双相质子—电子混合导体透氢膜的制备及性能研究

发布时间：2018-02-27 22:06

  本文关键词： 透氢膜 质子-电子混合导体 双相 电导率 化学稳定性　出处：《河北联合大学》2012年硕士论文　论文类型：学位论文

【摘要】：利用高温固相法制备出双相质子-电子混合导体BaCe_(0.8)Y_(0.2)O_3/Y_(0.09)Sr_(0.91)TiO_3、BaCe_(0.8)Y_(0.2)O_3/Ce_(0.8)Y_(0.2)O_2、BaCe_(0.8)Y_(0.2)O_3/LaCo_(0.9)Ni_(0.1)O_3。运用X射线衍射、扫描电子显微镜和交流阻抗谱法对试样的相组成、微观形貌和导电性能进行了表征，并对其在4%H_2/Ar、水蒸气、100%CO_2气氛中的稳定性进行了研究。探讨了不同氢浓度和温度对混合导体透氢膜透氢性能的影响，结果表明： 烧结温度及掺杂比例对混合导体相组成和微观形貌有显著影响。在一定的烧结温度下，三种混合导体均形成了理想的双相结构，没有杂质相的生成；随着烧结温度的提高，晶粒不断长大，样品的致密性不断增大。混合导体BaCe_(0.8)Y_(0.2)O_3/LaCo_(0.9)Ni_(0.1)O_3样品随着第二相比例的增加，晶型越来越清晰，单位尺寸的晶界数量明显减少。 稳定性实验表明，三种混合导体粉体在含有H_2或水蒸气的气氛下是相对稳定的，各衍射峰的强度、峰型和峰位置几乎没有发生变化；对CO_2均不够稳定，分解成BaCO_3和CeO_2。 烧结温度、掺杂比例、测试气氛影响混合导体的电性能。在一定的烧结温度下，混合导体BaCe_(0.8)Y_(0.2)O_3/Y_(0.09)Sr_(0.91)TiO_3样品在4%H_2/Ar气氛下的电导率随着电子导电相比例的增大而不断提高，1400℃烧结的混合导体BaCe_(0.8)Y_(0.2)O_3/Y_(0.09)Sr_(0.91)TiO_3=5/5样品具有最高的电导率。混合导体BaCe_(0.8)Y_(0.2)O_3/Ce_(0.8)Y_(0.2)O_2样品在不同气氛下具有不同的导电机制，1550℃烧结的BaCe_(0.8)Y_(0.2)O_3/Ce_(0.8)Y_(0.2)O_2=3/7样品在800℃，，4%H_2/Ar气氛下的电导率最高。1200℃烧结的不同比例的混合导体BaCe_(0.8)Y_(0.2)O_3/LaCo_(0.9)Ni_(0.1)O_3，在不同的测试气氛下，表现出不同的导电机制，低温段，氢气气氛下具有最高的电导率，随着温度的升高，电子电导成为主要的导电机制，空气气氛下的电导率最高。 混合导体BaCe_(0.8)Y_(0.2)O_3/Ce_(0.8)Y_(0.2)O_2透氢结果显示，透氢量随着测试温度及氢浓度的增加而不断提高，厚度为1.75mm的3/7样品，进气为40%H_2/N_2在850℃时的透氢量达2.4997mL·min~(-1)·cm~(-2)。
[Abstract]:Using the high temperature solid state method, the biphase proton electron mixed conductor BaCeS 0.8YT was prepared. The phase composition of the sample was characterized by X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The phase composition, microstructure and conductivity of the sample were characterized by means of X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The phase composition of the sample was characterized by means of X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The phase composition, microstructure and conductivity of the sample were characterized by X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The phase composition of the sample was characterized by X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The phase composition of the sample was characterized by scanning electron microscope and AC impedance spectroscopy. The phase composition of the sample was characterized by means of X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The phase composition of the sample was characterized by means of X-ray diffraction, scanning electron microscope and AC impedance spectroscopy. The stability of the film in the atmosphere of 4 / H2 / Arh, 100% H _ 2O _ 2 was studied. The effects of different hydrogen concentration and temperature on the hydrogen permeability of the film were discussed. The results show that:. The sintering temperature and doping ratio have a significant effect on the phase composition and micromorphology of the mixed conductors. At a certain sintering temperature, the three kinds of mixed conductors have formed ideal two-phase structure without the formation of impurity phase, and with the increase of sintering temperature, With the increase of the ratio of the second phase, the crystal form of the mixed conductor BaCe_(0.8)Y_(0.2)O_3/LaCo_(0.9)Ni_(0.1)O_3 sample becomes more and more clear, and the number of grain boundaries per unit size decreases obviously. The stability experiments show that the three kinds of mixed conductor powders are relatively stable in the atmosphere containing H _ 2 or water vapor, the intensity, peak type and peak position of each diffraction peak are almost unchanged, and they are not stable to CO_2 and decomposed into BaCO_3 and CeO2. The electric properties of mixed conductors are affected by sintering temperature, doping ratio and test atmosphere. The conductivity of mixed conductor BaCe_(0.8)Y_(0.2)O_3/Y_(0.09)Sr_(0.91)TiO_3 samples sintered at 1400 鈩

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