Rare earth barium cobaltites: potential candidates for low-temperature oxygen separation

Abstract

Oxygen storage materials with low operating temperatures have gained attraction in oxygen separation and enrichment applications. Herein, $$\hbox {YBaCo}_{2}\hbox {O}_{6-x}$$ , $$\hbox {Dy}_{0.5}\hbox {Y}_{0.5} \hbox {BaCo}_{2}\hbox {O}_{6-x}$$ and $$\hbox {DyBaCo}_{2}\hbox {O}_{6-x}$$ are explored for low-temperature oxygen enrichment. These oxides were synthesized through solid-state reaction and the oxygen separation properties at various temperatures were studied using a home-built volumetric setup. The oxygen intake temperatures of the sample were found to vary depending upon the rare-earth cation size. The lowest absorption temperature of 523 K was observed for $$\hbox {DyBaCo}_{2}\hbox {O}_{6-x}$$ . Interestingly, $$\hbox {DyBaCo}_{2}\hbox {O}_{6-x}$$ had the largest saddle point radii through which oxide ion migration occurs. The effect of the synthesis method and microstructure on the oxygen holding capacity of $$\hbox {DyBaCo}_{2}\hbox {O}_{6-x}$$ has also been analyzed. For this, $$\hbox {DyBaCo}_{2}\hbox {O}_{6-x}$$ was synthesized through a combination of solution combustion synthesis followed by calcination and sintering at different temperatures. The particle size was found to have a profound effect on the oxygen intake of $$\hbox {DyBaCo}_{2} \hbox {O}_{6-x}$$ .