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A series of oxygen permeable dual-phase composite oxides 60 wt% Ce0.8Gd0.2O2-δ-40 wt% Ln Ba Co2O5+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 2.8×10-7mol s-1 cm-2at 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.
A series of oxygen permeable dual-phase composite oxides 60 wt% Ce0.8Gd0.2O2- δ-40 wt% Ln Ba Co2O5 + δ (CGO-LBCO, Ln = La, Pr, Nd, Sm, Gd and Y) through a sol-gel route and effects of the Ln3 + cations on their phase structure, oxygen permeability and chemical stability against CO2 were investigated systematically 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 omitted formed. oxygen permeation flux, reaching 2.8 × 10-7 mol s-1 cm-2at 925 · C with 1 mm thickness under air / He gradient. The TG-DSC profiles in 20 mol% CO2 / N2 and oxygen permeability experiments experiments with CO2 as sweep gas show that CGO-YBCO demonstrates the best chemical stability against CO2, probably 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.