摘要
用高温固相反应法合成了非化学计量组成的Ba1.03Ce0.5Zr0.4La0.1O3-α质子导体.粉末X射线衍射(XRD)结果表明,该材料为单一钙钛矿型BaCeO3斜方晶结构,在高温下、CO2或水蒸气气氛中具有较高的稳定性.扫描电子显微镜(SEM)观察分析表明,材料经1550℃烧结20h非常致密.在500～900℃温度范围内,用交流阻抗谱技术测定了材料在湿润氢气和湿润空气气氛中的电导率;用气体浓差电池方法测定了材料在湿润氢气、湿润空气气氛中和氢-空气燃料电池条件下的离子迁移数,研究了材料的离子导电特性,并与化学计量组成的BaCe0.5Zr0.4La0.1O3-α材料进行了比较.结果表明,在500～900℃温度范围内、湿润氢气气氛中,Ba1.03Ce0.5Zr0.4La0.1O3-α材料的质子迁移数为1,是一个纯质子导体.在湿润空气气氛中,材料的氧离子迁移数为0.688～0.170,质子迁移数为0.218～0.017,是一个氧离子、质子和电子空穴的混合导体.在氢-空气燃料电池条件下,材料的离子(氧离子+质子)迁移数为0.990～0.796,是一个氧离子、质子和电子的混合导体.与化学计量组成的BaCe0.5Zr0.4La0.1O3-α材料相比较,在相同实验条件下非化学计量组成的Ba1.03Ce0.5Zr0.4La0.1O3-α材料具有较高的电导率和离子迁移数.
A proton conductor Ba1.03Ce0.5Zr0.4La0.1O3-α with a nonstoichiometric composition was prepared by a high temperature solid state reaction.X-ray powder diffraction pattern（XRD） shows that the material was of a single orthorhombic phase of perovskite-type BaCeO3 and good stability in CO2 or water steam atmosphere at a high temperature.The SEM morphologies of the surface and the fracture of Ba1.03Ce0.5Zr0.4La0.1O3-α show that the material was compact after sintered at 1550 ℃ for 20 h in air.The conductivities and ionic transport numbers of the material in different gases were measured by using ac impendence spectroscopy and gas concentration cell methods in the temperature range of 500～900 ℃,respectively.The results indicate that the material was a pure proton conductor with the protonic transport number of 1 from 500 to 900 ℃ in wet hydrogen.In wet air,the oxide-ionic transport numbers were 0.688～0.170,the protonic transport numbers were 0.218～0.017,and the material was a mixed conductor of oxide-ions,protons and electronic holes.Under the fuel cell condition,the material was a mixed conductor of oxide ions,protons and electrons with the ionic transport numbers of 0.990～0.796 from 500 to 900℃.The conductivity and ionic transport numbers of Ba1.03Ce0.5Zr0.4La0.1O3-α were higher than those of BaCe0.5Zr0.4La0.1O3-α under the same experimental conditions.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第3期276-282,共7页
Acta Chimica Sinica
基金
国家自然科学基金(No20771079)
江苏省高校"青蓝工程"
江苏省高校自然科学基金(No07KJB150126)资助项目
