La0.15Sr0.85Ga0.3Fe0.7O3-δ(LSGFO) and La0.15Sr0.85Co0.3Fe0.7O3-δ(LSCFO) mixed oxygen-ion and electron conducting oxides were synthesized by using a combined EDTA and citrate complexing method, and the corresponding ...La0.15Sr0.85Ga0.3Fe0.7O3-δ(LSGFO) and La0.15Sr0.85Co0.3Fe0.7O3-δ(LSCFO) mixed oxygen-ion and electron conducting oxides were synthesized by using a combined EDTA and citrate complexing method, and the corresponding dense membranes were fabricated. The properties of the oxide powders and membranes were characterized with combined SEM, XRD, H2-TPR, O2-TPD techniques, mechanical strength and oxygen permeation measurement. The results showed that LSGFO had much higher thermochemical stability than LSCFO due to the higher valence stability of Ga3+. After the temperature-programmed reduction by 5% H2 in Ar from 20℃to 1020℃, the basic perovskite structure of LSGFO was successfully preserved. LSGFO also favors the oxygen vacancy formation better than LSCFO. Oxygen permeation measurement demonstrated that LSGFO had higher oxygen permeation flux than LSCFO, but they had similar activation energy for oxygen transportation, with a value of 110 and 117 kJ ?mol^(-1), respectively. The difference in oxygen permeation展开更多
SrxBi1-xFeO3- (SBF) series mixed conductors were synthesized using Standard ceramic method. The properties of such materials were characterized by XRD, O2-TPD techniques. Ab-normal crystal phenomena were found and exp...SrxBi1-xFeO3- (SBF) series mixed conductors were synthesized using Standard ceramic method. The properties of such materials were characterized by XRD, O2-TPD techniques. Ab-normal crystal phenomena were found and explained and correlated with the oxygen permeation results. By analysis of the critical radius (rc), the degree of openness of the lattice (Fv) and the average metal-oxygen bonding energy of the perovskite lattice (ABE), it was proposed that the oxygen permeation flux is determined mainly by the oxygen diffusion rate in bulk when 1-x≤0.5, and by the concentration of oxygen vacancy when 1-x≥ 0.5. The stability of Sr0.5Bi0.5FeO3- was also investigated, and the high stability of it was attributed to the stable BO6 octahedra.展开更多
基金Supported by the National Natural Science Funds for Distinguished Young Scholars of China (20725313)the National Basic Research Program of China (973 Program,2005CB221404)
基金Acknowledgements This work was supported by the National Natural Science Foundation of China (Grant No. 59789201), the National Advanced Materials Committee of China (Grant No. 715-006-0122) and the Ministry of Science and Technology, China (Grant No. G1
文摘La0.15Sr0.85Ga0.3Fe0.7O3-δ(LSGFO) and La0.15Sr0.85Co0.3Fe0.7O3-δ(LSCFO) mixed oxygen-ion and electron conducting oxides were synthesized by using a combined EDTA and citrate complexing method, and the corresponding dense membranes were fabricated. The properties of the oxide powders and membranes were characterized with combined SEM, XRD, H2-TPR, O2-TPD techniques, mechanical strength and oxygen permeation measurement. The results showed that LSGFO had much higher thermochemical stability than LSCFO due to the higher valence stability of Ga3+. After the temperature-programmed reduction by 5% H2 in Ar from 20℃to 1020℃, the basic perovskite structure of LSGFO was successfully preserved. LSGFO also favors the oxygen vacancy formation better than LSCFO. Oxygen permeation measurement demonstrated that LSGFO had higher oxygen permeation flux than LSCFO, but they had similar activation energy for oxygen transportation, with a value of 110 and 117 kJ ?mol^(-1), respectively. The difference in oxygen permeation
文摘SrxBi1-xFeO3- (SBF) series mixed conductors were synthesized using Standard ceramic method. The properties of such materials were characterized by XRD, O2-TPD techniques. Ab-normal crystal phenomena were found and explained and correlated with the oxygen permeation results. By analysis of the critical radius (rc), the degree of openness of the lattice (Fv) and the average metal-oxygen bonding energy of the perovskite lattice (ABE), it was proposed that the oxygen permeation flux is determined mainly by the oxygen diffusion rate in bulk when 1-x≤0.5, and by the concentration of oxygen vacancy when 1-x≥ 0.5. The stability of Sr0.5Bi0.5FeO3- was also investigated, and the high stability of it was attributed to the stable BO6 octahedra.
