Electrochemical characterization of binary carbon supported electrode in polymer electrolyte fuel cells

In this paper, we report the use of binary carbon supports for fabricating electrodes of polymer electrolyte fuel cells and their detailed electrochemical characterization. The introduction of a secondary support in electrode is shown to provide a combination of high conductivity and good surface morphology. Cyclic voltammetry and cell polarization test indicate that the electrode prepared by binary carbon supports offers more catalytic sites and thus gives a better performance than that of single support. Comparison of kinetic parameters obtained from the model fitting shows that the improvement is not only due to the increased Pt active surface area. but also attributed to the enhanced kinetics, which is further supported by the decreased activation energy for ORR on binary-support electrode. Through the determination of pressure effect, reaction order of ORR with respect to O-2 is identified to be unity, which is in agreement with other researcher's result. (C) 2001 Elsevier Science B.V. All rights reserved.