本研究主要目標為發展用於直接甲醇燃料電池陰極之氧氣還原反應之雙金屬觸媒。實驗架構為將簡化複雜之傳統製程，以單步驟合成法合成中孔碳承載之PtFe雙金屬觸媒複合物，並以氫氣熱處理嘗試改變其觸媒結構，系統性地探討雙金屬組成、附載量與氫氣熱處理對觸媒之氧氣催化活性與穩定性之影響。
本研究首先合成不同雙金屬組成之PtFe雙金屬觸媒，探討雙金屬觸媒其原子組成對催化活性之影響。由結果得知以金屬組成為Pt3Fe7-mc之樣品有最佳的氧氣還原催化活性，其觸媒平均大小為2.00 nm，氧氣催化起始電位為0.896V，單位重量活性為4.04 mA/mg of Pt，皆優於商業化之JM-20 Pt觸媒（0.875 V ,1.81 mA/mg of Pt）。
進一步以表現最佳之Pt3Fe7-mc觸媒組成為基礎，合成不同金屬負載量之Pt3Fe7-mc雙金屬觸媒，並以低濃度氫氣對觸媒進行熱處理，探討金屬負載量與熱處理對觸媒結構與氧氣還原活性的影響。由TGA得知，熱處理後可提升碳材之石墨化程度，並由XRD結果得知，在700℃熱處理後，Pt3Fe7-mc觸媒粒徑沒有明顯之增加，顯示所使用之中孔碳材能有效抑制奈米粒子的成長，並預期同時能有結構之轉換。在電化學特性上，以氫氣熱處理過之PtFe雙金屬觸媒之氧氣還原催化活性與電化學穩定度皆優於未熱處理之觸媒，其中以H2-50%-Pt3Fe7-mc-700，有最佳的氧氣還原催化活性，起始電位為0.919 V，單位重量活性由6.50 mA/mg of Pt提升至8.55 mA/mg of Pt。在穩定度測試條件下，於掃描5000圈與10000圈後，比較電化學活性面積之損失率，以H2-30%-Pt3Fe7-mc-700觸媒具有最佳之穩定性，此觸媒活性與穩定度之提升推測為碳載體石墨化程度之增加與觸媒結構之轉換等因素所造成。

The aim of this work was to develop a bimetallic catalyst (PtFe embedded in mesoporous carbon (mc)) for the oxygen reduction reaction (ORR) in direct methanol fuel cells. The synthetic procedure developed replaces the complicated traditional approach with a simple one-pot method. Heat treatment under 5 % H2/Ar was investigated as a means of modifying the catalyst’s performance. The effects of: metallic composition, catalytic loading and heat treatment under H2, on the catalyst’s activity and stability were systematically studied.
At first, bimetallic catalysts with various Pt-to-Fe ratios were synthesized, and the relationship between the bimetallic composition and its electrochemical properties was investigated. It was found that Pt3Fe7-mc (with an average particle size, i.e. diameter, of 2.00 nm) exhibited the best ORR activity, with the onset potential and the mass activity, for the ORR, being 0.896 V and 4.04 mA/mg of Pt, respectively. Both of these measured electrochemical properties are better than those of commercial JM-20 Pt (0.875 V, 1.81 mA/ mg Pt).
Based on a Pt-to-Fe ratio of 3:7, different metallic loadings of Pt3Fe7-mc catalysts were synthesized with heat treatment being carried-out under 5 % H2/Ar. Correlations between electrochemical performance and metallic loadings were investigated. TGA analysis indicated that the degree of graphitization for Pt3Fe7-mc was improved after heat treatment. However, XRD results show the average size of the Pt-Fe nanoparticles didn’t increase significantly and that the mesoporous carbon can effectively inhibit the growth of nanoparticles. The transformative effect of the heat treatment on the crystalline structure of the Pt-Fe catalysts was investigated. In the electrochemistry test, the ORR activity and stability of PtFe bimetallic catalysts with heat treatment were shown to be better than when the catalyst was made without heat treatment. H2-50%-Pt3Fe7-mc-700 showed the best activity with an onset potential of 0.919 V (for the ORR) accompanied by a measured mass activity increase from 6.50 mA/mg of Pt to 8.55 mA/mg of Pt. In the accelerated stability test, we compared the loss of electrochemical surface area for catalysts after 5000 and 10000 CV cycles: H2-30%-Pt3Fe7-mc-700 was found to retain the best catalytic stability. Eventually, we inferred that the higher degree of graphization of the carbon support and the transformation of the catalytic structure are the main reasons for the increase in the catalytic activity and stability.

