选择性腐蚀法制备电化学还原脱氯催化剂－纳米多孔钯

项目名称： 选择性腐蚀法制备电化学还原脱氯催化剂－纳米多孔钯

项目编号： No.21073111

项目类型： 面上项目

立项/批准年度： 2011

项目学科： 电工技术

项目作者： 马厚义

作者单位： 山东大学

项目金额： 12万元

中文摘要： （1）选择亲水性的离子液体1－丁基－3－甲基咪唑四氟硼酸盐替代水溶液作为电解液，较好地解决了钯－铜合金选择性溶解过程中粗糙效应与平滑效应之间的协调性，制备出了具有均匀的孔壁厚度和规则的孔洞结构的纳米多孔钯；（2）使用纳米多孔钯电极可以将氢在钯表面的吸附过程和氢进入钯基体内的吸收过程分离开来，使得单独研究不同类型的氢物种的反应活性成为可能。研究结果表明：吸附态的氢比吸收态的氢对四氯化碳、氯苯的电化学还原降解具有更高的催化活性；（3）使用电化学沉积得到的纳米结构铁薄膜作为模板，通过氯钯酸与铁薄膜之间的置换反应制备了不同Fe:Pd比例的核壳型纳米双金属Pd/Fe催化剂。由于钯、铁金属间的电偶腐蚀以及两种金属组分间的催化协同效应，Pd/Fe双金属催化剂的脱氯效果明显高于微纳米的铁粉末；（4）以硫脲同时作为金组分溶解的配位剂和银组分的钝化剂，同时在电解液中添加了硫脲稳定剂和金溶解的加速剂，通过选择性控制阳极电位，以非常规的"逆向去合金化"手段从Au-Ag合金样品中去除了金组分，制备了自支撑的纳米多孔银，拓宽了去合金化方法的应用范围。

中文关键词： 多孔钯；离子液体；选择性腐蚀；脱氯活性；电偶腐蚀。

英文摘要： 1) Nanoporous palladium (np-Pd) with uniform wall thickness and regular pore structure was fabricated by selective dissolution of Cu from Pd-Cu alloy in 1-butyl-3-methylimidazolium tetrafluoroborate, a hydrophilic ionic liquid. The matching ability between selective dissolution of Cu (roughening effect) and surface diffusion of Pd (smoothing effect) was greatly enhanced in the ionic liquid as compared to that in aqueous solutions. 2) The use of the np-Pd electrodes enables us to separate the complicated processes of hydrogen adsorption and absorption and to further study the dechlorination activity of adsorbed and absorbed hydrogen species. The results have shown that the adsorbed hydrogen displays much higher activity than the absorbed hydrogen in the electrochemical reductive degradation of carbon tetrachloride (CT) and chlorobenzene (CB). 3) A series of nanostructured Pd/Fe bimetallic thin films were prepared by using the nanostructured Fe thin films fabricated through double-potential step electrodeposition as sacrificial templates, followed by galvanic replacement of partial Fe0 component in the templates by Pd(II) ions. Due to the galvanic corrosion between Pd and Fe components and the good synergistic effect between two components, the as-prepared Pd/Fe thin films with the novel microstructure exhibit a higher reactivity than micro/nano scale Fe0 powders. 4) Using thiourea as both the complexing agent for Au and the passivation agent for Ag, and adding Na2SiO3 and Na2SO3 to alkaline thiourea solutions to enhance the stability of thiourea, we prepared free-standing nanoporous silver (np-Ag) by selectively dissolving Au from Au-Ag alloys through an unconventional dealloying means, which broadens the application range of the dealloying method.

英文关键词： Nanoporous palladium; ionic liquid; selective corrosion; dechlorination activity; galvanic corrosion.