The electrochemical behavior of the Pt/C catalyst and its electrocatalytic activity toward hydrogen oxidation was characterized by cyclic voltammetry and rotated disk voltammetry. The modified Koutecky-Levich equation was used to determine the kinetic parameters. The current density was reduced by the presence of Nafion coating. By reducing the thickness of both the catalyst layer (≦10 μg Pt cm^(-2)) and the Nafion film (≦0.2 μm), the H2 mass-transport resistances can be neglected. The exchange current density based on the real electroactive surface area (110 m^2g^(-1) Pt) of the Pt/C catalyst was determined to be about 0.75 mA cm^(-2). The results of this study are useful for designing the electrodes for fuel cells using Pt/C catalyst.
