Electrooxidation of acetaldehyde on carbon-supported Pt, PtRu and Pt3Sn and unsupported PtRu0.2 catalysts: A quantitative DEMS study
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- 作者：H. Wang ; Z. Jusys and R.J. Behm
- 关键词：acetaldehyde oxidation ; CO2 current efficiency ; DEMS ; selectivity ; supported catalyst
- 刊名：Journal of Applied Electrochemistry
- 出版年：2006
- 出版时间：November, 2006
- 年：2006
- 卷：36
- 期：11
- 页码：1187-1198
- 全文大小：1,264 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Electrochemistry
Physical Chemistry
Industrial Chemistry and Chemical Engineering - 出版者：Springer Netherlands
- ISSN：1572-8838
文摘
The oxidation of acetaldehyde on carbon supported Pt/Vulcan, PtRu/Vulcan and Pt3Sn/Vulcan nanoparticle catalysts and, for comparison, on polycrystalline Pt and on an unsupported PtRu0.2 catalyst, was investigated under continuous reaction and continuous electrolyte flow conditions, employing electrochemical and quantitative differential electrochemical mass spectroscopy (DEMS) measurements. Product distribution and the effects of reaction potential and reactant concentration were investigated by potentiodynamic and potentiostatic measurements. Reaction transients, following both the Faradaic current as well as the CO2 related mass spectrometric intensity, revealed a very small current efficiency for CO2 formation of a few percent for 0.1 m acetaldehyde bulk oxidation under steady-state conditions on all three catalysts, the dominant oxidation product being acetic acid. Pt alloy catalysts showed a higher activity than Pt/Vulcan at lower potential (0.51 V), but do not lead to a better selectivity for complete oxidation to CO2. C–C bond breaking is rate limiting for complete oxidation at potentials with significant oxidation rates for all three catalysts. The data agree with a parallel pathway reaction mechanism, with formation and subsequent oxidation of COad and CH x, ad species in the one pathway and partial oxidation to acetic acid in the other pathway, with the latter pathway being, by far, dominant under present reaction conditions.