模板法制备Nafion纳米线阵研究

发布时间：2018-03-25 16:06

本文选题：热压法　切入点：质子交换膜燃料电池　出处：《太原理工大学》2015年硕士论文

【摘要】：当今环境问题特别是大气污染越来越得到人们的关注，对社会和经济的发展影响也愈来愈大。氢能源因其环境友好性被公认为将取代石化能源从而支撑全球经济，氢气的生产、运输、储存以及使用共同构成氢经济的市场体系。燃料电池作为氢能源产业链的最后一环，也是技术最为关键的一项，目前在世界各国科学家的共同努力下，燃料电池已经进入技术验证后期，商业化的前期。质子交换膜燃料电池作为低温燃料电池的一种，清洁且能量转换效率高从而被认为是未来车用动力的最佳选择。丰田、本田、日产和现代等车企都纷纷发布了自己的燃料电池汽车，并提出在未来1~5年内量产，2015年也被行业内同行称为氢燃料电池汽车元年。但质子交换膜燃料电池的成本过高还不能满足燃料电池汽车商业化普及的需求，其中很大一部分的原因是因为其催化剂对Pt的依赖，而Pt的储量不能满足亿级的世界汽车保有量，因此催化层必须做到无Pt或者低Pt，目前新型膜电极采用纳米线/棒制备技术制备有序化膜电极。而有序化膜电极利用纳米技术优化膜电极中的催化层结构即多相物质传输通道，降低Pt载量，从而实现成本和性能的提升，这正是目前世界各国高校及研究机构的研究重点。催化层的有序化可以从优化物质传输通道考虑，例如电子传导的有序化可以通过载体材料的有序化或催化剂材料的有序化来实现，而质子传导的有序化可以通过质子导体材料的有序化来实现，这些纳米线阵材料应用到PEMFC催化层中时，都可以同时实现气体和水传输通道的有序化。故而第三代膜电极按照材料类型分为载体材料有序化膜电极、催化剂材料有序化膜电极以及质子导体有序化膜电极。本研究课题方向就是探索可控制备Nafion纳米线阵有序化膜电极的制备工艺，经过大量尝试后，，发现以AAO为模板的热压法可以实现在Nafion膜表面原位生长Nafion纳米线阵。对热压工艺中的模板的预处理、热压温度、压强、热压时间等因素的分析，研究出一套科学的生长Nafion纳米线阵的方法。对原位生长出来的Nafion纳米线阵形貌、成分以及物化性能等进行表征分析，并解释Nafion纳米线阵的生长机理。研究发现：（1）在Nafion玻璃化温度以上，采用热压法和模板法结合的工艺可以可控制备Nafion纳米线阵；（2）在经过对Nafion纳米线阵成分和基团等信息的研究分析，发现该工艺原位生长出的Nafion纳米线阵与原Nafion211膜成分和基团等信息一致，并未发生变化；（3）通过失水率实验发现Nafion纳米线阵有蓄水自增湿的性能。在展望部分，对后续Nafion纳米线阵制备新型有序化膜电极课题的整体研究思路进行了规划。
[Abstract]:Nowadays, people pay more and more attention to environmental problems, especially air pollution, and their impact on social and economic development is also increasing. Hydrogen energy, because of its environmental friendliness, is recognized as a substitute for fossil energy and thus supports the global economy and hydrogen production. Transportation, storage and use of the market system that together make up the hydrogen economy. Fuel cells, as the last link in the hydrogen energy industry chain, are also the most crucial technology, and are now under the joint efforts of scientists from all over the world. Proton exchange membrane fuel cell (PEMFC), as a kind of low temperature fuel cell, is clean and energy conversion efficiency, so it is considered the best choice of future vehicle power. Both Nissan and Hyundai have launched their own fuel cell vehicles, offering to mass produce within the next 1 to 5 years, and are also called the first year of hydrogen fuel cell vehicles by their peers in 2015. But the proton exchange membrane fuel cell costs are too high to meet the commercial popularity of fuel cell vehicles, in large part because of its dependence on Pt for its catalysts. And the Pt reserves are not enough to meet the billion class of world car holdings, Therefore, the catalytic layer must be Pt free or low Pt.The novel membrane electrode uses nanowire / rod preparation technology to prepare the ordered membrane electrode, and the ordered membrane electrode uses nanotechnology to optimize the structure of the catalyst layer in the membrane electrode, that is, the multiphase mass transfer channel. Reducing Pt load to improve cost and performance is the research focus of universities and research institutions all over the world. The ordering of the catalytic layer can be considered from the optimization of the material transport channel, for example, the ordering of the electron conduction can be achieved through the ordering of the carrier material or the ordering of the catalyst material. The ordering of proton conduction can be achieved through the ordering of proton conductor materials, which are used in the PEMFC catalytic layer. Therefore, the third generation membrane electrode can be divided into carrier material ordered membrane electrode, catalyst material ordered membrane electrode and proton conductor ordered membrane electrode according to the material type. The research direction of this research is to explore the preparation process of controllable preparation of Nafion nanowire ordered film electrode, after a large number of attempts, It is found that Nafion nanowire array can be grown on the surface of Nafion film by hot-pressing method using AAO as template. The pretreatment of template, hot pressing temperature, pressure, hot pressing time and other factors in hot pressing process are analyzed. A set of scientific methods for the growth of Nafion nanowires were developed. The morphology, composition and physicochemical properties of Nafion nanowires grown in situ were characterized and analyzed, and the growth mechanism of Nafion nanowires was explained. It is found that Nafion nanowire array can be prepared by the combination of hot pressing and template method above the glass transition temperature of Nafion.) after studying and analyzing the composition and group information of Nafion nanowire array, It is found that the in-situ growth of Nafion nanowire array is consistent with that of the original Nafion211 film composition and group, and no change has taken place. The water loss rate experiment shows that the Nafion nanowire array has the property of water storage and self-humidification. In the part of prospect, the whole research idea of preparation of new ordered membrane electrode by Nafion nanowire array is planned.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM911.4;TB383.1

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