本篇論文以高溫與冷凍交互作用法，成功還原出具有高比表面積、高電子傳導率之三維結構氧化石墨烯(reduced Graphene Oxide, rGO)。並因為冰晶的作用下使GO在孔洞間有多層堆疊而增強其機械強度。利用微波還原法，沉積奈米顆粒於前述碳材之上，以提高觸媒承載量，利用石墨烯之材料特性提高白金觸媒高承載表面積，亦可提高觸媒分散性，目前已經可以沉積3~5奈米之白金觸媒於載體的表面及內部，且觸媒乘載量可達0.43mg/cm2。從其半電池循環伏安法性質可看出，白金氧化峰單位質量電流密度達到217.3 A/g，電化學活性面積（ECSA）達到25.87 m2/g，全電池結果在70℃之下，功率密度來到53.96 mW/cm2，此時電流密度為130.14 mA/cm2。並在增加rGO三維載體孔徑後，發現比起最小孔洞的效能提升約兩倍。未來期望利用氫氣將PtrGO電極進行熱退火，以提升電極導電性，進而提升整體全電池效能。應用於直接甲醇燃料電池中做為高效能、高反應面積、低成本之白金觸媒或多元材料觸媒。

In this paper, we successfully produced three-dimensional reduced Graphene Oxide (rGO) with high specific area and high electron conductivity by the method which combined heating and freezing, as the anode electrode for micro Direct Methanol Fuel Cells (μDMFC). And we deposit Pt catalyst on the rGO substrate by microwave reduction, which can produce 3~5 nm nanoparticles on the rGO substrate and loading weight has reached 0.43 mg/cm2. The mass current density has reached 217.3 A/g and electrochemical active surface area (ECSA) value 25.87 m2/g. The best fuel cell performance of PtrGO was 53.96 mW/cm2 for the power density and 130.14 mA/cm2 for the current density. And found that when we increase the pore size of PtrGO, the performance of power density increased 2 times with respect to the smallest pore size sample. For further experiment, the H2 annealing for the PtrGO should be operated to improve the conductivity.

[1] Y. S. Wu et al., “High efficient nanocatalysts synthesis by a semi-reflux chemical reduction system”, Proceedings of the 2010 5th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, Xiamen, China, pp. 702-705, January 20-23, 2010
[2] T. J. Yen, N. Fang, X. Zhang, G. Q. Lu, and C. Y. Wang, Appl. Phys. Lett., Vol. 83, No. 19, pp. 4056-4058, 2003.
[3] G. Q. Lu, C. Y. Wang, T. J. Yen, and X. Zhang, Electrochim. Acta , Vol. 49, pp.821-828, 2004.
[4] A. Lima, C. Coutanceau, J. -M. Leger, C. Lamy, J. Appl. Electrochem., Vol. 31, pp. 379-386, 2001.
[5] F. Gloaguen, J. M. Leger, C. Lamy, J. Appl. Electrochem., Vol. 27, pp. 1052-1060.
[6] John Wiley & Sons, Fuel Cell Systems Explained , Second Edition James Larminie and Andrew Dicks. 2003Ltd ISBN : 0-470-84857-X
[7] 黃鎮江, 燃料電池: 全華科技圖書股份有限公司, 2005.
[8] J. Larminie, A. Dicks, Fuel Cell Systems Explained, John Wiley and Sons Ltd., 2003.
[9] T. R. Ralph, M. P. Hogarth, Platinum Metals Rev., vol.3, pp. 46, 2002
[10] Y Takasu, T Fujiwara, Y Murakami, K Sasaki, M Oguri, T Asaki, and W Sugimoto, Journal of The Electrochemical Society, vol.147, pp. 4421, 2000
[11] N. M. Markovic, P. N. Ross, Surface Science Reports, vol.45, pp. 121, 2002
[12] Y Shimazaki, Y Kobayashi, S Yamada, T Miwa, M Konno, Journal of Colloid and Interface Science, vol.292, pp. 122, 2005
[13] G. S. Chai, S. B. Yoon, J. S. Yu, J. H. Choi, Y. E. Sung., “Ordered Porous Carbons with Tunable Pore Sizes as Catalyst Supports in Direct Methanol Fuel Cell”, J. Phys. Chem. B (2004), 108 , 7074-7079
[14] M. A. Scibioh, I. H. Oh, T. H. Lim, S. A. Hong, H. Y. Ha, “Investigation of various ionomer-coated carbon supports for direct methanol fuel cell applications”, Applied Catalysis B: Environmental 77 (2008) 373–385.
