多孔金属镍的相转化法制备及其电催化水分解性能的研究

发布时间：2018-01-16 19:41

  本文关键词：多孔金属镍的相转化法制备及其电催化水分解性能的研究　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 相转化 多孔镍 电催化 产氢反应 产氧反应 水分解

【摘要】：氢能是最有望替代化石能源的理想能源之一,其优点是清洁可循环、适用范围广、可无限供应等。电催化分解水是工业上生产高纯氢的最主要途径之一,它包含水还原产氢反应(HER)和水氧化产氧反应(OER)。目前,在电解水制氢领域中催化性能最佳的材料是贵金属及其氧化物,如Pt、Ru02、Ir02,但由于其价格昂贵且地球储量低,限制了其在工业电解水中的大规模应用。因此,开发高效且稳定的非贵金属催化材料成为了当前清洁能源领域的研究热点。镍基材料被广泛地用于碱性电解水反应中,其中多数以商业的泡沫镍为多孔基底,通过化学或者电化学的方法在其骨架上生长纳米物种,增大其表面积,提高电极的催化活性和电解水效率。但是,多孔镍基底的研究并未得到太多的关注。因此,本论文采用相转化流延法制备多孔镍电极并围绕其电催化水分解性能展开研究。第一章简要介绍了电催化水分解领域的非贵金属材料的研究现状和发展趋势,相转化法制备多孔材料的原理,并提出了本论文的主要研究内容。第二章采用相转化流延法和烧结工艺,制备了具有开放直孔结构的平板型多孔镍。研究了还原气氛下不同的烧结温度对其催化水还原性能的影响。实验结果表明:在1.0 M KOH电解液中,多孔镍的催化水还原性能均高于商业泡沫镍,并且烧结温度越低,其水还原产氢的催化活性越高。900 ℃,5h条件下制备的多孔镍催化性能最佳,该电极达到10 mAcm-2和50 mAcm-2的催化电流密度所需要的过电势分别为125 mV和190 mV,产氢法拉第效率接近100%。第三章以催化水还原性能最佳的多孔镍电极为研究对象,研究其催化水氧化和全分解性能。实验结果表明:在1.0MKOH电解液中,该电极达到10mAcm-2和50 mA cm-2的催化电流密度所需要的过电势分别为300 mV和362 mV,产氧法拉第效率高达92%。在全分解测试过程中,以多孔镍作为阴极和阳极构建的碱性电解池达到10 mmA cm-2的催化电流密度仅需要提供1.65 V的电压。第四章采用相转化挤出成型和烧结工艺制备金属镍中空纤维膜,探究了烧结温度对其微观结构、孔隙率、三点弯曲强度和气体通量的影响。随着烧结温度的升高,金属镍中空纤维膜的孔隙率和气体通量随之降低,三点弯曲强度随之升高。第五章对本论文的工作进行了总结,并对其他金属电极的相转化法制备以及多孔镍电极修饰的研究工作进行了展望。
[Abstract]:Hydrogen energy is one of the most promising alternative to fossil energy, its advantages are clean and recyclable, wide range of application, unlimited supply, etc. Electrocatalytic decomposition of water is one of the most important ways to produce high-purity hydrogen in industry. At present, noble metals and their oxides, such as PtnRu02, are the most catalytic materials in the field of hydrogen production from electrolytic water. Ir02, however, is limited to its large-scale application in industrial electrolytic water because of its high price and low Earth reserves. The development of efficient and stable non-noble metal catalytic materials has become a research hotspot in the field of clean energy. Nickel based materials are widely used in alkaline electrolytic water reactions, most of which are commercial nickel foam as porous substrate. Nanoscale species were grown on its skeleton by chemical or electrochemical methods to increase its surface area and improve the catalytic activity of the electrode and the efficiency of electrolytic water. The study of porous nickel substrates has not received much attention. In this paper, porous nickel electrode was prepared by phase conversion casting method and its electrocatalytic water decomposition performance was studied. In chapter 1, the research status and development trend of non-noble metal materials in the field of electrocatalytic water decomposition were briefly introduced. The principle of preparing porous materials by phase inversion method and the main research contents of this paper are put forward. In chapter 2, phase conversion casting method and sintering process are adopted. Plate porous nickel with open straight pore structure was prepared. The effect of sintering temperature on the catalytic water reduction performance was studied. The experimental results showed that the catalyst was in 1. 0 M KOH electrolyte. The catalytic performance of porous nickel was higher than that of commercial nickel foam, and the lower the sintering temperature, the better the catalytic activity of porous nickel was. 900 鈩，

本文编号：1434559