基于納米碳材料的直接甲醇燃料電池陽(yáng)極催化劑的控制合成及性能研究
發(fā)布時(shí)間：2019-03-15 11:07
【摘要】：由于能源危機(jī)與環(huán)境污染的持續(xù)加劇,直接甲醇燃料電池作為一種潛在的能源裝置因?yàn)榫哂休^高的能量轉(zhuǎn)換效率和較低的污染排放而吸引了學(xué)術(shù)界及工程界的廣泛關(guān)注。然而,低成本、高性能陽(yáng)極催化劑的匱乏使得直接甲醇燃料電池的大規(guī)模商業(yè)化受到了很大的限制。近年來(lái),納米碳材料(如碳納米管和石墨烯等)因其優(yōu)異的物理化學(xué)性質(zhì)和獨(dú)特的納米尺寸效應(yīng)而被認(rèn)為是一種十分有前景的支撐材料,可以用來(lái)構(gòu)建先進(jìn)的復(fù)合催化劑。本論文采用一系列新穎的制備路線合成了多種基于納米碳材料的直接甲醇燃料電池陽(yáng)極催化劑,同時(shí)深入考察了復(fù)合催化劑的微結(jié)構(gòu)、形貌及組成對(duì)于甲醇氧化反應(yīng)催化性能的影響。具體研究?jī)?nèi)容如下： 1.低缺陷碳納米管負(fù)載鉑及鉑鈷合金催化劑的控制合成及性能研究。 為了在碳納米管的外壁引入含氧官能團(tuán),我們利用硝酸鉑水解所產(chǎn)生的硝酸對(duì)碳納米管進(jìn)行輕微地氧化。由于水解產(chǎn)生的硝酸其濃度遠(yuǎn)遠(yuǎn)小于傳統(tǒng)酸處理過(guò)程中的酸濃度,因此在碳納米管表面僅會(huì)形成少量的結(jié)構(gòu)缺陷,從而顯著提高其導(dǎo)電性。與酸處理碳納米管負(fù)載鉑催化劑相比,低缺陷碳納米管負(fù)載鉑催化劑表現(xiàn)出較好的電催化活性和優(yōu)異的抗中毒能力。在此基礎(chǔ)上,鉑鈷合金催化劑也可以經(jīng)由相似的方法負(fù)載在低缺陷碳納米管表面。在復(fù)合體系中,鈷組分的存在不僅能使催化劑中鉑組分的還原態(tài)程度升高,還可以為反應(yīng)中間產(chǎn)物CO的氧化提供充足的氧源。因而鉑鈷合金-低缺陷碳納米管催化劑相比于鉑-低缺陷碳納米管和商用的鉑釕-炭黑(Vulcan XC-72)催化劑具有明顯增強(qiáng)的催化活性。 2.低缺陷石墨烯負(fù)載鉑及鈀催化劑的控制合成及性能研究。 從本質(zhì)上來(lái)說(shuō),石墨烯可以被認(rèn)為是碳納米管展開(kāi)之后的產(chǎn)物,這就意味著其物理化學(xué)性質(zhì)與碳納米管相似,但具有更大的比表面積�；诖�,低缺陷碳納米管負(fù)載催化劑的設(shè)計(jì)思路可以進(jìn)一步拓展來(lái)合成低缺陷石墨烯-鉑催化劑。由于合成條件更為溫和,負(fù)載于低缺陷石墨烯表面的鉑粒子相比于化學(xué)還原石墨烯表面的鉑粒子分散性更高。更為重要的是,幾乎完好的石墨烯結(jié)構(gòu)可以顯著降低復(fù)合材料的電荷轉(zhuǎn)移電阻并提高鉑顆粒的催化活性。此外,考慮到金屬鈀相對(duì)便宜的價(jià)格,我們采用鈀替換鉑來(lái)降低低缺陷石墨烯負(fù)載陽(yáng)極催化劑的制備成本。最終得到的鈀-低缺陷石墨烯催化劑對(duì)酸性介質(zhì)下的甲酸氧化和堿性介質(zhì)下的甲醇氧化均表現(xiàn)出了不同尋常的催化活性。相較而言,后者具有更好的電催化穩(wěn)定性。 3.二氧化錳改性的石墨烯負(fù)載鉑及鈀催化劑的控制合成及性能研究。 石墨烯骨架中的碳原子可以與Mn04一離子發(fā)生直接的氧化還原反應(yīng),生成二氧化錳-石墨烯復(fù)合物。研究表明,以二氧化錳-石墨烯作為載體材料可以促進(jìn)金屬鉑和金屬鈀顆粒的沉積,防止發(fā)生團(tuán)聚現(xiàn)象。在電催化反應(yīng)過(guò)程中,二氧化錳的引入一方面能加速電解質(zhì)的擴(kuò)散,同時(shí)還能保證毒性物種和質(zhì)子在電極表面的快速輸運(yùn)。因此,二氧化錳改性的石墨烯負(fù)載催化劑的催化性能明顯高于未改性的石墨烯及炭黑負(fù)載催化劑。 4.三維多孔的石墨烯-氮化碳雜化氣凝膠負(fù)載鉑催化劑的控制合成及性能研究。 氮摻雜被證明是一種提升石墨烯基催化劑電化學(xué)性能的有效手段。在該部分中,我們成功地構(gòu)建了由石墨烯和氮化碳納米層組成的三維多孔復(fù)合結(jié)構(gòu)。通過(guò)調(diào)節(jié)石墨烯與氮化碳的投料比,可以得到具有不同氮含量的石墨烯-氮化碳雜化氣凝膠。當(dāng)負(fù)載了金屬鉑納米顆粒之后,所獲得的復(fù)合材料被作為陽(yáng)極催化劑催化甲醇氧化反應(yīng)。電化學(xué)測(cè)試結(jié)果表明,三維多孔的石墨烯-氮化碳雜化氣凝膠負(fù)載鉑催化劑顯示出較高的電催化活性,突出的抗中毒能力以及可信賴(lài)的穩(wěn)定性,遠(yuǎn)遠(yuǎn)優(yōu)于對(duì)比樣品。
[Abstract]:Because of the continuous increase of energy crisis and environmental pollution, direct methanol fuel cell, as a potential energy device, has attracted the extensive attention of the academic community and the engineering community as a potential energy device because of higher energy conversion efficiency and lower pollution discharge. However, the lack of low cost, high performance anode catalysts has greatly limited the large-scale commercialization of direct methanol fuel cells. In recent years, nano-carbon materials (such as carbon nanotubes and graphene, etc.) are considered to be a very promising support material due to its excellent physical and chemical properties and unique nano-size effects, and can be used to build advanced composite catalysts. In this paper, a series of novel direct methanol fuel cell anode catalysts based on nano-carbon materials are synthesized by a series of novel preparation routes, and the effect of the microstructure, morphology and composition of the composite catalyst on the catalytic performance of the methanol oxidation reaction is also investigated. The specific contents of the study are as follows: 1. Synthesis and performance of low-defect carbon nanotube supported platinum and platinum-cobalt alloy catalyst to introduce an oxygen-containing functional