Anodic Oxidation of Ethylenediaminetetraacetic Acid on Platinum Electrode in Alkaline Medium
Anodic Oxidation of Ethylenediaminetetraacetic Acid on Platinum Electrode in Alkaline Medium
复制标题
DOI：
10.1149/1.1836691
复制
发表时间：
1996-05
影响因子：
3.9
通讯作者：
S. R. Pakalapati;B. Popov;R. White
中科院分区：
文献类型：
--
作者：
S. R. Pakalapati;B. Popov;R. White
乙二胺四乙酸（EDTA）形成强金属络合物，通常用于去除传热设备上的水垢和净化暴露于放射性物质的设备。然而，由于EDTA-金属络合物的高稳定性，所得到的EDTA-金属络合物形式的废物难以处理。研究了乙二胺四乙酸（EDTA）在碱性介质中在光滑铂电极上的阳极氧化。本体电解表明，稳定的有机中间体（甲醛和乙二醛）的EDTA的氧化过程中形成的，可以实现完全氧化为CO{sub 2}。提出的途径表明，EDTA中的乙酸酯基团最初被氧化，生成甲醛和乙二胺。EDTA的静止电位（0.066至0.164 V vs. Hg/HgO）被观察到高于其他有机物种。在碱性介质中，发现在裸铂上发生非常少的EDTA氧化。由于PtO形成而产生的极限电流行为在剩余电位为正时立即观察到。塔菲尔行为（塔菲尔斜率120 mV/dec）中观察到的电位区域的停止的大部分的氧化膜的形成和负的O{sub 2}演变的开始。EDTA的反应级数约为0.5，OH的反应级数约为0。与实验数据一致的反应机理涉及Temkin型吸附和第一电子转移速率决定步骤。«少
Ethylenediaminetetraacetic acid (EDTA) forms strong metal complexes and is often used to remove scale from heat-transfer equipment and to decontaminate equipment exposed to radioactive material. However, the resultant waste in the form of EDTA-metal complex is hard to treat due to the high stability of such complexes. The anodic oxidation of ethylenediaminetetraacetic acid (EDTA) was studied in alkaline medium on a smooth platinum electrode. Bulk electrolysis indicated that stable organic intermediates (formaldehyde and glyoxal) are formed during the oxidation of EDTA and that complete oxidation to CO{sub 2} can be achieved. The proposed pathway suggests that the acetate groups in EDTA are initially oxidized, generating formaldehyde and ethylenediamine. The rest potential of EDTA (0.066 to 0.164 V vs. Hg/HgO) was observed to be higher than for other organic species. In alkaline medium, very little EDTA oxidation was found to occur on bare platinum. Limiting-current behavior due to PtO formation was observed immediately positive of the rest potential. Tafel behavior (Tafel slope 120 mV/dec) was observed in the potential region positive of the cessation of the bulk of oxide film formation and negative of the onset of O{sub 2} evolution. The reaction order of EDTA was determined to be {approximately}0.5, andmore » that of OH{sup {minus}} was close to zero. The reaction mechanism consistent with the experimental data involves Temkin-type adsorption and a first-electron-transfer rate-determining step.« less