[15] S. Kim, H. J. Sohn, S. J. Park, “Preparation and characterization of carbon-related materials supports for catalysts of direct methanol fuel cells”, Current Applied Physics 10 (2010) 1142–1147
[16] J.R.C. Salgado, F. Alcaide, G. Alvarez, L. Calvillo, M.J. Lazaro, E. Pastor, “Pt–Ru electrocatalysts supported on ordered mesoporous carbon for direct methanol fuel cell”, Journal of Power Sources 195 (2010) 4022–4029
[17] M. C. Tsai et al., “A catalytic gas diffusion layer for improving the efficiency of a direct methanol fuel cell,” Electrochemistry Communications, vol. 9, pp. 2299-2303, 2007.
[18] S. K. Wang, F. G. Tseng, T. K. Yeh, and C. C. Chieng, Journal of Power Sources, vol. 167, pp. 413-419, May 2007
[19] Z. B. He, J. H. Chen, D. Y. Liu, H. Tang, W. Deng, and W. F. Kuang, Materials Chemistry and Physics, vol. 85, pp. 396-401, Jun 2004.
[20] N. Jha, A. L. Mohana, M. M. Shaijumon, N. Rajalakshmi, S. Ramaprabhu, International Journal of Hydrogen Energy 33 (2008)427-433
[21] Y. Liang, H. Zhang, B. Yi, Z. Zhang, Z. Tan, Carbon 43 (2005) 3144–3152
[22] 王鈞顯,「利用半開放式化學還原系統製備觸媒於奈米碳管-應用於微型直接甲醇燃料電池」, 國立清華大學碩士論文, 2009
[23] X. Wang, and I. M. Hsing, Electrochimica Acta, vol. 47, pp. 2981, 2002
[24] 賴羿如, 「利用奈米碳管與鉑釕化學沉積法製備直接甲醇燃料電池陽極觸媒」, 國立清華大學碩士論文, 2006
[25] C. Bock et al., “Size-selected synthesis of PtRu nano-catalysts: reaction and size control mechanism,” Journal of the American Chemical Society, vol. 126, pp. 8028-8037, 2004.
[26] C. K. Rhee et al., “Size Effect of Pt Nanoparticle on Catalytic Activity in Oxidation of Methanol and Formic Acid: Comparison to Pt(111), Pt(100), and Polycrystalline Pt Electrodes,” Langmuir vol.25(12),pp.7140–7147,2009.
[27] F.J. Liu et al., “Effect of deposition sequence of platinum and ruthenium particles into nanofibrous network of polyaniline–poly(styrene sulfonic acid) on electrocatalytic oxidation of methanol,” Synthetic Metals, vol.158, pp.603–609, 2008.
[28] J. Larminie et al. , Fuel Cell Systems Explained, 2nd Edition, John Wiley & Sons, Inc., England, 2003.
[29] S. Jiang et al., “Direct immobilization of Pt–Ru alloy nanoparticles on nitrogen-doped carbon nanotubes with superior electrocatalytic performance,” Journal of Power Sources, vol. 195, pp.7578-7582, 2010.
[30] M. C. Tsai et al., “Methanol oxidation efficiencies on carbon-nanotubesupported platinum and platinumeruthenium nanoparticles prepared by pulsed electrodeposition,” International Journal of hydrogen energy, vol. 36, pp.8261-8266, 2011.
