Manufacturing processes of catalyst layer for fuel cell

• US 20050026772A1
• Filed: 07/16/2004
• Published: 02/03/2005
• Est. Priority Date: 07/16/2003
• Status: Active Grant

• Current Assignee: GS Yuasa International Ltd. (GS Yuasa Corporation)
• Original Assignee: Japan Storage Battery Company Limited (GS Yuasa Corporation)
• Inventors: Yasunaga, Yoshinobu, Hitomi, Shuji
• Granted Patent: US 7,151,069 B2
• Time in Patent Office: Days
• US Class Current: 502/101
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 4/8647 consisting of more than one material, e.g. consisting of composites
• 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 feature of the process for ultra-low alloy catalyst loading electrode according this invention is to reduce its alloy formation period of aging process subsequent to hydrogen reduction process of catalyst ions after ion exchange process of their ions and proton in the cluster of the polymer electrolyte on the surface of the carbon powder. The process is able to drastically shorten the aging time with temperature rise beyond 200° C. up to 400° C. under hydrogen atmosphere for the formation of Pt—Ru binary alloy for example catalyst by the additional processes of pre-treatment of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Ba²⁺, Fe²⁺, Sr²⁺, Ra²⁺, Cu²⁺, Ag⁺, Zn²⁺, Ni²⁺, and Co²⁺ ions substitution for proton before the hydrogen reduction process. More preference, the further post-treatment of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Ba²⁺, Fe²⁺, Sr²⁺, Ra²⁺, Cu²⁺, Ag⁺, Zn²⁺, Ni²⁺, and Co²⁺ ions substitution for proton before the ion exchange process. This new process is little harmful to the CO tolerance performance of PEFC.

Claims

1. A process for the production of the catalyst for a fuel cell comprising:

a first step of absorbing a cation of catalyst metal element into the proton conductive polymer resin in a mixture of the resin and carbon particle by ion-exchange reaction between the cation and proton of a counter ion of the resin;

a second step of chemically reducing the cation absorbed in the mixture;

a third step of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Ba²⁺ Fe²⁺, Sr⁺, Ra²⁺, Cu²⁺, Ag⁺ Zn ²⁺ Ni²⁺ and Co²⁺ ions of substitution for proton in the cluster of proton conductive polymer; and

a fourth step of aging process at the high temperature range between 100°

C. and 400°

C.

3. A process for the production of the catalyst for a fuel cell according to claim 1, wherein the temperature range is between 200°

C. and 400°

C.

5. A process for the production of the catalyst for a fuel cell according to any one of claims 1, 2, 3 or 4, wherein the catalyst element belongs to platinum group.

6. A process for the production of the catalyst for a fuel cell according to any one of claims 1, 2, 3 or 4, wherein the catalyst element comprises two or more elements belonging to the platinum group.

7. A process for the production of the catalyst for a fuel cell according to claim 5, wherein the catalyst element comprises two or more elements belonging to the platinum group.

8. A process for the production of the catalyst for a fuel cell according to any one of claims 1, 2, 3 or 4, wherein the catalyst element comprises one element belonging to the platinum group and one element belonging to the group other than the platinum group.

9. A process for the production of the catalyst for a fuel cell according to claim 5, wherein the catalyst element comprises one element belonging to the platinum group and one element belonging to the group other than the platinum group.

10. A process for the production of the catalyst for a fuel cell according to any one of claims 1, 2, 3 or 4, wherein the catalyst element comprises Pt and Ru.

11. A process for the production of the catalyst for a fuel cell according to claim 5, wherein the catalyst element comprises Pt and Ru.

12. A process for the production of the catalyst for a fuel cell according to claim 1, wherein the atmosphere of said aging process is hydrogen, inert gas, or their mixed gases.

13. A process for the production of the catalyst for a fuel cell according to claim 12, wherein the inert gas is nitrogen gas.

15. A process for the production of the catalyst for a fuel cell according to any one of claims 1, 2, 3, or 4, wherein the catalyst is for anode.

2. A process for the production of the catalyst for a fuel cell comprising:

a first step of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg ²⁺, Ca²⁺, Ba²⁺, Fe 2+, Sr²⁺, Ra²⁺, Cu²⁺, Ag⁺, Zn²⁺, Ni²⁺, and Co²⁺ ions of substitution for proton in the cluster of proton conductive polymer resin in a mixture of the resin and carbon particle followed by heating at temperature range between 100°

C. and 400°

C. subsequent to acid treatment;

a second step of absorbing a cation of catalyst metal element into the proton conductive polymer resin in a mixture of the resin and carbon particle by ion-exchange reaction between the cation and proton of a counter ion of the resin;

a third step of chemically reducing the cation absorbed in the mixture;

a fourth step of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Ba^2+, Fe²⁺, Sr²⁺, Ra²⁺, Cu²⁺, Ag⁺, Zn²⁺, Ni²⁺, and Co²⁺ ions of substitution for proton in the cluster of proton conductive polymer; and

a fifth step of aging process at the high temperature range between 100°

C. and 400°

C.

4. A process for the production of the catalyst for a fuel cell according to claim 2, wherein the temperature ranges for said first and fifth steps are between 200°

C. and 400°

C.

14. A process for the production of the catalyst for a fuel cell according to claim 2, wherein the atmospheres for said first and fifth steps are hydrogen, inert gas, or their mixed gases.