SrFe_(0.6)Cu_(0.3)Ti_(0.1)O_(3-δ)混合导体透氧材料的稳定性

摘要

利用柠檬酸络合法制备了SrFe(Cu,Ti)O_(3-δ)混合导体透氧材料. 采用XRD、O_2-TPD、H_2-TPR、SEM等测试技术考察了材料的稳定性. 结果表明,SrFe_(0.7)Cu_(0.3)O_(3-δ)在低氧压下会发生相分解,产生SrCuO__2杂相,而掺杂Ti后的SrFe_(0.6)Cu_(0.3)Ti_(0.1)O_(3-δ)在低氧压下保持单一的钙钛矿结构. H_2-TPR和O_2-TPD的测试表明,Ti~(4+)的掺杂提高了材料的氧脱附起始温度和其它金属离子的还原温度. SrFe_(0.6)Cu_(0.3)Ti_(0.1)O_(3-δ)膜在透氧过程中,会有Cu~(2+)和Sr~(2+)从钙钛矿结构中析出,在原晶粒边界形成新的小晶粒,但这种轻微的组分偏析没有影响到材料的透氧量,此透氧膜在66 h的操作过程中显示了良好的稳定性.%SrFe(Cu,Ti) O_(3-δ) mixed conducting membrane materials were synthesized by citric acid complexing method. The stabilities of the materials were studied by means of XRD, O_2-TPD, H_2-TPR and SEM. It was found that phase decomposition occurred in SrFe_(0.7)Cu_(0.3)O_(3-δ) under a low oxygen partial pressure and a minor phase SrCuO_2 was formed. The addition of Ti~(4+) greatly enhanced the structure stability of the material, and SrFe_(0.6) Cu_(0.3) Ti_(0.1) O_(3-δ) maintained single-phased perovskite structure. H_2-TPR and O_2-TPD results showed that the addition of Ti~(4+) increased the initial oxygen desorption temperature of the material, and the reduction temperature of the other metal ions. Slight phase decomposition was found on the He-side surface of SrFe_(0.6)Cu_(0.3)Ti_(0.1)O_(3-δ) membrane after oxygen permeating test and fresh small grains congregated at the boundary of the initial grains. SrFe_(0.6)Cu_(0.3)Ti_(0.1)O_(3-δ) exhibits a high stability during 66 h oxygen permeating process.