Zirconium doping effect on the microstructure and properties of SrCe1-xZrxO3−δ (0.0≦x≦0.5) hydrogen transport membrane

• Main Authors: Kai-Ti Hsu, 許凱迪
• Other Authors: Jason Shian-Ching Jang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/70706801876487774699

碩士 === 國立中央大學 === 材料科學與工程研究所 === 101 === Strontium cerium oxide can be applicated on hydrogen transport membranes (HTM) beacuse of their relativity high proton and electrical conductivities and lower activations energy. HTM have a permeability to hydrogen, using for separating and purifing hydrogen from coal and limestone of fossil fuels. Therefore, the good chemical stability in the enviroment of corbon monoxide, corbon dioxide and sulfides, and to provide suitable mechanical strength by apropriating microstrctures design. In this study, SrCe1-xZrxO3−δ (x=0, 0.1, 0.2, 0.3, 0.4, 0.5) proton-conducting oxides have been prepared using a solid state reaction method. The relationship between the Zr doping content and microstructure, sinterability, chemical ability and conductivity of these SrCe1-xZrxO3−δ (0.0≦x≦0.5) proton-conducting oxides. SrCe1-xZrxO3−δ (0.0≦x≦0.5) are studied systematically by using X-ray Diffraction for the microstructure identification, by Scanning Electron Microscopy for surface mohpology observation. The results of SEM observation on the morphology of fracture surface reveals the porosity of sintered oxides increases with increasing the Zr doping content. Since the Zr doping content would decrease the siterability, the closed pores tranferring into open pores can be seen on the fracture surface. In addition, the results of thermo dilatometer analysis present a shrinkage of 5.98% and water absorption of 7.09% and porosity of 26.80 % occured at the composition of SrCe0.6Zr0.4O3-δ (SCZ0.4) sintered at 1500℃for 4 hurs, respectively. The results of CO2 enviroment test reveals that the relative intensity of CeO2 and SrCO3 phases decreases with increasing the Zr content. This evidences that the chemical stability of SrCe0.8Zr0.2O3-δ (SCZ0.2) would improved by increasing Zr content. However th condutivity of SrCe1-xZrxO3−δ (0.0≦x≦0.5) oxides decreases with increasing the Zr doping content. As a result, SCZ0.4 is suggested to be a potential support layer material for HTM applications.