Experimental study on the selective catalytic reduction of NO with C3H6 over Co/Fe/Al2O3/cordierite catalysts
-
摘要: 采用溶胶凝胶法和浸渍法制备了负载于蜂窝陶瓷上的Co/Fe/Al2O3/cordierite催化剂，在陶瓷管流动反应器上对其催化C3H6选择性还原NO的性能进行了测试。结果表明，该催化剂表现出最优脱硝性能，在模拟烟气条件下，当反应温度为550 ℃时可实现97%的脱硝效率。Co的引入可显著增强Fe/Al2O3/cordierite催化剂抗SO2和H2O的能力。在模拟烟气中同时引入0.02% SO2和3% H2O后，1.5Co/Fe/Al2O3/cordierite的脱硝性能受影响甚微，当反应温度高于500 ℃时1.5Co/Fe/Al2O3/cordierite催化C3H6还原NO的效率均可达到90%以上；相比之下，未经Co修饰的催化剂Fe/Al2O3/cordierite脱硝性能受到了严重的抑制，在整个反应温度区间（200-700 ℃）内，其催化C3H6还原NO的效率最高不足50%。XRD和SEM表征结果表明，经过适量的Co修饰后的1.5Co/Fe/Al2O3/cordierite表面变得更疏松，且形成了以钴铁和钴铝双金属氧化物为主要成分的球状晶粒。H2-TPR结果表明，相比于Fe/Al2O3/cordierite，1.5Co/Fe/Al2O3/cordierite有更好的低温还原性能。Py-FTIR结果表明，Co的引入可使催化剂表面的Lewis酸明显增加，且生成了Brønsted酸。N2吸附-脱附表征结果表明，Co可增大催化剂的比表面积。
-
关键词:
- 选择性催化还原 /
- Co/Fe/Al2O3/cordierite催化剂 /
- NO /
- 丙烯
Abstract: The Co/Fe/Al2O3/cordierite catalysts with different Co loadings were prepared by sol-gel and impregnation methods, and their performance in the selective catalytic reduction of NO with C3H6 over catalytic were experimentally studied in a ceramic tubular reactor. The results indicated that 1.5Co/Fe/Al2O3/cordierite showed the highest C3H6-SCR activity with 97% NO reduction in the simulated flue gas at 550 ℃. Cobalt was able to effectively improve the ability of Fe/Al2O3/cordierite catalysts to resist SO2 and H2O in flue gas. When 0.02% SO2 and 3% water vapor were added to the simulated flue gas, the NO reduction efficiency of 1.5Co/Fe/Al2O3/cordierite was almost unaffected, the NO reduction by 1.5Co/Fe/Al2O3/cordierite with C3H6 all surpassed 90%. In contrast, the catalytic activity of Fe/Al2O3/cordierite without cobalt modification was seriously suppressed by SO2 and H2O, the highest NO reduction efficiency of Fe/Al2O3/cordierite was less than 50% within the entire reaction temperature range (200-700 ℃).XRD and SEM results showed that the surface of 1.5Co/Fe/Al2O3/cordierite after the modification by cobalt became loose, and formed by the cobalt iron and cobalt aluminum metal oxide-based spherical grains.H2-TPR results showed that 1.5Co/Fe/Al2O3/cordierite had better low temperature reduction performance than Fe/Al2O3/cordierite. Py-FTIR results confirmed that Co can dramatically increased the Lewis acid and produced Brønsted acid on the catalyst surface. N2 adsorption/desorption characterization results proved that Co can increase the specific surface area of the catalyst.-
Key words:
- selective catalytic reduction of NO /
- Co/Fe/Al2O3/cordierite catalyst /
- NO /
- C3H6
-
图 1 实验系统示意图
Figure 1 Experimental setup
1, 2, 3: gas sources; 4: gas regulator; 5: flow meter; 6: ceramic tube; 7: electrically heated furnace; 8: Co/Fe/Al2O3/cordierite sample; 9: gas analyzer
