银基陶瓷复合电极的电性能及其在固体氧化物燃料电池中的应用

银基陶瓷复合电极可望在中低温固体氧化物燃料电池(SOFCs)、含碳燃料SOFCs和固体氧化物电解池(SOECs)中得到广泛应用。为优选出银基陶瓷复合电极的成分,本研究采用YSZ(钇稳定化氧化锆)电解质,先将Ag-YSZ和Ag-GDC(掺钆氧化铈)材料制备成对称电极,测试其在空气下的阻抗谱,由此判断其作为阴极的性能;发现在相同的Ag含量时, Ag-YSZ的阴极极化电阻普遍低于Ag-GDC;当Ag的质量分数为65%时, Ag-YSZ的极化电阻最低,而对于Ag-GDC, Ag的质量分数是70%。然后采用空气中极化电阻最低的Ag-YSZ和Ag-GDC作为电极制备了SOFC单电池,并采用加湿氢气燃料对电池的电化学性能进行了测试。根据电池的阻抗谱数据,将极化阻抗的数值减去上述阴极阻抗的数值可得到阳极阻抗值,其结果和电池的输出特性均表明, Ag-GDC作为阳极的性能优于Ag-YSZ,即在本实验条件下, Ag-YSZ更适合用作阴极,而Ag-GDC更适合用作阳极。本研究不仅提供了关于银基复合电极材料的有用数据,还提供了一种测试SOFC阳极极化电阻的方法。     

乙二胺N,N-二(4-乙酰胺基水杨酸)-二乙酸及其Gd3+、Eu3+配合物的合成与表征

通过乙二胺四乙酸二酐与4-氨基水杨酸的酰化反应得到乙二胺N,N-二 (4-乙酰胺基水杨酸)-二乙酸(H4L);在室温下,H4L与GdCl3、EuCl3在水溶液中进行配位组装反应,得到两个新的稀土金属配合物(Gd-L、Eu-L).通过FTIR、元素分析、UV、TG-DTA等测试手段对稀土金属配合物的组成进行了初步确定与表征,得到两个配合物中金属离子与配体之比均为1∶1,可表示为RE (HL)-3H2O(RE3+=Gd3+,Eu3+).     

A New Dinuclear Gadolinium Complex Constructed from p-Phenylenediamine-N,N,N′,N′-tetraacetic Acid and in situ Generated Oxalate

Routine solution reaction of Gd3+ and p-phenylenediamine-N,N,N′,N′-tetraacetic acid (p-PhDTA) yields a dinuclear complex [Gd2(ox)(p-PhDTA)2(H2O)10]·6H2O (ox = oxalate), which was characterized by single-crystal X-ray diffraction (MoKα radiation, = 0.71073), elemental analysis and IR. This complex crystallizes in the monoclinic system, space group P21/n with a = 10.2522(8), b = 10.0053(8), c = 23.8834(18), = 99.1080(10)°, V = 2419.0(3)3, Z = 2, Mr = 1367.32, Dc = 1.877 g/cm3, F(000) = 1368, = 2.830 mm-1, the final R = 0.0337 and wR = 0.0794 for 4747 observed reflections (I > 2 (I)). The exo-tetradentate oxalate ligand, generated in situ from the oxidative coupling of methanol, is incorporated to construct a dinuclear Gd2(ox)2 unit decorated with p-PhDTA ligands on the two sides with a monodentate coordination mode. The dinuclear molecules are further connected by the lattice water molecules to form a three-dimen- sional hydrogen network.