空心碳球負載鐵、鈷納米材料在氧還原反應中的應用
發(fā)布時間：2018-11-01 15:00
【摘要】：在燃料電池(MFC)技術中,質子交換膜燃料電池(PEMFC)以其低溫度工作、啟動快、綠色環(huán)保、高效率以及能量密度低等優(yōu)點,在小型發(fā)電機及便攜式電動裝置中呈現(xiàn)了廣闊的應用前景。在質子膜交換燃料電池中,反應速率及能量轉換速度主要受陰極氧還原反應(ORR)制約,因此,尋找催化性能良好的陰極電化學催化材料極其重要。目前應用較多的陰極催化劑是鉑系催化劑,但是該催化劑具有容易中毒、價格昂貴等特點,并不利于回收應用和商業(yè)化發(fā)展。而過渡金屬(Fe,Co)雜化材料卻具有電催化活性好和不易中毒的特點,是取代鉑催化劑的極佳候選者。因此,將含有過渡金屬(Fe,Co)的雜化材料負載在高比表面積和穩(wěn)定性良好的載體空心碳球(HCS)上是一種有前途的催化劑。在前期工作酞菁鐵負載在毗啶炔環(huán)加成石墨烯上(FePc/PyNG)的基礎上,本文通過采取不同的制備方法得到了不同的過渡金屬雜化物,并將其應用于ORR反應,其主要研究內容如下：(1)空心碳球負載氮化鈷(CoNx/NHCS):本文以酞菁鈷(CoPc)、2,4--"羥基苯甲酸(DA)、環(huán)六亞甲基四胺(HMT)為原料,通過水熱合成法制備了前驅體CoPc/HPS,然后將其在氨氣氣氛中700℃焙燒,便可以得到催化劑CoNx/HCS。SEM表征發(fā)現(xiàn),焙燒后得到的空心碳球結構完整,而且球殼上有利于電子和水分子轉移的“納米縫隙”；TEM表征發(fā)現(xiàn),大多數(shù)CoNx納米粒都是均勻的嵌入到含氮空心碳球(NHCS)球殼上；XRD表征發(fā)現(xiàn),CoNx呈現(xiàn)高度結晶狀態(tài),且化學配比應為C05.47N。在ORR測試中,與等量商業(yè)的Pt/C催化劑相比,CoNx/NHCS催化劑呈現(xiàn)了可媲美甚至更優(yōu)異的活性和穩(wěn)定性。(2)空心碳球負載氮化鐵鈷(C/FeCoNx/HCS):本文在制備了酞菁鐵、酞菁鈷負載吡啶空心碳球(FeCo/PyNGHCS)前驅體后,再在其外面包覆葡萄糖,然后在氨氣氣氛中700℃焙燒,便可以得到結構新穎的C/FeCoNx/HCS催化劑。TEM表征發(fā)現(xiàn),該催化劑最內層是空心碳球,中間是活性組分FeCoNx,最外層是無定形碳膜。將該催化劑應用于ORR測試時,發(fā)現(xiàn)它沒有等量商業(yè)的Pt/C催化劑的催化性能好。因此,在將來的工作中,有待改變實驗策略,進一步提高C/FeCoNx/HCS催化劑的催化活性。
[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，
本文編號：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，
本文編號：2304270
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