MOFs-石墨烯基M-N_x-rGO催化剂制备及其氧还原性能研究

发布时间：2018-03-26 11:49

本文选题：直接甲醇燃料电池(DMFC)　切入点：氧还原反应(ORR)　出处：《南京航空航天大学》2017年硕士论文

【摘要】：直接甲醇燃料电池(DMFC)作为一种清洁、高效以及便捷的新型能源,为研制便携式移动能源创造了可能,受到了世界各国的广泛关注。然而阴极氧还原催化剂作为一个难以攻克的瓶颈阻碍了其发展,这是由于阴极催化剂包含Pt、Pd等贵金属,其价格不但昂贵还难以承受甲醇以及电解质的腐蚀。目前,通过热解处理得到非贵金属M-N_x-C催化剂因氧还原催化性能良好,同时因以碳为载体而具有优异的耐甲醇性能以及电化学稳定性受到了广泛的关注。本文以金属有机骨架(MOF)作为前驱体引入M-N_x位点,以新型二维平面碳材料──石墨烯作为碳载体,制备了一系列的M-N_x-rGO催化剂,并对其进行了多种物理表征以及氧还原性能测试。主要研究内容以及结论如下:(1)通过Fe或者Co金属盐提供M-N_x-rGO催化剂中的金属,苯并咪唑为氮源,制备了一系列的M-N_x-rGO或者二元M-N_x-rGO催化剂,通过TEM、SEM、拉曼光谱、红外光谱、比表面积以及孔径测试、XRD、XPS等测试表明了广泛认可的M-N_x活性位点不仅存在于石墨烯边缘,而是很可能存在于层间,进一步提高了其氧还原催化性能。(2)通过改变制备条件得到一系列的M-N_x-rGO催化剂,探讨反应温度、rGO添加量、热解温度以及金属比对M-N_x-rGO催化剂氧还原催化性能的影响,最终通过LSV测试确定M-N_x-rGO催化剂最佳氧还原性能的制备条件。(3)对得到的氧还原性能最佳的M-N_x-rGO催化剂和Pt/C催化剂进行一系列的电化学测试,对比制备的M-N_x-rGO催化剂与Pt/C催化剂在氧还原催化性能、耐甲醇性能以及电化学稳定性的优劣。本论文以N,N二甲基甲酰胺(DMF)为溶剂,溶剂热法制备了一系列M-N_x-rGO氧还原催化剂,对所制得的催化剂结构进行了一定的研究,并探究了影响M-N_x-rGO氧还原催化性能的几个因素。为M-N_x-C的继续深入研究以及广泛应用于商业化生产提供了一定的借鉴依据。
[Abstract]:As a clean, efficient and convenient new energy source, DMFChas made it possible to develop portable mobile energy. However, cathodic oxygen reduction catalyst is a bottleneck that is difficult to overcome, which is due to the fact that the cathode catalyst contains precious metals such as PTO PD. It is not only expensive, but also difficult to withstand the corrosion of methanol and electrolyte. At present, the non-noble metal M-N_x-C catalyst has good catalytic performance due to oxygen reduction through pyrolysis. At the same time, due to the excellent methanol resistance and electrochemical stability due to carbon as the carrier, the metal-organic skeleton (MOF) was used as the precursor to introduce the M-N_x site. A series of M-N_x-rGO catalysts were prepared using a new two-dimensional planar carbon material, graphene, as a carbon carrier. The main contents and conclusions are as follows: (1) the metal in M-N_x-rGO catalyst was supplied by Fe or Co metal salts, and benzimidazole was used as nitrogen source. A series of M-N_x-rGO or binary M-N_x-rGO catalysts were prepared. The results of Tem, Raman, IR, specific surface area and pore size measurements showed that the widely recognized active sites of M-N_x not only existed at the edge of graphene, but also at the edge of graphene. A series of M-N_x-rGO catalysts were obtained by changing the preparation conditions, and the amount of RGO was discussed. Effects of pyrolysis temperature and metal ratio on the catalytic performance of M-N_x-rGO catalyst for oxygen reduction. Finally, the preparation conditions of the best oxygen reduction performance of M-N_x-rGO catalyst were determined by LSV test. (3) A series of electrochemical tests were carried out on the M-N_x-rGO catalyst and Pt/C catalyst, which had the best oxygen reduction performance. In this paper, a series of M-N_x-rGO oxygen reduction catalysts were prepared by solvothermal method, and their catalytic performance, methanol resistance and electrochemical stability were compared with those of the prepared M-N_x-rGO catalysts. The structure of the prepared catalyst was studied and several factors affecting the catalytic performance of M-N_x-rGO oxygen reduction were investigated. The results provided a reference for the further study of M-N_x-C and its wide application in commercial production.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.4

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