Phase pure WC nanoparticles were synthesized on high surface area carbon black (800 m(2) g(-1)) by a temperature programmed reaction (TPR) method. The particle size of WC can be controlled under 30 nm with a relatively high coverage on the carbon surface. The electrochemical testing results demonstrated that the corrosion resistance of carbon black was improved by 2-fold with a surface modification by phase pure WC particles. However, the WC itself showed some dissolution under potential cycling. Based on the X-ray diffraction (XRD) and inductively coupled plasma (ICP) analysis, most of the WC on the surface was lost or transformed to oxides after 5000 potential cycles in the potential range of 0.65-1.2 V. The Pt catalyst supported on WC/C showed a slightly better ORR activity than that of Pt/C, with the Pt activity loss rate for Pt/WC/C being slightly slower compared to that of Pt/C. The performance and decay rate of Pt/WC/C were also evaluated in a fuel cell. (C) 2011 Elsevier B.V. All rights reserved.