摘 要
　　介孔(mesoporous)材料具有高比表面積及孔洞分佈均一特性，應用相當廣泛，是近年來奈米材料科學領堿引人注目的研究領堿之一。本研究主要工作為合成介孔二氧化鈰(CeO2)及釤摻雜二氧化鈰(sm doped ceria, SDC)，應用在固態氧化物燃料電池(SOFC)陽極上。
　　本研究利用界面活性劑F127為模板，合成介孔CeO2及SDC，探討製程參數如前驅物種類、不同濃度HCl、時效(aging)溫度與時間及界面活性劑濃度對CeO2比表面積及孔洞型態之影響。並比較在不同煆燒溫度下奈米CeO2粉末與介孔CeO2粉末比表面積變化。分別利用XRD分析相結構，氮氣等溫吸/脫附曲線分析決定其介孔結構及比表面積，利用TEM觀察粉末表面型態。
　　實驗結果顯示：採用Ce(NO3)3·6H2O為前驅物，合成之CeO2粉末經BET及TEM分析，證實具有介孔結構且發現前驅物種類並不影響CeO2相結構。以Ce(NO3)3·6H2O為前驅物，在鹼性環境下所製備的CeO2粉體均為奈米顆粒，只有在酸性環境下才能合成介孔CeO2。當添加10克的1.5M HCl於30℃下時效處理7天且界面活性劑F127濃度為2.50wt％時所合成之介孔CeO2其比面積最大，為113 m2/g。
　　比較奈米CeO2 與介孔CeO2熱穩定性，發現隨煆燒溫度之提高，而奈米CeO2粉末與介孔CeO2粉末之比表面積皆下降，但介孔CeO2粉末之下降幅度遠小於奈米CeO2。經800℃煆燒2小時，介孔CeO2粉末仍有29 m2/g之比表面積，為奈米CeO2粉末的3倍之多。
　　採用介孔CeO2最佳之合成條件，合成介孔SDC。介孔SDC粉末之結晶度隨煆燒溫度之升高逐漸提高。當煆燒溫度度由300℃提高至800℃，介孔SDC之晶粒從3.7nm成長至25.7nm，但介孔結構逐漸消失，並使其比表面積由211m2/g減少至41m2/g。
　　分別利用比表面積為41 m2/g與 12 m2/g之SDC粉末研製SOFC陽極。經交流阻抗分析，發現高比表面積的SDC粉末所製作之陽極，其與電解質間之界面阻抗遠低於使用低比表面積的SDC粉末製作之陽極，尤其在操作溫度400℃時，其阻抗值分別為1479及19271Ω.cm-2, 兩者差距更大。
本研究成功利用界面活性劑F127及Ce(NO3)3·6H2O前驅物合成介孔CeO2及SDC，並將其應用於SOFC陽極上，有效降低界面阻抗。

Abstract
　　Mesoporous materials exhibit many applications due to the high surface area and uniform pore size distribution. The purpose of this study is to synthesize mesoporous CeO2 and mesoporous Sm doped ceria (SDC), for the anode of solid oxide fuel cell (SOFC).
　　Surfactant tri-block copolymer (F127) was used as the structure-directing agent for synthesis of mesoporous CeO2 and mesoporous SDC. The effects of experimental parameters, such as precursors, aging temperature and time, concentrations of HCl and tri-block copolymer (F127) on pore morphology and specific surface area of mesoporous CeO2. are determined. The specific surface area and crystallite size of nano-CeO2 and mesoporous CeO2 calcined at different temperature are evaluated. The phase structure, N2 adsorption/desorption isotherm and powder morphology are analyzed by XRD, BET and TEM.
　　From the results of BET and TEM, it is conformed that the mesoporous CeO2 can be synthesized by using Ce(NO3)3·6H2O as the precursor and the phase structure are determined as CaF2 cubic structure. The mesoporous CeO2. which was formed by adding 1.5M HCl, and aging at 30℃for 7 days the concentration of tri-block copolymer 2.50 wt％ exhibits a large specific surface area of 113 m2/g. The specific surface area of both nano-CeO2 and mesoporous CeO2 powders decreases with the calcined temperature increasing, however the decrease of specific surface area for the mesoporous CeO2 powder is much lower than that of nano-CeO2 powder for 3 times as calcined at 800℃.
　　The crystallite size of mesoporous SDC powder increases from 3.7 nm to 25.7 nm but the specific surface area decreases from 211 m2/g to 41 m2/g as the calcined temperature increases from 300℃ to 800℃.
