本文關(guān)鍵詞： 鈣鈦礦型陶瓷透氧膜 Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) 表面改性 Co_3O_4納米顆粒催化劑 BaFe_(1-y)Pr_yO_(3-δ)材料 陶瓷玻璃封接材料　出處：《合肥工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：鈣鈦礦結(jié)構(gòu)氧化物由于具有離子-電子混合電導(dǎo)特性,使其在氧傳感器、氧氣分離膜和固體氧化物燃料電池等領(lǐng)域得到了廣泛的應(yīng)用。一直以來,透氧性能和穩(wěn)定性是制約陶瓷透氧膜實際工業(yè)應(yīng)用的關(guān)鍵因素。目前提高透氧膜透氧性能的手段主要有表面修飾和降低膜厚等,而發(fā)展無Co材料可改善其穩(wěn)定性。此外,透氧膜反應(yīng)器能否長時間正常運行與封接材料的可靠性也密切相關(guān),因此發(fā)展陶瓷透氧膜密封技術(shù)也意義非凡。本論文首先以Ba_(0.5)Sr_(0.5)Co_(0.8)Fe0.2O_3-w材料為研究對象,通過表面負(fù)載Co304納米顆粒催化劑來探索其對透氧性能的影響。其次,發(fā)展了無Co透氧膜材料BaFeO_(3-δ),通過B位部分摻雜Prn+使其在低溫下保持立方相結(jié)構(gòu)。最后,研制了一種適用于透氧膜反應(yīng)器封接的陶瓷玻璃密封劑。本論文第二章在Ba_(0.5)Sr_(0.5)Co_(0.8)Fe0.2O_(3-δ)陶瓷透氧膜表面通過涂覆技術(shù)負(fù)載了一層Co_3O_4納米顆粒催化劑。XRD測試結(jié)果表明,Co_3O_4為單一的尖晶石結(jié)構(gòu)。SEM照片顯示樣品經(jīng)500 ℃熱處理后,Co_3O_4顆粒大小約為100nm且修飾層厚度約為20 μm。透氧率測試結(jié)果表明表面負(fù)載Co_3O_4納米顆粒催化劑顯著提升了Ba_(0.5)Sr_(0.5)Co_(0.8)Fe0.203-5透氧膜的透氧性能。當(dāng)測試溫度為600℃時,表面修飾前后透氧膜的透氧率分別為0.1080和0.4302 ml·cm~(-2)·min~(-1),此外,在600～800 ℃范圍內(nèi),透氧膜的表觀活化能從修飾前的91.42 kJ·mol-1降低至50.71 kJ·mol-1。本論文第三章通過固相法合成了 BaFe1-yPryO_(3-δ)粉體。XRD測試結(jié)果表明,BaFeO_(3-δ)和BaFe_(0.975)Pr_(0.025)O_(3-δ)在室溫下分別為六方相和三斜相,其余粉體為立方相,證明摻雜Prn+有利于材料的在低溫下保持立方相。燒結(jié)體試樣的電導(dǎo)率和透氧率都隨著摻雜量的增加而增加,當(dāng)摻雜量y=0.1時,兩者可分別達(dá)到6.5 S·cm~(-1)和1.112 ml·cm~(-2)·min~(-1)。BaFe_(0.975)Pr_(0.025)O_(3-δ)的高溫XRD測試結(jié)果表明粉體隨著溫度升高由三斜相逐漸向立方相轉(zhuǎn)變,到700 ℃時完全轉(zhuǎn)變?yōu)榱⒎较?這使得該材料在此溫度附近的透氧率突然增加。本論文第四章研制了一種適用于透氧膜器件封接的陶瓷玻璃密封劑。陶瓷粉和玻璃粉按不同比例球磨得到總體粒度約為1μm的復(fù)合粉體,通過與有機(jī)載體混合后制得陶瓷玻璃密封膠。XRD測試結(jié)果表明封接材料經(jīng)高溫處理后有相結(jié)構(gòu)的轉(zhuǎn)變,但陶瓷/玻璃質(zhì)量比為6:4的封接材料相對比較穩(wěn)定。在200～800℃范圍內(nèi)該種封接材料的熱膨脹系數(shù)為9.54×10-6 K~(-1),從400 ℃升高到800 ℃,電阻率從1.13×106 Ω·cm降低到6.85×105 Ω·cm。透氧膜器件的氣體泄漏率在600和800 ℃的測試溫度下分別為0.0165和0.0075 ml·cm~(-2)·min~(-1)。
[Abstract]:Perovskite oxides have been widely used in oxygen sensors, oxygen separation membranes and solid oxide fuel cells due to their ionic and electronic conductivity. Oxygen permeability and stability are the key factors restricting the practical industrial application of ceramic oxygen permeable membranes. At present, the main methods to improve the oxygen permeability of ceramic oxygen permeable membranes are surface modification and reduction of film thickness, while the development of Co-free materials can improve their stability. Whether oxygen permeable membrane reactor can run normally for a long time is closely related to the reliability of sealing material, so it is very important to develop ceramic oxygen permeable membrane sealing technology. The effect of surface supported Co304 nanoparticles on oxygen permeability was investigated. Secondly, the Co free oxygen permeable membrane material BaFeO- 未 was developed, and the cubic phase structure was maintained at low temperature by partially doped Prn at position B. A ceramic glass sealant suitable for sealing oxygen permeable membrane reactor has been developed. In the second chapter of this thesis, a layer of Co_3O_4 nanoparticle catalyst. The spinel structure. SEM photos showed that the particle size of Cos _ 3O _ 4 was about 100nm and the thickness of modified layer was about 20 渭 m after heat treatment at 500 鈩，

本文編號：1521151