Patent attributes
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.