Netsu Sokutei, 44 (1), p. 9, (2017)


酸素貯蔵材料BaLnMn2O5+δ (Ln = La, Nd, Gd, Y) による酸素吸収放出反応の熱力学

Thermodynamics of Oxygen Intake/Release Reactions with Oxygen Storage Materials BaLnMn2O5+δ (Ln = La, Nd, Gd, and Y)

Here, our recent study on the oxygen-storage materials BaLnMn2O5+δ with Ln = La, Nd, Gd, and Y is reviewed. The redox characteristics of these materials were systematically investigated employing the reductive water dissolution by the deoxygenated δ = 0 form. The Ln = La, Nd, and Gd compounds were found to show a capability to produce hydrogen gas through the water dissolution at 500 oC, whereas the Ln = Y compound was unreactive to water. The present study also revealed that the reactivity significantly depends on the Ln species: the larger the Ln3+ ionic size, the higher reactivity the BaLnMn2O5.0 samples exhibit. The experimental data were discussed on the basis of thermodynamic energetics by quantum chemical calculations.