Resistance change of an evaporated platinum film working as cathode or anode in acid solutions—II. Fractions of cathodic current in the catalytic and the electrochemical mechanisms of the hydrogen-evolution reaction
✍ Scribed by H. Shimizu
- Publisher
- Elsevier Science
- Year
- 1968
- Tongue
- English
- Weight
- 912 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
The results given in Part I of this series are analysed quantitatively.
From the resistance change of a platinum film electrode during cathodic and anodic polarization in lo-' N sulphuric acid solutions, the following results emerge.
(1) The rate constant and activation energy of the desorptive combination of hydrogen atoms on the electrode after current interruption are determined.
(2) The fractions of cathodic current consumed by the catalytic (or the slow combination) mechanism and by the electrochemical mechanism of electrolytic hydrogen evolution are determined from the analysis of the mathematical expression for the rate of accumulation of atomic hydrogen on the electrode during cathodic polarization.
(3) Two types of adsorbed hydrogen atoms taking part respectively in the catalytic and the electrochemical mechanisms are proposed.
(4) The rate constant of the desorptive combination of hydrogen atoms on the electrode is the same during cathodic polarization and after interruption of the current; with current density during the anodic coulometry of the species. but the rate constant changes (5) The interpretation of the two stages a, and a, in the anodic R/t curve reported in Part I is further conlirmed.