微型混合反应物燃料电池催化剂的制备及性能研究

发布时间：2018-03-16 08:43

本文选题：燃料电池　切入点：混合反应物　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：直接甲醇燃料电池(DMFC)的能量转换效率高、环境友好,在便携式电子设备领域显示出了巨大的应用潜力。DMFC的成本主要由催化剂和电极隔膜决定,是限制DMFC商业化的主要因素。本文在研究DMFC催化剂的电催化性能的基础上,利用氮掺杂碳纳米管(NCNTs)催化剂的氧还原反应(ORR)选择性设计了一种成本低廉、结构简单的混合反应物直接甲醇燃料电池(MRDMFC);在降低催化剂成本的同时,消除了传统碱性直接甲醇燃料电池对阴离子交换膜的依赖性。在阴极催化剂方面,采用微波等离子体化学气相沉积技术制备了氮掺杂碳纳米管(NCNTs)。基于微波功率、氨气流量、腔体气压和工作时间等4个工艺参数对NCNTs的ORR活性进行了优化。研究表明:低微波功率、低腔体气压以及适当的缩短反应时间,更有利于提高NCNTs的氧还原反应(ORR)活性。NCNTs催化剂优异的ORR性能主要来自于其制备过程中的低温沉积条件,其高表面缺陷程度、分布均匀的含氮官能团,有利于O2分子的吸附反应。在阳极催化剂方面,采用常温浸渍-还原法制备了不同原子比的碳纳米管负载型铂镍催化剂(PtxNiy/CNTs),研究了铂镍原子比对催化剂甲醇氧化活性的影响。结果表明,Pt的利用率随着Ni含量的增加而增加;Ni的使用,在提高Pt的催化活性的同时,降低了阳极催化剂的成本。基于NCNTs和Pt_1Ni_3/CNTs催化剂制作了催化电极。并采用廉价易得的多孔聚四氟乙烯滤膜作为电极隔膜,研究了阴极单通过注料模式下甲醇浓度、混合反应物流速和电解液浓度等3个工作条件对单电池性能的影响。实验结果表明,单电池的最佳工作条件为:3 M甲醇、0.5-1 mL min~(-1)流速、0.1 M KOH电解液。电池的最大开路电位为0.351 V,最大功率密度为0.151 mW cm~(-2)。
[Abstract]:Direct methanol fuel cell (DMFC) has high energy conversion efficiency and environmental friendliness. It shows great application potential in portable electronic equipment. The cost of DMFC is mainly determined by catalyst and electrode diaphragm. Based on the study of the electrocatalytic performance of DMFC catalysts, a low cost selective oxygen reduction reaction (ORR) has been designed using nitrogen-doped carbon nanotubes (CNTs) catalysts. A simple mixed reactant, direct methanol fuel cell (DMFC), reduces the cost of the catalyst and eliminates the dependence of the traditional alkaline direct methanol fuel cell on the anion exchange membrane. Nitrogen doped carbon nanotubes (NCNTsN) were prepared by microwave plasma chemical vapor deposition (MPCVD). The ORR activity of NCNTs was optimized by four process parameters, such as chamber pressure and working time. The results showed that: low microwave power, low chamber pressure and appropriate shortening reaction time, It was found that the excellent properties of NCNTs catalysts were mainly due to the low temperature deposition conditions, high surface defects and well-distributed nitrogen-containing functional groups. In the case of anodic catalyst, Carbon nanotube supported platinum nickel catalyst PtxNiy / CNTsN was prepared by dip-reduction method at room temperature. The effect of platinum / nickel ratio on methanol oxidation activity of catalyst was studied. The results showed that the utilization ratio of Pt was increased with the increase of Ni content. Added to increase the use of Ni, At the same time, the cost of anode catalyst was reduced while the catalytic activity of Pt was improved. The catalytic electrode was prepared based on NCNTs and Pt_1Ni_3/CNTs catalysts, and the porous PTFE filter membrane was used as the electrode separator. The effects of methanol concentration, flow rate of mixed reactants and electrolyte concentration on the performance of single cell were studied. The optimal operating conditions for a single cell are as follows: (1) the flow rate is 0.5 -1 mL / KOH electrolyte. The maximum open circuit potential and power density of the cell are 0.351V and 0.151MW / cm ~ (-1) 路min ~ (-1) 路min ~ (-1) 路min ~ (-1) 路min ~ (-1) 路min ~ (-1) 路min ~ (-1), respectively.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM911.4;O643.36

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