本文關鍵詞：多孔金屬鎳的相轉化法制備及其電催化水分解性能的研究　出處：《中國科學技術大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： 相轉化 多孔鎳 電催化 產氫反應 產氧反應 水分解

【摘要】：氫能是最有望替代化石能源的理想能源之一,其優(yōu)點是清潔可循環(huán)、適用范圍廣、可無限供應等。電催化分解水是工業(yè)上生產高純氫的最主要途徑之一,它包含水還原產氫反應(HER)和水氧化產氧反應(OER)。目前,在電解水制氫領域中催化性能最佳的材料是貴金屬及其氧化物,如Pt、Ru02、Ir02,但由于其價格昂貴且地球儲量低,限制了其在工業(yè)電解水中的大規(guī)模應用。因此,開發(fā)高效且穩(wěn)定的非貴金屬催化材料成為了當前清潔能源領域的研究熱點。鎳基材料被廣泛地用于堿性電解水反應中,其中多數以商業(yè)的泡沫鎳為多孔基底,通過化學或者電化學的方法在其骨架上生長納米物種,增大其表面積,提高電極的催化活性和電解水效率。但是,多孔鎳基底的研究并未得到太多的關注。因此,本論文采用相轉化流延法制備多孔鎳電極并圍繞其電催化水分解性能展開研究。第一章簡要介紹了電催化水分解領域的非貴金屬材料的研究現(xiàn)狀和發(fā)展趨勢,相轉化法制備多孔材料的原理,并提出了本論文的主要研究內容。第二章采用相轉化流延法和燒結工藝,制備了具有開放直孔結構的平板型多孔鎳。研究了還原氣氛下不同的燒結溫度對其催化水還原性能的影響。實驗結果表明:在1.0 M KOH電解液中,多孔鎳的催化水還原性能均高于商業(yè)泡沫鎳,并且燒結溫度越低,其水還原產氫的催化活性越高。900 ℃,5h條件下制備的多孔鎳催化性能最佳,該電極達到10 mAcm-2和50 mAcm-2的催化電流密度所需要的過電勢分別為125 mV和190 mV,產氫法拉第效率接近100%。第三章以催化水還原性能最佳的多孔鎳電極為研究對象,研究其催化水氧化和全分解性能。實驗結果表明:在1.0MKOH電解液中,該電極達到10mAcm-2和50 mA cm-2的催化電流密度所需要的過電勢分別為300 mV和362 mV,產氧法拉第效率高達92%。在全分解測試過程中,以多孔鎳作為陰極和陽極構建的堿性電解池達到10 mmA cm-2的催化電流密度僅需要提供1.65 V的電壓。第四章采用相轉化擠出成型和燒結工藝制備金屬鎳中空纖維膜,探究了燒結溫度對其微觀結構、孔隙率、三點彎曲強度和氣體通量的影響。隨著燒結溫度的升高,金屬鎳中空纖維膜的孔隙率和氣體通量隨之降低,三點彎曲強度隨之升高。第五章對本論文的工作進行了總結,并對其他金屬電極的相轉化法制備以及多孔鎳電極修飾的研究工作進行了展望。
[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，

本文編號：1434559