本文選題：金屬摻雜碳催化劑 + 多元共摻雜��； 參考：《中國礦業(yè)大學(xué)》2017年碩士論文

【摘要】：燃料電池作為一種清潔高效的新能源技術(shù),具有非常廣闊的應(yīng)用前景。由于陰極催化效率明顯低于陽極,所以燃料電池的電催化研究仍主要集中于陰極催化劑的開發(fā)上。目前,陰極催化活性較高的催化劑多為貴金屬鉑基催化劑,但由于其成本高、儲量少、耐甲醇能力低且穩(wěn)定性差等缺陷,嚴(yán)重限制了燃料電池的商業(yè)化發(fā)展。近年來大量研究表明Fe、Co等非貴過渡金屬摻入碳的網(wǎng)絡(luò)結(jié)構(gòu)能明顯改善碳催化劑的氧還原(ORR)活性,有望替換貴金屬催化劑。為開發(fā)高活性、低成本且穩(wěn)定性優(yōu)良,耐甲醇滲透性好的金屬摻雜碳催化劑,本文嘗試將鍺原子摻入碳的網(wǎng)絡(luò)結(jié)構(gòu),開發(fā)新型非貴金屬鍺、鍺氮共摻雜碳催化劑,及通過非貴金屬鐵與非金屬多元摻雜等方式,利用廉價(jià)生物質(zhì)開發(fā)低廉高效碳催化劑。具體研究內(nèi)容如下:1.通過氣相沉積法,以四乙基鍺為鍺源制備新型鍺摻雜碳納米管(Ge-CNTs)。通過掃描電鏡(SEM)、透射電鏡(TEM)、比表面積測定儀(BET)和X-射線光電子能譜(XPS)等手段對其形貌、比表面積及元素組成等進(jìn)行表征分析,結(jié)果表明鍺原子可以摻入碳納米管結(jié)構(gòu)網(wǎng)絡(luò)。同時(shí)電化學(xué)測試表明堿性條件下,Ge-CNTs的ORR活性明顯高于無摻雜CNTs,且耐甲醇性能和穩(wěn)定性能均優(yōu)于47.6 wt%商業(yè)Pt/C催化劑。Koutechy-Levich方程計(jì)算顯示Ge-CNTs表觀電子轉(zhuǎn)移數(shù)明顯高于CNTs,表明氧分子在Ge-CNTs表面上吸附方式不同于無摻雜CNTs,這可能由于鍺原子摻入碳的網(wǎng)絡(luò)結(jié)構(gòu),引起碳納米管表面的電荷分布及能帶等電子特性發(fā)生改變。2.通過氣相沉積法,以四乙基鍺為鍺源,苯胺為氮源制備鍺氮共摻雜碳納米管(GeN-CNTs)。通過SEM、TEM、BET、XPS等手段對其形貌、比表面積及元素組成等進(jìn)行表征分析,結(jié)果表明鍺原子和氮原子可以同時(shí)摻入到碳納米管結(jié)構(gòu)網(wǎng)絡(luò)。電化學(xué)測試表明堿性條件下GeN-CNTs的ORR活性明顯高于N-CNTs,且耐甲醇性能,穩(wěn)定性能均優(yōu)于47.6 wt%商業(yè)Pt/C。Koutechy-Levich方程計(jì)算顯示GeN-CNTs表觀電子轉(zhuǎn)移數(shù)大于3,表明其表面氧還原反應(yīng)多為四電子高效反應(yīng)途徑,顯示鍺和氮原子的摻入碳的網(wǎng)絡(luò)結(jié)構(gòu)能夠改變氧分子吸附方式。3.通過快速高溫?zé)峤馍镔|(zhì)桂花果中活性物質(zhì)、Fe_2(SO_4)_3及二氰二胺混合物,制備N、S、P和Fe多元摻雜碳納米孔與碳納米管復(fù)合材料。通過EDS、XPS、BET等手段,對其結(jié)構(gòu)、形貌、元素組成等進(jìn)行表征分析,結(jié)果表明N、S、P和Fe等元素可摻入碳納米結(jié)構(gòu)網(wǎng)絡(luò)中(Fe摻入量較小)。同時(shí)電化學(xué)測試表明所制備的復(fù)合材料在堿性和酸性條件下均顯示優(yōu)異ORR活性、耐甲醇性能和穩(wěn)定性能。Koutechy-Levich方程計(jì)算顯示所制備的復(fù)合材料表面上氧分子發(fā)生還原反應(yīng)時(shí)的電子轉(zhuǎn)移數(shù)在堿性和酸性條件下都接近4電子過程,表明N、S、P和Fe多元摻雜有利于氧分子的側(cè)基吸附。
[Abstract]:As a clean and efficient new energy technology, fuel cell has a very broad application prospect.Because the efficiency of cathode catalysis is obviously lower than that of anode, the electrocatalysis of fuel cell is mainly focused on the development of cathode catalyst.At present, most of the catalysts with high cathodic activity are precious metal platinum based catalysts. However, the commercial development of fuel cells is seriously restricted because of its high cost, low reserves, low methanol tolerance and poor stability.In recent years, a large number of studies have shown that the network structure of non-expensive transition metals, such as FeCo, can obviously improve the oxygen reduction ORR activity of carbon catalysts, which is expected to replace noble metal catalysts.In order to develop metal-doped carbon catalysts with high activity, low cost, good stability and good methanol permeability, this paper attempts to develop a new type of non-noble metal germanium and germanium nitrogen co-doped carbon catalysts by adding germanium atoms into the structure of carbon network.The low-cost and high-efficient carbon catalyst was developed by non-precious metal iron and non-metallic multi-doping.The specific contents of the study are as follows: 1.A new germanium doped carbon nanotube (Ge-CNTsN) was prepared by vapor deposition with tetraethyl