Fe-N-C复合材料的宏量合成及其在能量储存与转换中的应用研究

发布时间：2018-05-30 12:54

本文选题：溶剂热法 + Fe-N-C复合材料　；参考：《温州大学》2016年硕士论文

【摘要】：超级电容器的电极材料是决定其电容性能好坏的关键因素之一,因此,制备同时兼具高功率密度,高能量密度,高电容容量和循环稳定性的电极材料是解决问题的关键。目前燃料电池阴极氧还原电催化剂主要以铂基贵金属电催化剂为主,然而铂的储量极其有限,成本昂贵,并且铂基电催化剂的稳定性较差,这些因素严重制约了其在商业中的广泛应用,因此研究制备成本低,具有高稳定性的非贵金属碳基催化剂是燃料电池电催化剂的研究重点。基于此,本论文研究了一类Fe-N-C复合材料,并应用于超级电容器和燃料电池,具体研究结果如下:1.发展了一种通过一步法宏量合成Fe-N-C复合电极材料的新方法,以有机过渡金属化合物二茂铁为铁源,小分子有机化合物吡啶为氮源、碳源,卤代烃C_4Cl_6为碳源,通过溶剂热法成功宏量的合成了一类新型Fe-N-C_(urea)复合材料。通过测试表明,该电极材料的最高质量比电容可以达到346.7F/g,具有良好的超级电容性能。通过对其循环稳定性的测试,在电流密度为10A/g下,循环5000次,其质量比电容下降为原来的90%左右,可以看出其具有良好的循环稳定性。该Fe-N-C复合电极材料能够在大的扫描速率(500mv/s)以及大电流密度(80A/g)下充放电并且能够达到比较大的电容值,且循环稳定性良好,为研究低成本,大电流充放电电极材料开辟了一条新道路,具有潜在的研究价值。2.开发了一种基于过渡金属Fe原位还原有机卤代物的新方法,运用该方法不但可宏量合成具有新颖骨架结构、独特表面化学性质以及三维多级孔道结构的过渡金属和非金属原子共同掺杂的多孔碳基电催化剂,而且具有合成过程简便、经济且环境友好等优点。设计合成的非贵金属氮掺杂碳基电催化剂,拥有高的比表面积(1535.2m2/g)以及丰富的孔道结构,提供了更多的活性位点。该Fe-N-C复合电极材料对O2的还原是一个直接的四电子转移过程,直接将氧气还原成OH-,在氧还原反应过程,中间产物少,过程简单,反应速率快。并且与20%商业Pt/C相比,具有更好的抗甲醇中毒性,表现出了优异的氧还原活性和稳定性。
[Abstract]:The electrode material of supercapacitor is one of the key factors to determine the performance of supercapacitor. Therefore, the preparation of electrode material with high power density, high energy density, high capacitance and cycle stability is the key to solve the problem. At present, the cathodic oxygen reduction electrocatalyst for fuel cell is mainly platinum based noble metal electrocatalyst. However, platinum is very limited in storage and expensive in cost, and the stability of platinum based electrocatalyst is poor. These factors seriously restrict its wide application in commercial applications. Therefore, the research on non-noble metal carbon-based catalysts with low cost and high stability is the focus of research on fuel cell electrocatalysts. Based on this, a class of Fe-N-C composites are studied and applied to supercapacitors and fuel cells. The results are as follows: 1. A new method for the synthesis of Fe-N-C composite electrode materials by one step macrosynthesis was developed. The organic transition metal compound ferrocene was used as the Tie Yuan, the small molecular organic compound pyridine as the nitrogen source, the carbon source and the halogenated hydrocarbon C_4Cl_6 as the carbon source. A new type of Fe-N-C\ +\ -\ The test results show that the maximum mass specific capacitance of the electrode material can reach 346.7 F / g, and it has good super capacitor performance. Through the test of its cycle stability, under the current density of 10A/g, 5000 cycles, its mass specific capacitance decreased to about 90% of the original, it can be seen that it has good cycle stability. The Fe-N-C composite electrode material can charge and discharge at a high scanning rate of 500mv / s and a high current density of 80A / g. High current charge-discharge electrode materials have opened up a new way and have potential research value. 2. A new method of in-situ reduction of organic halides based on transition metal Fe was developed. The special surface chemical properties and the transition metal and nonmetallic atoms doped with transition metal and nonmetallic atom have the advantages of simple synthesis, economical and environment-friendly. The non-noble metal nitrogen-doped carbon-based electrocatalysts with high specific surface area of 1535.2 m2 / g) and abundant pore structure provide more active sites. The reduction of O2 by the Fe-N-C composite electrode is a direct four-electron transfer process. Oxygen is reduced to OH-directly. In the process of oxygen reduction, the intermediate product is less, the process is simple and the reaction rate is fast. Compared with 20% commercial Pt/C, it has better resistance to methanol toxicity, and shows excellent oxygen reduction activity and stability.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB33;TM53

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