Catalyst materials for a fuel cell stack

Patent metadata

Field	Value
Publication number	US-11894566-B2
Application number	US-202015930074-A
Country	US
Kind code	B2
Filing date	May 12, 2020
Priority date	May 12, 2020
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A fuel cell stack includes a first end region, a second end region, and a middle region. At least one of a first number of fuel cell units in the first end region is a first fuel cell unit including a membrane electrode assembly (MEA) with a first catalyst material on either or both an anode and a cathode of the first fuel cell unit. At least one of a second number of fuel cell units in the second end region is a second fuel cell unit including an MEA with a second catalyst material on either or both an anode and a cathode of the first fuel cell unit. The middle region is situated between the first and the second end region. At least one of a third number of fuel cell units in the middle region is a third fuel cell unit including an MEA with a third catalyst material on either or both an anode and a cathode of the first fuel cell unit. At least one of the first, the second, and the third catalyst material are different.

First claim

What is claimed is:

1. A fuel cell stack comprising:
a first end region having a first number of fuel cell units, the first end region connected to a first reactant inlet, the first reactant inlet connected to a first reactant source configured to provide a first reactant to the fuel cell stack, the first reactant source being a hydrogen source, at least one of the first number of fuel cell units being a first fuel cell unit including a membrane electrode assembly (MEA) with a first catalyst material on either or both an anode and a cathode of the first fuel cell unit, the first catalyst material including a first catalyst composition;
a second end region having a second number of fuel cell units, the second end region connected to a second reactant inlet, the second reactant inlet connected to a second reactant source configured to provide a second reactant to the fuel cell stack, the second reactant source being an oxygen source, at least one of the second number of fuel cell units being a second fuel cell unit including an MEA with a second catalyst material on either or both an anode and a cathode of the second fuel cell unit, the second catalyst material including a second catalyst composition; and
a middle region having a third number of fuel cell units, the middle region situated between the first and the second end region, at least one of the third number of fuel cell units being a third fuel cell unit including an MEA with a third catalyst material on either or both an anode and a cathode of the third fuel cell unit, the third catalyst material including a third catalyst composition, the first catalyst composition has a first catalytic activity and a first durability, the second catalyst composition has a second catalytic activity and a second durability, the third catalyst composition has a third catalytic activity and a third durability, the second catalytic activity is higher than the first and third catalytic activities, the first and third durabilities are higher than the second durability, at least one of the first, the second, and the third catalyst composition being different.

2. The fuel cell stack of claim 1 , wherein
the first catalyst composition is selected from the group consisting of pure Pt, a Pt-M alloy, and a Pt-M-M′ alloy, M is a metal element, and M′ is a metal element different than M;
the second catalyst composition is selected from the group consisting of pure Pt, a Pt-M alloy, and a Pt-M-M′ alloy; and
the third catalyst composition is selected from the group consisting of pure Pt, a Pt-M alloy and a Pt-M-M′ alloy.

3. The fuel cell stack of claim 2 , wherein M and M′ are each selected from the group consisting of Co, Ni, Re, W, Mo, Ge, Sn, Nb, Ta, and Ti.

4. The fuel cell stack of claim 1 , wherein
the first catalyst composition includes a first catalyst core made of an alloy and a catalyst skin made of pure Pt, the alloy being selected from the group consisting of a Pt-M alloy and a Pt-M-M′ alloy, M is a metal element, M′ is a metal element different than M, M and M′ are each selected from the group consisting of Co, Ni, Re, W, Mo, Ge, Sn, Nb, Ta, and Ti;
the second catalyst composition includes a second catalyst core made of an alloy and a catalyst skin made of pure Pt, the alloy being selected from the group consisting of a Pt-M alloy and a Pt-M-M′ alloy, M and M′ are each selected from the group consisting of Co, Ni, Re, W, Mo, Ge, Sn, Nb, Ta, and Ti; and
the third catalyst composition includes a third catalyst core made of an alloy and a catalyst skin made of pure Pt, the alloy being selected from the group consisting of a Pt-M alloy and a Pt-M-M′ alloy, M and M′ are each selected from the group consisting of Co, Ni, Re, W, Mo, Ge, Sn, Nb, Ta, and Ti, and at least one of the first, the second, and the third catalyst core being different.

