PtMo/C catalysts have been synthesized by the formic acid method. PtMo/C alloys show higher catalytic activity for the EOR than Pt/C in 0.5 M KOH. Pt3Mo1/C has shown the highest catalytic activity. The alloys oxidize CO at more negative potentials relative to Pt/C. The alloys promote the EOR in the alkaline media mostly through a 4e− route.