group on the outer wall of the carbon nanotube, the nitric acid produced by the hydrolysis of the platinum nitrate is used to make a slight reduction of the carbon nanotubes, The nitric acid produced by the hydrolysis is much smaller than the acid concentration in the conventional acid treatment process, so that only a small amount of structural defects are formed on the surface of the carbon nanotube, thereby remarkably improving the concentration of the nitric acid, Compared with the acid-treated carbon nanotube-supported platinum catalyst, the low-defect carbon nano-tube supported platinum catalyst exhibits good electrocatalytic activity and excellent resistance to corrosion On this basis, the platinum-cobalt alloy catalyst can also be supported in a low-defect carbon nanometer by a similar method. In that composite system, the existence of the cobalt component can not only increase the reduction state of the platinum component in the catalyst, but also provide sufficient oxidation of the CO in the reaction intermediate product. The platinum-cobalt alloy-low-defect carbon nanotube catalyst has a significantly enhanced acceleration compared to a platinum-low-defect carbon nanotube and a commercial platinum-carbon-black (Vulcan XC-72) catalyst as compared to a platinum-low-defect carbon nanotube catalyst. Chemical activity.2. Control and synthesis of low-defect grapheme supported platinum and catalyst and performance studies. in essence, the graphene can be considered a product of the carbon nanotube deployment, which means that its physicochemical properties are similar to that of the carbon nanotubes, but with The design idea of the low-defect carbon nanotube loading catalyst can be further expanded to synthesize the low-defect stone. ink-platinum catalyst, platinum particles supported on the surface of a low-defect graphene due to the more moderate synthesis conditions, platinum on the surface of the chemically-reduced graphene, More important, the almost intact graphene structure can significantly reduce the charge transfer resistance of the composite and increase the platinum The catalytic activity of the particles is also taken into account. In addition, considering the relatively inexpensive price of the metal, we use the replacement of platinum to lower the low-defect graphene load anode The preparation cost of the nodulizer is as follows: the finally obtained graphite-low-defect graphene catalyst has different effects on the oxidation of the methanol under the acid medium and the oxidation of the methanol under the alkaline medium The latter has a better catalytic activity than in the case of the latter. 3. Electrocatalytic stability of manganese dioxide-modified graphene-supported platinum and catalyst the carbon atoms in the graphene framework can be directly oxidized and reduced with the Mn4-ion to generate Manganese dioxide-graphene composites. The results show that the use of manganese dioxide-graphene as the carrier material can promote the metal-platinum and metal-graphite particles. during the electrocatalytic reaction, the introduction of the manganese dioxide can accelerate the diffusion of the electrolyte, and the catalytic performance of the manganese dioxide modified graphene loading catalyst is obviously higher than that of the non-modified graphene, Graphene and carbon black supported catalyst.4. Three-dimensional porous graphene-carbon nitride mixed gas gel supported platinum The control and synthesis of the catalyst