本文選題：燃料電池 + 氧還原反應(yīng)　； 參考：《湖南大學(xué)》2015年碩士論文

【摘要】：質(zhì)子交換膜燃料電池(PEMFCs)由于具有能量密度高、操作溫度低和污染物排放量少的優(yōu)勢(shì)引起了人們的普遍關(guān)注,有望應(yīng)用在便攜式電子產(chǎn)品和交通工具中。陰極電催化劑作為燃料電池的核心部分,極大地影響電極反應(yīng)的過(guò)電位,電化學(xué)反應(yīng)的速率以及電池的輸出電壓和穩(wěn)定性。目前應(yīng)用最多的氧還原催化劑為碳材料負(fù)載鉑基納米粒子,由于催化劑具有價(jià)格昂貴,穩(wěn)定性差以及無(wú)法克服“甲醇滲透”的缺點(diǎn),因而無(wú)法實(shí)現(xiàn)質(zhì)子交換膜燃料電池大規(guī)模的應(yīng)用。本文以金屬有機(jī)框架化合物(MOF)為前軀體,在氮?dú)饣蜓鯕夥諊袑?duì)不同類(lèi)型的MOF進(jìn)行熱處理,得到了立方體狀Co3O4與酸化碳管的復(fù)合材料(Co3O4/Ao-CN T)、氮摻雜的多孔石墨碳(NMGCs)以及包埋了鉑納米粒子(Pt NPs)的多面體介孔碳(Pt NPs@NMCs)。通過(guò)多種分析檢測(cè)方法,對(duì)材料的微觀(guān)形貌、晶體結(jié)構(gòu)以及氧還原(ORR)性能進(jìn)行研究。本論文的具體工作如下:(1)在ZIF-8配位生長(zhǎng)的過(guò)程中,Pt N Ps連續(xù)吸附到生長(zhǎng)的ZIF-8表面,ZIF-8配位結(jié)束以后,Pt NPs均勻鑲嵌在整個(gè)ZIF-8內(nèi)部。經(jīng)過(guò)一步高溫碳化,得到包埋了Pt NPs的氮摻雜多面體介孔碳(Pt NPs@NMCs)。通過(guò)SEM、TEM、XRD、XPS、Raman等分析方法對(duì)催化劑的表觀(guān)形貌、晶體結(jié)構(gòu)、孔隙分布以及元素組成進(jìn)行了分析,并在0.5 M H2SO4溶液中考察了Pt N Ps@N MCs的電化學(xué)性能。結(jié)果表明,Pt NPs@NMCs的比表面積為1226 m2 g-1,孔徑分布為3.9 nm,氮摻雜含量為5.4 At.%,粒徑為3.7 nm的Pt NPs均勻分散在整個(gè)介孔碳材料內(nèi)部。電化學(xué)測(cè)試結(jié)果表明,Pt NPs@NMCs除了能有效催化氧還原之外,還具有優(yōu)異的穩(wěn)定性和抗甲醇性能。(2)以鈷基金屬有機(jī)框架化合物ZIF-67為碳源、氮源和模板,在氮?dú)庵懈邷靥蓟?利用中心金屬鈷的催化作用形成了石墨結(jié)構(gòu)的多孔碳材料(NMGCs)。利用SEM、TEM、XRD、BET和Rama n對(duì)N MGCs的形貌特征和晶體結(jié)構(gòu)進(jìn)行研究,并用CV、LSV和I-t測(cè)試方法考察了NMGCs在0.1 M KOH中的氧還原性能。結(jié)果表明,NMGCs保留了前驅(qū)物ZIF-67的多面體形貌、比表面積大(576 m2 g-1)、N摻雜含量多(6.14 wt.%)、尺寸均一(300 nm)、并且石墨化程度很高。氧還原測(cè)試結(jié)果表明,NMGCs按照直接四電子途徑催化氧氣還原,與Pt/C催化性能相當(dāng)。此外,還具有優(yōu)異的穩(wěn)定性和抗甲醇性能。(3)在空氣中直接氧化ZIF-67、酸化碳管與ZIF-67的復(fù)合物,制備了立方體狀的Co3O4和Co3O4/Ao-CN T復(fù)合物催化劑。利用SEM、XRD、TGA對(duì)材料形貌結(jié)構(gòu)進(jìn)行了表征,用CV、LSV和I-t電化學(xué)測(cè)試技術(shù)研究了催化劑在0.1 M KOH中的氧還原催化性能。結(jié)果表明,與酸化碳管復(fù)合以后,Co3O4/Ao-CN T的電化學(xué)反應(yīng)阻抗變小,催化ORR性能提高,起峰電位雖然比Pt/C負(fù),但具有優(yōu)異的穩(wěn)定性和抗甲醇性能。
[Abstract]:Proton exchange membrane fuel cell (PEMFCs) has attracted much attention due to its advantages of high energy density, low operating temperature and low pollutant emission. It is expected to be used in portable electronic products and vehicles. As the core part of fuel cell, cathode electrocatalyst greatly affects the overpotential of electrode reaction, the rate of electrochemical reaction, the output voltage and stability of the cell. At present, the most widely used oxygen reduction catalyst is carbon material supported platinum-based nanoparticles, because the catalyst is expensive, stable and unable to overcome the shortcomings of "methanol permeation". Therefore, the proton exchange membrane fuel cell (PEMFC) can not be used on a large scale. In this paper, different types of MOF were heat-treated in nitrogen or oxygen atmosphere using organometallic frame compound (MOF) as precursor. Cubic Co3O4 and acidated carbon tube composites, such as Co _ 3O _ 4 / Ao-CN _ T, N-doped porous graphite carbon (NMGCs), and polyhedron mesoporous carbon (Pt-NPs) coated with platinum nanoparticles, have been obtained. The microstructure, crystal