【作者】 黄振华；

【导师】 马淳安；

【作者基本信息】 浙江工业大学 ， 应用电化学， 2004， 硕士

【摘要】 本文首先综述了铅合金电极的研究现状及其在有机电合成中的应用，根据其目前存在的问题，从冶金学原理和电化学原理的角度出发，设计了实验合金。采用金相结构分析、硬度分析以及电化学测试技术等手段系统地研究了不同合金的力学性能、电化学性能和耐腐蚀性能。 力学性能测试结果表明，通过添加其它金属元素后，合金的硬度都有所提高，其中以稀土元素的效果最好。添加金属镉、钙、锡、银、锑、稀土以后，各类铅合金的耐腐蚀性能也有所提高，其中以Pb-Ca-Sn-Al-Cd类合金效果最明显。 电化学测试结果表明，添加镉元素后，合金抑制析氢能力增强，而加入稀土元素会加快析氢能力。从电化学还原草酸性能和抑制析氢能力方面考虑，在所有研究电极中，以Pb-Ca-Sn-Al-Cd类合金性能为好，当镉含量为0.5％（即文中3^#电极）时，合金电化学性能最好。实验测得3^#电极基本动力学参数和表观活化能如下：电化学还原的草酸体系：i₁⁰=0.453 mA／cm²，W₁⁰=14.168 kJ／mol；在硫酸空白体系：i₂⁰=5.92×10^-6 mg／cm²，W₂⁰=38.542 kJ／mol。 利用3^#铅合金电极和纯铅电极为工作电极，在温度18～20℃、电流密度为600A／m²和电解时间为4小时的条件下，进行电解合成实验，产物为乙醛酸，两电极反应的电流效率分别为84.7％和79.5％，表明与纯铅电极相比，3^#铅合金电极具有更高的电流效率。 本文的研究工作表明，Pb-Ca-Sn-Al-Cd类铅合金电极用于电还原草酸反应中，不但具有较高的电流效率、而且耐腐蚀性能和机械性能也比较好，有望成为有机电合成中的优良电极材料。更多还原

【Abstract】 The development history and present situation of research of lead alloy and application of lead alloy electrode for organic electrochemical synthesis were reviewed in this paper.In the point of metallurgy and electrochemical principles,experimental alloys were designed,then the electrochemical performances, hardness properties and corrosion behavior were studied systematically through different types of techniques such as electrochemical measurement techniques,hardness test and meltallograph analysis.The results of hardness test show that the addition of metal can improve the hardness. The alloy has the best effect on improving lead alloy hardness when adding of rare earth. In comparison with pure lead electrode, the corrosion resistance of the as-prepared lead alloys are improved too,among which the Pb-Ca-Sn-Al-Cd lead alloy electrode has the best performances.The results of electrochemical test show that the lead alloys of overpotential of hydrogen evolution increase after addition of Cd,but decreases with adding of rare earth. The performances of electroreduction oxalic acid and hydrogen evolution overpotential on Pb-Ca-Sn-Al-Cd lead alloy electrode is better than those of other as-prepared lead alloys electrode. 3* lead alloy electrode(Cd content is 0. 5%) has the best performances of among all studied electrode. The kinetic parameters and apparent activation energytested at 3# lead alloy electrode are showed below: (1) in oxalic acid system: i01 =0.453 mA/cm2, W10 =14.168 kJ/mol, (2) in sulfuric acid system.i20 =5.92 10-6 mA/cm2, W20 =38.542 kJ/mol.Finally,oxalic acid is electroreduced on both 3# lead electrode and pure lead electrode,the current efficiency is up to 84. 5% and 79. 5%, respectively.Our works show that the application of Pb-Ca-Sn-Al-Cd lead alloy to organic synthesis exhibits the merits of high current efficiency and hydrogen overpotential, excellent corrosion resistance and hardness. Therefore, Pb-Ca-Sn-Al-Cd lead alloy will be a good electrode materiel for organic electrochemical synthesis.更多还原