碳载钯基二元合金催化剂的制备及电催化研究

发布时间：2018-02-03 04:03

本文关键词： 电催化氧化碳载Pd基催化剂二元合金　出处：《西北大学》2016年硕士论文　论文类型：学位论文

【摘要】：直接甲醇燃料电池(DMFC)因其方便储运和高效等优势,作为一种发展潜力巨大的绿色能源受到广泛关注。目前DMFC中甲醇阳极氧化催化剂大多数采用贵金属Pt及其合金,较高的成本限制了其商业化应用。本文利用溶胶凝胶法制备了Pt、Pd纳米金属催化剂。采用TEM、XRD和XPS以及循环伏安法分别研究了催化剂的组织形貌、组成、结构以及催化活性。以Pt/C对甲醇的电催化活性为基准,评价了非Pt单质催化剂对甲醇电催化的活性,为非Pt金属催化剂商业化提供了一定的参考。实验结果表明,Pt/C和Pd/C纳米催化剂均呈面心立方纳米晶体,微粒分布均匀,粒径约3nm～6nm。CV测试表明在1mol/L CH3OH+1mol/L NaOH溶液中,Pt/C的峰电流密度为1348mA/mg,起始氧化电位为一0.90V。同样条件下Pd/C的峰电流密度为890mA/mg,达Pt/C的66%,起始电位为-0.85V,比Pt/C的高50mV。表明单质催化剂Pd/C具有较好的催化活性。因其成本低廉,在替代传统的贵金属催化剂方面潜力巨大。利用溶胶凝胶法制备了Pd-Ni、Pd-Ag、Pd-Ru、Pd-W 和 Pd-Co钯基二元合金催化剂,并考察了其在碱性条件下甲醇电催化氧化的活性。结果表明,在1mol/L CH3OH+1mol/L NaOH溶液中,Pd1W1、Pd1Ru1、Pd1Ag1、Pd1Ni1、Pd1Co1峰电流密度分别为422.1mA/mg、263.2mA/mg、203.7mA/mg、195.8mA/mg、143mA/mg。催化活性大小顺序为：Pd1W1Pd1Ru1Pd1Ag1Pd1Ni1Pd1Co1。因此说明钯基二元合金催化剂具有良好的催化活性,其中Pd-W、Pd-Ru活性较高,P d-Ag、Pd-Ni、Pd-Co活性次之。
[Abstract]:Direct methanol fuel cell (DMFC) has the advantages of convenient storage and transportation and high efficiency. As a kind of green energy with great potential, most of the catalysts for methanol anodic oxidation in DMFC are precious metal Pt and its alloys. High cost limits its commercial application. In this paper, PTT Pd nanometallic catalysts were prepared by sol-gel method and TEM was used. XRD, XPS and cyclic voltammetry were used to study the morphology, composition, structure and catalytic activity of the catalyst. The electrocatalytic activity of Pt/C for methanol was used as the benchmark. The activity of non-Pt catalyst for methanol electrocatalysis was evaluated, which provided a certain reference for the commercialization of non-Pt metal catalyst. Both Pt/C and Pd/C nanocrystals are face-centered cubic nanocrystals and the particles are uniformly distributed. The measurement of particle size about 3nmnm. CV shows that the peak current density of PtP / C in 1mol / L CH3OH 1mol / L NaOH solution is 1348mAr / mg. The initial oxidation potential is -0.90 V. under the same conditions, the peak current density of Pd/C is 890 Ma / mg, which is 66% of that of Pt/C, and the initial potential is -0.85 V. The results show that Pd/C has better catalytic activity than that of Pt/C, because of its low cost. There is great potential to replace the traditional noble metal catalysts. Pd-NiPd-AgPd-Ru-Pd-W and Pd-Co palladium based binary alloy catalysts were prepared by sol-gel method. The activity of methanol electrocatalytic oxidation under alkaline conditions was also investigated. The results showed that in 1mol / L CH3OH 1mol / L NaOH solution, Pd1W1 / Pd1Ru1 was obtained. The peak current density of PD _ 1Ag _ 1 / PD _ 1Ni _ 1C _ (1) Pd _ 1Co _ 1 is 422.1mA / mg ~ (-1) 263.2mA / mg ~ (-1) 203.7mA / mg, respectively. 195.8mA/mg. The order of catalytic activity is as follows:. Pd1W1Pd1Ru1Pd1Ag1Pd1Ni1Pd1Co1Co1.Therefore, the palladium based binary alloy catalyst has good catalytic activity. The activity of Pd-Ru was higher than that of Pd-Ag-Pd-NiPd-Co.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.36

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