在本研究中，首先開發了一種快速，具有成本效益的方法來合成用於水電解的鈷鐵金屬氧化物催化劑。通過改變鈷和鐵的金屬比例，使用微波輔助水熱法合成了鈷鐵金屬氧化物催化劑。當鈷鐵比為2：1時，其電解池在10 mA cm-2處產生的起始電勢僅為1.56 V，接近熱力學可逆電勢。當電位為1.8 V時，其電流密度約為130 mA cm-2。穩定性測試的結果，在電壓為1.8 V連續16小時穩定性測試中，電流密度穩定保持為130 mA cm-2。
另一部分為了解決因氣體無法移除而堆積進而導致觸媒層崩散掉落的問題，故本實驗將嘗試製備出鐵-鈷特殊結構觸媒。此結構能改善在電解過程中，因氣體堆積在觸媒表面導致效能下降的現象以提高效能。在本計畫中，使用三氧化二鐵作為觸媒載體，在載體表面披覆一層觸媒，在不同的載體與鈷前驅物合成比例，得到最佳載體與前驅物比例。觸媒結構可由穿透式電子顯微鏡(TEM)得知，影像中顯示，在觸媒表面能明顯看出在觸媒與觸媒之間存在一小間隙，此間隙能讓水電解所產生的氣體更易移除與電解液補充，並藉由能量色散X-ray光譜(EDS-Mapping)可看出鈷元素均勻分布於載體表面。在這個計畫內，也進行全電池的組裝並進行測試。在進行長時間耐久性測試（200小時）後，其結果顯示電流密度和仍然保持在一開始的85%以上。

In this first work, a rapid, scalable, and cost-effective method was developed for synthesizing cobalt–iron metal oxide catalysts for water electrolysis. Cobalt-iron metal oxide catalysts were synthesized using the microwave-assisted hydrothermal methods by varying the molar ratios of cobalt and iron. When the cobalt to iron ratio was 2:1, its electrolytic cell yielded the onset potential of only 1.56 V at 10 mA cm-2, which is close to the thermodynamically reversible potential. When its cell potential was at 1.8 V, the cell current density was approximately 130 mA cm-2. The results of the stability test showed a steady-state cell current density of 130 mA cm-2 and remained constant for more than 16 h at a continuous cell potential of 1.8 V. Compared with other catalysts, cobalt–iron metal oxide catalysts showed lower overpotential and lower Tafel slope than did conventional precious metal catalysts such as PtO2 and IrO2. Cobalt-iron metal oxide catalysts serve as an inexpensive route to large-scale commercialization through facile synthesis for enhanced electrochemical water splitting.
Second work, this catalyst structure can be improved during the electrolysis process, because gas is accumulated in the catalyst, using Fe2O3 as the catalyst support materials, coating the cobalt catalyst on the support materials to be a catalyst. Fe2O3 support materials, and difference cobalt precursor ratio to find the best ratio in the water electrolysis catalyst. The transmission electron microscope (TEM) image shows that the catalyst surface structure can cleary to know. There is a small gap between the catalyst and the catalyst. This gap helps the gas produced by water electrolysis to be easier to remove. In this project, the assembly is also performed and test. After long-term testing (200 hours), the results show that the current density remains above 85%.

[1] F. Barbir, PEM electrolysis for production of hydrogen from renewable energy sources. Solar Energy, 78 (2005) 661-669.
[2] T. Smolinka, “Fuels - Hydrogen Production / Water Electrolysis,” in Encyclopedia of Electrochemical Power Sources (2009) 394–413
[3] C.C. Pavel, F. Cecconi, C. Emiliani, S. Santiccioli, A. Scaffidi, S. Catanorchi, M. Comotti, Highly efficient platinum group metal free based membrane-electrode assembly for anion exchange membrane water electrolysis. Angew. Chem. International Ed., 53 (2014) 1378-1381.
[4] M. Carmo, D.L. Fritz, J. Mergel, D. Stolten, A comprehensive review on PEM water electrolysis. International Journal Hydrogen Energy, 38 (2013) 4901-4934.
[5] P. Salvi, P. Nelli, M. Villa, Y. Kiros, G. Zangari, G. Bruni, A. Marini, C. Milanese, Hydrogen evolution reaction in PTFE bonded Raney-Ni electrodes. International Journal Hydrogen Energy, 36 (2011) 7816-7821.
[6] X. Wu, K. Scott, CuxCo3-xO4 (0 ≤ x < 1) nanoparticles for oxygen evolution in high performance alkaline exchange membrane water electrolysers. Journal Materials Chemistry, 21 (2011) 12344-12351.