germanium as a germanium source.The morphology, specific surface area and elemental composition were characterized by SEM, TEM, BET and X- ray photoelectron spectroscopy (XPS). The results showed that germanium atoms could be doped into CNT structure network.At the same time, electrochemical test showed that the ORR activity of Ge-CNTs in alkaline condition was significantly higher than that of undoped CNTs, and the methanol resistance and stability of Ge-CNTs were better than 47.6 wt% commercial Pt/C catalysts. Koutechy-Levich equation calculation showed that the apparent electron transfer number of Ge-CNTs was significantly higher than that of CNTs, and the apparent electron transfer number of Ge-CNTs was obviously higher than that of CNTs.The adsorption mode of Ge-CNTs is different from that of doped CNTs, which may be due to the network structure of carbon doped with germanium atoms.The surface charge distribution and energy band of carbon nanotubes are changed. 2. 2.GE N-doped carbon nanotubes were prepared by vapor deposition with tetraethylgermanium as germanium source and aniline as nitrogen source.The morphology, specific surface area and elemental composition were characterized by means of SEM-TEMP-BET-XPS. The results showed that germanium atom and nitrogen atom could be doped into CNT structure network at the same time.Electrochemical tests showed that the ORR activity of GeN-CNTs was significantly higher than that of N-CNTs under alkaline conditions, and the methanol resistance of GeN-CNTs was higher than that of N-CNTs.The stability of GeN-CNTs was better than that of 47.6 wt% commercial Pt/C.Koutechy-Levich equation. The results showed that the apparent electron transfer number of GeN-CNTs was greater than 3, which indicated that the surface oxygen reduction reaction was mainly a four-electron high efficiency reaction pathway.It is shown that the network structure of doped carbon with germanium and nitrogen atoms can change the adsorption mode of oxygen molecule. 3.The composite of carbon nanotubes and carbon nanotubes (CNTs) was prepared by pyrolysis of the active substances Fe2SO4Sn3 and dicyandiamide in biomass Osmanthus osmanthus fruit at high temperature.The structure, morphology and elemental composition were characterized by means of EDSS-XPS-BET. The results showed that the elements such as NbSfP and Fe could be doped into the carbon nanostructure network with relatively small amount of Fe doped.At the same time, the electrochemical test showed that the composites exhibited excellent ORR activity in alkaline and acidic conditions.The calculation of methanol resistance and stability. Koutechy-Levich equation showed that the electron transfer number of oxygen molecules on the surface of the composites was close to 4 in alkaline and acidic conditions.The results show that the doping of NbS- P and Fe is beneficial to the side group adsorption of oxygen molecules.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O643.36;TM911.4

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本文編號：1745659