Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
63824 | Journal of Energy Chemistry | 2015 | 8 Pages |
A series of oxygen permeable dual-phase composite oxides 60 wt% Ce0.8Gd0.2O2–δ-40 wt% LnBaCo2O5+δ (CGO-LBCO, Ln = La, Pr, Nd, Sm, Gd and Y) were synthesized through a sol-gel route and effects of the Ln3+ cations on their phase structure, oxygen permeability and chemical stability against CO2 were investigated systemically by XRD, SEM, TG-DSC and oxygen permeation experiments. XRD patterns reveal that the larger Ln3+ cations (La3+, Pr3+ and Nd3+) successfully stabilized the double-layered perovskite structure of sintered LBCO, while the smaller ones (Sm3+, Gd3+, and Y3+) resulted in the partial decomposition of LBCO with some impurities formed. CGO-PBCO yields the highest oxygen permeation flux, reaching 2.8×10−7 mol·s−1·cm−2 at 925 °C with 1 mm thickness under air/He gradient. The TG-DSC profiles in 20 mol% CO2/N2 and oxygen permeability experiments with CO2 as sweep gas show that CGO-YBCO demonstrates the best chemical stability against CO2, possibly due to its minimum basicity. The stable oxygen permeation flux of CGO-YBCO under CO2 atmosphere reveals its potential application in the oxy-fuel combustion route for CO2 capture.
The time dependence of oxygen permeation fluxes through 1 mm CGO-LBCO membranes with different concentration of CO2/He mixture gases as sweep gases at 925 °C.Figure optionsDownload full-size imageDownload as PowerPoint slide