碱性介质中醇类电氧化Pd系催化剂的制备及性能研究

发布时间：2018-05-28 13:29

本文选题：碱性介质 + 直接醇类燃料电池　；参考：《沈阳理工大学》2015年硕士论文

【摘要】：直接醇类燃料电池(DAFC)因能量转化效率高、燃料来源丰富、储运方便、成本低廉等优点而受到人们的广泛关注。阳极催化剂的研制是直接醇类燃料电池的关键。为提高碱性介质中Pd系催化剂对醇类的催化活性和稳定性,本文以炭材料为载体、乙二醇为还原剂,采用微波辅助合成法制备催化剂,通过引入其他金属粒子、使用不同类型导电聚合物修饰载体以及使用混合载体提高催化剂的活性和稳定性。采用透射电子显微镜(TEM)、X-射线光电子能谱(XPS)手段对催化剂的微观形貌、组成及结构进行表征。以循环伏安法(CV)、线性扫描伏安法(LSV)、电化学阻抗谱(EIS)及计时电流法(CA)等电化学方法考察催化剂对碱性介质中醇类电氧化反应中的催化活性及稳定性。主要研究结果如下:向Pd/CNTs催化剂中引入Ni、Fe、Cu金属粒子,合金粒子较Pd粒子分散性得到改善、粒径较小。Ni、Fe、Cu粒子能够提高Pd/CNTs催化剂对醇的电催化性能。Ni、Fe、Cu与Pd粒子均显示出双功能效应。壳聚糖(Chit)和聚二烯二甲基氯化铵(PDDA)修饰载体后制备的催化剂中Pd粒子粒径较小,几乎无团聚现象,且Pd(0)含量较高。相比于基础催化剂,Pd/C-Chit和Pd/CNTs-PDDA催化剂显示出优良的醇电催化氧化性能。聚吡咯修饰载体制备的催化剂中Pd粒子粒径较小,粒径分布范围较小。聚吡咯提高了醇在Pd/C催化剂上电氧化的催化性能。相比于Pd/C催化剂,PANI@Pd/C催化剂的催化性能未能得到全面改善。使用石墨烯纳米片-碳纳米管和石墨烯纳米片-炭黑改善Pd粒子的分散性,使粒径减小。相比于单一载体催化剂,使用混合载体制备的催化剂提高了催化剂对醇的电催化氧化性能。
[Abstract]:Direct alcohol fuel cell (DAFC) has been widely concerned because of its high energy conversion efficiency, abundant fuel sources, convenient storage and transportation, low cost and so on. The development of anode catalyst is the key of direct alcohol fuel cell. In order to improve the catalytic activity and stability of PD catalyst for alcohols in alkaline medium, the catalyst was prepared by microwave assisted synthesis with carbon material as support and ethylene glycol as reducing agent. Other metal particles were introduced into the catalyst. The activity and stability of the catalyst were improved by using different types of conductive polymer modified support and mixed support. The microstructure, composition and structure of the catalyst were characterized by means of transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The catalytic activity and stability of the catalysts for the electrooxidation of alcohols in alkaline media were investigated by cyclic voltammetry, linear scanning voltammetry, electrochemical impedance spectroscopy (EIS) and chronoamperometric method (CAA). The main results are as follows: the Pd/CNTs catalyst was introduced into the Pd/CNTs catalyst, the dispersion of the alloy particles was improved than that of the PD particles, and the particle size was smaller than that of the PD particles. The electrocatalytic activity of the Pd/CNTs catalyst for alcohols was improved. Both NiFE-Fe Cu and PD particles showed a bifunctional effect. The particle size of PD particles was small, almost no agglomeration, and the content of PD _ 0) was higher in the catalysts modified with chitosan (Chitt) and polydiene dimethyl ammonium chloride (PDDA-PDDA). Compared with the basic catalysts, PD / C-Chit and Pd/CNTs-PDDA catalysts showed excellent catalytic oxidation of alcohols. The particle size and distribution range of PD particles in the catalyst prepared by polypyrrole modified support were smaller. Polypyrrole improved the catalytic performance of alcohol electrooxidation on Pd/C catalyst. Compared with Pd/C catalyst, the catalytic performance of Pani @ PD / C catalyst has not been completely improved. Graphene nanoparticles-carbon nanotubes and graphene nanoparticles-carbon black were used to improve the dispersion of PD particles and reduce the particle size. Compared with single support catalyst, the electrocatalytic oxidation of alcohol was improved by using mixed support catalyst.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TM911.4

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