研究生: |
邱耀慶 Ciou, Yao-Cing |
---|---|
論文名稱: |
金屬鈷(Co)附載於不同氧活性之載體(CeO2, BZDy)對乙醇氧化蒸氣重組反應之影響與反應路徑探討 The Mechanistic Study of Oxidative Steam Reforming of Ethanol (OSRE) over Cobalt on CeO2 and Dy-doped BaZrO3 |
指導教授: |
王禎翰
Wang, Jeng-Han |
學位類別: |
碩士 Master |
系所名稱: |
化學系 Department of Chemistry |
論文出版年: | 2017 |
畢業學年度: | 105 |
語文別: | 中文 |
論文頁數: | 95 |
中文關鍵詞: | 乙醇氧化蒸氣重組反應 、鈷 、氧化鈰 、鋯酸鋇參雜鏑 、鈣鈦礦 、DRIFT |
英文關鍵詞: | oxidative steam reforming of ethanol, cobalt, CeO2, BZDy, perovskite, DRIFT |
DOI URL: | https://doi.org/10.6345/NTNU202202016 |
論文種類: | 學術論文 |
相關次數: | 點閱:139 下載:3 |
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本實驗使用10 %金屬鈷(Co)分別附載於親氧性之氧化鈰(CeO2¬)與親水性之鋯酸鋇參雜鏑(BZDy)上進行乙醇氧化蒸氣重組反應之探討。催化劑的製備方法為含淨法,催化劑之鑑定使用粉末繞射分析儀(XRD)、能量散射光譜儀(EDS)、程序升溫還原反應(TPR)與X光光電子光譜(XPS)進行。反應之測定使用氣相層析儀(GC)分析產率與選擇率之結果、in situ漫反射傅立葉轉換紅外光譜儀分析反應中間物與程序升溫還原反應(TPR)分析催化劑之狀態。在水與乙醇比例為1:7下,改變氧氣比例之反應,產率與選擇率結果之部分,當C/O ratio約為0.61,在Co/CeO2氫氣最高產率為77 %,CO/CO2選擇率分別為37 % / 59 %,CH4選擇率低於1% ,而Co/BZDy在C/O ratio = 0.61,最高氫氣產率為80 %,CH4/CO2選擇率分別為12 % / 83 %,而CO選擇率低於1 % ;水與乙醇比例為1:1、1:3與1:7時,Co/CeO2之最高氫氣產率分別在C/O ratio = 0.7為51 %、在C/O ratio = 0.6為76 %與在C/O ratio = 0.6為77 %,而Co/BZDy分別在C/O ratio = 0.7為60 %、在C/O ratio = 0.6為74 %與在C/O ratio = 0.6為81 %,由氫氣產率變化的結果表示Co/BZDy較Co/CeO2雨水反應之能力強;在水與乙醇比例為1:7下,C/O ratio為0.61時,改變溫度之結果氫氣產率可以顯示不同載體對氧與水受溫度影響之狀況,在溫度為450oC到600oC,Co/CeO2最高為45 %,而在350oC到450oC時,Co/BZDy之最高氫氣產率為150 % ,此顯示Co/CeO2較易與氧氣反應,造成H2被氧化為H2O,而Co/BZDy較易與水反應,使H2O之H形成H2。在in situ DRIFT之光譜結果顯示出 Co/CeO2與Co/BZDy之反應中間物皆出現acetate (CH3COO),而其在不同載體之催化劑上會因親氧性與親水性的不同產生不同的細微變化:Co/CeO2因CeO2造成親氧性較強,使acetate斷C—C鍵後生成之COO易於離去生成CO/CO2,而CH3分解為C與H產生CO、H2、H2O;Co/BZDy因BZDy親水性較強,使acetate斷C—C鍵後生成之COO形成CO2,而CH3與水產生之H形成CH4。由反應後之TPR結果顯示,Co/CeO2¬¬之Co反應時為Co0之狀態,而Co/BZDy反應時之Co形成Co3+之狀態。由此三者分析之結果,推論出Co/CeO2¬與Co/BZDy之可能反應路徑。
The oxidative steam reforming of ethanol (OSRE) over cobalt on oxygen-active CeO2 and steam-active dysprosium doped BaZrO3 (BZDy) was investigated with various ethanol/oxygen/steam compositions at 400oC. The catalysts were synthesized with impregnation method and characterized by X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). The results found that 10% Co was successfully composited on both CeO2 and BZDy with two oxidation states, Co0 and Co3+. The catalytic products were analyzed with gas-chromatography (GC), and the intermediates were identified by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs). The reforming results found that the catalytic reaction can be activated at 400oC with the 100% ethanol conversions efficiency and 80% hydrogen yield at high oxygen and steam ratios (specify ratio and catalysts). The selectivity of acetaldehyde decreased by the increased oxygen and steam ratios. The product of ethylene (C2H4) was negligible. The selectivity of CO2 was high on both catalysts and is higher over Co/BZDy (66 %) than Co/CeO2 (36 %). However, the selectivities of CO and CH4 are much different. The selectivity of CO was varied from 50% to 90% and that of CH4 was less than 1% over Co/CeO2.On the other hand, the selectivity of CO was less than 1% and that of CH4 was varied from 30% to 50% over Co/BZDy. The difference between Co/CeO2 and Co/BZDy corresponded to the key intermediate of acetate (COO), identified by DRIFT at 1450 cm-1 and 1550 cm-1. For Co/CeO2, the acetate (COO) became less with increased temperatures or oxygen contents, responsible for the high CO/CO2 selectivity; on the contrast, it was abundant on Co/BZDy, responsible for high CH4/CO2 selectivity. The different catalytic mechanisms on the two catalysts indicate that the oxygen active supporter (CeO2) provided oxygen for facilitating the formation of CO/CO2 and the steam active supporter (BZDy) supplied not only oxygen but also hydrogen to compose CH4/CO2. The TPR results after OSRE found that Co0 is abundant on Co/CeO2 while plenty Co3+ is found Co/BZDy.
1. Raud, M., J. Olt, and T. Kikas, N2 explosive decompression pretreatment of biomass for lignocellulosic ethanol production. Biomass and Bioenergy, 2016. 90: p. 1-6.
2. Walker, S.B., et al., Benchmarking and selection of Power-to-Gas utilizing electrolytic hydrogen as an energy storage alternative. International Journal of Hydrogen Energy, 2016. 41(19): p. 7717-7731.
3. Janajreh, I., L. Su, and F. Alan, Wind energy assessment: Masdar City case study. Renewable Energy, 2013. 52: p. 8-15.
4. Eissa, Y., M. Chiesa, and H. Ghedira, Assessment and recalibration of the Heliosat-2 method in global horizontal irradiance modeling over the desert environment of the UAE. Solar Energy, 2012. 86(6): p. 1816-1825.
5. Sims, R.E.H., et al., An overview of second generation biofuel technologies. Bioresource Technology, 2010. 101(6): p. 1570-1580.
6. Fierro, V., O. Akdim, and C. Mirodatos, On-board hydrogen production in a hybrid electric vehicle by bio-ethanol oxidative steam reforming over Ni and noble metal based catalysts. Green Chemistry, 2003. 5(1): p. 20-24.
7. Wang, Z., et al., Nitrogen-doped porous carbons with high performance for hydrogen storage. International Journal of Hydrogen Energy, 2016. 41(20): p. 8489-8497.
8. Fathima, A.A., et al., Direct utilization of waste water algal biomass for ethanol production by cellulolytic Clostridium phytofermentans DSM1183. Bioresource Technology, 2016. 202: p. 253-256.
9. Wang, F., et al., Active Site Dependent Reaction Mechanism over Ru/CeO2 Catalyst toward CO2 Methanation. Journal of the American Chemical Society, 2016. 138(19): p. 6298-6305.
10. Widmann, D., R. Leppelt, and R.J. Behm, Activation of a Au/CeO2 catalyst for the CO oxidation reaction by surface oxygen removal/oxygen vacancy formation. Journal of Catalysis, 2007. 251(2): p. 437-442.
