Electrochemical hydrogen evolution by catalyst membrane composed of platinum, alkyl viologen and Nafion: consideration of the kinetically dominant factor based on understanding of electron-mediating ability of the viologen molecule
✍ Scribed by Toshiyuki Abe; Takaki Fujita; Kouki Sekimoto; Akio Tajiri; Masao Kaneko
- Book ID
- 104422382
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 148 KB
- Volume
- 201
- Category
- Article
- ISSN
- 1381-1169
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✦ Synopsis
Electrocatalytic H 2 formation was carried out by using a Nafion membrane (Nf) embedding a Pt catalyst as well as an alkyl viologen (denoted as RV 2+ ; alkyl group (R): methyl, ethyl, propyl, heptyl, or dodecyl group). The H + reduction catalyzed by the Pt via the electrogenerated RV •+ was investigated. In order to understand the electron-mediating characteristic of the RV 2+ on kinetic aspect, turnover numbers (TON) of the RV 2+ for H 2 formation as well as electron transport kinetics (represented by the apparent diffusion coefficient of electron, D app ) of the mediator were studied with respect to RV 2+ concentration. In any RV 2+ system, both the TON and the D app exhibited a similar dependence on the concentration, showing that the overall kinetics is dominated by the electroreduction process of the mediator. When applying both the tetrachloroplatinate(II) (Pt 0 in catalytically active state) and the viologen mediator to the H 2 formation system, the TON was found to be controlled by the D app .