对氯苯酚电氧化过程中Pt电极的失活机制  

Deactivation Mechanism of Pt Anode in the Process of Electroxidation of p-Chlorophenol

作　　者：童少平[1] 费会[1] 张铁明[1] 马淳安[1] 

机构地区：[1]浙江工业大学化学工程与材料学院绿色化学合成技术国家重点实验室培育基地,杭州310032

出　　处：《环境科学》2008年第7期1937-1941,共5页Environmental Science

基　　金：国家自然科学基金项目(20406019)

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.Deactivation of Pt electrode in the process of electroxidation of p-chlorophenol （p-CP） was investigated using linear sweep vohammetry, 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）.

关 键 词：阳极失活 对氯苯酚 聚合物 有机自由基 

分 类 号：X703.1[环境科学与工程—环境工程]