[31] 江朝源,「陽極使用二元合金觸媒之直接甲醇燃料電池在不同製備條件下的電化學特性分析」, 國立清華大學碩士論文, 2005
[32] M. Watanabe et al., “Preparation of highly dispersed Pt-Ru alloy clusters and the activity for the electrooxidation of methanol,” Journal of Electroanalytic Chemistry, vol. 229, pp.395-406, 1987.
[33] X. Wang et al., “Surfactant stabilized Pt and Pt alloy electrocatalyst for polymer electrolyte fuel cells,” Electrochimica Acta, vol. 47, pp. 2981-2987, 2002.
[34] Daping He et al., “Graphene/carbon nanospheres sandwich supported PEM fuel cell metal nanocatalysts with remarkably high activity and stability” J. Mater. Chem. A, vol.1 , pp.2126-2132, 2013.
[35] Yongseon Hwang et al., “Role of direct covalent bonding in enhanced heat dissipation property of flexible graphene oxide–carbon nanotube hybrid film” Thin Solid Films vol.545 pp. 116–123, 2013.
[36] J. Mater. Chem et al., “Graphene: The New Two-Dimensional Nanomaterial”, Nanomaterials, 2009,19, 2457–2469
[37] Dongdong Zhang et al. ”Preparation, Characterization, and Application of Electrochemically Functional Graphene Nanocomposites by One-Step Liquid-PhaseExfoliation of Natural Flake Graphite with Methylene Blue, Nano Res. 2012, 5(12): 875–887
[38] Sukang Bae et al, “Roll-to-roll production of 30-inch graphene films for transparent electrodes.”, Nat.Nanotec . 2010, 5, 574–578
[39] Cecilia Mattevi et al,”A review of chemical vapour deposition of graphene on copper” J. Mater. Chem., 2011, 21, 3324–3334
[40] Hua Bai et al, “Functional Composite Materials Based on Chemically Converted Graphene” Adv. Mater. 2011, 23, 1089–1115
[41] Daping He et al.” Graphene/carbon nanospheres sandwich supported PEM fuel cell metal nanocatalysts with remarkably high activity and stability.” J. Mater. Chem. A, 2013, 1, 2126
[42] B. P. Vinayan and S. Ramaprabhu,” Platinum–TM (TM ¼ Fe, Co) alloy nanoparticles dispersed nitrogen doped (reduced graphene oxidemultiwalled carbon nanotube) hybrid structure cathode electrocatalysts for high performance PEMFC applications” Nanoscale, 2013, 5, 5109–5118
[43] Hengchang Bi et al.” Low Temperature Casting of Graphene with High Compressive Strength”.Adv. Mater. 2012, 24, 5124–5129
[44] R. Imran Jafri et al.” Preparation of Nitrogen-Doped Graphene Sheets by a Combined Chemical and Hydrothermal Reduction of Graphene Oxide.” International journal of hydrogen energy 40 (2015 ) 4337 -4348
[45] Donghui Long et al, “Preparation of Nitrogen-Doped Graphene Sheets by a Combined Chemical and Hydrothermal Reduction of Graphene Oxide.” Langmuir 2010, 26(20), 16096–16102
[46] Ling Qiu et al, “Biomimetic Superelastic Graphene-Based Cellular Monoliths.” Nature communications 2012, DOI: 10.1038/ncomms2251
[47] Zhuo Han et al, “Ammonia solution strengthened three-dimensional macro-porous graphene aerogel.” Nanoscale 2013, 5, 5462–5467
[48] Juan Zhao et al, “Performance and stability of Pd–Pt–Ni nanoalloy electrocatalysts in proton exchange membrane fuel cells.” Journal of Power Sources 2011,196, 4515–4523
[49] Paromita Kundu et al, “Ultrafast Microwave-Assisted Route to Surfactant-Free Ultrafine Pt Nanoparticles on Graphene: Synergistic Co-reduction Mechanism and High Catalytic Activity.” Chem. Mater. 2011, 23, 2772–2780