Detection of OH radicals as the effect of Pt particles in the membrane of polymer electrolyte fuel cells

The formation of OH radicals (OH) for polymer electrolyte fuel cell (PEFC) was investigated with a homemade test cell by means of a fluorescence probe method for several kinds of membrane electrode assembly (MEA) consisting of Nafion. After 12-h operation under open circuit condition, OH was detected at both the anode and the cathode sides but the amount was much larger for the anode side. The formation of OH considerably depended on the amount of Pt/C catalyst loaded in the MEA. Dispersion of Pt particles in Nafion membranes increased the OH formation, but Pt ions did not. Based on the results, the formation mechanism was discussed.