Degradation of polymer electrolyte fuel cells under the existence of anion species

The degradation of Pt supported on carbon catalysts (Pt/C) due to four anion species (Cl-, F-, SO42-, NO3-) was investigated by operation tests using single cells of a polymer electrolyte fuel cell (PEFC). A loss of cell voltage and of electrochemical surface area (ECA) of the cathode catalyst, and an increase in oxygen gain were shown only when a solution containing Cl- was supplied. Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis after 50 h tests showed partial Pt dissolution and deposition in the membrane (Pt band) only in the inlet-side of the membrane electrode assembly (MEA). The partial loss of Pt led to the concentration of current density and degradation of cell performances. (C) 2008 Elsevier B.V. All rights reserved.