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直接乙醇燃料电池的原位紫外拉曼光谱研究
In-Situ UV Raman Study on the Direct Ethanol Fuel Cells
【作者】 吕新新；
【导师】 熊光；
【作者基本信息】 大连理工大学 ， 工业催化， 2011， 硕士
【摘要】 直接乙醇燃料电池使用的燃料乙醇是一种可再生能源,因其能够取代直接甲醇燃料电池,避免甲醇有毒,渗透等问题,而受到人们广泛的关注。到目前为止,研究人员已经运用各种分析手段对乙醇燃料电池展开了深入研究,其目的是提高乙醇燃料电池催化剂的活性,提高燃料电池的工作效率和使用寿命。对乙醇电催化氧化机理这一难题,进行深入研究探讨的报道还很少,而采用紫外拉曼光谱技术与原位单电池相结合的方式,对直接乙醇燃料电池机理进行研究,尚无报道。对乙醇燃料电池电催化氧化机理的探索和认识,有助于提高乙醇燃料电池的电化学反应速率,设计新型高效的乙醇燃料电池。本实验通过紫外拉曼光谱与气相色谱相结合的方法,研究乙醇燃料电池原位反应过程中,中间物种的生成及变化。其中,特别设计的原位反应单池,能够正常与紫外拉曼光谱结合使用,并且可以检测到有反应物,催化剂及中间物种产生的拉曼信号。燃料电池中的阳极燃料乙醇与阴极氧气在催化剂作用下发生反应,生成的CO2和水可由气相色谱检测到,说明电池性能和运行状态良好,并且乙醇已发生电催化氧化反应。在反应过程中,通过原位紫外拉曼光谱观察到1713 cm-1处出现了表征中间物种乙醛和乙酸的C=O峰。另外,本文在实验过程中优化各种反应操作条件,确定产物及中间物种的变化,有助于进一步观察乙醇燃料电池电催化氧化的过程,对乙醇机理的进一步分析和认识提供了帮助。
【Abstract】 People pay much attention on direct ethanol fuel cells (DEFCs) as ethanol is a renewable and clean resource. The DEFCs is a potential replacement of methanol fuel cell due to its non-toxic and non-permission characters. Researchers have studied DEFCs using different techniques aiming at improving the activity of catalyst, the performance of the fuel cell and the operating life. There have been fewer reports on the mechanism of ethanol catalytic oxidation by far. The investigation on ethanol catalytic oxidation mechanism by UV-Raman spectroscopy technology combining with in-situ single cell has not been reported. The study on the mechanism of ethanol catalytic oxidation can improve the electrochemical reaction rate and design efficient ethanol fuel cells.In this study, the intermediates and products of the ethanol oxidation reaction were investigated by in-situ UV Raman spectroscopy and gas chromatography. The Raman signals of ethanol, catalyst and intermediates were successfully detected by the UV-Raman spectroscopy combined with specially designed in-situ single cell.CO2 and H2O produced in the catalytic oxidation reaction of ethanol can be detected by gas chromatography, indicating that the good operation condition of the fuel cell. A new peak at 1713 cm-1, which is assigned to stretching mode of C=O in acetaldehyde or acetic acid, is observed in Raman spectra. Furthermore, more about ethanol catalytic oxidation mechanism can be obtained by improving the conditions of experiment and observing the changes of the intermediates and products.