Three types of MEA were prepared using Pt/C (46.6 wt% Pt), PtCo/C (47 wt% Pt, 5.4 wt% Co), and PtCoMn/C (46.9 wt% Pt, 4.1wt% Co, 0.9 wt% Mn) (Tanaka, TKK) as the cathode catalyst; these are denoted as MEA-Pt/C, MEA-PtCo/C, and MEA-PtCoMn/C, respectively.