US 11,894,566 B2
Catalyst materials for a fuel cell stack
Soo Kim, Cambridge, MA (US); Jonathan Mailoa, Cambridge, MA (US); Ulrich Berner, Stuttgart (DE); Nathan Craig, Santa Clara, CA (US); and Charles Tuffile, Swansea, MA (US)
Assigned to Robert Bosch GmbH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on May 12, 2020, as Appl. No. 15/930,074.
Prior Publication US 2021/0359310 A1, Nov. 18, 2021
Int. Cl. H01M 4/92 (2006.01); H01M 8/1004 (2016.01); H01M 8/0438 (2016.01); H01M 8/2483 (2016.01)
CPC H01M 4/921 (2013.01) [H01M 8/04388 (2013.01); H01M 8/04395 (2013.01); H01M 8/1004 (2013.01); H01M 8/2483 (2016.02)] 20 Claims
OG exemplary drawing
 
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.