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Pt-Ag-Co三元合金催化剂对H2O2的催化还原性能研究

时间:2018-10-17 21:02来源:毕业论文
催化剂颗粒能很好的分布在碳载体上,二元合金催化剂粒径在10nm左右,三元合金催化剂的粒径大小为2-4nm。经分析XRD数据得出,所制备的催化剂材料均为面心立方结构。 CV结果表明: 在

摘要:本论文采用浸渍还原法制备了以碳粉Vulcan XC-72为载体的不同比例Pt-Ag二元合金催化剂、Pt-Ag-Co三元合金催化剂。利用循环伏安法、线性扫描伏安法和电流时间等方法分别研究Ag含量对Pt-Ag二元合金催化剂及Co含量对Pt-Ag-Co三元合金催化剂电催化性能和催化稳定性的影响。利用 CHI660d 电化学工作站,在不同温度(200C、250C、300C、400C)、不同电解质(NaOH)摩尔浓度(M=0.5,1,2,3)和不同反应物(H2O2)摩尔浓度(M=0.03,0.1,0.15,0.2)条件下进行电化学性能测试。通过透射电子显微镜(TEM)和X-射线衍射(XRD)进行催化剂粒径、晶体结构等表征,从而找出最佳的配比。29171
从TEM分析得到:催化剂颗粒能很好的分布在碳载体上,二元合金催化剂粒径在10nm左右,三元合金催化剂的粒径大小为2-4nm。经分析XRD数据得出,所制备的催化剂材料均为面心立方结构。 CV结果表明: 在Pt/C催化剂中引入单金属Ag制备成Pt-Ag/C催化剂,在一定程度上提高了催化剂的催化活性,而在Pt-Ag/C催化剂引入Co制成Pt-Ag-Co/C催化剂,其催化效果要优于Pt-Ag/C催化剂。测定了Pt-Ag-Co质量比例分别为5-10-15和10-10-15时的交流阻抗,在25°C时,分别以Pt5-Ag10-Co15/C、Pt10-Ag10-Co15/C为阴极催化剂,商业Pt/C(40%)为阳极催化剂制成了直接NaBH4 / H2O2燃料电池(DBHFC),并测定了这两种电池分别在H2O2浓度分别0.06mol/L,0.2mol/L 时的恒电流放电曲线,由此计算出两种电池的功率密。计算结果表明以Pt10-Ag10-Co15/C为阴极催化剂的DBHFC在H2O2浓度为0.2mol/L 时拥有良好的电池性能,常温下的最大功率密度110.7mW/cm2。
毕业论文关键词:直接 NaBH4 / H2O2燃料电池(DBHFC)、Pt-Ag二元合金催化剂、Pt-Ag-Co三元合金催化剂、阴极催化剂
The electro-chemical performance study of Pt-Ag-Co ternary alloy catalyst for H2O2 reduction
Abstract:In this paper, by using impregnation-reduction method, we prepared the different mass ratios of Pt-Ag and Pt-Ag-Co on the carbon Vulcan XC-72. The effect on catalytic performance and catalytic stability of Ag content for Pt-Ag binary alloy catalyst and Co content for of Pt-Ag-Co ternary alloy catalyst were charged by cyclic voltammetry, linear sweep voltammetry  and current time method. The electrochemical performance of these catalysts were tested by using CHI660d electrochemical workstation at different temperature, the different molar concentration of electrolytes and reactants. In order to find the best ratio of Pt-Ag/C Pt-Ag-Co/C catalysts, using TEM and for the characterize of catalyst particle size, crystal structures .
The TEM tells that catalyst particles can be well distributed on carbon supports, and the particle size of binary alloy catalysts is about 10nm, while ternary alloy catalyst is about 2-4nm. From XRD we can know that the catalyst material prepared are all in face-centered cubic structure. The CV results show that replacing Pt by Ag to form the Pt-Ag/C alloy catalyst has improved the catalytic activity in some extent. While the catalytic effect of Pt-Ag-Co/C is superior to Pt-Ag/C when the metal Co is introduced into Pt-Ag/C catalysts. The EIS curves of Pt5-Ag10-Co15/C and Pt10-Ag10-Co15/C catalysts were measured at 25°C. We assembled two NaBH4/H2O2 fuel cells, their cathode catalysts were Pt5-Ag10-Co15/C and Pt10-Ag10-Co15/C respectively, their anode catalysts were both commercial Pt/C (40%). The constant current discharge curves of these two cells were tested in 0.06mol/L and 0.2mol/L H2O2 respectively, and then we calculated the power density of them. The results show that the cell with the Pt10-Ag10-Co15/C cathode catalyst has the best battery performance in 0.2mol/L H2O2, and the maximum power density can reach 110.7mW/cm2.
Key Word: Direct NaBH4 / H2O2 fuel cell (DBHFC),Pt-Ag binary alloy catalyst, Pt-Ag-Co ternary alloy catalyst, cathode catalyst
 目录 Pt-Ag-Co三元合金催化剂对H2O2的催化还原性能研究:http://www.youerw.com/huaxue/lunwen_24296.html
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