新型非铂微纳电催化材料的制备及在新能源器件中的性能研究
发布时间：2018-11-16 17:58
【摘要】：在当前能源危机和环境污染严重的背景下,开发高效清洁能源变得十分迫切。染料敏化太阳能电池(Dye-sensitized solar cells, DSCs)由于具有能量转换效率高、易制作、低成本、环境友好等优点而引起广泛关注,目前效率已经达到14%。燃料电池(Fuel cells, FCs)作为新型发电装置,可以直接将燃料的化学能转化为电能,具有能量转换效率高、环境污染小、燃料来源广等优点,被誉为继水力、火力和核能之后的第四代发电技术。这两种新能源器件的研究将有助于能源危机和环境污染问题的解决。这两种新能源器件都涉及到阴极催化还原反应,开发高效、廉价、稳定的阴极催化材料对推动其产业化发展意义重大。目前DSCs和FCs中最常用的阴极材料是贵金属铂(Pt),其价格昂贵且造成电池成本高；另外,Pt具有稳定性差、反应迟缓、易受燃料渗透影响等缺点。因此,为推动两种新能源器件的产业化发展,研究开发高效、低成本、高稳定性的非贵金属阴极催化材料成为一个迫切任务。同时需深入研究阴极催化材料在器件中的催化机理,探索电池效率的影响机制,为研究新材料提供指导。为解决上述问题,本论文以设计合成高效稳定的非贵金属阴极催化剂为目标,系统研究了催化材料的形貌、组成、结构与催化性能的构效关系,深入探索了非贵金属催化材料对I3- (IRR, Iodine reduction reaction)和O2 (ORR, Oxygen reduction reaction)还原反应的催化机制。首先,以NbSe2为切入点,通过控制合成过程的降温速率实现了对NbSe2纳米催化材料的形貌调控,研究了催化剂形貌与其对DSCs中13-/I-电对催化性能之间的关系。以NbSe2/C为对电极的DSCs最终获得了7.80%的能量转换效率,性能接近溅射Pt电极。通过改变过渡金属硒化物的组成,合成了Cr5.6Se8、MoSe2、WSe2、TaSe2和HfSe3等系列硒化物,研究了材料组成与其催化性能的关系,并利用泛函密度理论对具有相似形貌和结构但催化活性差异较大的MoSe2和WSe2进行了理论研究,发现两种催化剂催化活性差异的原因是对13-的吸附能力和电子传导能力不同。进一步拓宽了硒化物的应用范围,设计构建了超薄二维石墨烯-无机石墨烯类似物层状复合催化剂并应用于燃料电池氧还原反应。复合催化剂具有更高的比表面积和更加优异的结构,更加有利于02的吸附和传质,从而表现出优异的ORR反应催化性能。其次,首次将碲化物用作DSCs高效对电极催化材料。利用复合碱媒介法成功合成了CoTe和NiTe2,并用作对电极,DSCs器件获得了6.92%和7.21%的光电转换效率,与溅射Pt对电极相当。调控铁基化合物的组成,合成了FeS2、FeSe2和FeTe2三种铁基硫属化合物并应用于DSCs对电极体系,三者对13-/I-电对均表现出良好的电催化活性,电池效率分别为8.00%、7.92%和7.21%。其中FeTe2微米级的尺寸导致其催化活性位点相对较少,从而表现出稍差的电催化性能。理论计算表明FeS2对I具有较大的吸附能,而FeTe2则具有较小的功函数,有利于界面电荷交换。第三,利用溶剂热法在石墨烯表面合成了W18049纳米棒,并将其用作燃料电池阴极催化剂。原位复合得到的催化剂中,W18049纳米棒与部分还原氧化石墨烯之间存在强烈的相互作用。结合W18049纳米棒的一维结构、丰富的表面氧空位,以及石墨烯良好的导电性,合成出的复合催化剂有效保障了02的吸附和电荷的传输,最终表现出了良好的ORR催化性能。研究表明,复合催化剂在ORR过程中电子转移数大约为3.88,与商业Pt/C催化剂接近。同时,该复合催化剂还具有良好的耐久性和抗甲醇性能,是一种有潜力的非Pt阴极催化材料。
[Abstract]:In the background of the current energy crisis and environmental pollution, it is very urgent to develop high-efficiency clean energy. Dye-sensitized solar cells (DSCs) have attracted wide attention due to the advantages of high energy conversion efficiency, easy production, low cost and environmental protection. The present efficiency has reached 14%. The fuel cell (FCs), as a new type of power generation device, can directly convert the chemical energy of the fuel into electric energy, and has the advantages of high energy conversion efficiency, small environmental pollution, wide fuel source and the like, and is praised as the fourth generation power generation technology following hydraulic, fire and nuclear power. The research of these two new energy devices will help solve the energy crisis and the problem of environmental pollution. The two new energy devices are involved in the catalytic reduction reaction of the cathode, and the high-efficiency, low-cost and stable cathode catalytic material is important for promoting the industrial development of the cathode. At present, the most common cathode materials in DSCs and FCs are noble metal platinum (Pt), which is expensive and has high battery cost; in addition, Pt has the disadvantages of poor stability, slow reaction, and easy to be influenced by fuel permeation. Therefore, in order to promote the industrialization development of two new energy devices, the research