11. Song, Y.-L., et al., A DFT + U study of CO oxidation at CeO2(110) and (111) surfaces with oxygen vacancies. Surface Science, 2013. 618: p. 140-147.
12. Chou, C.-C., C.-F. Huang, and T.-H. Yeh, Investigation of ionic conductivities of CeO2-based electrolytes with controlled oxygen vacancies. Ceramics International, 2013. 39, Supplement 1: p. S627-S631.
13. Thalinger, R., et al., Ni–perovskite interaction and its structural and catalytic consequences in methane steam reforming and methanation reactions. Journal of Catalysis, 2016. 337: p. 26-35.
14. Jin, Y., et al., Autothermal reforming of ethanol in dense oxygen permeation membrane reactor. Catalysis Today, 2016. 264: p. 214-220.
15. de Lima, S.M., et al., Steam reforming, partial oxidation, and oxidative steam reforming of ethanol over Pt/CeZrO2 catalyst. Journal of Catalysis, 2008. 257(2): p. 356-368.
16. Crowley, S. and M.J. Castaldi, Mechanistic Insights into Catalytic Ethanol Steam Reforming Using Isotope-Labeled Reactants. Angew Chem Int Ed Engl, 2016. 55(36): p. 10650-5.
17. Kubacka, A., M. Fernandez-Garcia, and A. Martinez-Arias, Catalytic hydrogen production through WGS or steam reforming of alcohols over Cu, Ni and Co catalysts. Applied Catalysis a-General, 2016. 518: p. 2-17.
18. Delima, S., et al., Steam reforming, partial oxidation, and oxidative steam reforming of ethanol over Pt/CeZrO2 catalyst. Journal of Catalysis, 2008. 257(2): p. 356-368.
19. Munoz, M., S. Moreno, and R. Molina, Synthesis of Ce and Pr-promoted Ni and Co catalysts from hydrotalcite type precursors by reconstruction method. International Journal of Hydrogen Energy, 2012. 37(24): p. 18827-18842.
20. Muñoz, M., S. Moreno, and R. Molina, Promoting effect of Ce and Pr in Co catalysts for hydrogen production via oxidative steam reforming of ethanol. Catalysis Today, 2013. 213: p. 33-41.
21. Munoz, M., S. Moreno, and R. Molina, The effect of the absence of Ni, Co, and Ni-Co catalyst pretreatment on catalytic activity for hydrogen production via oxidative steam reforming of ethanol. International Journal of Hydrogen Energy, 2014. 39(19): p. 10074-10089.
22. Osorio-Vargas, P., et al., Improved stability of Ni/Al2O3 catalysts by effect of promoters (La2O3, CeO2) for ethanol steam-reforming reaction. Catalysis Today, 2016. 259, Part 1: p. 27-38.
23. Hung, C.-C., et al., Oxidative steam reforming of ethanol for hydrogen production on M/Al2O3. International Journal of Hydrogen Energy, 2012. 37(6): p. 4955-4966.
24. Li, D., X. Li, and J. Gong, Catalytic Reforming of Oxygenates: State of the Art and Future Prospects. Chem Rev, 2016. 116(19): p. 11529-11653.
25. Ferencz, Z., et al., Effects of Support and Rh Additive on Co-Based Catalysts in the Ethanol Steam Reforming Reaction. ACS Catalysis, 2014. 4(4): p. 1205-1218.
26. Maia, T.A., J.M. Assaf, and E.M. Assaf, Study of Co/CeO2-γ-Al2O3 catalysts for steam and oxidative reforming of ethanol for hydrogen production. Fuel Processing Technology, 2014. 128: p. 134-145.
27. Słowik, G., M. Greluk, and A. Machocki, Microscopic characterization of changes in the structure of KCo/CeO2 catalyst used in the steam reforming of ethanol. Materials Chemistry and Physics, 2016. 173: p. 219-237.
28. Greluk, M., M. Rotko, and A. Machocki, Conversion of Ethanol Over Co/CeO2 and KCo/CeO2 Catalysts for Hydrogen Production. Catalysis Letters, 2015. 146(1): p. 163-173.
