研究生: |
郭伯揚 Kuo, Po-Yang |
---|---|
論文名稱: |
還原時間、鎳(Ni)的摻入及載體(CeO2, BZDy)對於鈷(Co)催化劑在乙醇氧化蒸氣重組反應之影響與反應機構探討 The Mechanistic Study and Effects of Reduction Time and Ni-Dopant and Support for Cobalt-Based catalysts on Oxidation Steam Reforming of Ethanol (OSRE) |
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: | 2018 |
畢業學年度: | 106 |
語文別: | 中文 |
論文頁數: | 68 |
中文關鍵詞: | 乙醇氧化蒸汽重組 、產氫 、鈷 、氧化態 、氧化鈰 、鋯酸鋇摻鏑 、in situ DRIFT 、XPS |
英文關鍵詞: | oxidation steam reforming of ethanol, hydrogen production, oxidation state, cobalt, CeO2, BZDy, in situ DRIFT, XPS |
DOI URL: | http://doi.org/10.6345/THE.NTNU.DC.006.2018.B05 |
論文種類: | 學術論文 |
相關次數: | 點閱:165 下載:5 |
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本實驗以含浸法來合成10%金屬鈷(Co)與鈷鎳合金分別附載於氧流動性之氧化鈰(CeO2)與親水性之鋯酸鋇摻雜鏑(BZDy)之催化劑,在進行乙醇氧化蒸汽重組反應(OSRE)前,催化劑分別在氫氣下進行還原0小時、還原1.5小時及還原4小時的前處理。催化劑鑑定方面使用能量散射光譜儀(EDS)、X-ray粉末繞射分析儀(XRD)、X-ray光電子能譜儀(XPS)、程序升溫還原反應(TPR)進行催化劑的特性鑑定。透過氣相層析儀GC分析產物選擇率、轉換效率及氫氣產率的催化性能。以原位漫反射傅立葉轉換紅外光譜儀(in situ DRIFTS IR)來推測乙醇氧化蒸汽重組之反應路徑。實驗結果顯示Co附載於親氧性之CeO2上時在OSRE反應過程中能很容易被氧化或還原,但Co在親水性之BZDy上則較難。兩者在氫氣還原4小時前處理下的反應性相似,但Co/CeO2表面活性氧較多,因此CO2選擇率較高,Co/BZDy表面活性氧較少,則CO選擇率較高。Ni摻入Co/CeO2後會使斷C-C鍵能力增強,也會使CO進行WGS反應而導致、H2產率及CO2選擇率提高,但同時也造成CH4選擇率較高及積碳失活的問題。在situ DRIFTS 實驗中,Co/CeO2的表面較具氧流動性,易使乙醛氧化成CH3COO-,而Co/BZDy的氧流動性較差,較易形成CH3CO-。氧氣的加入會促使CH3COO-及CH3CO-在200OC時就能斷C-C鍵而形成CH3 + CO2與CH3 + CO以及促使CH3和CO的氧化。Ni摻入Co/CeO2後會使得acetate的訊號較小,代表Ni對於斷C-C鍵有很高的活性。
Co and Co-Ni bimetallic catalysts on oxophilic CeO2 and hydrophilic Dy-doped BaZrO3 (BZDy) were synthesized by impregnation method and treated with H2 reduction for 0, 1.5 and 4 hours before proceeding the oxidation steam reforming of ethanol reaction (OSRE). The catalysts were characterized by Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The catalytic performance of product selectivity, conversion efficiency and H2 yield was analyzed by gas chromatography. The catalytic mechanism was investigated by in situ DRIFTS IR. The experimental results found that Co can be easily reduced/oxidized on the oxophilic CeO2, but hard on the hydrophilic BZDy in OSRE. Both of the catalysts showed similar reactivity after 4-hour H2 pretreatment, but Co/CeO2 with more surface active oxygen showed higher, CO2 selectivity. Introducing Ni in the formation of Ni-Co bimetal can assist C-C bond cleavage and enhance the H2 yield as well as CO2 selectivity due to the water-gas-shift reaction (WGSR); however, it also results in a higher CH4 selectivity and carbon inactivation problems. The In situ DRIFT result showed that Co/CeO2 has better oxygen mobility and can easily to oxidize acetaldehyde to CH3COO-, while Co/BZDy with the poor oxygen mobility easily form CH3CO- instead. The addition of oxygen would assist the C-C bond cleavage of CH3COO- and CH3CO- at 200 OC to form CH3 + CO2 and CH3 + CO, respectively, as well as to promote the following oxidation of CH3 and CO. The doping Ni could reduce acetate signal, indicating its assistance for the C-C bond cleavage.
1. El-Nashar, A.M., Effect of dust deposition on the performance of a solar desalination plant operating in an arid desert area. Solar Energy, 2003. 75(5): p. 421-431.
2. Devine-Wright, P., Beyond NIMBYism: towards an integrated framework for understanding public perceptions of wind energy. Wind Energy, 2005. 8(2): p. 125-139.
3. 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.
4. 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.
5. Fathima, A.A., et al., Direct utilization of waste water algal biomass for ethanol production by cellulolytic Clostridium phytofermentans DSM1183. Bioresour Technol, 2016. 202: p. 253-6.
6. Soykal, I.I., H. Sohn, and U.S. Ozkan, Effect of Support Particle Size in Steam Reforming of Ethanol over Co/CeO2 Catalysts. Acs Catalysis, 2012. 2(11): p. 2335-2348.
7. 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.
8. 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.
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. Shin, H.H., et al., Cobalt Catalysts Decorated with Platinum Atoms Supported on Barium Zirconate Provide Enhanced Activity and Selectivity for CO2 Methanation. Acs Catalysis, 2016. 6(5): p. 2811-2818.
