact with an oxidizing solution one or more times to elute the cobalt and manganese at the surface of the catalyst particles.

7. The method according to claim 6 for producing the catalyst for a solid polymer fuel cell, wherein the oxidizing solution comprises sulfuric acid, nitric acid, phosphorous acid, potassium permanganate, hydrogen peroxide, hydrochloric acid, chloric acid, hypochlorous acid, or chromic acid.

8. The method according to claim 6 for producing the catalyst for a solid polymer fuel cell, wherein a treatment of the contact with the oxidizing solution has a treatment temperature of from 40 to 90°

C., and a contact time of from 1 to 10 hours.

9. The catalyst for a solid polymer fuel cell according to claim 2, wherein the catalyst particles have a cobalt concentration and manganese concentration at a surface of the catalyst particles which is lower than a cobalt concentration and manganese concentration at a center of the particles.

10. The catalyst for a solid polymer fuel cell according to claim 2, wherein a supported density of the catalyst particles is from 30 to 70%.

11. The catalyst for a solid polymer fuel cell according to claim 3, wherein a supported density of the catalyst particles is from 30 to 70%.

12. The catalyst for a solid polymer fuel cell according to claim 9, wherein a supported density of the catalyst particles is from 30 to 70%.

13. A method for producing the catalyst for a solid polymer fuel cell according to claim 2, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

14. A method for producing the catalyst for a solid polymer fuel cell according to claim 3, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

15. A method for producing the catalyst for a solid polymer fuel cell according to claim 4, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

16. A method for producing the catalyst for a solid polymer fuel cell according to claim 9, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

17. A method for producing the catalyst for a solid polymer fuel cell according to claim 10, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

18. A method for producing the catalyst for a solid polymer fuel cell according to claim 11, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

19. A method for producing the catalyst for a solid polymer fuel cell according to claim 12, comprising the steps of:

allowing a platinum catalyst which supports a platinum particle on a carbon powder carrier to support cobalt and manganese; and

performing a heat treatment at from 700 to 1100°

C. for the platinum catalyst which supports the cobalt and manganese in the above step.

20. The method according to claim 13 for producing the catalyst for a solid polymer fuel cell, comprising the step of:

bringing the catalyst that has undergone the heat treatment into contact with an oxidizing solution one or more times to elute the cobalt and manganese at the surface of the catalyst particles.