Struktur und thermische Zersetzung von Bis(triethanolamin)kupfer(II)-acetat [Cu{N(CH2CH2OH)3}2](CH3COO)2

Structure and Thermal Decomposition of Bis(triethanolamine)copper(II) Acetate [Cu{N(CH₂CH₂OH)₃}₂](CH₃COO)₂ Bis(triethanolamine)copper(II) acetate [Cu{N · (CH₂CH₂OH)₃}₂](CH₃COO)₂ was prepared using the basic components; the structure was determined by single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁/c with a = 9.101 Å, b = 13.136 Å, c = 9.819 Å, β = 111.63°. Details of the synthesis, X-ray data, and the thermal decomposition are reported.     

Oxygen Transport in the SOFC Cathode

The impedance of the La_0.75Sr_0.2MnO₃-cathode/electrolyte interface for cathodes with different porosity is measured. The impedance spectra are fitted using a developed model of the oxygen transport at this interface. After the measurements, the cathode is removed from the electrolyte. The contact area and the three-phase boundary length (TPBL) at the interface are estimated from SEM images of the electrolyte surface. The dependence of the interfacial electrical resistance on the microstructure is discussed. It is shown that the bulk diffusion of oxygen vacancies at the interface at 950°C is high enough to use the whole La_0.75Sr_0.2MnO₃/YSZ contact area F for the oxygen transport into the electrolyte for microstructures with 2F/TPBL 2 m. The impact of the surface diffusion of oxygen species on polarization resistance at operation temperatures <900°C is discussed. The polarization resistance and the morphology of composite cathodes made from La_0.75Sr_0.2MnO₃/YSZ and yttria- or scandia-stabilized zirconia powders (3YSZ, 8YSZ, 10ScSZ) are investigated by impedance spectroscopy at 800–950°C. The polarization (interfacial) resistance decreases gradually with addition of electrolyte powder in the uLSM cathode material independent of the electrolyte powder used. The interfacial resistance of the uLSM/3YSZ, uLSM/8YSZ, and uLSM/10ScSZ composite cathodes is almost the same. The interaction between uLSM and doped zirconia particles is discussed on the basis of the interfacial resistance, activation energies, and high-frequency impedance.