铁掺杂浓度对Ba_(0.5)Sr_(0.5)Co_xFe(1-x)O(3-δ)混合导体膜性质的影响

Effect of Fe Content on Properties of Ba_(0.5) Sr_(0.5) Co_x Fe_(1-x) O_(3-δ) Mixed Conducting Membranes

用湿化学法合成了Ba0 .5Sr0 .5CoxFe1 xO3 δ系列混合导体透氧膜材料 ,并用XRD ,O2 TPD ,H2 TPR和透氧测定等手段考察了铁离子掺杂浓度对导体膜相结构及其稳定性、氧脱附性能和透氧能力等的影响 .在氧浓度为 2 .13× 10 4 ～ 0 .1Pa的范围内 ,x =0 .2～ 0 .8时材料保持为立方钙钛矿结构 .铁含量的增加有利于材料钙钛矿结构在低温的稳定化 ,并提高了材料的热化学稳定性 .然而 ,导体膜的透氧量却随着铁含量的增加而减小 .

Mixed oxygen ionic and electronic conducting Ba 0.5 Sr 0.5 Co x Fe 1 x O 3 δ (BSCFO) oxide powders were synthesized by using a combined EDTA citrate complexing method. The effect of Fe content on the properties of the material, such as phase structure, phase stability, thermochemical stability and oxygen permeability, were investigated with combined XRD, O 2 TPD, H 2 TPR techniques and oxygen permeation measurement. For the material under investigation ( x =0.2～0.8), they all demonstrate the pure phase of cubic perovskite structure at high temperature and within the oxygen partial pressure of 2.13×10 4～0.1 Pa. The increase in Fe content is beneficial to the phase stability of BSCFO at lower temperature. However, the oxygen permeability of the material decreases with the increase of Fe content, being likely due to the increase in surface exchange kinetics of the membrane in the rate determination of the oxygen permeation process with the increase of Fe content.