In situ FTIR spectroscopic investigations of reaction mechanism of isopropanol oxidation on platinum single crystal electrodes

✍ Scribed by Shi-Gang sun; Yan Lin

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 864 KB
• Volume: 41
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(95)00358-4

✦ Synopsis

The oxidation of isopropanol on Pt(lll), Pt(ll0) and Pt(100) electrodes was studied using in situ FTIR spectroscopy and cyclic voltammetry. The reaction intermediates containing >C-0, >C-c< and -CH, functional groups were determined by in situ FTIR spectroscopy. The acetone species produced from the dehydrogenation of isopropanol plays both intermediate and product role, and the final product of isopropanol oxidation is CO,. No chemically adsorbed species were evidenced by FTIRS data, but molecular adsorption of isopropanol which is easily to be oxidized into CO, was suggested by experimental data. In considering the same intermediates identified with different planes of platinum single crystal, the same reaction pathway in the reaction mechanism was established for isopropanol oxidation on the three platinum single crystal electrodes investigated. However, the kinetics of the reaction varies with Pt single crystal electrodes used. This was demonstrated either by the difference of the maximum current intensity of isopropanol oxidation measured in cyclic voltammograms, or by the different variation of the intensity of specified ir band with potential for species produced within a defined time window (in situ FTIR spectroscopy). The results indicate that the oxidation of isopropanol is a surface structure sensitive reaction, and different orientation of platinum single crystal exhibits different reactivity towards this reaction.