图 2 Co不同负载量分别对NO和C3H6的转化率及其相应N2选择性的影响
Figure 2 Effect of Co loading on the conversion of NO and C3H6 and N2 selectivity
(a): NO conversion; (b): C3H6 conversion; (c): N2 selectivity (flow rate=1.5 L/min, NO=0.05%, C3H6=0.3%, O2=1%, N2 balanced)
图 3 SO2和水蒸气对1.5Co/Fe/Al2O3/cordierite催化剂催化活性的影响
Figure 3 Effect of SO2 and water vapor on the catalytic activity of 1.5Co/Fe/Al2O3/cordierite on NO conversion
(a): NO conversion vs temperature with/without 0.02% SO2 and 3% H2O; (b): effect of 0.02% SO2; (c): 2.5% H2O on NO conversion vs reaction time (flow rate=1.5 L/min, NO=0.05%, C3H6=0.3%, O2=1%, N2 balanced, 550℃)
图 8 催化剂的N2吸附-脱附等温曲线及孔径分布
Figure 8 Adsorption isotherms of nitrogen on different samples at -196 ℃
(a): N2 adsorption/desorption isotherms; (b): BJH pore size distribution
表 1 三组典型的催化剂中酸性位的含量
Table 1 Acid amount of the three typical catalyst samples
Sample 40 ℃ 170 ℃ 300 ℃ B/
(μmol·g-1)L/
(μmol·g-1)B/
(μmol·g-1)L/
(μmol·g-1)B/
(μmol·g-1)L/
(μmol·g-1)Fe/Al2O3/cordierite[19] 0 6 0 4.18 0 1.9 1.5Co/Fe/Al2O3/cordierite 16.4 686 11.2 427 0 75 4.3Co/Fe/Al2O3/cordierite 16.2 343 15 239 0 85 
下载: 导出CSV
表 2 不同负载量催化剂的微孔隙特性
Table 2 Textural properties of the catalysts with different Co/Fe loadings
Catalyst ABET/(m2·g-1) vp/(cm3·g-1) dp/nm Fe /Al2O3/cordierite [38] 19 0.039 6.54 0.5Co/Fe/Al2O3/cordierite 18 0.038 8.51 1.5Co/Fe/20Al2O3/cordierite 23 0.039 6.90 4.3Co/Fe/20Al2O3/cordierite 24 0.041 7.13
下载: 导出CSV
-
[1] HELD W, KÖNIG A, RICHTER T, PUPPE L. Catalytic MOx reduction in net oxidizing exhaust gas[J]. SAE Trans, 1990, 99(4):209-216. [2] CHEN L, TATSURO H, TOSHIAKI M. On the promotional effect of Sn in Co-Sn/Al2O3 catalyst for NO selective reduction[J]. Catal Lett, 2001, 78(1/2):71-75. [3] MIYAHARA Y, TAKAHASHI M, MASUDA T, IMAMURA S, KANAI H, IWAMOTO S, WATANABE T, INOUE M. Selective catalytic reduction of NO with C1-C3 reductants over solvothermally prepared Ga2O3-Al2O3 catalysts:Effects of water vapor and hydrocarbon uptake[J]. Appl Catal B:Environ, 2008, 84(1):289-296. https://www.sciencedirect.com/science/article/pii/S0926337308001331 [4] YASHNIK S A, SALNIKOV A V, VASENIN N T, ANUFRIENKO V F, LSMAGILOV Z R. Regulation of the copper-oxide cluster structure and DeMOx activity of Cu-ZSM-5 catalysts by variation of OH/Cu2+[J]. Catal Today, 2012, 197(1):214-227. doi: 10.1016/j.cattod.2012.08.033 [5] 苏亚欣, 任立铭, 苏阿龙, 邓文义.甲烷在金属铁及氧化铁表面还原NO的研究[J].燃料化学学报, 2013, 41(11):1393-1400. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract18303.shtmlSU Ya-xin, REN Li-ming, SU A-long, DENG Wen-yi. NO reduction by methane on the surface of iron oxides[J]. J Fuel Chem Technol, 2013, 41(11):1393-1400. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract18303.shtml [6] 苏亚欣, 苏阿龙, 成豪.