Perovskite-type (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) oxides: structural stability, oxygen nonstoichiometry, and oxygen sorption/desorption properties

The perovskite-type Ba- and Ti/Nb-doped (Ba 0.15 Sr 0.85 )(B 0.15 Co 0.85 )O 3 − δ (B = Ti, Nb) oxides were synthesized successfully by the solid-state reaction method. Crystal structure, elemental compositions, and oxygen nonstoichiometry of the as-synthesized (Ba 0.15 Sr 0.85 )(B 0.15 Co 0.85 )O 3 − δ (B = Ti, Nb) oxides were investigated by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), inductively coupled plasma (ICP)-atomic emission spectrometry, thermogravimetry (TG), and iodometric titration. XRD results demonstrate that the as-obtained (Ba 0.15 Sr 0.85 )(B 0.15 Co 0.85 )O 3 − δ (B = Ti, Nb) oxides possess purely cubic perovskite-type structures. The temperature-swing oxygen sorption/desorption properties of the as-synthesized (Ba 0.15 Sr 0.85 )(B 0.15 Co 0.85 )O 3 − δ (B = Ti, Nb) perovskite-type oxides were studied by the dynamic TG. Results show that the structural stability of the co-doped (Ba 0.15 Sr 0.85 )(B 0.15 Co 0.85 )O 3 − δ (B = Ti, Nb) oxides is improved greatly, and the high oxygen sorption capacity for the perovskite-type (Ba 0.15 Sr 0.85 )(B 0.15 Co 0.85 )O 3 − δ (B = Ti, Nb) oxides is also obtained between 300 and 950 °C in air.