1.Carrette, L., Friedrich, K.A., and Stimming, U., "Fuel Cells - Fundamentals and Applications." Fuel Cells, 2001. 1(1): 5-39.
2.Sundmacher, K., Schultz, T., Zhou, S., Scott, K., Ginkel, M., and Gilles, E.D., "Dynamics of the direct methanol fuel cell (DMFC): experiments and model-based analysis." Chemical Engineering Science, 2001. 56(2): 333-341.
3.Frelink, T., Visscher, W., and Veen, J.A.R.v., "On the role of Ru and Sn as promotors of methanol electro-oxidation over Pt." Surface Science, 1995. 335(C): 353-360.
4.Gasteiger, H.A., Markovic, N., Ross Jr, P.N., and Cairns, E.J., "Methanol electrooxidation on well-characterized Pt-Ru alloys." Journal of Physical Chemistry, 1993. 97(46): 12020-12029.
5.Bruce R. Rauhe, J., McLarnon, F.R., and Cairns, E.J., "Direct Anodic Oxidation of Methanol on Supported Platinum/Ruthenium Catalyst in Aqueous Cesium Carbonate." Journal of The Electrochemical Society, 1995. 142(4): 1073-1084.
6.Brankovic, S.R., Marinkovic, N.S., Wang, J.X., and Adzic, R.R., "Carbon monoxide oxidation on bare and Pt-modified Ru(1010) and Ru(0001) single crystal electrodes." Journal of Electroanalytical Chemistry, 2002. 532(1-2): 57-66.
7.Zhu, Y.M., Uchida, H., Yajima, T., and Watanabe, M., "Attenuated total reflection-Fourier transform infrared study of methanol oxidation on sputtered Pt film electrode." Langmuir, 2001. 17(1): 146-154.
8.Lu, C., Rice, C., Masel, R.I., Babu, P.K., Waszczuk, P., Kim, H.S., Oldfield, E., and Wieckowski, A., "UHV, Electrochemical NMR, and Electrochemical Studies of Platinum/Ruthenium Fuel Cell Catalysts." The Journal of Physical Chemistry B, 2002. 106(37): 9581-9589.
9.Beden, B., Kadirgan, F., Lamy, C., and Leger, J.M., "Electrocatalytic oxidation of methanol on platinum-based binary electrodes." Journal of Electroanalytical Chemistry, 1981. 127(1-3): 75-85.
10.Hamnett, A., "Mechanism and electrocatalysis in the direct methanol fuel cell." Catalysis Today, 1997. 38(4): 445-457.
11.Lin, W.F., Zei, M.S., Eiswirth, M., Ertl, G., Iwasita, T., and Vielstich, W., "Electrocatalytic activity of Ru-modified Pt(111) electrodes toward CO oxidation." Journal of Physical Chemistry B, 1999. 103(33): 6968-6977.
12.Liu, R., Iddir, H., Fan, Q., Hou, G., Bo, A., Ley, K.L., and Smotkin, E.S., "Potential-dependent infrared absorption spectroscopy of adsorbed CO and X-ray photoelectron spectroscopy of arc-melted single-phase Pt, PtRu, PtOs, PtRuOs, and Ru electrodes." Journal of Physical Chemistry B, 2000. 104(15): 3518-3531.
13.Zhong, C.J. and Maye, M.M., "Core-shell assembled nanoparticles as catalysts." Advanced Materials, 2001. 13(19): 1507-1511.