金属铁直接催化还原NO的实验研究[J].煤炭学报, 2013, 38(s1):206-210. http://www.cqvip.com/QK/96550X/2013A01/45886921.htmlSU Ya-xin, SU A-long, CHENG Hao. Experimental study on direct catalytic reduction of NO by metallic iron[J]. J China Coal Soc, 2013, 38(s1):206-210. http://www.cqvip.com/QK/96550X/2013A01/45886921.html [7] 苏亚欣, 陆哲惺, 周皞, 窦逸峰, 邓文义.丙烷在金属铁表面还原NO的实验研究[J].燃料化学学报, 2014, 42(12):1470-1477. doi: 10.3969/j.issn.0253-2409.2014.12.009SU Ya-xin, LU Zhe-xing, ZHOU Hao, DOU Yi-feng, DENG Wen-yi. Experimental study on NO reduction by propane over iron[J]. J Fuel Chem Technol, 2014, 42(12):1470-1477. doi: 10.3969/j.issn.0253-2409.2014.12.009 [8] 窦逸峰, 苏亚欣, 陆哲惺, 周嗥, 邓文义.乙烷在金属铁表面还原NO的实验研究[J].燃料化学学报, 2015, 43(10):1273-1280. doi: 10.3969/j.issn.0253-2409.2015.10.017DOU Yi-feng, SU Ya-xin, LU Zhe-xing, ZHOU Hao, DENG Wen-yi. Experimental study of NO reduction by ethane over iron[J]. J Fuel Chem Technol, 2015, 42(10):1273-1280. doi: 10.3969/j.issn.0253-2409.2015.10.017 [9] 周皞, 廖文裕, 苏亚欣, 林辛越. H2O和SO2对甲烷在金属铁表面还原NO的影响[J].洁净煤技术, 2015, 21(2):51-55.ZHOU Hao, LIAO Wen-yu, SU Ya-xin, LIN Xin-yue. Influence of H2O and SO2 on NO reduction by methane on the surface of iron[J]. Clean Coal Technol, 2015, 21(2):51-55. [10] ZHOU H, SU Y X, LIAO W Y, ZHONG F C. Preparation, characterization, and properties of monolithic Fe/Al2O3/cordierite catalysts for NO reduction with C2H6[J]. Appl Catal A:Gen, 2015, 505:402-409. doi: 10.1016/j.apcata.2015.08.025 [11] ZHOU H, SU Y X, LIAO W Y, ZHONG F C. NO reduction by propane over monolithic cordierite-based Fe/Al2O3 catalyst:Reaction mechanism and effect of H2O/SO2[J]. Fuel, 2016, 182:352-360. doi: 10.1016/j.fuel.2016.05.116 [12] LI Y, ARMOR J. N. Metal exchanged ferrierites as catalysts for the selective reduction of MOx with methane[J]. Appl Catal B:Environ, 1993, 3(1):L1-L11. doi: 10.1016/0926-3373(93)80064-K [13] LI Y J, ARMOR J N. Selective catalytic reduction of NO with methane on gallium catalysis[J]. J Catal, 1994, 145(1):1-9. doi: 10.1006/jcat.1994.1001 [14] LI Y J, ARMOR J N. Catalytic reduction of nitrogen oxides with methane in the presence of excess oxygen[J]. Appl Catal B:Environ, 1992, 1(4):L31-L40. doi: 10.1016/0926-3373(92)80050-A [15] HORIUCHI T, FUJIWARA T, CHEN L, SUZUKI K, MORI T. Selective catalytic reduction of NO by C3H6 over Co/Al2O3 catalyst with extremely low cobalt loading[J]. Catal Lett, 2002, 78(1/4):319-323. doi: 10.1023/A:1014952400564 [16] VAN DEN BRINK R W, BOONEVELD S, VERHAAK M J F M, DEBRUIJN F A. Selective catalytic reduction of N2O and MOx in a single reactor in the nitric acid industry[J]. Catal Today, 2002, 75(1):227-232. [17] YAN J Y, KUNG M C, SACHTLER W M H, KUNG H. Co/Al2O3 lean MOx reduction catalyst[J]. J Catal, 1997, 172(1):178-186. doi: 10.1006/jcat.1997.1869 [18] 周皞, 苏亚欣, 邓文义, 钟方川.