and the performance study. The nitrogen doping is proved to be a kind of lifting graphite. The effective means of the electrochemical performance of the alkenyl catalysts. In this part, we successfully constructed a graphene and a nitride, by adjusting the feeding ratio of the graphene and the carbon nitride, the three-dimensional porous composite structure can obtain the three-dimensional porous composite structure with different nitrogen, the content of the graphene-carbon nitride hybrid aerogel is The electrochemical test results show that the three-dimensional porous graphene-carbon-nitride mixed gas-gel supported platinum catalyst shows high electrocatalytic activity, outstanding anti-poisoning ability and can
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：B
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TM911.4;O643.36
本文編號(hào)：2440571
[Abstract]:Because of the continuous increase of energy crisis and environmental pollution, direct methanol fuel cell, as a potential energy device, has attracted the extensive attention of the academic community and the engineering community as a potential energy device because of higher energy conversion efficiency and lower pollution discharge. However, the lack of low cost, high performance anode catalysts has greatly limited the large-scale commercialization of direct methanol fuel cells. In recent years, nano-carbon materials (such as carbon nanotubes and graphene, etc.) are considered to be a very promising support material due to its excellent physical and chemical properties and unique nano-size effects, and can be used to build advanced composite catalysts. In this paper, a series of novel direct methanol fuel cell anode catalysts based on nano-carbon materials are synthesized by a series of novel preparation routes, and the effect of the microstructure, morphology and composition of the composite catalyst on the catalytic performance of the methanol oxidation reaction is also investigated. The specific contents of the study are as follows: 1. Synthesis and performance of low-defect carbon nanotube supported platinum and platinum-cobalt alloy catalyst to introduce an oxygen-containing functional group on the outer wall of the carbon nanotube, the nitric acid produced by the hydrolysis of the platinum nitrate is used to make a slight reduction of the carbon nanotubes, The nitric acid produced by the hydrolysis is much smaller than the acid concentration in the conventional acid treatment process, so that only a small amount of structural defects are formed on the surface of the carbon nanotube, thereby remarkably improving the concentration of the nitric acid, Compared with the acid-treated carbon nanotube-supported platinum catalyst, the low-defect carbon nano-tube supported platinum catalyst exhibits good electrocatalytic activity and excellent resistance to corrosion On this basis, the platinum-cobalt alloy catalyst can also be supported in a low-defect carbon nanometer by a similar method. In that composite system, the existence of the cobalt component can not only increase the reduction state of the platinum component in the catalyst, but also provide sufficient oxidation of the CO in the reaction intermediate product. The platinum-cobalt alloy-low-defect carbon nanotube catalyst has a significantly enhanced acceleration compared to a platinum-low-defect carbon nanotube and a commercial platinum-carbon-black (Vulcan XC-72) catalyst as compared to a platinum-low-defect carbon