【摘要】：碳納米材料因比表面積高、孔隙率發(fā)達(dá)、環(huán)境友好、價(jià)格低廉及獨(dú)特的構(gòu)架組成等特點(diǎn)而成為一種優(yōu)良的催化劑載體。近年來,碳納米材料在電化學(xué)領(lǐng)域得到了更廣泛的應(yīng)用,例如用作傳感器或燃料電池的電極催化劑等。所以,為了提高燃料電池電催化劑的電化學(xué)性能,通過向碳材料中摻雜雜原子可以調(diào)節(jié)其結(jié)構(gòu)和表面化學(xué)性能,改善它的電催化行為。本論文詳細(xì)探究了氮、磷雜原子單或雙摻雜低鉑或無金屬碳納米材料的制備方法,并且將其作為低溫燃料電池催化劑時(shí)的電化學(xué)性能。本論文主要內(nèi)容由緒論、實(shí)驗(yàn)和結(jié)論三部分組成,具體如下:1.使用硬模板法合成了不同磷含量的有序介孔碳納米復(fù)合材料Pt/POMCs,并將其作為直接甲醇燃料電池的陽極催化劑。利用透射電鏡(TEM)、X-射線光電子能譜法(XPS)等表征了Pt/POMCs的表面結(jié)構(gòu),用循環(huán)伏安法(CV)和計(jì)時(shí)電流法(CA)研究了修飾電極表面的電化學(xué)行為。實(shí)驗(yàn)結(jié)果顯示,與Pt/OMCs、Pt Ru/XC和商業(yè)Pt/C催化劑相比,Pt/POMC有更大的電化學(xué)活性比表面積(ECSA)、對(duì)甲醇有更高的電催化氧化性能,同時(shí)有較強(qiáng)的抗CO中毒能力。這些性能的改善表明了摻雜適量P的納米復(fù)合材料Pt/P7OMCs可作為一種優(yōu)良的直接甲醇燃料電池陽極催化劑。2.磷摻雜、聚吡咯功能化的含氮碳納米管(P/NCNTs)作為無金屬的電催化劑,用于增強(qiáng)堿性溶液中氧化還原反應(yīng)(ORR)活性。TEM、XPS等表征顯示P/NCNTs復(fù)合材料中P原子和碳骨架共價(jià)結(jié)合,這可以在催化劑中引進(jìn)缺陷位點(diǎn)并且可以誘導(dǎo)電荷不均勻分布。另外,摻雜磷原子后吡啶氮含量增加,這對(duì)提高ORR活性有很大的促進(jìn)作用。CV和旋轉(zhuǎn)圓盤電極(RDE)循環(huán)伏安法結(jié)果顯示P/NCNTs復(fù)合材料可大幅度提高ORR的電催化活性、穩(wěn)定性和抗甲醇干擾能力。這些性能的提高表明了P/NCNTs復(fù)合材料可作為一種優(yōu)良的非金屬氧還原電催化劑。
[Abstract]:Carbon nanomaterials have become an excellent catalyst carrier due to their high specific surface area, developed porosity, environmentally friendly, low cost and unique structure composition. In recent years, carbon nanomaterials have been widely used in the field of electrochemistry, for example, as electrode catalysts for sensors or fuel cells. Therefore, in order to improve the electrochemical performance of fuel cell electrocatalysts, the structure and surface chemical properties can be adjusted by doping hetero-atoms into carbon materials, and its electrocatalytic behavior can be improved. In this paper, the preparation methods of low platinum or metal-free carbon nanomaterials with single or double doped nitrogen and phosphorus atoms were investigated in detail, and their electrochemical properties were used as catalysts for low temperature fuel cells. This thesis is composed of three parts: introduction, experiment and conclusion, as follows: 1. Ordered mesoporous carbon nanocomposites (Pt/POMCs,) with different phosphorus contents were synthesized by hard template method and used as anode catalysts for direct methanol fuel cells (DMFC). The surface structure of Pt/POMCs was characterized by transmission electron microscopy (TEM) X-ray photoelectron spectroscopy (XPS). The electrochemical behavior of the modified electrode was studied by cyclic voltammetry (CV) and chronoamperometric method (CA). The results showed that compared with Pt/OMCs,Pt Ru/XC and commercial Pt/C catalysts, (ECSA), had higher electrochemical activity and higher specific surface area for methanol oxidation, and had a stronger ability to resist CO poisoning. The improvement of these properties indicates that the nano-composite Pt/P7OMCs doped with appropriate amount of P can be used as an excellent anode catalyst for direct methanol fuel cell (DMFC). Phosphorus doped and polypyrrole functionalized nitrogen-containing carbon nanotubes (P/NCNTs) were used as metal-free electrocatalysts to enhance the (ORR) activity of redox reaction in alkaline solution. The defect sites can be introduced into the catalyst and the charge distribution can be induced inhomogeneously. In addition, the content of pyridine nitrogen increased after doping phosphorus atom, which promoted the activity of ORR greatly. CV and (RDE) cyclic voltammetry of rotating disk electrode showed that P/NCNTs composite could improve the electrocatalytic activity of ORR significantly. Stability and ability to resist methanol interference. The improvement of these properties indicates that P/NCNTs composite can be used as an excellent electrocatalyst for non-metallic oxygen reduction.
【學(xué)位授予單位】：東北師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：O613.71;TM911.4

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相關(guān)期刊論文 前1條

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本文編號(hào)：2246810