| 研究生: |
廖建達 Chien-Ta Liao |
|---|---|
| 論文名稱: |
氧化鋁擔載奈米金觸媒之製備與應用研究 Preparation and application of alumina-supported gold catalysts |
| 指導教授: |
張奉文
Feg-Wen Chang |
| 口試委員: | |
| 學位類別: |
碩士 Master |
| 系所名稱: |
工學院 - 化學工程與材料工程學系 Department of Chemical & Materials Engineering |
| 畢業學年度: | 92 |
| 語文別: | 中文 |
| 論文頁數: | 104 |
| 中文關鍵詞: | 甲醇部份氧化 、氧化鋁 、金觸媒 |
| 外文關鍵詞: | partial oxidation of methanol, hydrogen, alumina, particle size effect, gold catalyst |
| 相關次數: | 點閱:13 下載:0 |
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本研究以氧化鋁為擔體,利用沈澱固著法製備成奈米氧化鋁擔體金觸媒(簡稱為Au/γ- Al2O3觸媒),同時利用感應耦合電漿原子放射光譜儀(ICP-AES)、氮吸附法、熱重分析(TGA)、X射線繞射分析儀(XRD)、掃描式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)、X-射線光電子分析儀(XPS)等各項儀器與分析技術,分別對擔體及觸媒進行鑑定,並利用甲醇部份氧化反應為為催化活性的測試,藉以評估奈米氧化鋁擔體金觸媒應用於質子交換膜燃料電池(PEMFC)的可行性。由ICP-AES 分析結果,顯示Au/γ- Al2O3觸媒的金載量取決於pH值及製備時氯化金溶液的濃度,在低於等電位點金可達到60 %;氮吸附分析指出,以沈澱固著法製備的Au/γ- Al2O3觸媒,BET比表面積幾乎不會受煅燒溫度及載量的影響。從XRD圖譜中,可發現不同沈澱劑所形成不同大小的金晶粒。從TEM分析結果,發現Au/γ- Al2O3觸媒製備時pH值若超過等電位點時,可形成金晶粒大小約4 nm,且均勻分散在擔體表面上。而XPS分析結果可發現,以沈澱固著法所製備的Au/γ- Al2O3觸媒,表面會形成氫氧化金沈澱,且隨著煅燒溫度的增加,會逐漸熱解成金屬態的金。經過反應活性的測試,我們找出最佳的操作變數為金載量需小於1 wt%、製備pH值為9、沈澱劑為Na2CO3、煅燒溫度為573 K。若以此條件所製備出的觸媒,於523 K下進行甲醇部份氧化反應,能得到最佳的甲醇轉化率與氫氣選擇率。與文獻上銅觸媒、鈀觸媒的催化結果做比較,Au/γ- Al2O3觸媒不僅催化活性高,且幾乎沒有CO氣體的產生。由此結果可看出奈米金觸媒對於催化甲醇部份氧化反應,能夠選擇性的抑制CO的產生,相信可應用在燃料電池的氫氣源供應。
In this work, γ-Al2O3 was used as a catalyst support. Nanosized Au/γ-Al2O3 catalysts were prepared by the deposition-precipitation method.
The supported Au catalysts were characterized by inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray diffraction (XRD), thermogravimetric analyzer(TGA), nitrogen adsorption method , scanning electron microcopy (SEM), transmission elecron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS).
The ICP-AES analysis indicates that gold loading is significantly affected by the preparation pH value. When the pH value is below isoelectric point of support precipitates reach 60% loading. The nitrogen adsorption analysis shows that the catalyst preparation procedure does not affect the surface area of the support. Furthermore , the TEM analysis demonstrates that the mean size of gold crystallites decreases with increasing pH value.
Au/γ-Al2O3 catalysts was tested by the partial oxidation of methanol at 503-563K. The results indicate that the optimal preparations and operating conditions for best methanol conversion and hydrogen selectivity are 0.15 wt% in gold loading, 673 K in calcinations temperature, Na2CO3 in precipitation reagent, pH value 9 in prepared condition and 563K in reaction temperature. Moreover, compare to copper and palladium catalysts in POM reaction, Au/γ-Al2O3catalysts display good activity and highly CO selectivity. Nanosized Au/γ-Al2O3 catalysts may have an opportunity to apply in proton exchange membrane fuel cell.
Agrell ,J., G. Germani, S. G. Järås, M. Boutonnet,” Production of hydrogen by partial oxidation of methanolover ZnO supported palladium catalysts preparedby microemulsion technique”, Applied Catalysis A: General , Vol 242 ,233–245,(2003).
Alejo, L., Lago, R., Pena, M. A. and Fierro, J. L. G. “Partial oxidation of methanol to produce hydrogen over Cu-Zn based catalysts”, Applied Catalysis A: General , Vol 162,281-297, (1997).
