Nafion®/SBA-15質子交換複合膜之製備及其於直接甲醇燃料電池電解質之應用

Preparation of Nafion®/SBA-15 Composites as Proton Exchange Membranes and Their Applications in DMFC

王悅筑(Yueh-Chu Wang)

指導教授 ： 鄭淑芬

國立臺灣大學/理學院/化學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201603298

摘要

直接甲醇燃料電池因甲醇擁有高能量密度、不易揮發的特點而可作為可攜帶式電子產品的能量來源，此種電池的操作溫度低，也可以保持其中電解質質子交換膜的含水度。甲醇燃料電池的電解質為質子交換膜，需要將質子從陽極傳到陰極，也必須具備防止甲醇穿透的能力，才不會使電池陰極被毒化造成電壓降低以及電池壽命減短。商業化的質子交換膜Nafion® 具有高穩定性及不錯的質子傳導能力，但是其甲醇穿透度也高。為了克服甲醇穿透的問題，同時保有良好的質子傳導效果，本研究以介孔SBA-15作為Nafion質子交換膜的填充材料，使用溶劑揮發法添加介孔SBA-15材料進入Nafion®，製成複合膜。SBA-15材料的模板試劑可以當作質子的固態溶劑，也可以幫助質子傳導，因此在本研究中討論加入不同形貌的SBA-15材料、有無保留SBA-15的模板試劑、將SBA-15接上幫助質子傳導的磺酸根官能基、以及使用不同的溶劑來進行溶劑揮發對複合膜表現的影響。填充材料的性質以小角度X光繞射儀、氮氣吸脫附及掃描式電子顯微鏡來鑑定，複合膜的性質則以螺旋測微器量測其厚度、測量甲醇穿透度、質子傳導率、計算選擇率以及測量全電池表現來鑑定。

關鍵字

直接甲醇燃料電池 ； 質子交換膜 ； Nafion&reg ； SBA-15 ； 複合膜

並列摘要

Direct methanol fuel cell (DMFC) is considered a promising power supplier for various applications because of its high theoretical energy density of methanol, low emission, and moderate operation temperature. Generally, a high selective membrane with high proton conductivity and low methanol crossover is suitable for DMFC. Commercialized Nafion® exhibits high chemical stability and proton conductivity, but suffers high methanol crossover which leads to decrease of cell voltage and lifetime. In the present study, mesoporous SBA-15 silica was used as the additive of Nafion membrane. Mesoporous silica SBA-15 of different morphologies with and without surfactant are synthesized then imbedded into the Nafion® membrane by solvent-recasting procedure using N,N’-dimethylacetamide (DMAc) and 2-propanol (iPA) as the solvents. Pore directing agent of SBA-15, P123, can serve as nonaqueous proton transporter which may assist proton conductivity of composite membrane. The additive materials were characterized with powder-XRD, N2 sorption, and SEM. The characteristics of composite membranes prepared by solvent recasting procedure were examined with thickness from spiral micrometer, methanol permeability, proton conductivity, selectivity, and single cell performance test.

並列關鍵字

Direct methanol fuel cell (DMFC) ； Proton exchange membrane (PEM) ； Nafion&reg ； SBA-15 ； composite membrane

參考文獻

[67] S.-Y. Chen, L.-Y. Jang, S. Cheng, Chemistry of Materials 2004, 16, 4174-4180.

[35] C.-Y. Yen, C.-H. Lee, Y.-F. Lin, H.-L. Lin, Y.-H. Hsiao, S.-H. Liao, C.-Y. Chuang, C.-C. M. Ma, Journal of Power Sources 2007, 173, 36-44.

[47] L. Li, J. Zhang, Y. Wang, Journal of Membrane Science 2003, 226, 159-167.

[19] B. Smitha, S. Sridhar, A. A. Khan, Journal of Membrane Science 2005, 259, 10-26.

[56] S. S. Mohtar, A. F. Ismail, T. Matsuura, Journal of Membrane Science 2011, 371, 10-19.