14.Shukla, A.K., Raman, R.K., Choudhury, N.A., Priolkar, K.R., Sarode, P.R., Emura, S., and Kumashiro, R., "Carbon-supported Pt-Fe alloy as a methanol-resistant oxygen-reduction catalyst for direct methanol fuel cells." Journal of Electroanalytical Chemistry, 2004. 563(2): 181-190.
15.Watanabe, M., Furuuchi, Y., and Motoo, S., "Electrocatalysis by ad-atoms. Part XIII. Preparation of ad-electrodes with tin ad-atoms for methanol, formaldehyde and formic acid fuel cells." Journal of Electroanalytical Chemistry, 1985. 191(2): 367-375.
16.Ledjeff-Hey, K. and Heinzel, A., "Critical issues and future prospects for solid polymer fuel cells." Journal of Power Sources, 1996. 61(1-2): 125-127.
17.Carrette, L., Friedrich, K.A., and Stimming, U., "Fuel cells: Principles, types, fuels, and applications." ChemPhysChem, 2000. 1(4): 163-193.
18.Yajima, T., Uchida, H., and Watanabe, M., "In-situ ATR-FTIR spectroscopic study of electro-oxidation of methanol and adsorbed CO at Pt-Ru alloy." Journal of Physical Chemistry B, 2004. 108(8): 2654-2659.
19.Watanabe, M., Uchida, M., and Motoo, S., "Preparation of highly dispersed Pt + Ru alloy clusters and the activity for the electrooxidation of methanol." Journal of Electroanalytical Chemistry, 1987. 229(1-2): 395-406.
20.Chu, D. and Gilman, S., "Methanol electro-oxidation on unsupported Pt-Ru alloys at different temperatures." Journal of The Electrochemical Society, 1996. 143(5): 1685-1690.
21.Venkataraman, R., Kunz, H.R., and Fenton, J.M., "Development of new CO tolerant ternary anode catalysts for proton exchange membrane fuel cells." Journal of The Electrochemical Society, 2003. 150(3): A278-A284.
22.Ley, K.L., Liu, R., Pu, C., Fan, Q., Leyarovska, N., Segre, C., and Smotkin, E.S., "Methanol oxidation on single-phase Pt-Ru-Os ternary alloys." Journal of The Electrochemical Society, 1997. 144(5): 1543-1548.
23.Reddington, E., Sapienza, A., Gurau, B., Viswanathan, R., Sarangapani, S., Smotkin, E.S., and Mallouk, T.E., "Combinatorial electrochemistry: A highly parallel, optical screening method for discovery of better electrocatalysts." Science, 1998. 280(5370): 1735-1737.
24.Arico, A.S., Poltarzewski, Z., Kim, H., Morana, A., Giordano, N., and Antonucci, V., "Investigation of a carbon-supported quaternary PtRuSnW catalyst for direct methanol fuel cells." Journal of Power Sources, 1995. 55(2): 159-166.
25.Choi, W.C., Kim, J.D., and Woo, S.I., "Quaternary Pt-based electrocatalyst for methanol oxidation by combinatorial electrochemistry." Catalysis Today, 2002. 74(3-4): 235-240.
26.Lin, Y.C., Chou, H.L., Tsai, M.C., Hwang, B.J., Sarma, L.S., Lee, Y.C., and Chen, C.I., "Combined Experimental and Theoretical Investigation of Nanosized Effects of Pt Catalyst on Their Underlying Methanol Electro-Oxidation Activity." Journal of Physical Chemistry C, 2009. 113(21): 9197-9205.
27.Ramesh, K.V., Sarode, P.R., Vasudevan, S., and Shukla, A.K., "Preparation and characterization of carbon-based fuel-cell electrodes with platinum-group bimetallic catalysts." Journal of Electroanalytical Chemistry, 1987. 223(1-2): 91-106.
28.Couturier, G., Kirk, D.W., Hyde, P.J., and Srinivasan, S., "Electrocatalysis of the hydrogen oxidation and of the oxygen reduction reactions of Pt and some alloys in alkaline medium." Electrochimica Acta, 1987. 32(7): 995-1005.