Andreev, D., Idakiev, V., Tabakova, T. and Andreev, A. “Low-temperature water-gas shift reaction over Au/Alpha-Fe2O3”, Journal of Catalysis, Vol 158,354 –355,(1996).
Bethke, G.K., H.H. Kung ,” Selective CO oxidation in a hydrogen-rich
stream over Au/r-Al2O3 catalysts” Applied Catalysis A: General ,Vol 194 –195, 43–53 (2000).
Boccuzi,F. , A. Chiorino, M. Manzoli, P. Lu, T. akita, S. Ichikawa, M. Haruta,” Au/TiO2 nanosized samples - a catalytic, TEM, and FTIR study of the effect of calcination temperature on the CO oxidation”, Journal of Catalysis , Vol 202,Iss 2 , 256-267 ,(2001).
Bond, G. C. , M.Mahan, Catalysis Today, 72, 5-9, (2002),“University chemistry “ Benjamin/Cummings Pub. Co.,Menlo Park, p. 546-548,and846-847(1987).
Bond, G. C., P. A. Sermon, Gold Bull., Vol 102,p6,(1973).
Bond, G. C., D. T. Thompson, “Catalysis by gold” , Catal. Rev.-SCI. ENG., Vol 41(3&4), 319-388, (1999).
Bond, G. C. , D. T. Thompson, Gold Bull. Vol 33, ,41-51,(2000).
Chang, C. K., Y. J. Chen, C. T. Yeh,” Characterizations of alumina supported gold with temperature-programmed reduction”, Applied Catalysis A: General ,Vol 174 ,13-23, (1998).
Costello, C.K., M.C. Kung, H.-S. Oh, Y. Wang, H.H. Kung ,” Nature of the active site for CO oxidation on highly active Au/r-Al2O3”, Applied Catalysis A: General ,Vol 232 , 159–168,(2002).
Cubeiro, M. L. and Fierro, J. L. G. “Selective production of hydrogen by partial oxidation of methanol over ZnO-supported palladium catalysts”, Applied Catalysis A: General,Vol 168,307-322, (1998).
Date, M, Yamashita, Chiorino, Boccuzzi, and Haruta, M. “Performance of Au/TiO2 catalyst under ambient conditions”, Catalysis Today, Vol 72,Iss 1-2 , 89-94, (2002).
Dietz, W. A., ”Response factors for gas chromatographic analyses”, J. of G. C. February: 68 (1967)
Emonts, B., Hansen, J. B., Jorgensen, S. I., Höhlein, B. and Peters, R. “Compact methanol reformer test for fuel-cell powered light-duty vehicles”, Journal of Power Sources, Vol 71,Iss1-2, 288-293 (1998).
Gardner, S. D., Hoflund, G. B., Upchurch, B. T., Schryer, D. R., Kielen, E. J. and Schryer, J. “Comparison of the performance-characteristics of Pt/SnOx and Au/MnOx catalysts for low-temperature CO oxidation”, Journal of Catalysis, Vol 129,Iss 1,114 –120,(1991).
Gardner,S. D. ,G. B. Hoflund, D. R. Schryer, B. T. Upchurch , E. J. Kielin, ”Au/MnOx catalytic performance characteristics for low temperature carbon monoxide oxidation.”, Applied Catalysis B: Environmental, Vol 6,117-126,(1995).
Goodman ,D W.,M. Valden, X. Lai, ,” Onset of catalytic activity of gold clusters on titania with the appearance of nonmetallic properties”, Science , Vol 281,Iss 5383, 1647-1650,(1998).
Grisel, R. J. H. ,P. J. Kooyman, and B. E. Nieuwenhuys,”Influence of the preparation of Au/Al2O3 on CH4 oxidation activity”, Journal of Catalysis, Vol 191,430-437, (2000).
Haruta ,M. , T. Kobayashi , H. Sano , N. Yamada,” Novel gold catalysts for the oxidation of carbon-monoxide at a temperature far below 0-degrees-C”, Chemistry Letters, Iss 2, 405-408,(1987).
Haruta, M. , G. R. Bamwenda, S. Tsubota , T. Nakamura “The influence of the preparation methods on the catalytic activity of platinum and gold supported on TiO2 for CO oxidation” , Catalysis Letters, Vol 44, Iss 1-2,83-87, (1997).
Haruta ,M., M. Daté ,” Advances in the catalysis of Au nanoparticles”, Applied Catalysis A: General, Vol 222, 427–437,(2001).
Haruta, M., S. Tsubota, T. Kobayashi, H.Kageyama, M. J. Genet and B. Delmon, ” Low-temperature oxidation of Co over gold supported on TiO2, alpha-Fe2O3, and Co3O4” Journal of Catalysis, Vol 144,175-192 , (1993).
