A series of LaAl 1-xFe xO 3 catalysts prepared with lanthanum nitrate, aluminium nitrate and iron nitrate was investigated in catalytical syntheses of carbon nanotubes with high yields and purity. The properties ...A series of LaAl 1-xFe xO 3 catalysts prepared with lanthanum nitrate, aluminium nitrate and iron nitrate was investigated in catalytical syntheses of carbon nanotubes with high yields and purity. The properties of carbon nanotubes prepared by the method of CVD(chemical vapor deposition) with n-hexane as the carbon resource were studied and it was shown that the diameter of carbon nanotubes can be controlled by the molar ratio of iron to aluminum in the catalysts and that the diameter of carbon nanotubes changes a little with the decrease of the iron content in the catalysts. From the TEM pictures of carbon nanotubes, it can be found that the LaAl 1-xFe xO 3 catalysts have a significant influence on the wall thickness of the carbon nanotubes, whereas they have little influence on the inner diameter of the carbon nanotubes.展开更多
采用溶胶-凝胶法制备Y0.06Sr0.94Ti1-xFexO3-δ（x为原子分数。x=0.2，0.3，0.4，0.5）混合导体材料，用X射线衍射（XRD）分析该材料的物相，采用交流阻抗法和电子阻塞电极法分别测定其总电导率与离子电导率，研究铁含量对Y0.06Sr0.94T...采用溶胶-凝胶法制备Y0.06Sr0.94Ti1-xFexO3-δ（x为原子分数。x=0.2，0.3，0.4，0.5）混合导体材料，用X射线衍射（XRD）分析该材料的物相，采用交流阻抗法和电子阻塞电极法分别测定其总电导率与离子电导率，研究铁含量对Y0.06Sr0.94TiO3混合导体材料的结构及电性能的影响。结果表明该材料属于单一立方相钙钛矿结构；在测试温度范围内，Y0.06Sr0.94Ti1-xFexO3-δ的总电导率和离子电导率都随温度升高而增大；随 Fe 掺杂量增加，总电导率和离子电导率都增大。在800℃下Y0.06Sr0.94Ti1-xFexO3-δ（x=0.2，0.3，0.4，0.5）的总电导率为0.019～0.12 S/cm，离子电导率为0.0106～0.0153 S/cm。根据传导活化能可以看出，x从0.3增加到0.4时材料的传导机制发生改变。展开更多
In order to develop the new cathode materials suitable for intermediate and low temperature solid oxide fuel cells (IT/LTSOFCs), LaNi1-xFexO3 (x=0.4-0.8) (LNF) materials were synthesized using coprecipitation method. ...In order to develop the new cathode materials suitable for intermediate and low temperature solid oxide fuel cells (IT/LTSOFCs), LaNi1-xFexO3 (x=0.4-0.8) (LNF) materials were synthesized using coprecipitation method. Their structures and morphologies were investigated by XRD and SEM, and their electronic conductivities at different temperatures were measured by dc four terminal method. Fuel cells were fabricated to evaluate the electrochemical properties of the LNF materials as cathodes at different temperatures. The performance of 450-497 mW·cm-2 was obtained in the temperature region of 580-650 ℃ for the LaNi0.2Fe0.8O3 cathode, and of 209-227 mW·cm-2 at 400-500 ℃ for the LaNi0.4Fe0.6O3. The excellent fuel cell performances indicate that the LNF materials are good cathodes for IT/LTSOFCs.展开更多
基金Supported by the Natural Science Foundation of Guangdong Province(No.0 314 2 0 ),the Guangzhou City Science andTechnology Project(No.2 0 0 3Z3- D2 0 71) and the Science and Technology Project of Guangdong Province(No.2 0 0 3C335 0 5
文摘A series of LaAl 1-xFe xO 3 catalysts prepared with lanthanum nitrate, aluminium nitrate and iron nitrate was investigated in catalytical syntheses of carbon nanotubes with high yields and purity. The properties of carbon nanotubes prepared by the method of CVD(chemical vapor deposition) with n-hexane as the carbon resource were studied and it was shown that the diameter of carbon nanotubes can be controlled by the molar ratio of iron to aluminum in the catalysts and that the diameter of carbon nanotubes changes a little with the decrease of the iron content in the catalysts. From the TEM pictures of carbon nanotubes, it can be found that the LaAl 1-xFe xO 3 catalysts have a significant influence on the wall thickness of the carbon nanotubes, whereas they have little influence on the inner diameter of the carbon nanotubes.
基金Project Supported by the National Science Foundation of China (19934003)the State Key Project of Fundamental Research of China(001CB610604)+1 种基金the State Key Project of Fundamental Research of China (2007CB925001)the Natural Science Foundation of the Anhui Higher Education Institutions of China(2006KJ266B, ZD2007003-1)
文摘采用溶胶-凝胶法制备Y0.06Sr0.94Ti1-xFexO3-δ（x为原子分数。x=0.2，0.3，0.4，0.5）混合导体材料，用X射线衍射（XRD）分析该材料的物相，采用交流阻抗法和电子阻塞电极法分别测定其总电导率与离子电导率，研究铁含量对Y0.06Sr0.94TiO3混合导体材料的结构及电性能的影响。结果表明该材料属于单一立方相钙钛矿结构；在测试温度范围内，Y0.06Sr0.94Ti1-xFexO3-δ的总电导率和离子电导率都随温度升高而增大；随 Fe 掺杂量增加，总电导率和离子电导率都增大。在800℃下Y0.06Sr0.94Ti1-xFexO3-δ（x=0.2，0.3，0.4，0.5）的总电导率为0.019～0.12 S/cm，离子电导率为0.0106～0.0153 S/cm。根据传导活化能可以看出，x从0.3增加到0.4时材料的传导机制发生改变。
文摘In order to develop the new cathode materials suitable for intermediate and low temperature solid oxide fuel cells (IT/LTSOFCs), LaNi1-xFexO3 (x=0.4-0.8) (LNF) materials were synthesized using coprecipitation method. Their structures and morphologies were investigated by XRD and SEM, and their electronic conductivities at different temperatures were measured by dc four terminal method. Fuel cells were fabricated to evaluate the electrochemical properties of the LNF materials as cathodes at different temperatures. The performance of 450-497 mW·cm-2 was obtained in the temperature region of 580-650 ℃ for the LaNi0.2Fe0.8O3 cathode, and of 209-227 mW·cm-2 at 400-500 ℃ for the LaNi0.4Fe0.6O3. The excellent fuel cell performances indicate that the LNF materials are good cathodes for IT/LTSOFCs.