　　The powders with high specific surface area (41 m2/g ) and low specific surface area (41 m2/g ) SDC powders were used as anode of SOFC respectively. From the AC impedance results, it is found that the impedance of SOFC anode which was prepared from high specific surface area (41 m2/g) SDC powder is much lower than that prepared from lower specific surface area (12 m2/g) one during 400℃ to 650℃.

參考文獻
1. M. Grätzel, “Ultrafast colour displays ”, Nature, 409, 575 (2001).
2. H. Verweij, “Nanocrystalline and nanoporous ceramics ” , Adv. Mater, 17, 1483 (1998).
3. M. Itoh, H. Hattori and K. Tanabe, “Catalytic sites on SnO2 and TiO2-SnO2 for the isomerzation of 1-Butene”, J. Catal., 43, 192 (1976).
4. A. Camanzi and G. Sberveglierri, U. S. patent 5, 185, 130 (1993).
5. S. S. Park and J. D. Mackenzie, “Thickness and microstructure effects on alcohol sensing of tin oxide thin films”, Thin Solid Films, 274, 154 (1996).
6. K. Langer, E. Mutschler, G. Lambrecht, D. Mayer, G. Troschau, F. Stieneker and J. kreuter, “Methylmethacrylate sulfopropylmethacrylate copolymer nanoparticles for drug delivery part Ⅲ: evaluation as drug delivery system for ophthalmic application”, International Journal of Pharmaceutics, 158, 219 (1997).
7. B. C. H. Steele, “Running on natural gas”, Nature, 400, 619 (1999).
8. E. P. Murray, T. Tsai and S. A. Barnett, “A direct-methane fuel cellwith a ceria-based anode”, Nature, 400, 649 (1999).
9. L. A. Chick, L. R. Pederson and G. J. Exarhos, “Glycine-nitrate combustion synehesis of oxide ceramic powder”, Materials Letters, 10, 6 (1990).
10. C. T. Kresge, M. J. Roth, J. C. Vartuli, and J. S. Beck, “Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism”, Nature, 359, 22 (1992).
11. J. S. Beck, J. C. Vartuli, W. J. Roth, M. E. Leonowicz,. C.T. Kresge, K. D. Schmitt, C. T. W. Chu, D. H. Olson, E. W. Sheppard, S. B. Higgins, and J. L. Schlenker, “A new family of mesoporous molecular sieves prepared with liquid crystal templates”, J. Am. Chem. Soc., 114, 10834 (1992).
12. F. Schüth, “Non-siliceous mesostructured and mesoporous materials”, Chem. Mater. 13, 3184 (2001).
13. A. Stein, “Advances in microporous and mesoporous solids-highlights of recent progress”, Adv. Mater, 15, 763 (2003).
14 J. Y. Ying, C. P. Mehnert and M. S. Wong, “ Synthesis and applications of supramolecular-templated mesoporous materials”, Angew. Chem. Int. Ed. 38, 56 (1999).
15. F. Schüth and W. Schmidt, “Microporous and mesoporous materials”, Adv. Mater, 14, 629 (2002).
16. X. He and D. Antonelli, “Recent advances in synthesis and applications of transition metal containing mesoporous molecular sieves”, Angew. Chem. Int. Ed. 41, 214 (2002).
17. P. Yang, D. Zhao and D. I. Margoless, “Generalized syntheses of large-pore mesoporous metal oxides with semicrystalline frameworks”, Nature, 396, 152 (1998).
18 P. Yang, D. Zhao, D. I. Margolese, B. F. Chmelka, and G. D. Stucky, “Block copolymer templating syntheses of mesoporous metal oxides with large ordering lengths and semicrystalline framework”, Chem. Mater. 11, 2813 (1999).
19. W.J. Ward, “Molecular sieve catalysts”, in applied industrial catalysis, Academic press, New York, p.11 (1984).
20. S. Bhatia, “Zeolite catalysis principles and application”, CRC press, Floridr, p.7(1990).
21 IUPAC Manual of Symbols and Terminology, Appendix 2, Part I, Colloid and surface chemistry, Pure Appl. Chem., 31, 578 (1972).
22. C. G. Wu and T. Bein, “Conducting polyaniline filaments in a mesoporous channel host”, Science, 266, 1757 (1994).
23. C. G. Wu and T. Bein, “Polyaniline wires in oxidant-containing mesoporous channel hosts ”, Chem. Mater. , 6, 1109 (1994).