[7] Y.-C. Cao, X. Wu, K. Scott, A quaternary ammonium grafted poly vinyl benzyl chloride membrane for alkaline anion exchange membrane water electrolysers with no-noble-metal catalysts. International Journal Hydrogen Energy, 37 (2012) 9524-9528.
[8] J. Hnat, M. Paidar, J. Schauer, J. Zitka, K. Bouzek, Polymer anion-selective membranes for electrolytic splitting of water. Part II: Enhancement of ionic conductivity and performance under conditions of alkaline water electrolysis. Journal of Applied Electrochemistry, 42 (2012) 545-554.
[9] Y. Leng, G. Chen, A.J. Mendoza, T.B. Tighe, M.A. Hickner, C.Y. Wang, Solid-state water electrolysis with an alkaline membrane. Journal of the American Chemical Society, 134 (2012) 9054-9057.
[10] X. Wu, K. Scott, A polymethacrylate-based quaternary ammonium OH- ionomer binder for non-precious metal alkaline anion exchange membrane water electrolysers. Journal Power Sources, 214 (2012) 124-129.
[11] L. Xiao, S. Zhang, J. Pan, C. Yang, M. He, L. Zhuang, J. Lu, First implementation of alkaline polymer electrolyte water electrolysis working only with pure water. Energy and Environmental Science, 5 (2012) 7869-7871.
[12] D. Aili, M.K. Hansen, R.F. Renzaho, Q. Li, E. Christensen, J.O. Jensen, N.J. Bjerrum, Heterogeneous anion conducting membranes based on linear and crosslinked KOH doped polybenzimidazole for alkaline water electrolysis. Journal of Membrane Science, 447 (2013) 424-432.
[13] X. Wu, K. Scott, A Li-doped Co3O4 oxygen evolution catalyst for non-precious metal alkaline anion exchange membrane water electrolysers. International Journal Hydrogen Energy, 38 (2013) 3123-3129.
[14] X. Wu, K. Scott, F. Xie, N. Alford, A reversible water electrolyser with porous PTFE based OH- conductive membrane as energy storage cells. Journal Power Sources, 246 (2014) 225-231.
[15] J. Qiao, J. Zhang, J. Zhang, Anion conducting poly(vinyl alcohol)/poly(diallyldimethylammonium chloride) membranes with high durable alkaline stability for polymer electrolyte membrane fuel cells. Journal Power Sources, 237 (2013) 1-4.
[16] G. Merle, M. Wessling, K. Nijmeijer, Anion exchange membranes for alkaline fuel cells: A review. Journal of Membrane Science, 377 (2011) 1-35.
[17] M. Piana, M. Boccia, A. Filpi, E. Flammia, H.A. Miller, M. Orsini, F. Salusti, S. Santiccioli, F. Ciardelli, A. Pucci, H2/air alkaline membrane fuel cell performance and durability, using novel ionomer and non-platinum group metal cathode catalyst. Journal Power Sources, 195 (2010) 5875-5881.
[18] J.R. Varcoe, R.C.T. Slade, Prospects for alkaline anion-exchange membranes in low temperature fuel cells. Fuel Cells, 5 (2005) 187-200.
[19] M. Mori, T. Mrzljak, B. Drobnic, M. Sekavcnik, Integral characteristics of hydrogen production in alkaline electrolysers. Strojniski Vestnik/Journal of Mechanical Engineering, 59 (2013) 585-594.
[20] K. Zeng, D. Zhang, Recent progress in alkaline water electrolysis for hydrogen production and applications. Progress in Energy and Combustion Science, 36 (2010) 307-326.
[21] J.P. Singh, N.K. Singh, R.N. Singh, Electrocatalytic activity of metal-substituted Fe3O4 obtained at low temperature for O2 evolution. International Journal Hydrogen Energy, 24 (1999) 433-439.
[22] E.B. Castro, S.G. Real, L.F. Pinheiro Dick, Electrochemical characterization of porous nickel-cobalt oxide electrodes. International Journal Hydrogen Energy, 29 (2004) 255-261.
[23] B. Chi, H. Lin, J. Li, N. Wang, J. Yang, Comparison of three preparation methods of NiCo2O4 electrodes. International Journal Hydrogen Energy, 31 (2006) 1210-1214.
[24] Y. Li, P. Hasin, Y. Wu, NixCo3-XO4 nanowire arrays for electrocatalytic oxygen evolution. Advanced Materials, 22 (2010) 1926-1929.
[25] A. Kalendova, D. Vesely, J. Brodinova, Anticorrosive spinel-type pigments of the mixed metal oxides compared to metal polyphosphates. Anti-Corrosion Methods and Materials, 51 (2004) 6-17.