29.呂崇銘, 白金-合金/Nafion觸媒電極之製備與其氣固氣-固相氧氣還原反應之動力探討, in 化學工程系. 1992, 東海大學.
30.Mukerjee, S., Srinivasan, S., and Soriaga, M.P., "Role of structural and electronic properties of Pt and Pt alloys on electrocatalysis of oxygen reduction." Journal of The Electrochemical Society, 1995. 142(5): 1409-1422.
31.Carl H., H., Andrew, H., and Wolf, V., "Electrochemistry." 2007, Wiley-VCH, Weinheim.
32.Wroblowa, H.S., Yen Chi, P., and Razumney, G., "Electroreduction of oxygen a new mechanistic criterion." Journal of Electroanalytical Chemistry, 1976. 69(2): 195-201.
33.Tarasevich, M.R., Sadkowski, A., and Yeager, E., "Comprehensive Treatise of Electrochemistry." Oxygen Electrochemistry, ed. J.O. Bockris, E.E. Conway, E. Yeager, S.U.M. Khan, and R.E. White. 1983, New York. 301.
34.Yeager, E., "Dioxygen electrocatalysis: mechanisms in relation to catalyst structure." Journal of Molecular Catalysis, 1986. 38(1-2): 5-25.
35.林冠男, 密度泛涵理論在Pt15, Pt11Fe4和Pt11Co4團簇上對氧氣還原之研究, in 化學工程所. 2006, 台灣科技大學.
36.Damjanovic, A. and Brusic, V., "Electrode kinetics of oxygen reduction on oxide-free platinum electrodes." Electrochimica Acta, 1967. 12(6): 615-628.
37.Yeager, E., Razaq, M., Gervasio, D., and Razaq, A., "Structural Effects in Electrocatalysis and Oxygen Electrochemistry." ed. D. Scheerson, D. Tryk, M. Daroux, and X. Xing. Vol. 92-11. 1992: The Electrochemical Society Inc., Pennington, NJ, 40
38.Brosha, E., Davey, J., Garzon, F., Hamon, C., Kim, Y.S., Neergat, M., Piela, P., Pivovar, B., Purdy, G., Ramsey, J., Rowley, J., Wilson, M., and Zelenay, P., "Direct Methanol Fuel Cells." Hydrogen, Fuel Cells & Infrastructure Technologies Program 2004 Annual Review, 2004.
39.Liu, J.G., Zhou, Z.H., Zhao, X.X., Xin, Q., Sun, G.Q., and Yi, B.L., "Studies on performance degradation of a direct methanol fuel cell (DMFC) in life test." Physical Chemistry Chemical Physics, 2004. 6(1): 134-137.
40.Piela, P., Eickes, C., Brosha, E., Garzon, F., and Zelenay, P., "Ruthenium crossover in direct methanol fuel cell with Pt-Ru black anode." Journal of The Electrochemical Society, 2004. 151(12): A2053-A2059.
41.Hwang, B.J., Sarma, L.S., Chen, C.H., Wang, G.R., Hsueh, K.L., Huang, C.P., Sheu, H.S., Liu, D.G., and Lee, J.F., "Investigations of direct methanol fuel cell (DMFC) fading mechanisms." Journal of Power Sources, 2007. 167(2): 358-365.
42.Ferreira, P.J., la O', G.J., Shao-Horn, Y., Morgan, D., Makharia, R., Kocha, S., and Gasteiger, H.A., "Instability of Pt/C electrocatalysts in proton exchange membrane fuel cells - A mechanistic investigation." Journal of The Electrochemical Society, 2005. 152(11): A2256-A2271.
43.Zhang, J.L., Vukmirovic, M.B., Sasaki, K., Nilekar, A.U., Mavrikakis, M., and Adzic, R.R., "Mixed-metal Pt monolayer electrocatalysts for enhanced oxygen reduction kinetics." Journal of the American Chemical Society, 2005. 127(36): 12480-12481.