24. D. Zhao, J. Feng, Q. Huo, N. Melosh, G. H. Fredrickson, B. F. Chmelka and G. D. Stucky, “Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 Å pores”, Science, 279, 548 (1998).
25. M. J. Maclachlan, N. Coombs and G. A. Ozin, “Non-aqueous supramolecular assembly of mesostructured metal germanium sulphides from (Ge4S10)4- clusters”, Nature, 397, 681 (1999).
26 T. F. Todros, “Surfactant”, Academic Press, London, p.46 (1984).
27. D. F. Evans and H. Wennerstrom, “The colloidal domain: where Physics, chemistry, biology, and technology meet”, VCH Publisher, New York, P.84 (1994).
28. B. Lindmanm and H. Wennerstrom, “Micelles: amphiphile aggregation in aqueous solution, springer-verlag”, Heidelberg, p.6 (1980).
29. A. A G. J. de. Soler-Illia, C. Sanchez, B. dicte Lebeau, and J. Patarin, “Chemical strategies to design textured materials: from microporous and mesoporous oxides to nanonetworks and hierarchical structures”, Chem. Rev., 102, 4093 (2002).
30. D. M. Antonelli, A. Nakahira and J. Y. Ying, “Ligand-assisted liquidcrystal templating in mesoporous niobium oxide molecular sieves”, Inorg. Chem., 35, 3126 (1996).
31. W. Hammond, E. Prouzet, S. D. Mahanti and T. J. Pinnavaia, “Structure factor for the periodic walls of mesoporous MCM-41 molecular sieves”, Microporous and Mesoporous Materials, 27, 19 (1999).
32. S. Brunauer, L. S. Deming, W. S. Deming and E. T. Teller, “On a theory of the van der waals adsorption of gases”, J. Am. Chem. Soc., 62, 1723 (1940).
33. G. Ertl, H. Knozinger and J. Weitkamp, “Handbook of Heterogeneous Catalysis”, vol 3,VCHD-69451 Weinheim, p.1508 (1997).
34. N. B. Kirk and J. V. Wood, “The effect of the calcinations process on the crystallite shape of sol-gel cerium oxide used for glass polishing”, j. Mater. Sci. , 30, 2171 (1995)
35. H. K. Varma, P. Mukundan, K. G. K. Warrier and A. D. Damodaram, “Flash combustion synthesis of cerium oxide” , J. Mater. Sci. Lett, 9, 377 (1990).
36. T. V. Mani, H.K. Varma, A. D. Damodaran and K. G. K Warrier, “Sol-spray technique for fine-graines ceria particles”, Ceram. Int., 19, 125 (1993).
37. T. Yamaguchi, N. Ikeda and K. Tanabe, “Surface and Catalytic properties of cerium oxide”, J. Catal., 67,324 (1981).
38. B. Ailen, W. P. Hsu and E. Matijevic, “Preparation and properties of monodispersed colloidal particles of lanthanide compounds： Ⅲ, yttrium(Ⅲ) and mixed yttrium(Ⅲ)/cerium(Ⅲ) systems”, J. Am. Ceram. Soc, 71, 845 (1988).
39. Y. C. Zhou and M. N. Rahaman, “Effect of redox reaction on the sintering behavior of cerium oxide”, Acta Mater, 45, 3635 (1997).
40. 陳德源， “添加劑對LaGaO3 系及LaAlO3系離子導體晶體構與導電性影響之研究” , 國立成功大學材料科學及工程學系碩士論文， p6. (2000).
41. A. V. Virkar and K. Z. Fung, U. S. Patent, No. 5,183,801 (1993).
42. H. Inaba and H. Tagawa, “Ceria-based solid electrolytes”, Solid State Ionics, 83, 1 (1996).
43. Z. Peng, K. A. Mahone and M. Liu, “Preparation of mesoporous La0.85Sr0.15MnO3 using a as surfactant-templated sol-ggel process”, J. Mater. Sci. Letter, 19, 1473 (2000).
44. F. Chen and M. Liu, “Preparation of mesoporous yttria stabilized zirconia (YSZ) and YSZ-NiO using triblock copolymer as surfactant”, J. Mater. Chem., 10, 2603 (2000).
45. F. Chen, C. Xia and M. Liu, “Preparation of order mesoporous Sr0.5Sm0.5CoO3 as cathode for solid oxide fuel cell”, Chem. Letter, 1032 (2001).
46. M. Mamak, N. Coombs and G. Ozin, “Self-assembling solid oxide fuel cell materials: mesoporous yttria-zirconia and metal-yttria-zirconia solid solutions” , J. Am. Chem. Soc., 122, 8932 (2000).
