空心碳球负载铁、钴纳米材料在氧还原反应中的应用
发布时间：2018-11-01 15:00
【摘要】：在燃料电池(MFC)技术中,质子交换膜燃料电池(PEMFC)以其低温度工作、启动快、绿色环保、高效率以及能量密度低等优点,在小型发电机及便携式电动装置中呈现了广阔的应用前景。在质子膜交换燃料电池中,反应速率及能量转换速度主要受阴极氧还原反应(ORR)制约,因此,寻找催化性能良好的阴极电化学催化材料极其重要。目前应用较多的阴极催化剂是铂系催化剂,但是该催化剂具有容易中毒、价格昂贵等特点,并不利于回收应用和商业化发展。而过渡金属(Fe,Co)杂化材料却具有电催化活性好和不易中毒的特点,是取代铂催化剂的极佳候选者。因此,将含有过渡金属(Fe,Co)的杂化材料负载在高比表面积和稳定性良好的载体空心碳球(HCS)上是一种有前途的催化剂。在前期工作酞菁铁负载在毗啶炔环加成石墨烯上(FePc/PyNG)的基础上,本文通过采取不同的制备方法得到了不同的过渡金属杂化物,并将其应用于ORR反应,其主要研究内容如下：(1)空心碳球负载氮化钴(CoNx/NHCS):本文以酞菁钴(CoPc)、2,4--"羟基苯甲酸(DA)、环六亚甲基四胺(HMT)为原料,通过水热合成法制备了前驱体CoPc/HPS,然后将其在氨气气氛中700℃焙烧,便可以得到催化剂CoNx/HCS。SEM表征发现,焙烧后得到的空心碳球结构完整,而且球壳上有利于电子和水分子转移的“纳米缝隙”；TEM表征发现,大多数CoNx纳米粒都是均匀的嵌入到含氮空心碳球(NHCS)球壳上；XRD表征发现,CoNx呈现高度结晶状态,且化学配比应为C05.47N。在ORR测试中,与等量商业的Pt/C催化剂相比,CoNx/NHCS催化剂呈现了可媲美甚至更优异的活性和稳定性。(2)空心碳球负载氮化铁钴(C/FeCoNx/HCS):本文在制备了酞菁铁、酞菁钴负载吡啶空心碳球(FeCo/PyNGHCS)前驱体后,再在其外面包覆葡萄糖,然后在氨气气氛中700℃焙烧,便可以得到结构新颖的C/FeCoNx/HCS催化剂。TEM表征发现,该催化剂最内层是空心碳球,中间是活性组分FeCoNx,最外层是无定形碳膜。将该催化剂应用于ORR测试时,发现它没有等量商业的Pt/C催化剂的催化性能好。因此,在将来的工作中,有待改变实验策略,进一步提高C/FeCoNx/HCS催化剂的催化活性。
[Abstract]:In fuel cell (MFC) technology, proton exchange membrane fuel cell (PEMFC) has the advantages of low temperature, fast start, green environment, high efficiency and low energy density. It is widely used in small generators and portable electric devices. In proton membrane exchange fuel cells (PEMFC), the reaction rate and energy conversion rate are mainly restricted by the cathodic oxygen reduction reaction (ORR). Therefore, it is very important to find cathode electrochemical catalytic materials with good catalytic performance. At present, the cathodic catalyst which is widely used is platinum catalyst, but it is easy to be poisoned and expensive, so it is not conducive to the development of recycling and commercialization. However, transition metal (Fe,Co) hybrid materials have good electrocatalytic activity and are not easy to be poisoned, so they are excellent candidates to replace platinum catalysts. Therefore, it is a promising catalyst to load the hybrid material containing transition metal (Fe,Co) on the hollow carbon ball (HCS) with high specific surface area and good stability. Based on the work of iron phthalocyanine supported on pyridine cycloaddition graphene (FePc/PyNG), different transition metal hybrids were obtained by different preparation methods and applied to ORR reaction. The main research contents are as follows: (1) Cobalt nitride (CoNx/NHCS) loaded with hollow carbon spheres: in this paper, the raw material of (DA), cyclohexamethylenetetramine (HMT) is cobalt phthalocyanine cobalt (CoPc), _ 2o _ 4- "hydroxybenzoic acid." The precursor CoPc/HPS, was prepared by hydrothermal synthesis and calcined at 700 鈩，
本文编号：2304270
[Abstract]:In fuel cell (MFC) technology, proton exchange membrane fuel cell (PEMFC) has the advantages of low temperature, fast start, green environment, high efficiency and low energy density. It is widely used in small generators and portable electric devices. In proton membrane exchange fuel cells (PEMFC), the reaction rate and energy conversion rate are mainly restricted by the cathodic oxygen reduction reaction (ORR). Therefore, it is very important to find cathode electrochemical catalytic materials with good catalytic performance. At present, the cathodic catalyst which is widely used is platinum catalyst, but it is easy to be poisoned and expensive, so it is not conducive to the development of recycling and commercialization. However, transition metal (Fe,Co) hybrid materials have good electrocatalytic activity and are not easy to be poisoned, so they are excellent candidates to replace platinum catalysts. Therefore, it is a promising catalyst to load the hybrid material containing transition metal (Fe,Co) on the hollow carbon ball (HCS) with high specific surface area and good stability. Based on the work of iron phthalocyanine supported on pyridine cycloaddition graphene (FePc/PyNG), different transition metal hybrids were obtained by different preparation methods and applied to ORR reaction. The main research contents are as follows: (1) Cobalt nitride (CoNx/NHCS) loaded with hollow carbon spheres: in this paper, the raw material of (DA), cyclohexamethylenetetramine (HMT) is cobalt phthalocyanine cobalt (CoPc), _ 2o _ 4- "hydroxybenzoic acid." The precursor CoPc/HPS, was prepared by hydrothermal synthesis and calcined at 700 鈩，
本文编号：2304270
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