Kinetics of Hydrogen Oxidation and Oxygen Reduction on Electrodes Prepared with Nafion and Pt Supported on Carbon
Date Issued
2006
Date
2006
Author(s)
Hsu, Jui-Fu
DOI
zh-TW
Abstract
The hydrogen oxidation reaction and oxygen reduction reaction on electrodes prepared with Nafion and Pt/C were investigated by the rotating disk electrode (RDE) and cyclic voltammetry (CV) techniques. From this work, electrochemical active surface decreased as the Nafion/Pt content increased. The effects of Pt-loading and Nafion/Pt ratio are slight for the current density of hydrogen oxidation reaction. The hydrodynamic voltammograms were analyzed to determine the kinetic parameters by using the modified Koutecky-Levich equation. This work showed that the electrocatalytic reaction of hydrogen on electrodes was very fast (reversible), and the reactions were controlled by the diffusion of hydrogen in electrolyte solution. The measured current densities here were all the mass-transfer rates.
From the Tafel plots (uncorrected for diffusion), the reaction rate of oxygen reduction reaction increased as Pt-loading increased. However, from the corrected Tafel plots, we could understand the mechanisms of oxygen reduction reaction were chemical reaction control and mixed kinetic-diffusion control at low and high overpotential, respectively. The hydrodynamic voltammograms were analyzed to determine the kinetic parameters by using the Koutecky-Levich equation. The exchange current density for Pt/C was determined to be 6.07×10-3 mAcm-2 based on the real Pt surface area.
The results of this study are useful for designing the electrodes for fuel cells using Pt/C electrocatalyst.
Subjects
電催化
旋轉電極
氫氣氧化
氧氣還原
白金
燃料電池
Electrocatalysis
Rotating disk electrode
Hydrogen oxidation
Oxygen reduction
Platinum
Polymer electrolyte
Fuel cell
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-95-R93524042-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):b56dab351fb1b392101123914d974310