The electrochemical promotion of CO combustion over nano-dispersed Platinum particles supported on yttria stabilized zirconia (YSZ) is investigated at 300 degrees C under high vacuum conditions. By polarizing the nanoparticles, we were able to enhance the reaction rate by a factor of 500. Charging the Pt clusters promotes the catalytic rate of CO combustion over the surface of the catalyst. The experimental facts prove that the catalytic activity of platinum nanoparticles can be electrochemically activated. Having a tuning capability on every nanoparticle rather than on a thin film opens new possibilities for the application of nano-dispersed catalysts in electrochemical promotion. (C) 2010 Elsevier B.V. All rights reserved.