Laboratory of Analytical Chemistry, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, FI-20500 Turku-Åbo, Finland.
Phys Chem Chem Phys. 2015 May 7;17(17):11609-14. doi: 10.1039/c4cp05800c.
The recently reported electro-catalytic reaction mechanism for the oxidation of cellulose is proposed to work also for the electro-oxidation of other polysaccharides (e.g. hemicelluloses). In this report, the electrochemical reactivity of some hemicelluloses (xylan, arabinoxylan, glucomannan, xyloglucan, and glucuronoxylan) in 1.3 M NaOH solution is described. The electrochemical property of each of the studied hemicelluloses at the Au electrode surface was characterized by cyclic voltammetry. Xylan, xyloglucan and glucuronoxylan were found to be electrochemically active. Electrochemical properties of xylan were further studied by electrochemical impedance spectroscopy. The electrochemical reaction products of xylan, obtained by extensive electrolysis of the xylan solution by cyclic voltammetry, were characterized by FTIR spectroscopy, (13)C-NMR spectroscopy, SEM and TEM. The structural studies suggest that the oxidized xylan is a functional material where some of the OH-groups have been oxidized to carboxyl groups making that part of the oxidation product soluble in water under ambient conditions (23 °C, pH 7). The other part remains insoluble in water and contains Au nanoparticles. This work indicates that other polysaccharides than cellulose can also be electrochemically oxidized.
最近报道的纤维素电催化氧化反应机制也被提出可用于其他多糖（如半纤维素）的电氧化。在本报告中，描述了一些半纤维素（木聚糖、阿拉伯木聚糖、葡甘露聚糖、木葡聚糖和半乳甘露聚糖）在 1.3 M NaOH 溶液中的电化学活性。通过循环伏安法表征了研究中的每种半纤维素在 Au 电极表面的电化学性质。发现木聚糖、木葡聚糖和半乳甘露聚糖具有电化学活性。通过电化学阻抗谱进一步研究了木聚糖的电化学性质。通过循环伏安法对木聚糖溶液进行广泛电解获得的木聚糖电化学反应产物通过傅里叶变换红外光谱（FTIR）、（13）C-NMR 光谱、SEM 和 TEM 进行了表征。结构研究表明，氧化的木聚糖是一种功能材料，其中一些 OH 基团已被氧化为羧基基团，使得部分氧化产物在环境条件（23°C，pH7）下可溶于水。另一部分仍然不溶于水，并含有金纳米颗粒。这项工作表明，除纤维素以外的其他多糖也可以进行电化学氧化。