structure and ORR properties of the materials were studied by various analytical methods. The specific work of this thesis is as follows: (1) during the ZIF-8 coordination growth, Pt-NPs are continuously adsorbed to the surface of the grown ZIF-8 (ZIF-8). After the completion of the coordination, the Pt NPs is uniformly embedded in the whole ZIF-8. After one step of carbonization at high temperature, the nitrogen-doped polyhedron carbon oxide (PNPs) deposited in Pt NPs was obtained. The apparent morphology, crystal structure, pore distribution and elemental composition of the catalyst were analyzed by means of SEMTEMX Ps@N MCs Raman analysis. The electrochemical properties of Pt N Ps@N MCs were investigated in 0.5 M H2SO4 solution. The results show that the specific surface area of Pt NPs@NMCs is 1226 m ~ 2 g ~ (-1), the pore size distribution is 3.9 nm, the nitrogen doping content is 5.4At.and the particle size is 3.7nm Pt NPs is uniformly dispersed in the whole mesoporous carbon material. The electrochemical test results showed that Pt NPs@NMCs not only can effectively catalyze oxygen reduction, but also has excellent stability and methanol resistance. (2) Cobalt-based organometallic frame compound ZIF-67 was used as carbon source, nitrogen source and template as carbon source, and carbonized in nitrogen at high temperature. A porous carbon material with graphite structure was formed by the catalytic action of cobalt in the center. The morphology and crystal structure of N MGCs were studied by SEMTEMX RDET and Rama n, and the oxygen reduction properties of NMGCs in 0. 1 M KOH were investigated by CVLSV and I-t measurements. The results show that NMGCs retain the polyhedron morphology of the precursor ZIF-67, with a large specific surface area of 576 m ~ 2 g ~ (-1) and N doping content of 6.14 wt.The size is homogeneous to 300 nm ~ (-1), and the graphitization degree is very high. The results of oxygen reduction test showed that NMGCs catalyzed oxygen reduction by direct four-electron pathway, which was comparable to that of Pt/C. In addition, ZIF-67 was oxidized directly in air, and the complex of ZIF-67 and carbon tube was acidified. Cube-like Co3O4 and Co3O4/Ao-CN T complex catalysts were prepared. The morphology and structure of the catalyst were characterized by SEMX KOH TGA. The catalytic performance of the catalyst for oxygen reduction in 0. 1 M KOH was studied by CVN LSV and I-t electrochemical test techniques. The results show that the electrochemical reaction impedance of Co _ 3O _ 4 / Ao-CN _ T decreases, the catalytic ORR performance is improved, and the peak initiation potential is negative than that of Pt/C, but it has excellent stability and methanol resistance.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：O643.36;TM911.4

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 于亞明;基于氮摻雜碳材料的氧還原電催化劑研究[D];湖南大學(xué);2012年

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本文編號(hào)：1928918