A位置换对LnMnO_3体系氧的吸附-脱附特性影响的研究

Study on Oxygen Sorption-Desorption of A-sustitued LnMnO_3

采用醋酸盐共沉淀法合成了Ln_(1-x)Sr_xMnO_3(Ln=La,Pr,Nd,Sm,Gd;x=0,0.2,0.4,0.6,0.8,1.0)系列共26个试样,对其中17个试样通过X射线衍射(XRD)的测定证实均为钙钛矿型复合氧化物(ABO_3)结构。同时用氧的程度升温脱附(TPD)装置测定了全部试样氧的吸附—脱附特性,结果表明:Ln_(1-x)Sr_xMnO_3系列试样氧的吸附-脱附特性与La_(-x)Sr_xMnO_3相似,它们均属于阳离子空位型复合氧化物,具有与其相似的变化特点。

26 samples, Ln1-xSrxMnO3 (Ln=La,Pr,Nd,Sm,Gd; x = 0,0. 2,0.4,0.6,0.8,1.0) are prepared by the acetate co-precipitation method. By means of XRD technique, 17 of them examined are all found to be perovskite-type mixed oxides structure. Oxygen adsorp-tion-desorption behaviors are examined by TPD technique for all samples. It's found that: Similar to La1-xSrxMnO3, Ln1-xSrxMnO3 having oxygen adsorption-desorption behaviours belong to cation vacancy-type mixed oxides.