An X-ray photoelectron spectroscopic study of electrocatalytic activity of platinum group metals for chlorine evolution
✍ Scribed by M. Hara; K. Asami; K. Hashimoto; T. Masumoto
- Publisher
- Elsevier Science
- Year
- 1983
- Tongue
- English
- Weight
- 829 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
A correlation of the catalytic activity for anodic chlorine evolution on platinum group metals to the nature of the surface film formed during chlorine evolution in a sodium chloride solution was studied by X-ray photoelectron spectroscopy. The change in the surface film with increasing potential was found on platinum, includingan increase in thecationicvalence. Thisseemed responsible for the decreasein theactivity for chlorine evolution on platinum in the high potential region. Increasing potential did not result in the appreciable increase in the cationic valence in the surface film on the other platinum group metals. Replacement of hydroxyl ions m the surface film by chloride ions became easier m the order of rhodmm, iridium and palladium, and the activity for anodic chlorme evolution increased m this order due possibly to an increase in the amount of chloride ions in the film which seemed to be one of the reactants in the rate determining electrochemical desorption of adsorbed chlorine alom. Chlorine molecules adsorbed on the surface film were also found. It wasassumed that the activity foranodicchlorine evolution might be low when the metal surface was covered by a large amount of molecular chlorine which was the reaction product.