采用柠檬酸-硝酸盐自蔓延燃烧法分别合成了Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(PSCF)和Gd_(0.2)Ce_(0.8)O_(2-δ)(GDC)粉体,高温固相法合成La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)电解质粉体。以LSGM为电解质,PSCF同时...采用柠檬酸-硝酸盐自蔓延燃烧法分别合成了Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(PSCF)和Gd_(0.2)Ce_(0.8)O_(2-δ)(GDC)粉体,高温固相法合成La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)电解质粉体。以LSGM为电解质,PSCF同时作为阴极和阳极,GDC作为功能层材料,构建了对称固体氧化物燃料电池PSCF│GDC│LSGM│GDC│PSCF。利用X射线衍射法研究材料的成相以及相互间的化学稳定性,交流阻抗法记录界面极化行为,用扫描电子显微镜观察电池的断面微结构,用自组装的测试系统评价电池输出性能。结果表明,合成的PSCF粉体呈立方钙钛矿结构,具有良好的氧化–还原可逆性。使用GDC功能层明显改善了氢气环境下PSCF与LSGM材料间的化学相容性以及电池的输出性能,800℃时,电极│电解质界面极化电阻从6.892?·cm^2下降到0.314?·cm^2;以加湿H_2(含体积分数3%的水蒸气)为燃料气,空气为氧化气时,单电池输出功率密度由269 m W/cm2增大至463 m W/cm^2。研究结果显示,PSCF是对称固体氧化物燃料电池良好的候选电极材料,GDC功能层对改善电池长期稳定性能具有潜在的应用价值。展开更多
采用溶胶-凝胶法制备Sr Ti_(0.6)Fe_(0.4)O_(3-δ),通过掺杂少量YSZ制备YSZ-Sr Ti_(0.6)Fe_(0.4)O_(3-δ)复相陶瓷。采用电化学工作站测试样品电子-离子混合传导及离子传导的阻抗谱和频谱特性,结果表明,YSZ-Sr Ti_(0.6)Fe_(0.4)O_(3-δ...采用溶胶-凝胶法制备Sr Ti_(0.6)Fe_(0.4)O_(3-δ),通过掺杂少量YSZ制备YSZ-Sr Ti_(0.6)Fe_(0.4)O_(3-δ)复相陶瓷。采用电化学工作站测试样品电子-离子混合传导及离子传导的阻抗谱和频谱特性,结果表明,YSZ-Sr Ti_(0.6)Fe_(0.4)O_(3-δ)在电子-离子混合传导过程中存在三种不同的极化过程,分别来自于晶粒,晶界和电极/样品,通过等效电路对阻抗谱的拟合,活化能分别为0.16 e V,0.62 e V和0.42 e V,随温度的升高,晶粒弛豫不明显,样品电阻主要由晶界的极化过程控制;在离子传导过程中,只存在一个晶界弛豫过程,晶界弛豫随温度的升高而减小,试样的弛豫时间为~0.13-0.29 s。展开更多
以丙烯酰胺辅助柠檬酸为络合试剂,采用溶胶-凝胶燃烧法制备La0.6Sr0.4Co1-xMnxO3催化剂(x=0.3、0.5、0.7)并与La Co O3进行比较,进行XRD、BET、SEM、XPS和苯的催化氧化性能和稳定性表征。结果表明,催化活性顺序为:La0.6Sr0.4Co0.7Mn0.3O...以丙烯酰胺辅助柠檬酸为络合试剂,采用溶胶-凝胶燃烧法制备La0.6Sr0.4Co1-xMnxO3催化剂(x=0.3、0.5、0.7)并与La Co O3进行比较,进行XRD、BET、SEM、XPS和苯的催化氧化性能和稳定性表征。结果表明,催化活性顺序为:La0.6Sr0.4Co0.7Mn0.3O3>La0.6Sr0.4Co0.5Mn0.5O3>La0.6Sr0.4Co0.3Mn0.7O3>La Co O3。La0.6Sr0.4Co1-xMnxO3催化剂生成钙钛矿相的同时还伴生少量Sr CO3杂相。与La Co O3对比,La0.6Sr0.4Co1-xMnxO3催化剂拥有更大的比表面积、孔容和抗团聚性,具有更好的催化氧化活性。在La0.6Sr0.4Co1-xMnxO3(x=0.3、0.5、0.7)催化剂中,La0.6Sr0.4Co0.7Mn0.3O3催化剂比其他两种催化剂具有更高的钙钛矿相结晶度和更多的表面吸附氧与晶格氧,活性最高。78 h稳定性测试结果表明,La0.6Sr0.4Co0.7Mn0.3O3催化剂表现出良好的稳定性。展开更多
The conventional Ni cermet anode suffers from severe carbon deposition and sulfur poisoning when fossil fuels are used. Alternative anode materials are desired for high performance hydrocarbon fuel solid oxide fuel ce...The conventional Ni cermet anode suffers from severe carbon deposition and sulfur poisoning when fossil fuels are used. Alternative anode materials are desired for high performance hydrocarbon fuel solid oxide fuel cells （SOFCs）. We report the rational design of a very active Ni doped La0.6Sr0.4FeO3‐δ（LSFN） electrode for hydrocarbon fuel SOFCs. Homogeneously dispersed Ni‐Fe alloy nanoparticles were in situ extruded onto the surface of the LSFN particles during the operation of the cell. Sym‐metric SOFC single cells were prepared by impregnating a LSFN precursor solution onto a YSZ （yt‐tria stabilized zirconia） monolithic cell with a subsequent heat treatment. The open circuit voltage of the LSFN symmetric cell reached 1.18 and 1.0 V in humidified C3H8 and CH4 at 750？？, respective‐ly. The peak power densities of the cells were 400 and 230 mW/cm2 in humidified C3H8 and CH4, respectively. The electrode showed good stability in long term testing, which revealed LSFN has good catalytic activity for hydrocarbon fuel oxidation.展开更多
