二氧化钛—石墨烯复合载体的构筑及其电催化性能的研究

发布时间：2018-07-05 17:39

本文选题：微波辅助法 + TiO_2　；参考：《江苏师范大学》2017年硕士论文

【摘要】：质子交换膜燃料电池具有清洁、高效、便携以及启动温度低等优点,拥有广阔的应用前景。催化剂作为质子交换膜燃料电池的核心材料,其催化性能和耐久性能直接决定了电池的输出功率和使用寿命。微波辅助法具有反应迅速、加热快、节能、无污染等优点,有利于制备粒径小、高分散的催化剂材料。本论文采用微波辅助合成法制备了二氧化钛与石墨烯的复合载体及载Pt催化剂。通过现代谱学显微技术和电化学方法对其结构、电催化活性、稳定性进行了研究,并剖析了可能的反应机理,主要结果如下:(1)采用改良的Hummers实验方案制备出氧化石墨烯,再通过微波辅助法还原得到石墨烯。该石墨烯的片层结构明显,比表面积为388.37 m2/g。(2)采用微波辅助法制备TiO_2。与传统加热方式制备的TiO_2相比,微波辅助法制备的TiO_2纳米颗粒更小,结晶度更高,制备周期短。在合成温度较低时,TiO_2的结晶不完全;温度过高时,TiO_2的晶核相互聚集,形成不规则的形貌。(3)分别采用机械化学法和原位生长法结合微波辅助法制备了TiO_2-Graphene复合材料。研究结果表明机械化学法复合的样品能更好地保持石墨烯和二氧化钛各自的形貌。(4)采用微波辅助法制备的Pt/graphene-TiO_2催化剂,锐钛矿型TiO_2均匀的分散在石墨烯的片层上,且Pt粒子均匀的分散在复合载体上,粒径均匀,平均粒径约为2.5 nm。与Pt/C催化剂相比,复合催化剂呈现了良好的催化活性和稳定性。当TiO_2的含量为20%时,其综合性能最好。
[Abstract]:Proton exchange membrane fuel cells (PEMFC) have many advantages, such as clean, efficient, portable and low start-up temperature. As the core material of proton exchange membrane fuel cell (PEMFC), the catalytic performance and durability of the catalyst directly determine the output power and service life of the cell. The microwave-assisted method has the advantages of rapid reaction, quick heating, energy saving and no pollution. It is beneficial to the preparation of catalyst materials with small particle size and high dispersion. In this paper, the composite supports of titanium dioxide and graphene and Pt supported catalysts were prepared by microwave assisted synthesis. The structure, electrocatalytic activity and stability of graphene oxide were studied by modern spectroscopic microscopy and electrochemical methods. The possible reaction mechanism was analyzed. The main results were as follows: (1) graphene oxide was prepared by modified Hummers method. Then the graphene was reduced by microwave assisted method. The specific surface area of the graphene is 388.37 m2 / g. (2) TiOs _ 2 was prepared by microwave-assisted method. Compared with the TIO _ 2 prepared by traditional heating method, the TIO _ 2 nanoparticles prepared by microwave-assisted method are smaller, higher crystallinity and shorter preparation period. When the synthesis temperature is low, the crystallization of tio _ 2 is incomplete, and the crystal nuclei of tio _ 2 gather together to form irregular morphology when the temperature is too high. (3) TiO2-Graphene composites are prepared by mechanochemical method and in situ growth method combined with microwave-assisted method, respectively. The results show that the composite samples can better maintain the morphology of graphene and titanium dioxide. (4) the anatase TIO _ 2 catalyst prepared by microwave-assisted method is uniformly dispersed on the graphene layer. The Pt particles were uniformly dispersed on the composite support, and the average particle size was about 2.5 nm. Compared with PT / C catalyst, the composite catalyst showed good catalytic activity and stability. When the content of tio _ 2 is 20, its comprehensive performance is the best.
【学位授予单位】：江苏师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.4

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