This Paper describes an experimental met,that that established a local Pt/Nafion interface on the Platinum Plane, so that the boundary conditions and the initial condition of the (diffusion equation about the diffusion of adsorbde hydrogen atom the platinum plane can be controlled.The average diffusion coefficient of underpotential deposition of hydrogen on a surface of platinum was obained for the first time and D=1.50 ×10-4cm2.s-1.The accuracy of the datum was discussed.
