Use of Cyclic Voltammetry as an Effective Tool for Selecting Efficient Enhancers for Oxidative Bioprocesses: Importance of pH

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• 作者：Elisabetta Aracri ; Tzanko Tzanov ; Teresa Vidal
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：January 30, 2013
• 年：2013
• 卷：52
• 期：4
• 页码：1455-1463
• 全文大小：543K
• 年卷期：v.52,no.4(January 30, 2013)
• ISSN：1520-5045

文摘

Seven natural phenols and two synthetic compounds were evaluated by means of cyclic voltammetry as enhancers for the oxidation of the lignin model compound veratryl alcohol (VAl) and a sulfonated lignin (SL). Their electrochemical behaviors and catalytic efficiencies (CEs) against both substrates were assessed as a function of pH. A general increase in CE of the phenols was for the first time observed in the oxidation of VAl at pH 7 and 8. Methyl syringate (MS), syringic acid (SRC), and syringaldehyde (SRD) exhibited the highest CEs against VAl among the studied phenolic compounds despite the reduced stabilities of their phenoxy radicals. This was a result of favorable stability鈥搑eactivity balances, which were apparently influenced by both the chemical structures of the enhancers and the experimental conditions. Violuric acid (VAc) proved the most efficient compound in oxidizing lignin, followed by SRD and MS, which showed regeneration in the interval of pHs studied.