掺硼金刚石电极电催化氧化酚类有机物的取代基效应

发布时间：2019-02-15 04:44

【摘要】：本文主要以当前水环境中存在酚类有机污染物为研究对象,探讨酚类有机污染物在掺硼金刚石(BDD)电极上的取代基效应,具体研究具有不同位置及种类官能团的取代酚类有机污染物在BDD电极上的电催化氧化过程,通过化学需氧量和浓度变化考察有机污染物在电催化降解过程中的降解趋势,深入分析电极种类、官能团位置与种类与电催化氧化活性之间的联系的同时,研究阳极材料电催化氧化有机污染物的机理及动力学。结果表明,有机物在电极表面的电催化过程以电产生羟基自由基为媒介,对苯二酚在不同电极上的电催化活性与电极析氧电位及表面产生羟基自由基量有着重要的联系,BDD电极拥有最强的电催化氧化活性;不同取代基团的对位取代酚在BDD电极上的电化学降解实验显示电催化反应速率受取代官能团自身的电子效应制约,有机物矿化过程中羟基自由基首先进攻苯环的对位发生取代反应,同时取代基脱离苯环过程成为整个取代酚类电化学降解过程的决速步骤,且有机物的电催化反应速率与取代基特征Hammett常数σ呈近似线性关系。
[Abstract]:In this paper, the substitution effect of phenolic organic pollutants on boron-doped diamond (BDD) electrode was studied. The electrocatalytic oxidation of substituted phenolic organic pollutants with different positions and functional groups on BDD electrode was studied. The degradation trend of organic pollutants in electrocatalytic degradation process was investigated through the change of chemical oxygen demand and concentration. The mechanism and kinetics of electrocatalytic oxidation of organic pollutants by anodic materials were studied, while the relationship between electrode type, functional group location and electrocatalytic oxidation activity was analyzed. The results show that the electrocatalysis of organic compounds on the electrode surface is mediated by the electrogenerated hydroxyl radical. The electrocatalytic activity of hydroquinone on different electrodes is closely related to the oxygen evolution potential of the electrode and the amount of hydroxyl radical produced on the surface. The BDD electrode has the strongest electrocatalytic oxidation activity. The electrochemical degradation of p-substituted phenols with different substituents on BDD electrode showed that the rate of electrocatalytic reaction was restricted by the electronic effect of the substituents themselves. In the process of organic matter mineralization, the hydroxyl radical firstly attacks the para-position substitution reaction of benzene ring, and at the same time, the dissociation of substituted group from benzene ring becomes the decisive step of the whole process of electrochemical degradation of substituted phenols. The electrocatalytic reaction rate of organic compounds is approximately linear with the characteristic Hammett constant 蟽 of the substituents.
【作者单位】：吉林大学化学学院;吉林大学超硬材料国家重点实验室;
【基金】：国家自然科学基金(21273097,21573093) 广东省引进创新创业团队计划项目(2013C092) 吉林省重大科技攻关招标项目(20130204003GX) 国家重点研发计划(2016YFC1102802)资助~~
【分类号】：O621.251

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