and development of the non-noble metal cathode catalytic material with high efficiency, low cost and high stability has become an urgent task. At the same time, it is necessary to study the catalytic mechanism of the cathode catalytic material in the device, to explore the mechanism of the effect of the efficiency of the battery, and to provide guidance for the study of new materials. In order to solve the above problems, this paper aims to design and synthesize a highly efficient and stable non-noble metal cathode catalyst. The structure, composition, structure and catalytic performance of the catalytic material are studied, and the non-noble metal catalytic material pair I3-(IRR, Iodine reduction reaction)鍜孫2 (ORR, Oxygen reduction reaction)杩樺師鍙嶅簲鐨勫偓鍖栨満鍒，
本文编号：2336220
[Abstract]:In the background of the current energy crisis and environmental pollution, it is very urgent to develop high-efficiency clean energy. Dye-sensitized solar cells (DSCs) have attracted wide attention due to the advantages of high energy conversion efficiency, easy production, low cost and environmental protection. The present efficiency has reached 14%. The fuel cell (FCs), as a new type of power generation device, can directly convert the chemical energy of the fuel into electric energy, and has the advantages of high energy conversion efficiency, small environmental pollution, wide fuel source and the like, and is praised as the fourth generation power generation technology following hydraulic, fire and nuclear power. The research of these two new energy devices will help solve the energy crisis and the problem of environmental pollution. The two new energy devices are involved in the catalytic reduction reaction of the cathode, and the high-efficiency, low-cost and stable cathode catalytic material is important for promoting the industrial development of the cathode. At present, the most common cathode materials in DSCs and FCs are noble metal platinum (Pt), which is expensive and has high battery cost; in addition, Pt has the disadvantages of poor stability, slow reaction, and easy to be influenced by fuel permeation. Therefore, in order to promote the industrialization development of two new energy devices, the research and development of the non-noble metal cathode catalytic material with high efficiency, low cost and high stability has become an urgent task. At the same time, it is necessary to study the catalytic mechanism of the cathode catalytic material in the device, to explore the mechanism of the effect of the efficiency of the battery, and to provide guidance for the study of new materials. In order to solve the above problems, this paper aims to design and synthesize a highly efficient and stable non-noble metal cathode catalyst. The structure, composition, structure and catalytic performance of the catalytic material are studied, and the non-noble metal catalytic material pair I3-(IRR, Iodine reduction reaction)鍜孫2 (ORR, Oxygen reduction reaction)杩樺師鍙嶅簲鐨勫偓鍖栨満鍒，
本文编号：2336220
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