As a mixed ion-electronic conductor, doped ceria, especially rare earth doped ceria, were used as anodes or components of anodes in SOFCs. In this work, calcium doped ceria （CCO） was synthesized to be used in intermediate-temperature SOFCs （IT-SOFCs） anodes in order to reduce the cost of anode-supported SOFCs. Electrical conductivity of 20% calcium doped ceria （20CCO） reached 0.209 S·cm^-1 in hydrogen at 850 ℃, and 0.041 S·cm^-1 in air at 800℃, which is about 0.04 S·cm^-1 lower than that of conventional samaria-doped ceria （0.079 S·cm^-1）. Electrochemical performance of Ni-20CCO cermet as anode was investigated using a fuel cell with 35μm-thick SDC electrolyte and Sm0.5Sr0.5 Co-SDC cathode. Maximum power density was 623 mW·cm^-2 under humidified （3% H2O） hydrogen at 650 ℃, inferring high catalytic activity of the Ni-20CCO anode.
Praseodymium β-diketone chelate, Pr （DPM）3 [ DPM = 2,2,6,6 -tetramethyl-3,5-heptanedionato ], was successfully synthesized from the inorganic salt praseodymium chloride and HDPM（2,2,6,6-tetramethyl-3,5-heptane-dione） in an ethanol/aqueous solution followed distillation at low pressure and recrystallization from toluene. The physical and thermal properties of the chelate, including volatility, stability, and thermal decomposition, were investigated by elemental analyses, 1^H NMR spectroscopy, XRD, TG/DTG/DTA analysis, infrared spectroscopy, and mass spectroscopy. The chelate with high purity prepared by the authors of this study also shows sufficient volatility and Stability in inert gases, which could be used as the precursor for metal-organic chemical vapor deposition（MOCVD）.
LIU Ming-fei HU Yong-xing JIANG Yin-zhu GAO Jian-feng WANG Yan-yan MENG Guang-yao
