Oxygen permeability of Ce0.8Sm0.2O2 − δ–LnBaCo2O5 + δ (Ln=La, Nd, Sm, and Y) dual-phase ceramic membranes

Abstract

Ce 0.8 Sm 0.2 O 2 − δ -LnBaCo 2 O 5 + δ (SDC-LnBCO, Ln=La, Nd, Sm, and Y) composites were prepared and characterized as dense ceramic membranes for oxygen separation. Ce 0.8 Sm 0.2 O 2−δ (SDC) shows a good chemical compatibility with LaBaCo 2 O 5+δ (LBCO), NdBaCo 2 O 5+δ (NBCO), and SmBaCo 2 O 5+δ (SBCO), while a little of impurity is detected in the sample with YBaCo 2 O 5+δ (YBCO). The SDC-SBCO and SDC-YBCO samples exhibit larger grain size than SDC-LBCO and SDC-NBCO. The incorporation of SDC increases the structural stability and decreases the thermal expansion coefficient of LnBCO at high temperature. The oxygen permeation flux of SDC-LnBCO dual-phase membrane decreases with decreasing Ln 3+ radius, which is 2.57×10 −7 , 1.58×10 −7 , 8.05×10 −8 , and 7.57×10 −8 mol cm −2 s −1 at 925°C for SDC-LBCO, SDC-NBCO, SDC-SBCO, and SDC-YBCO membranes, respectively. Increasing the flow rate of feeding and sweeping gas can create oxygen partial pressure gradient, and thus, increase the oxygen permeability. These results indicate that SDC-LBCO and SDC-NBCO composites are promising candidates for oxygen permeation membrane.

Characterization of SrFe0.9‐xCuxMo0.1O3‐δ (x = 0, 0.1 and 0.2) as cathode for intermediate‐temperature solid oxide fuel cells

“…From 200 С to 1000 С, the obtained average TECs are 20.4 × 10 −6 K −1 , 21.3 × 10 −6 K −1 , and 21.8 × 10 −6 K −1 , respectively. The obtained average TEC values are lower in comparison with some reported cobalt-based and other iron-based cathode materials, such as LaBaCo 2 O 5 + δ (TEC: 27.8 × 10 −6 K −1 ),34 NdBa 0.5 Sr 0.5 Co2O 5 + δ (TEC: 26.3 × 10 −6 K −1 ),35 SrNb x Fe 1-x O 3-δ (TEC: 27.6 × 10 −6 K −1 ),…”

Novel cobalt-free BaFe1−xGdxO3−δ perovskite membranes for oxygen separation

“…The oxygen permeation properties of the considered BaFe 1Àx -Gd x O 3Àd membranes were measured by the gas chromatography method using a vertical high temperature oxygen permeation apparatus described in previous work. 44,45 Aer being polished, the as-prepared BaFe 1Àx Gd x O 3Àd membranes, with a thickness of 0.5-1.2 mm, were sealed on a quartz tube by a silver ring, with an effective inner circular area of 1.28 cm 2 . Compressed air was applied to sweep one side of the membrane as the feed gas, with a ow rate of 120 mL min À1 (STP).…”

Oxygen content and defect structure of the perovskite La0.5Ba0.5CoO3–δ

“…Depending on the synthesis method, the final annealing temperature, T, reported in the literature, varies within the fairly wide limits -from 750 [18] to 1300 °C [2]. However, the samples of La 0.5 Ba 0.5 CoO 3-δ obtained at T ≤ 850 °C are usually found to contain some impurities [8,18,19]. Hence, regardless of the synthesis method, a single-phase cubic perovskite La 0.5 Ba 0.5 CoO 3-δ can be prepared only at temperatures above 850 °C in air [16].…”