Influence of Adsorption Kinetics upon the Electrochemically Reversible Hydrogen Oxidation Reaction
The hydrogen oxidation reaction was studied at bright polycrystalline platinum microelectrodes. A smaller steady-state current was observed in experiment as compared to that anticipated for a diffusion limited process. To facilitate physical insight into this system, a simulation model based on the...
| Main Authors: | , , , , |
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| 格式: | Journal article |
| 出版: |
American Chemical Society
2015
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| 總結: | The hydrogen oxidation reaction was studied at bright polycrystalline platinum microelectrodes. A smaller steady-state current was observed in experiment as compared to that anticipated for a diffusion limited process. To facilitate physical insight into this system, a simulation model based on the Tafel-Volmer mechanism for the hydrogen oxidation reaction was developed. Under conditions of reversible electron transfer, the adsorption kinetics k<inf>a</inf> and k<inf>d</inf> are found to have distinctly different influences upon the voltammetry responses. Correspondence between the simulated and the experimental voltammograms is found, confirming the decrease of the steady-state current is caused by the slow adsorption process. The combined adsorption parameter k<inf>a</inf>γmax<sup>2</sup> on the Tafel-Volmer mechanism was approximately 5.0 × 10<sup>-4</sup> m s<sup>-1</sup>, where γ <inf>max</inf> (mol m<sup>-2</sup>) is the maximum surface coverage of adsorption hydrogen atoms. |
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