copd和coptmm=pd ru纳米催化剂的制备 去合金化及电催化性能分析word格式论文.docxVIP

（2）在 30℃条件下，采用连续还原和共还原的方法，控制合成三元 CoPtPd合金和 CoPtRu 合金催化剂，采用 SEM、TEM、XRD 等手段分析三元合金催化 剂形貌、结构和组成。采用循环伏安法研究 CoPtM(M=Pd、Ru)纳米催化剂对甲 醇的电催化性能。同时采用电化学去合金化方法重构电极表面，期望在去合金化 的同时能进一步提高 CoPtM(M=Pd、Ru)纳米催化剂的电催化性能。结果显示： 两种 CoPtPd 纳米催化剂在碱性体系中，对甲醇有很好的催化性能。但是去合金 化后，催化剂对甲醇的催化性能反而降低。将催化剂转入到酸性体系中，对不同 浓度甲醇溶液做电催化测试，发现三元合金 CoPtPd 纳米催化剂在酸性体系中， 对甲醇有很好的电催化性能。采用相同合成方法得到的两种 CoPtRu，在酸性溶 液中同样会发生去合金化行为，对甲醇的电催化性能较好。比较四种 CoPtPd 和 CoPtRu 纳米粒子，我们发现 CoPtPd-2 对甲醇溶液的电催化性能最好，说明在 30℃ 条件下，连续还原方法更有利于三元合金 CoPtM(M=Pd、Ru)的合成。（3）运用电感耦合等离子质谱(ICP-MS)技术，定量检测二元 CoPd 合金在酸性 溶液中去合金化程度的大小，测试活泼金属 Co 元素的溶解量。建立两种不同方 法做对比分析：一种是根据催化剂在酸性溶液中发生去合金化行为，定量采取电 解质溶液，测量电解质溶液中所溶解的 Co 元素含量；另一种是在催化剂完成整 个电性能测试后，刮取电极表面所剩余的催化剂，测量残存于电极表面的 Co 元 素含量。通过 ICP-MS 的测量结果，我们发现在酸性溶液中，二元合金 CoPd 确 实发生了去合金化，Co 元素部分溶解。关键词：燃料电池、去合金化、甲醇氧化、CoPdAbstractThe economy of the world has a rapid development since 21 century. The requirement of the energy is increasing day after day. At the same time, theenvironment has been polluted seriously. So we have to develop a new clean、environmental friendly energy to replace the traditional energy. Fuel Cells are cleaner and more environmental friendly than the traditional fuels. It is an important way to solve the problem of the pollution. Directly methanol fuel cells (DMFCs) are widely used by most researchers because of its high energy density, transportation conveniently in its field. But the high cost of the DMFCs is a huge problem. Ptnanocatalyst was commonly used in the DMFCs so far. But Pt is too expensive，meanwhile it has a low catalytic activity and poor stability. So how to reduce the dosage of precious metal in the DMFCs is a great matter, while we have to keep its high activity and stability.As to Pt，Pd and the transition metal are more cheaper. So, add the transitionmetal to the Pd alloy is an ideal way to decrease the cost of the DMFCs. In this paper, four kinds of CoPd alloy were prepared at 0 oC and 30 oC. By imported the third metal, the CoPtM (M=Pd, Ru) were obtained on the base of CoPd a