Start up of frozen fuel cell

摘要

During start up, a fuel cell is warmed to operating temperature by introducing a dilute hydrogen/air mixture into the normal process oxidant channels of the fuel cell where it reacts with a noble metal or noble metal alloy catalyst to produce heat at subflame temperatures. In one embodiment, catalyst is provided in a structure between the cathode and the process oxidant channels; if the structure is not sufficiently hydrophobic to allow the hydrogen/fuel mixture to reach it, such structure may be specially produced with hydrophobic regions to assure ice-free passages; in a structure with sufficient hydrophobic regions, only the catalyst need be added. In embodiments with a hydrophobic cathode, no structural modification is required; or a hydrophilic cathode may be provided with hydrophobic regions.