添加劑對BaCeO3系質子導體導電率及穩定性之影響

本研究目的在探討陽離子摻雜對BaCeO3系質子導體導電率與相穩定性之影響。實驗採用固相反應法製備Ba1-xNxCe1-yMyO3-δ(N=Sr,M=Y, Sm)。以Y3+與Sm3+取代B位置，結果顯示：各成份導電率皆隨著溫度上升而增加，且以BaCe0.8Y0.2O3-δ導電率最高，於750 ℃、3 RH% (relative humidity)空氣下為0.026 S/cm；相較於BaCe1-ySmyO3-δ (0.019 S/cm)高出36.8 %。在750 ℃、3 RH % CO2環境下，BaCe0.8Y0.2O3-δ導電率為0.025 S/cm，與在3 RH%空氣下比較，其導電率下降了3.8 %。發現經過CO2環境處理後之BaCe1-yYyO3-δ，皆產生BaCO3與CeO2雜相，代表BaCe0.8Y0.2O3-δ已與CO2反應。在A位置摻雜對BaxCe1-ySmyO3-δ導電率影響方面，雖可製備 BaxCe1-ySmyO3-δ純相，但不論Ba2+離子增加或減少皆無法增加導電率。在相穩定性方面，BaCe0.8Y0.2O3-δ優於BaCe0.8Sm0.2O3-δ，在80 ℃水氣環境處理4小時後僅有微量Ba(OH)2相產生。為了進一步增加Ba1-xNxCe1-yMyO3-δ穩定性，採用Sr2+取代Ba2+之方法。Ba0.9Sr0.1Ce0.8Y0.2O3-δ導電率在750 ℃、3 RH%空氣下，其導電度為0.023 S/cm，相較於BaCe0.8Y0.2O3-δ下降9.7 %。雖然摻雜Sr2+會使得導電率下降，但相穩定性明顯增加，在80 ℃水氣環境處理8小時後依然維持Ba0.9Sr0.1Ce0.8Y0.2O3-δ純相。另外本研究亦探討粒徑大小對導電率之影響。利用Modified Pechini process可成功製備BaCe0.8Y0.2O3-δ奈米粉末，於900 ℃煆燒之粉體粒徑大小約為80 nm，導電率為0.025 S/cm，與固相反應法製備之微米BaCe0.8Y0.2O3-δ相當，並未明顯增加導電率。

關鍵字

固態氧化物燃料電池電解質；質子導體； BaCeO3

並列摘要

The aim of this study was to investigate the influence of cation doped on conductivity and phase stability of BaCeO3-based proton conductors. Ba1-xNxCe1-yMyO3-δ (N=Sr, M=Y, Sm) were prepared by solid state reaction. For Y3+ and Sm3+ doped, BaCe0.8Y0.2O3-δ had the highest conductivity of 0.026 S/cm and higher 36.8 % than BaCe0.8Sm0.2O3-δ (0.019 S/cm) at 750 ℃ in 3 RH% (relative humidity) air atmosphere. The conductivity of BaCe0.8Y0.2O3-δ was 0.025 S/cm at 750 ℃ in 3 RH% CO2 environment which was lower 3.8 % than that at in 750 ℃ 3 RH% atmosphere. was produced BaCO3 and CeO2 impure phase after CO2 environment treatment in BaCe1-yYyO3-δ system, which meant BaCe1-yYyO3-δ reacted with CO2. Although pure BaxCe0.8Sm0.2O3-δ phase can be could prepare, they did not increase the conductivities in A site defect of BaCeO3-based proton conductors. The phase stability of BaCe0.8Y0.2O3-δ was better than BaCe0.8Sm0.2O3-δ. In this work, Sr2+ was doped in order to increase the phase stability of Ba1-xNxCe1-yMyO3-δ. Although the conductivity of Ba0.9Sr0.1Ce0.8Y0.2O3-δ was 0.023 S/cm at 750 ℃ in 3 RH% atmosphere which was lower 9.7 % than BaCe0.8Y0.2O3-δ, however, the phase stability of Ba0.9Sr0.1Ce0.8Y0.2O3-δ was much better than that of BaCe0.8Y0.2O3-δ. Nano BaCe0.8Y0.2O3-δ particle was prepared by modified Pehicni process with the particle size was about 80 nm. The conductivity was 0.025 S/cm which is similar to BaCe0.8Y0.2O3-δ prepared by solid state reaction.

並列關鍵字

SOFC electrolyte ； proton conductor ； BaCeO3

參考文獻

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添加劑對BaCeO3系質子導體導電率及穩定性之影響

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