【作者】 李嘉明；

【导师】 谭欣；

【作者基本信息】 天津大学 ， 核燃料循环与材料， 2010， 硕士

【摘要】 电极材料及其制备方法是影响电极涂层的表面结构,从而影响电极的电催化氧化性能的一个主要因素,本文以Ce、Y、La、Nd稀土元素和Mn元素掺杂的Ti/SnO₂-Sb改性电极的制备及性能评价为主要研究内容,以对氯苯酚（4-CP）为电化学氧化降解目标物,初步探讨了4-CP的电化学催化氧化降解转化机理,以及电极结构与电催化氧化活性之间的关系。本文以溶胶凝胶法分别制备了Ti/SnO₂-Sb涂层电极,稀土掺杂Ti/SnO₂-Sb涂层电极和Mn掺杂Ti/SnO₂-Sb涂层电极。利用SEM、EDX、XRD、XPS等现代分析工具对电极的形貌、结构进行表征,利用电化学工作站,紫外可见分光光谱（UV-vis）和高效液相色谱（HPLC）对电极降解4-CP的机理过程进行了探讨,并确定了热处理温度,Sb、Mn和稀土掺杂比例等工艺条件。实验研究表明,热处理温度为500℃时为Ti/SnO₂-Sb电极最佳制备温度;Sb、稀土元素和Mn的掺杂对SnO₂涂层电极的电催化活性都有一定的提高,其中稀土元素Ce、Y、La、Nd中La元素的掺杂表现的对4-CP降解优势最为明显;通过试验确定了Sb掺杂量在6%,La掺杂量在1.5%,Mn掺杂量在6%时,提高电极电催化活性效果相对最好;通过高效液相色谱对电极降解4-CP的机理过程分析如下:Ti/SnO₂-Sb电极和稀土掺杂的Ti/SnO₂-Sb电极电化学氧化作用将4-CP降解反应生成以对苯醌为主体的中间产物,最终对苯醌被进一步开环降解为丁烯二酸等物质,丁烯二酸等被进一步氧化降解,最终生成二氧化碳和水;Mn掺杂的Ti/SnO₂-Sb电极则将4-CP降解反应生成以邻苯醌为主体的中间产物,最终邻苯醌被进一步开环降解为丁烯二酸等物质,丁烯二酸等被进一步氧化降解,最终生成二氧化碳和水。更多还原

【Abstract】 Surface structure of electrode coating is affected greatly by electrode materials and the preparation methods, thus it is a key effect factor to the electrocatalytic oxidation properties. In this paper, the preparation and performance evaluation of Mn, Ce, Y, La, Nd and other rare earth elements which doped into the Ti/SnO₂-Sb electrodes were discussed. At the same time, chlorophenol （4-CP） was selected as the target of electro-catalytic degradation. It was preliminary investigated the mechanism of electrochemical oxidation degradation and transformation, and the the relationship between the electro-catalytic properties and the electrode structure was discussed in detail.In this paper, Sol-Gel method were employed to prepared Ti/SnO₂-Sb coated electrode, Mn doped Ti/SnO₂-Sb electrode and rare earth doped Ti/SnO₂-Sb coated electrode. SEM, EDX, XRD, XPS were used to characterize the morphology and structure of as-prepared electrode. Electrochemical workstation, UV-visible spectrophotometer （UV-vis） and high performance liquid chromatography （HPLC） were used to analyze the degradation process of 4-CP from the angle of mechnisam. Meanwhile, operating parameters, such as the heat treatment temperature, the doping ratio of Sb, Mn and rare earth element were defined.Experimental results showed that, the optimal heat treatment temperature for the Ti/SnO₂-Sb electrode was 500℃. The electrocatalytic activity of SnO₂ coated electrode can be improved by doping Sb, Mn and rare earth elements,and the doping effect of rare earth elements, such as Ce, Y, La, Nd is better than the doping effect of Mn. In addition, La showed the best performance in the four rare earth elements. Sb doped percentage at 6%, La’s at 1.5%, and Mn’s at 6% is the best ratios for the catalytic activity of prepared electrode, inspectively. Based on the HPLC results the mechanism of degradating 4-CP was introduced as follow: P-benzoquinone was the main by-product during the raction process of 4-CP degradation using electrocatalytic Ti/SnO₂-Sb electrodes and rare earths doped Ti/SnO₂-Sb as electrodes. Finally, P-benzoquinone was degraded to maleic acid and other substances, which can be furtherly degradated into CO₂ and H2O. While Mn doped Ti/SnO₂-Sb electrodes degradate 4-CP into O-benzoquinone, which was as the main intermediate. Then O-benzoquinone was degraded to maleic acid and other substances, maleic acid and other substances are furtherly degradated and ultimately generated carbon dioxide and water.更多还原