Kinetic analysis of the hydrogen oxidation reaction on Pt-black/Nafion electrode

Abstract

The hydrogen oxidation reaction on Pt-black/ Nafion electrode was investigated using a rotating disk electrode and cyclic voltammetry technique. The voltammetric results demonstrated that the electrode can be prepared with good reproducibility and that Ptblack particles without direct contact with Nafion were still electrochemically active in taking part in the Hadsorption/desorption process. For hydrogen oxidation, the limiting current density was reduced by the presence of Nafion coating. The H 2 diffusion resistance in Nafion film was avoided when the film thickness was less than 0.2 lm for a Pt-black loading of 20 lg. Moreover, the uncertainties in the kinetic results were discussed.

Kinetics of hydrogen oxidation reaction on Nafion-coated Pt/C electrodes under high overpotentials

“…(6). The critical film thickness, 0.2 mm, at which the diffusional resistance of the film becomes negligible, is the same as that determined in our previous work (Lin and Shih, 2006) for Pt-black/Nafion electrodes and that reported by Watanabe et al (1995) for Nafion coated smooth Pt electrodes, but is thinner than the thickness of 0.3 mm reported by Schmidt and Gasteiger (2003) or 0.5 mm reported by Schmidt et al (1998).…”

“…The CV shows two well-resolved H-adsorption or desorption peaks. The hydrogen adsorption/desorption charge, Q H , was evaluated from the CV data in the potential range between 0.05 and (Lin and Shih, 2006;Nart and Vielstich, 2003;Schmidt et al, 1998) was found to be the same as the real Pt surface area of the electrode and independent of the Nafion film thickness. This result indicates that the penetration depth of Nafion into the catalyst layer was shallow and the area of the catalyst surface blocked by the Nafion coating was very small as compared with the total catalyst surface area.…”

Kinetic Study of the Hydrogen Oxidation Reaction on Membrane Coated Electrodes. Part II: Applications~!2009-10-21~!2010-02-10~!2010-04-20~!

“…A literature revision showed that there are only a few studies of the hor with the required characteristics and measured on steady state conditions [4][5][6]11]. The work chosen for the application of the present model and the determination of the kinetic parameters is that carried out by J. Maruyama et al [11], who reported the most complete and self-consistent set of experimental results.…”

“…The model takes into account not only the diffusion process in each layer but also the transfer of molecular hydrogen through the corresponding interfaces. This is a limitation to the hydrogen diffusion from the bulk solution to the reaction plane, which had not been taken into account in previous analysis [2][3][4][5][6]. Starting from this model and on the basis of the kinetic treatment previously developed [7][8][9][10], the expressions for the current-potential dependence for the hor on electrodes covered by n polymeric layers were obtained.…”

Kinetic Study of the Hydrogen Oxidation Reaction on Membrane Coated Electrodes. Part I: Theoretical Aspects

“…For kinetic studies, the electrocatalysts are usually covered by a protonic conductor membrane to reproduce the conditions observed in the fuel cell. In most cases a unique membrane was used [4][5][6][7][8][9][10], but recently new arrangements with a multilayer membrane were proposed [11][12][13]. However, the formalism for an appropriate interpretation of these results has not been developed yet.…”