11. Sažinas, R., et al., Effect of CO2Exposure on the Chemical Stability and Mechanical Properties of BaZrO3-Ceramics. Journal of the American Ceramic Society, 2016. 99(11): p. 3685-3695.
12. Han, D., et al., Dopant Site Occupancy and Chemical Expansion in Rare Earth-Doped Barium Zirconate. Journal of the American Ceramic Society, 2014. 97(2): p. 643-650.
13. Pirez, C., et al., Steam reforming, partial oxidation and oxidative steam reforming for hydrogen production from ethanol over cerium nickel based oxyhydride catalyst. Applied Catalysis A: General, 2016. 518: p. 78-86.
14. Konsolakis, M., et al., Hydrogen Production by Ethanol Steam Reforming (ESR) over CeO2 Supported Transition Metal (Fe, Co, Ni, Cu) Catalysts: Insight into the Structure-Activity Relationship. Catalysts, 2016. 6(3): p. 39.
15. 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.
16. Fukuhara, C., et al., A novel nickel-based structured catalyst for CO 2 methanation: A honeycomb-type Ni/CeO 2 catalyst to transform greenhouse gas into useful resources. Applied Catalysis A: General, 2017. 532: p. 12-18.
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. Zhang, B., et al., Hydrogen production by steam reforming of ethanol over an Ir/CeO2 catalyst: Reaction mechanism and stability of the catalyst. International Journal of Hydrogen Energy, 2008. 33(16): p. 4377-4386.
19. 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.
20. Liu, Z., et al., Mechanistic Insights of Ethanol Steam Reforming over Ni–CeOx(111): The Importance of Hydroxyl Groups for Suppressing Coke Formation. The Journal of Physical Chemistry C, 2015. 119(32): p. 18248-18256.
21. 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.
22. 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.
23. Song, H. and U.S. Ozkan, Ethanol steam reforming over Co-based catalysts: Role of oxygen mobility. Journal of Catalysis, 2009. 261(1): p. 66-74.
24. 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.
25. Bayram, B., et al., Ethanol steam reforming over Co-based catalysts: Investigation of cobalt coordination environment under reaction conditions. Journal of Catalysis, 2011. 284(1): p. 77-89.
26. Saeki, T., et al., Synergistic effects of CeO2-supported bimetallic Ni-Cu, Co-Cu, and Ni-Fe catalysts on steam reforming of ethanol. Journal of the Ceramic Society of Japan, 2015. 123(1442): p. 955-960.
27. He, L., et al., Co-Ni Catalysts Derived from Hydrotalcite-Like Materials for Hydrogen Production by Ethanol Steam Reforming. Topics in Catalysis, 2009. 52(3): p. 206-217.
28. Maia, T.A., J.M. Assaf, and E.M. Assaf, Study of Co/CeO2-gamma-Al2O3 catalysts for steam and oxidative reforming of ethanol for hydrogen production. Fuel Processing Technology, 2014. 128: p. 134-145.
29. Karim, A.M., et al., Catalytic Roles of Co-0 and Co2+ during Steam Reforming of Ethanol on Co/MgO Catalysts. Acs Catalysis, 2011. 1(4): p. 279-286.
30. Sun, J.M., et al., New insights into reaction mechanisms of ethanol steam reforming on Co-ZrO2. Applied Catalysis B-Environmental, 2015. 162: p. 141-148.
31. Yu, S.W., et al., The effect of accessible oxygen over Co3O4-CeO2 catalysts on the steam reforming of ethanol. International Journal of Hydrogen Energy, 2014. 39(35): p. 20700-20711.
32. <1-s2.0-0022459681903285-main.pdf>.
33. Pal, P., et al., Defect-Induced Efficient Partial Oxidation of Methane over Nonstoichiometric Ni/CeO2 Nanocrystals. The Journal of Physical Chemistry C, 2015. 119(24): p. 13610-13618.
34. Sohn, H., et al., Effect of Cobalt on Reduction Characteristics of Ceria under Ethanol Steam Reforming Conditions: AP-XPS and XANES Studies. Journal of Physical Chemistry C, 2016. 120(27): p. 14631-14642.
35. Lukashuk, L., et al., Operando XAS and NAP-XPS studies of preferential CO oxidation on Co 3 O 4 and CeO 2 -Co 3 O 4 catalysts. Journal of Catalysis, 2016. 344: p. 1-15.
36. 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.
37. 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.
38. Passos, A.R., et al., Effect of the balance between Co(II) and Co(0) oxidation states on the catalytic activity of cobalt catalysts for Ethanol Steam Reforming. Catalysis Today, 2014. 229: p. 88-94.
39. Carrasco, J., et al., Theoretical Studies of the Adsorption of CO and C on Ni(111) and Ni/CeO2(111): Evidence of a Strong Metal-Support Interaction. Journal of Physical Chemistry C, 2013. 117(16): p. 8241-8250.
40. Lu, S., et al., Catalytic oxidation of formaldehyde over CeO 2 -Co 3 O 4 catalysts. Journal of Rare Earths, 2017. 35(9): p. 867-874.
41. 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.
42. de Lima, S.M., et al., Study of catalyst deactivation and reaction mechanism of steam reforming, partial oxidation, and oxidative steam reforming of ethanol over Co/CeO2 catalyst. Journal of Catalysis, 2009. 268(2): p. 268-281.
43. Song, H., et al., Adsorption/Desorption Behavior of Ethanol Steam Reforming Reactants and Intermediates over Supported Cobalt Catalysts. Catalysis Letters, 2011. 141(1): p. 43-54.
44. Xu, X., J. Li, and Z. Hao, CeO2-Co3O4 Catalysts for CO Oxidation. Journal of Rare Earths, 2006. 24(2): p. 172-176.