nanotube catalyst. Chemical activity.2. Control and synthesis of low-defect grapheme supported platinum and catalyst and performance studies. in essence, the graphene can be considered a product of the carbon nanotube deployment, which means that its physicochemical properties are similar to that of the carbon nanotubes, but with The design idea of the low-defect carbon nanotube loading catalyst can be further expanded to synthesize the low-defect stone. ink-platinum catalyst, platinum particles supported on the surface of a low-defect graphene due to the more moderate synthesis conditions, platinum on the surface of the chemically-reduced graphene, More important, the almost intact graphene structure can significantly reduce the charge transfer resistance of the composite and increase the platinum The catalytic activity of the particles is also taken into account. In addition, considering the relatively inexpensive price of the metal, we use the replacement of platinum to lower the low-defect graphene load anode The preparation cost of the nodulizer is as follows: the finally obtained graphite-low-defect graphene catalyst has different effects on the oxidation of the methanol under the acid medium and the oxidation of the methanol under the alkaline medium The latter has a better catalytic activity than in the case of the latter. 3. Electrocatalytic stability of manganese dioxide-modified graphene-supported platinum and catalyst the carbon atoms in the graphene framework can be directly oxidized and reduced with the Mn4-ion to generate Manganese dioxide-graphene composites. The results show that the use of manganese dioxide-graphene as the carrier material can promote the metal-platinum and metal-graphite particles. during the electrocatalytic reaction, the introduction of the manganese dioxide can accelerate the diffusion of the electrolyte, and the catalytic performance of the manganese dioxide modified graphene loading catalyst is obviously higher than that of the non-modified graphene, Graphene and carbon black supported catalyst.4. Three-dimensional porous graphene-carbon nitride mixed gas gel supported platinum The control and synthesis of the catalyst and the performance study. The nitrogen doping is proved to be a kind of lifting graphite. The effective means of the electrochemical performance of the alkenyl catalysts. In this part, we successfully constructed a graphene and a nitride, by adjusting the feeding ratio of the graphene and the carbon nitride, the three-dimensional porous composite structure can obtain the three-dimensional porous composite structure with different nitrogen, the content of the graphene-carbon nitride hybrid aerogel is The electrochemical test results show that the three-dimensional porous graphene-carbon-nitride mixed gas-gel supported platinum catalyst shows high electrocatalytic activity, outstanding anti-poisoning ability and can
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：B
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TM911.4;O643.36
【引證文獻(xiàn)】
相關(guān)碩士學(xué)位論文 前5條
1 王冬;碳納米管@介孔碳三維復(fù)合材料的電化學(xué)性能研究及其對(duì)雙酚A的靈敏檢測(cè)[D];武漢工程大學(xué);2017年
2 王燕;一維Pt-M(M=Fe、Co、Ni)納米催化劑：合成及電催化性能的研究[D];燕山大學(xué);2017年
3 田茶;三維鈦基納米線復(fù)合結(jié)構(gòu)的可控合成與甲醇氧化性能研究[D];合肥工業(yè)大學(xué);2017年
4 曹肱舶;石墨烯基納米復(fù)合結(jié)構(gòu)的可控生長(zhǎng)及電化學(xué)性能研究[D];合肥工業(yè)大學(xué);2016年
5 佟月宇;堿性直接甲醇燃料電池陽(yáng)極鎳磷復(fù)合催化劑的研究[D];浙江大學(xué);2016年
，本文編號(hào)：2440571
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