Conductivity improvement of Ce0.8Gd0：2O1.9 solid electrolyte

Solid oxide fuel cells based on doped ceria electrolytes offer operating temperatures of 600 °C. During recent years much attention was aimed at successful powder preparation with high sinter activity and high conductivity. The properties of ceria electrolyte are very sensitive to impurities introduced during powder and electrolyte fabrication. One of the most successful and commercially available processes for the production of clean powders is based on the addition of several percent metallic cations that will react with impurities and segregate into the triple points of grain boundaries. In this work the results obtained from doping of CGO20 by 2% Ca and prepared by different routes were presented. The way of introducing Ca seemed to play an important role.     

Study of Sm0.2Ce0.8O1.9 （SDC） electrolyte prepared by a simple modified solid-state method

Sm0.2Ce0.8O1.9(SDC) electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes were investigated by X-ray diffraction(XRD) and field emission scanning electron microscopy(FESEM) technologies. A relative density of SDC electrolyte sintered at 1300 oC reached 97.3% and the mean SDC grain size was about 770 nm. Their ionic conductivity and thermal expansion coefficient were also measured by electrochemical workstation and dilatometer. The electrolyte attained a high conductivity of 5×10–2 S/cm at 800 oC with an activation energy of 1.03 eV and a proper thermal expansion coefficient of 12.6×10–6 K–1.     

Synthesis of La_xK_(1–x)CoO_3 nanorod and their catalytic performances for CO oxidation

A series of Lax K1–x CoO3 nanorod oxides with perovskite structure were synthesized by sol-gel method using polyvinyl alcohol(PVA) as additive.These perovskite-type complex oxide catalysts were characterized by the techniques of X-ray diffraction(XRD),infrared(IR),Brumauer-Emmett-Teller(BET) and scanning electron microscopy(SEM).And the results showed that nanorods of La1–x Kx CoO3 perovskite-type complex oxides were fabricated by sol-gel method when the mass concentration of PVA was 4% and the calcined temperature kept at 700 ℃ for 4 h.The catalytic results of CO oxidation showed that the Lax K1–x CoO3 catalysts had high activity.LaCoO3 nanorods exposed more {110} plane than LaCoO3 nanoparticles,which was beneficial to the catalytic oxidation of CO.LaCoO3 nanorods had the best catalytic performance for the oxidation of CO.At 200 oC,the CO conversion could reach 100%.     

Ce0.8Sm0.1Gd0.1O1.9电解质的制备及其性能研究

通过凝胶浇注法制备了Sm, Gd共同掺杂的CeO2(SGC)粉末, 将制得的粉末经1400 ℃高温烧结4 h得到相应的SGC电解质烧结体, 并对SGC粉末及相应的烧结体的性能进行了表征. 实验结果表明: 凝胶浇注法制备出了Sm, Gd共同掺杂的纳米CeO2粉末;所得粉末有良好的烧结活性, 1400 ℃下烧结所得电解质材料的相对密度大于94%. 电导率的测试表明, SGC电解质材料在中温范围有较高的电导率, 800 ℃时, 其电导率达到了0.082 S·cm-1, 有望成为中温固体氧化物燃料电池的电解质材料.