【作者】 李谦；

【导师】 刘景军；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2012， 硕士

【摘要】 燃料电池铂系阴极催化剂的高成本严重制约其商业化的发展。本论文旨在寻找替代铂系阴极催化剂的材料。采用了水相直接聚合方法，制备出具有高长径比的聚苯胺纳米管，然后经过碳化活化处理，得到掺氮碳纳米管，并探讨了其碱性介质中氧还原反应电催化活性。首先通过直接聚合法合成了聚苯胺纳米管，研究了掺杂酸的种类，浓度，反应温度等因素对聚苯胺形貌、结构的影响，在水相中成功合成出了聚苯胺纳米管，管径约170nm，壁厚约60nm，长为4-6μm。本文以多壁碳纳米管为硬模板成功合成了形貌均一的聚苯胺接枝碳纳米管复合材料。对前躯体材料进行碳化和活化处理，发现碳化后聚苯胺的纳米管状结构保持完整。找到了处理温度和氮结合态的关系：在600℃下不含有石墨型的氮元素，随着处理温度的提高，其吡咯型氮元素含量下降，石墨氮含量增加。得到了氮碳比为1.78-6.72%的掺氮碳纳米管，其比表面积高达2065m~2/g，其中微孔约占91.5%。在碱性介质中，研究了不同氮含量对于的催化氧气还原反应的影响。随着吡啶氮和石墨氮/碳含量的增加，其氧气还原反应活性增加。当吡啶氮和石墨氮/碳含量为2.43%时催化活性最高，其ORR活性高于聚苯胺接枝碳纳米管活化处理的碳材料，接近于商业铂碳催化剂。通过研究掺氮碳纳米管的ORR动力学过程，当啶氮和石墨氮/碳含量为2.43%时，计算得电子数为3.6-3.8，其ORR以4电子反应路径进行。更多还原

【Abstract】 The high cost of s platinum cathode catalyst seriously restrict thedevelopment of commercial of the fuel cells. This paper aims to serach for thecathode materials to replace platinum catalyst. Through directlypolymerization methods at water phase, we got high length-diameter ratio ofpolyaniline nanotubes, we carbonized and activated this materials, then we gotN-doping carbon nanotubes, and we discusses electricity catalytic activity ofthe oxygen reduction reactions at alkaline medium.Firstly, we got polyailine nanotubes by the way of chemical oxidationdirectly. We study the rationship of the types of doping acid, concentration,reaction temperature and the appearance, structure of polyaniline. We got thepolyaniline nanotubes at water phase, the polyaniline diameter is about170nmand the wall thickness is about60nm, long about4-6μm.This article alsostudies the synthesis methods of as multi-walled carbon nanotubes for hardtemplate to got carbon nanotube grafted polyaniline composite materials.Before the precursor of material through the treatment of carbonization and activation, we found that carbon nanotubes the structure completely thesame with the polyaniline.We find the relations of the processing temperatureand nitrogen combination state:at600℃,there is not contain graphite type ofnitrogen, with the improvement of processing temperature, the content ofpyrrole-type nitrogen decreased, graphite nitrogen content increased. We gotthe nitrogen carbon ratio1.78-6.72%of the nitrogen-doped carbon nanotubeswith its specific surface area as high as2065m2/g, including91.5%.of microhole.In alkaline medium, we researched the influence of different nitrogencontent with the catalytic oxygen reduction. With the content of pyridinenitrogen and carbon graphite nitrogen/carbon increased, the oxygen reductionreaction activity increased. When pyridine nitrogen and graphitenitrogen/carbon content was2.43%,the catalytic activity are highest, its ORRwere higher than polyaniline grafted carbon nanotubes activation treatment ofcarbon materials,it is close to business platinum catalyst carbon.Through the research of kinetic process of ORR nitrogen-doped of thecarbon nanotubes, when pyridine nitrogen and graphite nitrogen/carboncontent was2.43%, we calculated that the electronic transfer number is3.6-3.8,the electronic reaction paths of ORR is4.更多还原