5. The fuel cell stack of claim 1 , wherein
the first catalyst composition is loaded onto a first catalyst support at a first loading;
the second catalyst composition is loaded onto a second catalyst support at a second loading; and
the third catalyst composition is loaded onto a third catalyst support at a third loading, at least one of the first, the second, and the third loading being different.

6. The fuel cell stack of claim 5 , wherein at least another one of the first number of fuel cell units being a fourth fuel cell unit including an MEA with a fourth catalyst material on either or both an anode and a cathode of the fourth fuel cell unit, the fourth fuel cell unit positioned between the first reactant inlet and the first fuel cell unit, the fourth fuel cell unit being more susceptible to a pooling of a liquid, an acid corrosion, a pressure drop or a contaminant than the first fuel cell unit, the fourth catalyst material including a fourth catalyst composition, the fourth catalyst composition being different from the first catalyst composition, the fourth catalyst composition being loaded onto a fourth catalyst support at a fourth loading, the fourth loading being higher than the first loading.

7. The fuel cell stack of claim 5 , wherein at least another one of the second number of fuel cell units being a fifth fuel cell unit including an MEA with a fifth catalyst material on either or both an anode and a cathode of the fifth fuel cell unit, the fifth fuel cell unit positioned between the second fuel cell unit and the second reactant inlet, the fifth fuel cell unit being more susceptible to a pooling of a liquid, an acid corrosion, a pressure drop or a contaminant than the second fuel cell unit, the fifth catalyst material including a fifth catalyst composition, the fifth catalyst composition being different from the second catalyst composition, the fifth catalyst composition being loaded onto a fifth catalyst support at a fifth loading, the fifth loading being higher than the second loading.

8. The fuel cell stack of claim 5 , wherein at least another one of the third number of fuel cell units being a sixth fuel cell unit including an MEA with a sixth catalyst material, the sixth fuel cell unit being more susceptible to a pooling of a liquid, an acid corrosion, a pressure drop or a contaminant than the third fuel cell unit, the sixth catalyst material including a sixth catalyst composition, the sixth catalyst composition being different from the third catalyst composition, the sixth catalyst composition being loaded onto a sixth catalyst support at a sixth loading, the sixth loading being higher than the third loading.

9. The fuel cell stack of claim 1 , wherein the first and third catalyst compositions are pure Pt and the second catalyst composition is a Pt-M alloy, where M is a metal element.

10. The fuel cell stack of claim 1 , wherein the Pt-M alloy is Pt 3 Co.

11. A fuel cell stack comprising:
a first end region having a first number of fuel cell units, the first end region connected to a first reactant inlet, the first reactant inlet connected to a first reactant source configured to provide a first reactant to the fuel cell stack, the first reactant source being a hydrogen source, at least one of the first number of fuel cell units being a first fuel cell unit including a membrane electrode assembly (MEA) with a first catalyst material on either or both an anode and a cathode of the first fuel cell unit, the first catalyst material including a first catalyst composition;
a second end region having a second number of fuel cell units, the second end region connected to a second reactant inlet, the second reactant inlet connected to a second reactant source configured to provide a second reactant to the fuel cell stack, the second reactant source being an oxygen source, at least one of the second number of fuel cell

Assignees

• Bosch Gmbh Robert

Inventors

• Kim Soo
• Mailoa Jonathan
• Berner Ulrich
• Craig Nathan
• Tuffile Charles

Classifications

• H01M4/921 Primary

  Alloys or mixtures with metallic elements · CPC title

• H01M8/04388

  of anode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04395

  of cathode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M8/2483

  characterised by internal manifolds · CPC title