Sm(Nd) doped ceria materials for multifunctional application

• Published in: Ceramics international 2021-08, Vol.47 (15), p.22201-22208
• Main Authors: Zagaynov, Igor V., Shelepin, Ivan V., Fedorov, Sergey V., Naumkin, Alexander V., Bykov, Alexey V., Konovalov, Anatoly A.
• Format: Article
• Language: English
• Subjects: Ceria; CO oxidation; Electrolyte; Solid solution
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2021.04.243

Ceria based solid solution doped by Cu, Mn, Sm(Nd) were synthesized by the co-precipitation method, followed by calcination at the temperature of 500°С. It was shown that all obtained powders of solid solutions crystallized into a cubic structure of the fluorite type, with an average particle size of 4–10 nm. However, such complex solid solutions were only stable up to 1050 °C. The characterization results revealed that solid solutions had significantly enhanced surface area, increased oxygen mobility and higher quantity of oxygen vacancies. The catalytic activity of the samples in the oxidation of CO was determined by the flow method at atmospheric pressure. The system containing neodymium was more active than the one containing samarium: Cu0.08Mn0.02Sm0.05Ce0.85O2-δ (Т100% = 180 °C) and Cu0.08Mn0.02Nd0.05Ce0.85O2-δ (Т100% = 130 °C). These materials were tested as a potential low-cost solid electrolyte for application in solid oxide fuel cells operating at intermediate temperature (IT-SOFC). The highest conductivity for intermediate temperature application (σ600°C = 4·10−3 S/cm) was found in system Cu0.08Mn0.02Sm0.05Zr0.1Ce0.75O2-δ: the system with zirconium makes it possible to stabilize the ceria lattice during high-temperature sintering, thereby increasing the electrical conductivity. The detailed study of the composition effect on both the structural properties and the textural and surface properties in Cu0.08Mn0.02Sm(Nd)xCe0.9-xO2-δ oxides was carried out in this work.