In a fuel cell assembly, nickel-based anodes are readily oxidized when
exposed to oxygen as may happen through atmospheric invasion of the
assembly during cool-down following shutdown of the assembly. Repeated
anode oxidation and reduction can be destructive of the anodes, leading to
cracking and failure. To prevent such oxygen migration, check valves and
oxygen getter devices containing oxygen-scavenging material such as
metallic nickel are provided in the reformate passageways leading to and
from the anodes. The check valves preferably are closed by gravity.
Oxidation of the oxygen-gettering material is readily reversed through
reduction by reformate when the assembly is restarted.