47. M. Mamak, N. Coombs and G. Ozin, “mesoporous yttria zirconia and metal yttria zirconia solid solutions for fuel cells” , Adv. Mater., 12, 198; (2000).
48. M. Mamak, N. Coombs and G. Ozin, “mesoporous nickel-yttria-zirconia fuel cell materials”, Chem. Mater., 3, 3564 (2001).
49. M. Mamak, N. Coombs and G. Ozin, “Electroactive mesoporous yttria stabilized zirconia containing platinum or nickel oxide nanoclusters: a new class of solid oxide fuel cell electrode materials”, Adv. Funct. Mater., 11, 59 (2001).
50. M. Mamak, N. Coombs and G. Ozin, “Practical solid oxide fuel cells with anodes derived from self-assembled mesoporous-NiO-YSZ”, Chem. Commun., 2300 ( 2002)..
51. M. Mamak, G. S. M. traux, S. Petrov, N. Coombs, G. Ozin, and M. A. Green , “Lanthanum strontium manganite/yttria-stabilized zirconia nanocomposites derived from a surfactant assisted, Co-assembled mesoporous phase” J. Am. Chem. Soc., .125, 5161 (2003).
52. 廖聖茹，黃依蘋，林仁章，黃瑞呈，“多孔性奈米材料比面積/孔隙度檢測技術”，工業材料, 190期，p.115 (2002).
53. D. Zhao, Q. Huo, J. Feng, F. Chmelka and D. Stucky, “Nonionic triblock and star diblock copolymer and oligomeric surfactant syntheses of highly ordered, hydrothermally stable, mesoporous silica structures”, J. Am. Chem. Soc., 120, 6024 (1998).
54. P. C. A. Alberius, K. L. Frindell, R. C. Hayward, E. J. Kramer, D. Stucky and B. F. Chmelka,“General predictive syntheses of cubic, hexagonal, and lamellar silica and titania mesostructured thin films”, Chem. Mater., 14, 3284 (2002).
55. Q. Huo, D. I. Margolese, U. Ciesla, D. G. Demuth, P. Feng, T. E. Gier, P. Sieger, A. Firouzi, B. F. Chmelka, F. Schüth and D. Stucky, “Organization of organic molecules with inorganic molecular species into nanocomposite biphase arrays”, Chem. Mater, 6, 1176 (1994).
56. A. C. Voegtlin, A. Matijasic, J. Partarin, C. Sauerland, Y. Grillet and L. Huve, “Room-temperature synthesis of silicate mesoporous MCM-41-type materials: Influence of the synthesis pH on the porosity of the materials obtained”, Microporous. Materials, 10, 137 (1997).
57. H. P. Lin, S. Cheng and C. Y. Mou, “Effect of delayed neutralization on the synthesis of mesoporous MCM-41 molecular sieves”, Microporous. Materials, 10, 111 (1997).
58. Y. Sakamoto, M. Kaneda, O. Terasaki,. D. Zhao, J. M. Kim, D. Stucky, H. J. Shim,.and R Ryoo, “Direct imaging of the pores and cages of three-dimensional mesoporous materials”, Nature, 408, 449 (2000).
59. M. Kruk, and M. Jaroniec, “Gas adsorption characterization of ordered organic-inorganic nanocomposite materials”, Chem. Mater., 13, 3169 ( 2001).
60. D. M. Antonelli and J. Y. Ying, “Synthesis of hexagonally packed mesoporous TiO2 by a modified sol-gel method”, Angew. Chem. Int. Ed. Engl., 34, 2014 (1995).
61. Q. Huo, I. M. David, C. Ulrike, F. Schüth and D. Stucky, “Generalized synthesis of periodic surfactant/inorganic composite materials”, Nature , 368, 317 (1994).
62. P. T Tanev and T. J Pinnavaia,“A neutral templating route to mesoporous molecular sieves”, Science , 267, 865 (1995).
63. D. M. Antonelli, and J. Y. Ying, “Synthesis and characterization of hexagonal packed mesoporous tantalum oxide molecular sieves”, Chem. Mater., 8, 874 (1996).
64. Q. Huo, D. I. Margolese and D. Stucky, “Surfactant control of phases in the synthesis of mesoporous silica-based materials”, Chem. Mater., 8, 1147 (1996).
65. C. F. Cheng, W. Zhoug and J. Klinowski, “The role of surfactant micelles in the synthesis of the mesoporous molecular sieve MCM-41”, Langmuir, 11, 2815 (1995).