文摘采用柠檬酸-硝酸盐自蔓延燃烧法分别合成了Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(PSCF)和Gd_(0.2)Ce_(0.8)O_(2-δ)(GDC)粉体,高温固相法合成La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)电解质粉体。以LSGM为电解质,PSCF同时作为阴极和阳极,GDC作为功能层材料,构建了对称固体氧化物燃料电池PSCF│GDC│LSGM│GDC│PSCF。利用X射线衍射法研究材料的成相以及相互间的化学稳定性,交流阻抗法记录界面极化行为,用扫描电子显微镜观察电池的断面微结构,用自组装的测试系统评价电池输出性能。结果表明,合成的PSCF粉体呈立方钙钛矿结构,具有良好的氧化–还原可逆性。使用GDC功能层明显改善了氢气环境下PSCF与LSGM材料间的化学相容性以及电池的输出性能,800℃时,电极│电解质界面极化电阻从6.892?·cm^2下降到0.314?·cm^2;以加湿H_2(含体积分数3%的水蒸气)为燃料气,空气为氧化气时,单电池输出功率密度由269 m W/cm2增大至463 m W/cm^2。研究结果显示,PSCF是对称固体氧化物燃料电池良好的候选电极材料,GDC功能层对改善电池长期稳定性能具有潜在的应用价值。
文摘采用溶胶-凝胶法制备Sr Ti_(0.6)Fe_(0.4)O_(3-δ),通过掺杂少量YSZ制备YSZ-Sr Ti_(0.6)Fe_(0.4)O_(3-δ)复相陶瓷。采用电化学工作站测试样品电子-离子混合传导及离子传导的阻抗谱和频谱特性,结果表明,YSZ-Sr Ti_(0.6)Fe_(0.4)O_(3-δ)在电子-离子混合传导过程中存在三种不同的极化过程,分别来自于晶粒,晶界和电极/样品,通过等效电路对阻抗谱的拟合,活化能分别为0.16 e V,0.62 e V和0.42 e V,随温度的升高,晶粒弛豫不明显,样品电阻主要由晶界的极化过程控制;在离子传导过程中,只存在一个晶界弛豫过程,晶界弛豫随温度的升高而减小,试样的弛豫时间为~0.13-0.29 s。
文摘以丙烯酰胺辅助柠檬酸为络合试剂,采用溶胶-凝胶燃烧法制备La0.6Sr0.4Co1-xMnxO3催化剂(x=0.3、0.5、0.7)并与La Co O3进行比较,进行XRD、BET、SEM、XPS和苯的催化氧化性能和稳定性表征。结果表明,催化活性顺序为:La0.6Sr0.4Co0.7Mn0.3O3>La0.6Sr0.4Co0.5Mn0.5O3>La0.6Sr0.4Co0.3Mn0.7O3>La Co O3。La0.6Sr0.4Co1-xMnxO3催化剂生成钙钛矿相的同时还伴生少量Sr CO3杂相。与La Co O3对比,La0.6Sr0.4Co1-xMnxO3催化剂拥有更大的比表面积、孔容和抗团聚性,具有更好的催化氧化活性。在La0.6Sr0.4Co1-xMnxO3(x=0.3、0.5、0.7)催化剂中,La0.6Sr0.4Co0.7Mn0.3O3催化剂比其他两种催化剂具有更高的钙钛矿相结晶度和更多的表面吸附氧与晶格氧,活性最高。78 h稳定性测试结果表明,La0.6Sr0.4Co0.7Mn0.3O3催化剂表现出良好的稳定性。
基金supported by the National Natural Science Foundation of China (51372271,51172275)the National Basic Research Program of China (973 Program,2012CB215402)~~
文摘The conventional Ni cermet anode suffers from severe carbon deposition and sulfur poisoning when fossil fuels are used. Alternative anode materials are desired for high performance hydrocarbon fuel solid oxide fuel cells （SOFCs）. We report the rational design of a very active Ni doped La0.6Sr0.4FeO3‐δ（LSFN） electrode for hydrocarbon fuel SOFCs. Homogeneously dispersed Ni‐Fe alloy nanoparticles were in situ extruded onto the surface of the LSFN particles during the operation of the cell. Sym‐metric SOFC single cells were prepared by impregnating a LSFN precursor solution onto a YSZ （yt‐tria stabilized zirconia） monolithic cell with a subsequent heat treatment. The open circuit voltage of the LSFN symmetric cell reached 1.18 and 1.0 V in humidified C3H8 and CH4 at 750？？, respective‐ly. The peak power densities of the cells were 400 and 230 mW/cm2 in humidified C3H8 and CH4, respectively. The electrode showed good stability in long term testing, which revealed LSFN has good catalytic activity for hydrocarbon fuel oxidation.
