Mechanism of Water Oxidation by Ferrate(VI) at pH 7-9
Mechanism of Water Oxidation by Ferrate(VI) at pH 7-9
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DOI：
10.1002/chem.201803757
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发表时间：
2018-12-12
影响因子：
4.3
通讯作者：
Lau, Tai-Chu
中科院分区：
文献类型：
--
作者：
Chen, Gui;Lam, William W. Y.;Lau, Tai-Chu
K2FeO4 氧化水的动力学已通过 UV/Vis 分光光度法在 0.2 m 磷酸盐缓冲液中的 pH 7-9 范围内进行了重新研究。发现 [FeO42-] 和 [H+] 的反应速率均为二级。这些结果与提出的机制一致，其中第一步涉及 FeO42- 的初始平衡质子化，得到 FeO3(OH)(-)，然后进行限速 O-O 键形成。对 (H2O)-O-18 反应的 O-2 同位素组成分析表明，高铁酸盐氧化水的主要途径是分子内 O-O 偶联。还进行了 DFT 计算，支持所提出的机制。
The kinetics of water oxidation by K2FeO4 has been reinvestigated by UV/Vis spectrophotometry from pH 7-9 in 0.2 m phosphate buffer. The rate of reaction was found to be second-order in both [FeO42-] and [H+]. These results are consistent with a proposed mechanism in which the first step involves the initial equilibrium protonation of FeO42- to give FeO3(OH)(-), which then undergoes rate-limiting O-O bond formation. Analysis of the O-2 isotopic composition for the reaction in (H2O)-O-18 suggests that the predominant pathway for water oxidation by ferrate is intramolecular O-O coupling. DFT calculations have also been performed, which support the proposed mechanism.