本文選題：Pd + Pt��； 參考：《哈爾濱師范大學(xué)》2015年碩士論文

【摘要】：燃料電池被公認(rèn)為是一種高效綠色的能源技術(shù),它不經(jīng)過熱機(jī)過程,因此不受卡諾循環(huán)的限制,能量轉(zhuǎn)換效率高,環(huán)境污染小,被認(rèn)為是21世紀(jì)首選的清潔、高效的發(fā)電技術(shù)。盡管低溫燃料電池近年來已經(jīng)取得了很大的研究進(jìn)展,但離商業(yè)化還有一定距離。電催化劑的活性和穩(wěn)定性是影響直接型燃料電池性能的最關(guān)鍵因素之一。提高催化劑的活性和穩(wěn)定性能較大程度的提高整個(gè)電池的電化學(xué)性能。催化劑的穩(wěn)定性除了與催化劑活性組分相關(guān)外,還與催化劑載體材料以及催化劑的負(fù)載方法有關(guān),特別是活性組分和載體間的相互作用密切相關(guān)。本文以具有良好導(dǎo)電性和高比表面積Vulcan XC-72R活性碳作為碳源,采用浸漬及高溫?zé)崽幚磉�原法,在活性碳表面原位還原鎢酸銨,形成表面包覆鎢的碳化物結(jié)構(gòu)的載體。并以制備的C@WC為載體制備Pd基催化劑和Pt基催化劑。討論了不同W:C原子比對(duì)制備C@WC載體性能的影響,以及不同制備方法對(duì)催化劑性能的影響。研究發(fā)現(xiàn),當(dāng)W:C原子比為1:10、1:15和1:20制備出的C@WC-6、C@WC-7和C@WC-8載體中元素鎢的主要存在形式是WC和W2C;由C@WC制備出的催化劑有較高電催化氧化活性。采用X射線衍射(XRD)、掃描電鏡(SEM)、透射電鏡(TEM)、熱重(TG)等手段對(duì)載體C@WC進(jìn)行了表征。通過XRD方法對(duì)催化劑載體的組成進(jìn)行了分析;用循環(huán)伏安法(CV),計(jì)時(shí)電流曲線法(CA),此外還通過電勢(shì)階躍法,對(duì)催化劑活性衰減及穩(wěn)定性進(jìn)行了討論。比較了常規(guī)化學(xué)合成法及微波輔助催化劑合成法對(duì)制備的Pd/C@WC催化劑的影響,研究發(fā)現(xiàn),采用常規(guī)化學(xué)合成法制備的電催化劑對(duì)甲酸的電催化氧化具有更高的活性和穩(wěn)定性。比較了W:C原子比為1:10、1:15和1:20載體的電化學(xué)性質(zhì)和表面形貌;并比較了制備出的Pd/C@WC-6、Pd/C@WC-7和Pd/C@WC-8催化劑對(duì)甲酸的電催化氧化性能,發(fā)現(xiàn)C@WC-7為載體制備的催化劑對(duì)甲酸的氧化具有最高的活性和穩(wěn)定性。以C@WC-6、C@WC-7和C@WC-8為載體制備了Pt/C@WC-6、Pt/C@WC-7和Pt/C@WC-8催化劑,分別研究了這三種催化劑對(duì)甲醇和乙醇的電催化氧化性能,發(fā)現(xiàn)C@WC-7作為載體制備的催化劑Pt/C@WC-7對(duì)甲醇和乙醇的氧化具有最好的電催化活性和穩(wěn)定性。
[Abstract]:Fuel cell is recognized as a kind of efficient green energy technology, it does not go through heat engine process, so it is not restricted by Carnot cycle, energy conversion efficiency is high, environmental pollution is small, it is considered to be the first choice of clean and efficient power generation technology in the 21st century.Although cryogenic fuel cells have made great progress in recent years, they are still far from commercialization.The activity and stability of electrocatalyst is one of the most important factors affecting the performance of direct fuel cell.The electrochemical performance of the whole battery was improved greatly by improving the activity and stability of the catalyst.The stability of the catalyst is not only related to the active component of the catalyst, but also to the support material and the method of the catalyst support, especially the interaction between the active component and the support.In this paper, Vulcan XC-72R active carbon with good electrical conductivity and high specific surface area was used as carbon source. In this paper, ammonium tungstate was reduced in situ on the surface of activated carbon by impregnation and high temperature heat treatment.PD-based catalysts and Pt-based catalysts were prepared on C@WC.The effects of different W: C atomic ratios on the properties of C@WC support and the effects of different preparation methods on the performance of the catalysts were discussed.It is found that when the W: C atom ratio is 1: 10 / 1: 15 and 1:20, the main forms of tungsten in the support of CWC-6R CWC-7 and C@WC-8 are WC and W2C.The catalysts prepared from C@WC have higher electrocatalytic oxidation activity.The C@WC was characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TG).The composition of catalyst support was analyzed by XRD method, and the catalytic activity attenuation and stability were discussed by cyclic voltammetry, chronoelectric curve method and potential step method.The effects of conventional chemical synthesis and microwave-assisted catalyst synthesis on the preparation of Pd/C@WC catalysts were compared. It was found that the electrocatalysts prepared by conventional chemical synthesis had higher activity and stability for the electrocatalytic oxidation of formic acid.The electrochemical properties and surface morphology of the supports with a W: C ratio of 1: 10 to 1: 15 and 1:20 were compared, and the electrocatalytic oxidation of formic acid over PD / CWC-6W / C / C @ WC-7 and Pd/C@WC-8 catalysts were compared.It was found that the catalyst prepared with C@WC-7 as the carrier had the highest activity and stability for the oxidation of formic acid.Using CWC-6C @ CWC-7 and C@WC-8 as the supports, the catalytic properties of the three catalysts for the electrocatalytic oxidation of methanol and ethanol were studied.It was found that the catalyst Pt/C@WC-7 prepared with C@WC-7 as the carrier had the best electrocatalytic activity and stability for the oxidation of methanol and ethanol.
【學(xué)位授予單位】：哈爾濱師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：O643.36;TM911.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉瑞;易丹青;李薦;;納米WC粉末的制備研究[J];材料科學(xué)與工程學(xué)報(bào);2006年03期

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本文編號(hào)：1756619