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, YBaCo 2 O 6−x , Dy 0.5 Y 0.5 BaCo 2 O 6−x and DyBaCo 2 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 DyBaCo 2 O 6−x. Interestingly, DyBaCo 2 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 DyBaCo 2 O 6−x has also been analyzed. For this, DyBaCo 2 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 DyBaCo 2 O 6−x .