44.Toda, T., Igarashi, H., Uchida, H., and Watanabe, M., "Enhancement of the Electroreduction of Oxygen on Pt Alloys with Fe, Ni, and Co." Journal of The Electrochemical Society, 1999. 146(10): 3750-3756.
45.Shim, J., Yoo, D.Y., and Lee, J.S., "Characteristics for electrocatalytic properties and hydrogen-oxygen adsorption of platinum ternary alloy catalysts in polymer electrolyte fuel cell." Electrochimica Acta, 2000. 45(12): 1943-1951.
46.Kim, J., Lee, Y., and Sun, S., "Structurally Ordered FePt Nanoparticles and Their Enhanced Catalysis for Oxygen Reduction Reaction." J. AM. CHEM. SOC., 2010. 132(14): 4996-4997.
47.Zhao, D., Huo, Q., Feng, J., Chmelka, B.F., and Stucky, G.D., "Nonionic Triblock and Star Diblock Copolymer and Oligomeric Surfactant Syntheses of Highly Ordered, Hydrothermally Stable, Mesoporous Silica Structures." Journal of the American Chemical Society, 1998. 120(24): 6024-6036.
48.Chen, C.-Y., Li, H.-X., and Davis, M.E., "Studies on mesoporous materials : I. Synthesis and characterization of MCM-41." Microporous Materials, 1993. 2(1): 17-26.
49.Zana, R., "Micellization of amphiphiles: selected aspects." Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1997. 123-124: 27-35.
50.Yang, C.-M., Zibrowius, B., Schmidt, W., and Schuth, F., "Consecutive Generation of Mesopores and Micropores in SBA-15." Chemistry of Materials, 2003. 15(20): 3739-3741.
51.Wade, A. and Weller, P.J., "Handbook of Pharmaceutical Excipients." 2nd ed. 1994.
52.Knox, J.H., Kaur, B., and Millward, G.R., "Structure and performance of porous graphitic carbon in liquid chromatography." Journal of Chromatography A, 1986. 352: 3-25.
53.Ryoo, R., Joo, S.H., and Jun, S., "Synthesis of Highly Ordered Carbon Molecular Sieves via Template-Mediated Structural Transformation." The Journal of Physical Chemistry B 1999. 103(37): 7743-7746.
54.Shin, H.J., Ryoo, R., Kruk, M., and Jaroniec, M., "Modification of SBA-15 pore connectivity by high-temperature calcination investigated by carbon inverse replication." Chemical Communications, 2001(4): 349-350.
55.Ryoo, R., Joo, S.H., Kruk, M., and Jaroniec, M., "Ordered mesoporous carbons." Advanced Materials, 2001. 13(9): 677-681.
56.Lee, J., Kim, J., and Hyeon, T., "Recent progress in the synthesis of porous carbon materials." Advanced Materials, 2006. 18(16): 2073-2094.
57.Li, W.Z., Liang, C.H., Qiu, J.S., Zhou, W.J., Han, H.M., Wei, Z.B., Sun, G.Q., and Xin, Q., "Carbon nanotubes as support for cathode catalyst of a direct methanol fuel cell." Carbon, 2002. 40(5): 791-794.
58.Chai, G.S., Yoon, S.B., Yu, J.S., Choi, J.H., and Sung, Y.E., "Ordered porous carbons with tunable pore sizes as catalyst supports in direct methanol fuel cell." Journal of Physical Chemistry B, 2004. 108(22): 7074-7079.
59.Joo, S.H., Pak, C., You, D.J., Lee, S.A., Lee, H.I., Kim, J.M., Chang, H., and Seung, D., "Ordered mesoporous carbons (OMC) as supports of electrocatalysts for direct methanol fuel cells (DMFC): Effect of carbon precursors of OMC on DMFC performances." Electrochimica Acta, 2006. 52(4): 1618-1626.
