Electrooxidation of glycerol studied by combined in situ IR spectroscopy and online mass spectrometry under continuous flow conditions

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• 作者：Johannes Schnaidt ; ^{johannes.schnaidt@uni-ulm.de} ; Martin Heinen¹ ; Dorothee Denot ; Zenonas Jusys ; R. Jü ; rgen Behm ; ^{juergen.behm@uni-ulm.de}
• 关键词：Adsorption kinetics ; Organic Molecule Oxidation ; Attenuated total reflection IR spectroscopy ; DEMS ; Pt ; Glycerol
• 刊名：Journal of Electroanalytical Chemistry
• 出版年：2011
• 出版时间：1 October 2011
• 年：2011
• 卷：661
• 期：1
• 页码：250-264
• 全文大小：2482 K

文摘

Using a combined spectro-electrochemical DEMS/ATR-FTIRS set-up, we have investigated the adsorption/oxidation of glycerol on a Pt thin film electrode by potentiodynamic, potentiostatic, and adsorbate-stripping experiments. The potential and time dependent development of the glycerol adlayer was followed by highly surface sensitive in situ ATR-FTIR spectroscopy, while the volatile products formed during the glycerol adsorption/oxidation process were simultaneously monitored by online differential electrochemical mass spectrometry (DEMS). For the assignment of the detected glycerol adsorbates, comparative experiments were carried out, investigating the adsorption/oxidation of glyceraldehyde and glyceric acid. The data show that (i) during the adsorption/oxidation of glycerol, CO_ad is formed in the potential range between 0.1 and 0.7 V_RHE, which can be oxidized further to CO₂ at potentials above 0.5 V, that (ii) beside CO_ad, adsorbed glycerol (at 0.3 and 0.4 V) and glycerate (between 0.6 and 0.9 V) are formed, that (iii) glyceric acid is a dead end in the electrochemical oxidation of glycerol, and that (iv) glyceraldehyde is an intermediate to CO_ad formation.