The electrocatalytic stability of the carbon supported Ru85Se15 nanoparticles has been improved by the modification of titanium dioxide for proton exchange membrane fuel cells (PEMFCs). Transmission electron microscopy (TEM), X-ray diffraction (XRD) measurements and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) are applied for characterizing Ru85Se15/C and titanium dioxide modified Ru85Se15/C (Ru85Se15/TiO2/C) electrocatalysts. Electrochemical measurements and single cell tests are conducted for the evaluation of the electrocatalysts. The results indicate that Ru85Se15/TiO2/C electrocatalyst, presenting similar initial oxygen reduction reaction (ORR) activity with Ru85Se15/C, reveals better electrochemical stability. The final potential of Ru85Se15/TiO2/C is 137 mV higher than that of Ru85Se15/C at 2 mAcm(-2) after the electrochemical durability test. Moreover, in the single cell stability test Ru85Se15/TiO2/C also shows comparable initial performance with Ru85Se15/C, but better final performance. Therefore, the Ru85Se15/C is expected to be used as an effective cathode electrocatalyst for PEMFCs by TiO2 modification on the carbon support. (C) 2010 Elsevier B.V. All rights reserved.