The Pt/C electrocatalysts containing Pr₆O₁₁ nanorods were successfully prepared. By various electrochemical characterization methods, it was demonstrated that the Pr₆O₁₁ nanorods have an obviously promotive role for ethanol electrooxidation catalyzed by Pt/C. However, according to the stripping experiment, the promotive effect of Pr₆O₁₁ does not result from the easier electrooxidation of the intermediate adsorbate on Pt–Pr₆O₁₁/C than on Pt/C. It was supposed that Pr₆O₁₁ could promote a certain step in ethanol oxidation, and that the special morphology of the nanorods could further enhance the activity compared with nanoparticles.