Temperature effects for oxygen reduction on Ru-nanoparticles in acid solution

The investigation of the temperature effects on the oxygen reduction kinetics at the nanoparticle of ruthenium/Nafion(R) interface, is of great importance in the advancement of the proton-exchange-membrane fuel cell technology. A rotating disk electrode was used to determine the oxygen reduction kinetics in an acid medium (0.5 M H2SO4) in the range of temperature of 298-348 K. An analysis of the electrochemical data showed an independent variation of Tafel slope with temperature and a corresponding linear variation of the transfer coefficients with temperature. In order to explain this behavior, the enthalpic and entropic component of the transfer coefficient were evaluated and the apparent activation energy of this process was calculated from the electrochemical Arrhenius plot. (C) 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.