对氯苯酚电氧化过程中Pt电极的失活机制 |
摘要点击 2779 全文点击 2098 投稿时间:2007-07-03 修订日期:2007-07-30 |
查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
中文关键词 阳极失活 对氯苯酚 聚合物 有机自由基 |
英文关键词 anode deactivation p-chlorophenol polymer organic radical |
|
中文摘要 |
利用线性伏安法、LC/MS和光谱技术研究了Pt电极在电化学氧化降解对氯苯酚过程中的失活现象.结果表明,由于电极表面的聚合反应,Pt电极会在短时间内失活.现场红外分析表明,电氧化过程中Pt电极在1 200 cm-1>和1 800 cm-1>处分别出现了芳醚和羰基的特征吸收峰.提高对氯苯酚初始浓度和溶液pH均会加快电极的失活速率.对失活Pt电极的乙腈浸洗液进行LC/MS分析表明,电极表面形成的聚合物并不是具有单一结构的化合物,而是一些混合物,其形成的机理主要包括自由基之间的相互偶合、自由基与底物、中间产物或低聚物的取代反应等方式. |
英文摘要 |
Deactivation of Pt electrode in the process of electroxidation of p-chlorophenol (p-CP) was investigated using linear sweep voltammetry, LC/MS and spectrum analysis techniques. The experiment results indicated that Pt would lose its electro-catalytic activity soon because polymer formed at the electrode surface. The in-site IR spectra of Pt showed two weak absorption bands appeared at 1 200 and 1 800 cm-1 during the oxidation of p-CP, which are characteristics of aromatic ether and carbonyl group, respectively. Increasing initial concentration of p-CP and pH value of solution would accelerate the deactivation speed of Pt. Acetonitrile lixivium for deactivated Pt was analyzed by LC/MS, and it was found that the polymers formed at the surface of Pt were some mixed compounds. The mechanism of polymerization includes the following ways: coupling reaction of organic radical each other; substituting reaction of organic radical with p-CP (or intermediates or small polymers). |
|
|
|