In this paper, we evaluated the oxygen reduction reaction (ORR) activities of Pt/C, PtCo/C, and PtCoMn/C catalysts using charge-transfer resistance (R-ct) and Delta R-ct onset voltage from electrochemical impedance spectroscopy as indicators in proton exchange membrane fuel cells (PEMFC) over a wide voltage range of 0.66 V similar to 0.95 V. ORR activity of the PtCoMn/C ternary alloy catalyst is higher than that of Pt/C over a large voltage range. A decal transfer method was used to prepare a membrane electrode assembly (MEA) with PtCoMn/C as a cathode catalyst. The cross-sectional micrograph of MEA-PtCoMn/C was characterized using scanning electron microscopy. A continuous ultrathin cathode catalyst layer that was 3 mu m thick was successfully prepared. The performance of MEA-PtCoMn/C with an ultralow Pt loading of 0.147 mg/cm(2) was evaluated using the single cell test. The highest achieved power density of MEA-PtCoMn/C was 1.42 W/cm(2). The corresponding amount of platinum was 0.1035 gPt/kW, which reaches the index of the Department of Energy (DOE). (C) The Author(s) 2019. Published by ECS.