纳米多孔金属对葡萄糖的电催化氧化及其在燃料电池中的应用

发布时间：2018-05-12 19:53

本文选题：燃料电池 + 葡萄糖　；参考：《天津理工大学》2017年硕士论文

【摘要】：葡萄糖作为我们日常生活以及生命活动中常见的物质,是一种无毒、廉价、可再生的绿色能源,具有以下特点:1、来源广泛,造纸、酿酒以及人体内都含有葡萄糖。2、反应的条件相对温和,能在常温、常压、中性条件下反应,并且易于操作、控制和维护。3、生物相容性好,可为植入人体的人造器官或生物传感器提供能量。葡萄糖作阳极的直接葡萄糖燃料电池(DGFC)具有绿色无污染、能量转换效率高、响应速度快、噪声低等优点,有望应用于小型可移动电源和可植入医疗设备方面。但是,缺乏高效的葡萄糖氧化反应催化剂是阻碍实际应用的最大问题,最初研究的酶和微生物催化剂具有易失活、操作复杂等问题,而后来广泛使用的粉末状非生物催化剂也面临活性低的问题。通过脱合金得到的具有三维双连续孔道的纳米多孔金(nanoporous gold,NPG),凭借其特殊的纳米尺寸效应和良好的电化学性能而获得广泛关注,这种材料具有较高孔隙率、高比表面积、超高导电性等优点,并且NPG本身便可以作为一些氧化反应的催化剂,并显示出了良好的催化活性。此外,NPG本身还具有良好的生物相容性和较高稳定性,显示出良好的应用前景。因此,本文主要探究了纳米多孔金属对葡萄糖的电催化氧化性能及其在葡萄糖燃料电池中的应用,具体研究内容如下:(1)通过自由腐蚀和电化学腐蚀两种方法得到了两种韧带/骨架尺寸的纳米多孔金薄膜,通过扫描电子显微镜对其形貌结构和韧带尺寸进行表征,分别在碱性和中性溶液中对葡萄糖的电催化氧化行为进行表征,结果发现:不管在碱性或是中性环境中,电化学腐蚀制备的韧带尺寸较小的NPG对葡萄糖的催化性能都优于自由腐蚀制备的尺寸较大的NPG。在此基础上,将纳米多孔金作为基底,通过化学还原法沉积了致密的Pt壳,得到NPG-Pt核壳结构催化剂,选用同样的方法分析NPG-Pt对葡萄糖电催化氧化反应的活性,得到了与NPG一致的结果:骨架尺寸较小的NPG-Pt催化活性明显优于骨架较大的。(2)通过电镀的方法在NPG-Pt上修饰分散的Bi颗粒,组成NPG-PtBi作阳极和商业Pt/C作阴极的直接葡萄糖燃料电池,通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)分析了材料的形貌结构,X射线光电子能谱仪(XPS)分析Bi元素的存在状态。研究讨论了操作温度和葡萄糖燃料浓度以及NaOH浓度对直接葡萄糖燃料电池性能的影响,在阳极贵金属负载量仅为0.45 mg cm-2(Au 0.3 mg和Pt 0.15 mg)的情况下,获得0.9 V的开路电压(OCV),最大(表面积)功率密度为8 mW cm-2,最大重量功率密度为18 mW mg-1,比商业Pt/C高约4.5倍。
[Abstract]:Glucose, as a common substance in our daily life and life activities, is a non-toxic, cheap, renewable green energy, with the following characteristics: 1, a wide range of sources, paper, Both brewery and human body contain glucose. 2, the reaction condition is relatively mild, can react under normal temperature, atmospheric pressure, neutral condition, and easy to operate, control and maintain. 3, good biocompatibility, It can provide energy for artificial organs or biosensors implanted into the human body. Direct glucose fuel cell (DGFC) with glucose as anode has the advantages of green non-pollution, high energy conversion efficiency, fast response speed and low noise. It is expected to be used in small removable power supply and implantable medical equipment. However, the lack of efficient catalysts for the oxidation of glucose is the biggest problem that hinders the practical application. The enzyme and microbial catalysts studied at the beginning have many problems, such as easy deactivation, complex operation and so on. The powder-like non-biocatalysts, which were widely used later, also faced the problem of low activity. Nano-porous gold nanoparticles with three dimensional double continuous channels obtained by dealloying have attracted wide attention due to their special nanometer size effect and good electrochemical properties. This material has high porosity and high specific surface area. Moreover, NPG can be used as a catalyst for some oxidation reactions, and it shows good catalytic activity. In addition, NPG also has good biocompatibility and high stability, showing a good prospect of application. Therefore, the electrocatalytic oxidation of glucose by nano-porous metal and its application in glucose fuel cell were studied in this paper. The main contents are as follows: (1) Nano-porous gold thin films of ligament / skeleton size were obtained by free corrosion and electrochemical corrosion. The morphology and size of ligaments were characterized by scanning electron microscope (SEM). The electrocatalytic oxidation of glucose was characterized in alkaline and neutral solutions. The catalytic properties of NPG prepared by electrochemical etching for glucose were better than those prepared by free etching. On this basis, the dense Pt shell was deposited by chemical reduction method, and the NPG-Pt core-shell structure catalyst was obtained. The activity of NPG-Pt in the electrocatalytic oxidation of glucose was analyzed by the same method. The results are consistent with the results of NPG: the catalytic activity of NPG-Pt with small skeleton size is obviously better than that with larger skeleton. By electroplating, the dispersed Bi particles are modified on NPG-Pt, and the direct glucose fuel cells composed of NPG-PtBi as anode and commercial Pt/C as cathode are formed. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the morphology and structure of the materials. X-ray photoelectron spectroscopy (XPS) was used to analyze the existence of Bi elements. The effects of operating temperature, glucose fuel concentration and NaOH concentration on the performance of direct glucose fuel cell were studied. When the loading of noble metal in anode was only 0.45 mg cm-2(Au 0.3 mg and Pt 0.15 mg), The maximum (surface area) power density is 8 MW cm ~ (-2) and the maximum weight power density is 18 MW mg ~ (-1), which is 4.5 times higher than commercial Pt/C.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.4

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