Preparation and Characterization of the Sr(Ce0.6Zr0.4)1-xYxO3-δ High Temperature Proton Conductor

• Main Authors: Yen-Jiun chiang, 江衍均
• Other Authors: I-Ming Hung
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/jn85h6

碩士 === 元智大學 === 化學工程與材料科學學系 === 103 === Sr(Ce0.6Zr0.4)1-xYxO3-δ (x = 0.1, 0.15, 0.2, 0.25, 0.3) perovskite proton-conducting ceramic was synthesized using EDTA-Citric acid complex method. The sintered samples show a perovskite crystal structure with the small amount of SrY2O4 impurity phases. In this paper, The effects of the Y ratio on various material properties are systematically investigated. It focus on the effects of different atmosphere to the electrical properties and hydrogen flux. The structure of sample was characterized by X-ray diffraction (XRD). The conductivity of the sintered Sr(Ce0.6Zr0.4)1-xYxO3-δ disk measured at different temperature and in different atmosphere using the 2-probe DC method. The electrical properties of Sr(Ce0.6Zr0.4)1-xYxO3-δ proton conductor under different atmosphere are investigated. The X-ray diffraction shows that the single phase SCZY powder was successfully synthesized. The conductivity of the sample shows that when Y was doped into the lattice structure, a pronounced rise in conductivity can be observed under both air and hydrogen atmosphere due to the enhancement of oxygen vacancy of Y dopant. However, as the Y concentration rised over 20%, the total conductivity start to decrease because of the generation of the second phase. The relative sintering density of Sr(Ce0.6Zr0.4)1-xYxO3-δ is all greater than 96%. The XRD analysis of Sr(Ce0.6Zr0.4)0.85Y0.15O3-δ samples before and after operating in dry, PH2O= 2.46 x 10-2 atm, PH2O = 4.93 x 10-2 atm hydrogen atmosphere shown that there is no second phase after different treatment condition. All of the diffraction peaks are sharp and the intensity is high. The result shows that SCZY performed a good stability properties under different humid hydrogen atmospheres. In the hydrogen flux test, we find that the hydrogen flux of SCZY is excellent, the flux of each concentration x=0.1, 0.15, 0.2, 0.25, 0.3, at 800 oC is 1.47、1.74、1.60、0.72、0.45 ml/min.cm2. From the SEM images, the thickness of the membrane dense layer is about 60 μm. The dense layer and the support layer is well combined, and the support layer represent good porous structure.