Haruta, M. , A. Ueda, S. Tsubota , R. m. Torres Sanchez “Low temperature catalytic combustion of methanol and its decomposed
derivatives over supported gold catalysts”Catalysis Today , Vol 29 , 443-447,(1996).
Haruta, M. , A. Ueda,” Reduction of nitrogen monoxide with propene overAu/Al2O3 mixed mechanically with Mn2O3”, Applied Catalysis B: Environmental ,Vol 18,115-121,(1998).
Haruta, M., N. Yamada, T. Kobayashi and S. Iijima, “Gold Catalysts Prepared by Coprecipitation for Low-Temperature Oxidation of Hydrogen and of Carbon-Monoxide” Journal of Catalysis , Vol 115,Iss2, 301-309,(1989).
Hcyashi , T. and Haruta, M. “Effect of an loading on selectivity in the reaction of propylene on Au/TiO2 catalyst”, Shokubai, Vol 37,75 ,(1995).
Huang, T. J. and Chren, S. L. “Kinetics of partial oxidation of methanol over a copper-zinc catalyst”, Applied Catalysis, Vol 40,Iss 1-2,43-52, (1988).
Hutchings, G. J. , Gold Bull., 29, 123 (1996)
Kang, Y. M. and B. Z. Wan, ” Pretreatment effect of gold iron zeolite-Y on carbon-monoxide oxidation” , Catalysis Today, Vol 26, Iss 1, 59-69, (1995).
Klabunde, K. J. , “Nanoscale materials in chemistry” John Wiley &Sons Inc. New York, Chapter 2 ,(2001).
Kumar, R., Ahmed, S., Krumplet, M., Myles, K. M., Agron National Laboratory Report, ANL-92/31, Argone, IL, USA, 1992
Kung , M. C.,C. K. costello, H.-S. Oh, Y. Wang, H. H. Kung, ” Nature of the active site for CO oxidation on highly active Au/r-Al2O3”, Applied Catalysis A: General. , Vol 232,159-168 ,(2002).
Lewis, L. J. , P. Jensan and J. L. Barrat,” Melting, Freezing, and Coalescence of gold nanoclusters”, Physical Review B-Condensed Matter , Vol 56,Iss 4, 2248-2257,(1997).
Mavrikakis, M. , P. Stoltze and J. K. Norskov,” Making gold less noble”, Catalysis Letters , Vol 64, Iss 2-4,101-106,(2000).
Minico, S., Scire, S., Crisafulli, C., Maggiore, R. and Galvagmo, S. “Catalytic combustion of volatile organic compounds on gold/iron oxide catalysts”, Applied Catalysis B: Environmental, Vol 28,245-251,(2000).
Okumura, M. T. , Akita, M. Haruta, “ Hydrogenation of 1,3-butadiene and of crotonaldehyde over highly dispersed Au catalysts”, Catal. Today, Vol 74,265-269,(2002).
Park, E. D., J. S. Lee,” Effects of pretreatment conditions on CO oxidation oversupported Au catalysts”, Journal of Catalysis, Vol 186,Iss 1, 1-11,(1999).
Rapson, W. S., Gold Bull. ,Vol 29, 143 (1996).
Suzuki, K. ,S. Velu, T. Osaki,” Selective production of hydrogen by partial oxidation of methanol over catalystsderived from Cu/Zn/Al -layered double hydroxides” Catalysis Letters, Vol 62, Iss 2-4, 159-167, (1999).
Wang, D., Z. Hao, D. Cheng, X. Shi, C. Hu,” Influence of pretreatment conditions on low-temperature CO oxidation over Au/MOx/Al2O3 catalysts”, Journal of Molecular Catalysis A: Chemical, Vol 200, 229–238,(2003).
Wang, Z. , W. Wang, G. Lu ,"Studies on the active species and on dispersion of Cu in Cu/SiO2 and Cu/Zn/SiO2 for hydrogen production via methanol partial oxidation", International Journal of Hydrogen Energy 28,151-158,(2003).
Wang, Z., Xi, J., Wang, W. and Lu, G. “Selective production of hydrogen by partial oxidation of methanol over Cu-/Cr catalysts”, Journal of Molecular Catalysis A: Chemical , Vol 191,123-134,(2003).
Wolf ,A., F. Schüth.” A systematic study of the synthesis conditions for
the preparation of highly active gold catalysts”, Applied Catalysis A: General ,Vol 226, 1–13, (2002).
Yeh, C. T. and Y. J. Chen , “Deposition of highly dispersed gold on alumina support” , Journal of Catalysis ,Vol 200, 59-68,(2001).
陳永杰,洪華聖,葉君棣, “支撐性金觸媒在甲醇部分氧化製氫反應上的應用”, 第19屆觸媒與反應工程研討會(2001).
蔡克群,”燃料電池導論”,化工技術第10卷第六期(2002).