Effect of agglomeration of Pt/C catalyst on hydrogen peroxide formation

Abstract

Various amounts of 20wt.% Pt/C catalyst (56.7-5.7 μgcarbon cm-2) were loaded on glassy carbon (GC) disk electrode, and the effect of its agglomeration on hydrogen peroxide formation in oxygen reduction was investigated by the rotating ring-disk electrode technique. The formation of H2O2 was enhanced with a reduction in agglomeration of Pt/C. Even in the operating potential range of PEFC cathodes (0.6-0.8 V), 10% hydrogen peroxide was formed at 5.7 μgcarbon cm-2 Pt/C loaded on GC. These results revealed that series 2-electron reduction pathway, which is negligible on clean bulk Pt surface, does exist on Pt particles supported on carbon.