一维钯基纳米催化剂的合成及其在直接醇类燃料电池中的应用研究

发布时间：2018-03-20 04:36

本文选题：钯基纳米材料　切入点：中空结构　出处：《华中农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：直接醇类燃料电池因其燃料来源广泛、储存运输安全、能量转化效率高和环保等优点,在燃料电池领域具有广阔的应用前景。催化剂作为影响其能量转化效率和价格的重要因素之一,减少催化剂的用量并提高催化活性是直接醇类燃料电池进一步发展过程中极为重要且亟待解决的问题。基于此,本论文着眼于高效、低价的直接醇类燃料电池催化剂的设计,从纳米材料的组分、结构、形貌和载体四个方面来进行调控,合成了几种不同类型的一维Pd基中空纳米催化剂,并研究了其在直接醇类燃料电池中的电催化性能。主要研究内容及结果如下:1.设计了一种以氧化石墨烯(GO)为稳定剂和分散剂,Te纳米线为模板,可控合成一维Pd基纳米管/GO复合材料的方法。通过加入不同的金属盐前体,在室温水溶液中成功合成了三种不同组分(PdTe,PdPtTe和PdAuTe)的纳米管/GO复合材料,在这三种材料中,Pd基纳米管均具有较均一的形貌,且在GO上有良好的分散性。通过电化学方法将GO还原后,研究了不同比例的PdAuTe纳米管/还原石墨烯(rGO)复合材料电催化乙醇氧化的性能,结果表明,合成的Pd47Au33Te20、Pd31Au49Te20和Pd62Au17Te21纳米管/rGO复合材料的质量比活性分别为5.31 mA ug~(-1)Pd、4.87 m A ug~(-1)Pd和2.94 mA ug~(-1)Pd,分别是商业Pd/C(1.03 mA ug~(-1)Pd)催化剂的5.16、4.59和2.77倍。该方法为设计合成具有特定形貌的石墨烯基纳米催化剂提供了新的思路。2.以Te纳米线和Ag纳米粒子为模板,合成了一种全新的中空Pt球/PdPt管纳米结构,并研究了其电催化乙二醇和丙三醇氧化的性能。结果表明,合成的中空铂纳米球/钯铂纳米管结构电催化乙二醇氧化的质量活性为5.21 A mg~(-1)metal,分别是商业Pt/C和商业Pd/C催化剂的2.29倍和5.15倍;其电催化丙三醇氧化的质量活性为1.60A mg~(-1)metal,分别是商业Pt/C和商业Pd/C催化剂的1.46倍和3.96倍。同时,这种材料在电催化过程中表现出增强的稳定性。这种全新的零维/一维中空纳米结构具有一维纳米管的结构稳定性、中空纳米球空腔的区域限制效应以及Pd、Pt两种金属的协同效应等多重优势,使得其表现出优异的电催化性能。
[Abstract]:Direct alcohol fuel cells have the advantages of wide fuel sources, safe storage and transportation, high energy conversion efficiency and environmental protection. The catalyst is one of the most important factors affecting the energy conversion efficiency and price of the fuel cell. Reducing the amount of catalyst and improving the catalytic activity are the most important and urgent problems in the further development of direct alcohol fuel cell. Therefore, this paper focuses on the design of high efficiency and low price catalyst for direct alcohol fuel cell. Based on the composition, structure, morphology and support of nanomaterials, several kinds of one-dimensional PD based hollow nanocrystalline catalysts were synthesized. The main contents and results are as follows: 1. Using graphene oxide (GOO) as stabilizer and dispersant TTE nanowire as template, One-dimensional PD based nanotubes / go composites were synthesized by controllable synthesis. By adding different metal salt precursors, three kinds of nanotube / go composites with different components (PdTeN, PdPtTe and PdAuTe3) were successfully synthesized in aqueous solution at room temperature. In these three materials, the Pd-based nanotubes have uniform morphology and good dispersion on go. After the reduction of go by electrochemical method, The electrocatalytic performance of PdAuTe nanotubes / reduced graphene oxide (GOG) composites for ethanol oxidation was studied. The mass specific activities of the synthesized Pd47Au33Te20Pd31Au49Te20 and Pd62Au17Te21 nanotube / rgo composites were 5.31 Ma ug-1a ug~(-1)Pd and 2.94 Ma ug-1Pdl respectively, which were 5.164.59 and 2.77 times of commercial Pd/C(1.03 mAug-1Pd) catalysts, respectively. This method was used to design and synthesize graphene groups with specific morphologies. Using Te nanowires and Ag nanoparticles as templates, A novel hollow Pt sphere / PdPt nanostructure was synthesized and its electrocatalytic properties for the oxidation of ethylene glycol and glycerol were studied. The electrocatalytic activity of the hollow platinum nanospheres / palladium platinum nanotubes for ethylene glycol oxidation is 5.21 A mg / L metal, which is 2.29 and 5.15 times higher than that of commercial Pt/C and commercial Pd/C catalysts, respectively. The electrocatalytic activity of propanediol oxidation is 1.60 A mg / L metal, which is 1.46 times and 3.96 times higher than that of commercial Pt/C and commercial Pd/C respectively. The new zero-dimensional / one-dimensional hollow nanostructures have the structural stability of one-dimensional nanotubes. The region limiting effect of hollow nanospheres and the synergistic effect of PD / Pt and Pt make them exhibit excellent electrocatalytic performance.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.4

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