60.Joo, J.B., Kim, P., Kim, W., Kim, J., and Yi, J., "Preparation of mesoporous carbon templated by silica particles for use as a catalyst support in polymer electrolyte membrane fuel cells." Catalysis Today, 2006. 111(3-4): 171-175.
61.Liu, S.H., Yu, W.Y., Chen, C.H., Lo, A.Y., Hwang, B.J., Chien, S.H., and Liu, S.B., "Fabrication and characterization of well-dispersed and highly stable PtRu nanoparticles on carbon mesoporous material for applications in direct methanol fuel cell." Chemistry of Materials, 2008. 20(4): 1622-1628.
62.Lin, M.L., Huang, C.C., Lo, M.Y., and Mou, C.Y., "Well-ordered mesoporous carbon thin film with perpendicular channels: Application to direct methanol fuel cell." Journal of Physical Chemistry C, 2008. 112(3): 867-873.
63.Shanahan, P.V., Xu, L.B., Liang, C.D., Waje, M., Dai, S., and Yan, Y.S., "Graphitic mesoporous carbon as a durable fuel cell catalyst support." Journal of Power Sources, 2008. 185(1): 423-427.
64.Fang, B., Kim, J.H., Lee, C., and Yu, J.S., "Hollow macroporous Core/Mesoporous shell carbon with a tailored structure as a cathode electrocatalyst support for proton exchange membrane fuel cells." Journal of Physical Chemistry C, 2008. 112(2): 639-645.
65.Fang, B.Z., Kim, J.H., Kim, M., Kim, M., and Yu, J.S., "Hierarchical nanostructured hollow spherical carbon with mesoporous shell as a unique cathode catalyst support in proton exchange membrane fuel cell." Physical Chemistry Chemical Physics, 2009. 11(9): 1380-1387.
66.Yu, C.-M., Yoon, S.-K., Lee, S.-J., Lee, J.-Y., and Kim, S.S., "Catalytic asymmetric allylic transfer reaction: (4-trimethylsilylbut-2-ynyl)stannane as a new reagent leading to the enantioselective synthesis of dienyl alcohols." Chem. Commun., 1998: 2749-2750.
67.Kuno, M., Naka, T., Negishi, E., Matsui, H., Terasaki, O., Ryoo, R., and Toyota, N., "Magnetic susceptibility and electrical resistivity of a mesoporous carbon CMK-1." Synthetic Metals, 2003. 135-136: 721-722.
68.Zhou, H.S., Zhu, S.M., Hibino, M., Honma, I., and Ichihara, M., "Lithium storage in ordered mesoporous carbon (CMK-3) with high reversible specific energy capacity and good cycling performance." Advanced Materials, 2003. 15(24): 2107-2111.
69.Liu, S.-H., Lu, R.-F., Huang, S.-J., Lo, A.-Y., Chien, S.-H., and Liu, S.-B., "Controlled synthesis of highly dispersed platinum nanoparticles in ordered mesoporous carbons." Chem. Commun., 2006: 3435-3437.
70.Holmes, S.M., Foran, P., Roberts, E.P.L., and Newton, J.M., "Encapsulation of metal particles within the wall structure of mesoporous carbons." Chemical Communications, 2005(14): 1912-1913.
71.彭文權, 以沈積法製備甲醇燃料電池用之Pt-Ru雙金屬觸媒, in 化學工程與材料科學學系. 1997, 元智工學院.
72.Tran, T.D. and Langer, S.H., "Electrochemical measurement of platinum surface areas on particulate conductive supports." Analytical Chemistry 1993. 65(13): 1805-1807.
73.Markovic, N.M., Grgur, B.N., Lucas, C.A., and Ross, P.N., "Electrooxidation of CO and H2/CO Mixtures on Pt(111) in Acid Solutions." The Journal of Physical Chemistry B, 1999. 103(3): 487-495.
74.胡啟章, "電化學原理與方法." 2002: 五南圖書出版公司.
75.Gasteiger, H.A., Kocha, S.S., Sompalli, B., and Wagner, F.T., "Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs." Applied Catalysis B-Environmental, 2005. 56(1-2): 9-35.