Effect of A-/B-site Doping on Oxygen Non-Stoichiometry, Structure characteristics, and O2 Releasing Behavior of La1−xCaxCo1−yFeyO3−δ Perovskites

Abstract

Oxy-fuel combustion is one of the proposed technologies with the potential to achieve zero CO 2 emission. La 1−x Ca x Co 1−y Fe y O 3−δ (LCCF) perovskites are promising materials with high selectively for oxygen. In this study, the oxygen non-stoichiometry of perovskites LCCF was investigated by means of iodometric titration. LCCF was prepared using the liquid citrate method, and the phase structures were identified by X-ray diffraction. Fixed-bed experiments were performed to study the oxygen desorption performance of LCCF. The oxygen deficiency of LCCF increased with increasing Ca molar content of A site, but the value of δ of LCCF with increasing Fe molar content in B site is nearly constant. Experimental observation demonstrated that the O 2 release amount of LCCF does not depend on oxygen non-stoichiometry δ generated from A-site doping. At the same time, doping Fe in B site has an obvious impact on the oxygen desorption amount.

Crystal structure, cobalt and iron speciation and oxygen non-stoichiometry of La0.6Sr0.4Co1-yFeyO3-δ nanorods for IT-SOFC cathodes

“…Figure7shows d as a function of Fe content in the B site of the perovskite-type structure, showing a decreasing trend. The same behavior has been reported by other authors in similar materials, which can be attributed to the fact that Co on the B site has a smaller binding energy for oxygen compared to Fe[23,24,25]. This is probably related…”

Controlling phase transformation of La/Ni oxides by switching annealing conditions and their resultant pseudocapacitive behaviour

“…There was negligible color change in LNON phase materials (no color change even upon addition of starch) and in contrast, LNOA phase materials exhibited a significant color change to dark brown confirming the liberation of I 2 . The room temperature oxygen vacancies for the LNOA phase materials are plotted against the temperature (shown in figure 4(c)) [26]. The δ values increase with a rise in annealing temperatures.…”