[26] C.C.L. McCrory, S. Jung, J.C. Peters, T.F. Jaramillo, Benchmarking heterogeneous electrocatalysts for the oxygen evolution reaction. Journal of the American Chemical Society, 135 (2013) 16977-16987.
[27] J. Yu, Y. Zhong, X. Wu, J. Sunarso, M. Ni, W. Zhou, Z. Shao, Bifunctionality from Synergy: CoP Nanoparticles Embedded in Amorphous CoOx Nanoplates with Heterostructures for Highly Efficient Water Electrolysis. Advanced Science, 5 (2018).
[28] Z. Wu, Z. Zou, J. Huang, F. Gao, NiFe2O4 Nanoparticles/NiFe Layered Double-Hydroxide Nanosheet Heterostructure Array for Efficient Overall Water Splitting at Large Current Densities. ACS Applied Materials and Interfaces, 10 (2018) 26283-26292.
[29] S. Wang, L. Xu, W. Lu, Synergistic effect: Hierarchical Ni3S2@Co(OH)2 heterostructure as efficient bifunctional electrocatalyst for overall water splitting. Applied Surface Science, 457 (2018) 156-163.
[30] S.K. Singh, V.M. Dhavale, S. Kurungot, Low surface energy plane exposed Co3O4 nanocubes supported on nitrogen-doped graphene as an electrocatalyst for efficient water oxidation. ACS Applied Materials and Interfaces, 7 (2015) 442-451.
[31] Y. Qiu, L. Xin, W. Li, Electrocatalytic oxygen evolution over supported small amorphous ni-fe nanoparticles in alkaline electrolyte. Langmuir, 30 (2014) 7893-7901.
[32] W. Yan, Z. Yang, W. Bian, R. Yang, FeCo2O4/hollow graphene spheres hybrid with enhanced electrocatalytic activities for oxygen reduction and oxygen evolution reaction. Carbon, 92 (2015) 74-83.
[33] J. Wang, T. Qiu, X. Chen, Y. Lu, W. Yang, Hierarchical hollow urchin-like NiCo2O4 nanomaterial as electrocatalyst for oxygen evolution reaction in alkaline medium. Journal Power Sources, 268 (2014) 341-348.
[34] H. Xia, Z. Huang, C. Lv, C. Zhang, A Self-Supported Porous Hierarchical Core-Shell Nanostructure of Cobalt Oxide for Efficient Oxygen Evolution Reaction. ACS Catalysis, 7 (2017) 8205-8213.
[35] J. Hu, C. Zhang, X. Meng, H. Lin, C. Hu, X. Long, S. Yang, Hydrogen evolution electrocatalysis with binary-nonmetal transition metal compounds. Journal of Materials Chemistry A, 5 (2017) 5995-6012.
[36] B. Li, S. Chen, J. Tian, M. Gong, H. Xu, L. Song, Amorphous nickel-iron oxides/carbon nanohybrids for an efficient and durable oxygen evolution reaction. Nano Research, 10 (2017) 3629-3637.
[37] G. Liu, D. He, R. Yao, Y. Zhao, J. Li, Amorphous NiFeB nanoparticles realizing highly active and stable oxygen evolving reaction for water splitting. Nano Research, 11 (2018) 1664-1675.
[38] A. Indra, P.W. Menezes, N.R. Sahraie, A. Bergmann, C. Das, M. Tallarida, D. Schmeicer, P. Strasser, M. Driess, Unification of catalytic water oxidation and oxygen reduction reactions: Amorphous beat crystalline cobalt iron oxides. Journal of the American Chemical Society, 136 (2014) 17530-17536.
[39] Z. kx, C. Jin, Z. Klencsár, D.A.S. Ganeshraja, J. Wang, S. Wang, X. Duan, Cobalt-iron Oxide, Alloy and Nitride: Synthesis, Characterization and Application in Catalytic Peroxymonosulfate Activation for Orange II Degradation. Catalysts, 7 (2017) 138.
[40] T.H. Wondimu, G.C. Chen, D.M. Kabtamu, H.Y. Chen, A.W. Bayeh, H.C. Huang, C.H. Wang, Highly efficient and durable phosphine reduced iron-doped tungsten oxide/reduced graphene oxide nanocomposites for the hydrogen evolution reaction. International Journal Hydrogen Energy, 43 (2018) 6481-6490.
[41] R. Zhang, Y.C. Zhang, L. Pan, G.Q. Shen, N. Mahmood, Y.-H. Ma, Y. Shi, W. Jia, L. Wang, X. Zhang, W. Xu, J.J. Zou, Engineering Cobalt Defects in Cobalt Oxide for Highly Efficient Electrocatalytic Oxygen Evolution. ACS Catalysis, 8 (2018) 3803-3811.