2.5. Open circuit voltage testing
Under the condition of open circuit voltage (OCV), hydroxyl
radicals are produced from hydrogen peroxide, which is formed
from oxygen and hydrogen at low anode potentials. The membrane
in the MEA is vulnerable to hydroxyl radicals, and OCV testing is
therefore used to accelerate the degradation of MEAs [3]. The
membrane in MEAswas hydrated by operating a single cell at 0.2 A/
cm2 for 150 h. Then, the cell was operated under OCV conditions
(120 C, anode/cathode 18/18%RH (inlet), H2/Air stoichiometric
ratios of 2.0/2.0 at 0.2 A/cm2 equivalent flow, ambient pressure) for
Fig. 1. Chemical structure of the PFSA polymer. 150 h.