29. Choi, S.M., et al., Determination of Electronic and Ionic Partial Conductivities of BaCeO3 with Yb and In Doping. Journal of The Electrochemical Society, 2015. 162(7): p. F789-F795.
30. Iwahara, H., et al., Formation of high oxide ion conductive phases in the sintered oxides of the system Bi2O3Ln2O3 (Ln = LaYb). Journal of Solid State Chemistry, 1981. 39(2): p. 173-180.
31. Turczyniak, S., et al., Effect of the surface state on the catalytic performance of a Co/CeO2 ethanol steam-reforming catalyst. Journal of Catalysis, 2016. 340: p. 321-330.
32. Li, M.-R., J. Chen, and G.-C. Wang, Reaction Mechanism of Ethanol on Model Cobalt Catalysts: DFT Calculations. The Journal of Physical Chemistry C, 2016. 120(26): p. 14198-14208.
33. Konsolakis, M., M. Sgourakis, and S.A.C. Carabineiro, Surface and redox properties of cobalt–ceria binary oxides: On the effect of Co content and pretreatment conditions. Applied Surface Science, 2015. 341: p. 48-54.
34. Konsolakis, M., et al., Effect of cobalt loading on the solid state properties and ethyl acetate oxidation performance of cobalt-cerium mixed oxides. J Colloid Interface Sci, 2017. 496: p. 141-149.
35. de Caprariis, B., et al., Rh, Ru and Pt ternary perovskites type oxides BaZr(1-x)MexO3 for methane dry reforming. Applied Catalysis A: General, 2016. 517: p. 47-55.
36. Varga, E., et al., The Effect of Rh on the Interaction of Co with Al2O3 and CeO2 Supports. Catalysis Letters, 2016. 146(9): p. 1800-1807.
37. Peiretti, L.F., et al., CeO2 and Co3O4-CeO2 nanoparticles: effect of the synthesis method on the structure and catalytic properties in COPrOx and methanation reactions. Journal of Materials Science, 2016. 51(8): p. 3989-4001.
38. Chen, Y., et al., Ternary composite oxide catalysts CuO/Co3O4–CeO2 with wide temperature-window for the preferential oxidation of CO in H2-rich stream. Chemical Engineering Journal, 2013. 234: p. 88-98.
39. Sohn, H., et al., Effect of Cobalt on Reduction Characteristics of Ceria under Ethanol Steam Reforming Conditions: AP-XPS and XANES Studies. The Journal of Physical Chemistry C, 2016. 120(27): p. 14631-14642.
40. de Lima, A.E.P. and D.C. de Oliveira, In situ XANES study of Cobalt in Co-Ce-Al catalyst applied to Steam Reforming of Ethanol reaction. Catalysis Today, 2017. 283: p. 104-109.
41. Ni, M., D.Y.C. Leung, and M.K.H. Leung, A review on reforming bio-ethanol for hydrogen production. International Journal of Hydrogen Energy, 2007. 32(15): p. 3238-3247.
42. Song, H. and U.S. Ozkan, The role of impregnation medium on the activity of ceria-supported cobalt catalysts for ethanol steam reforming. Journal of Molecular Catalysis A: Chemical, 2010. 318(1-2): p. 21-29.
43. Barroso, M.N., et al., Effect of the water-ethanol molar ratio in the ethanol steam reforming reaction over a Co/CeO2/MgAl2O4 catalyst. Reaction Kinetics Mechanisms and Catalysis, 2015. 115(2): p. 535-546.
44. Xu, W.Q., et al., Steam Reforming of Ethanol on Ni/CeO2: Reaction Pathway and Interaction between Ni and the CeO2 Support. Acs Catalysis, 2013. 3(5): p. 975-984.
45. Soykal, I.I., H. Sohn, and U.S. Ozkan, Effect of Support Particle Size in Steam Reforming of Ethanol over Co/CeO2Catalysts. ACS Catalysis, 2012. 2(11): p. 2335-2348.