金属氧化物类催化剂上HC-SCR研究进展[J].环境科学与技术, 2016, (1):93-100. http://www.cqvip.com/QK/90776X/201601/667998883.htmlZHOU Hao, SU Ya-xin, DENG Wen-yi, ZHONG Fang-chuan. A review of HC-SCR over metal oxides-based catalysts[J]. Environ Sci Technol, 2016, (1):93-100. http://www.cqvip.com/QK/90776X/201601/667998883.html [19] 李伉锴, 周皞, 苏亚欣, 袁旻昊, 邓文义, 赵兵涛.丙烷在Ce-Fe/Al2O3/cordierite上选择性催化还原NO[J].燃料化学学报, 2018, 46(1):99-109. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract19157.shtmlLI Kang-kai, ZHOU Hao, SU Ya-xin, YUAN Min-hao, DENG Wen-yi, ZHAO Bing-tao. Selective catalytic reduction of NO by C3H8 over Ce-Fe/Al2O3/cordierite catalysts[J]. J Fuel Chem Technol, 2018, 46(1):99-109. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract19157.shtml [20] SHAO C, LIU X, MENG D, XU Q, GUO Y. Catalytic performance of Co-Fe mixed oxide for NH3-SCR reaction and the promotional role of cobalt[J]. RSC Adv, 2016, 6(70):66169-66179. doi: 10.1039/C6RA12025C [21] LIU R, XU Y, YE F, FENG J, XU R. Influence of transition metal (Fe, Co, Ag) doping on the MnOx-CeO2/Ti-bearing blast furnace slag catalyst for selective catalytic reduction of MOx with NH3 at low temperature[J]. New J Chem, 2017, 41:11299-11307. doi: 10.1039/C7NJ00775B [22] QIAO J S, WANG N, WANG Z H, SUN W, SUN K N. Porous bimetallic Mn2Co1Ox catalysts prepared by a one-step combustion method for the low temperature selective catalytic reduction of MOx with NH3[J]. Catal Commun, 2015, 72:111-115. doi: 10.1016/j.catcom.2015.09.023 [23] MAUNULA T, AHOLA J, HAMADA H. Reaction mechanism and kinetics of MOx reduction by propene on CoOx/alumina catalysts in lean conditions[J]. Appl Catal B:Environ, 2000, 26(3):173-192. doi: 10.1016/S0926-3373(00)00118-1 [24] 陈九玉, 朱宝忠, 堵同宽, 孙运兰, 朱自成. Co改性Fe2O3/AC催化剂低温SCR脱硝性能[J].有色金属工程, 2017, 7(2):99-102.CHEN Jiu-yu, ZHU Bao-zhong, DU Tong-kuan, SUN Yun-lan, ZHU Zi-cheng. Low-temperature selective catalytic reduction of MOx with NH3 over Co modified Fe2O3/AC catalysts[J]. Nonf Met Eng, 2017, 7(2):99-102. [25] GONZALEZ-VELASCO J R, FERRET R, LOPEZ-FONSECA R, GUTIERREZ-ORTIZ M A. Influence of particle size distribution of precursor oxides on the synthesis of cordierite by solid-state reaction[J]. Powder Technol, 2005, 153(1):34-42. doi: 10.1016/j.powtec.2005.01.022 [26] MIHAYLOV M, HADJⅡVANOV K. Redox couples in the selective catalytic reduction of MOx with hydrocarbons over Co-ZSM-5 and Ni-ZSM-5 catalysts:An FT-IR study[J]. Chem Commun, 2004, 10(19):2200. https://es.scribd.com/doc/12880656/2003 [27] CHEN X M, ZHU A, SHI C. The nature of active sites of Co/Al2O3 for the selective catalytic reduction of NO with C2H4[J]. Catal Lett, 2009, 133:134-141. doi: 10.1007/s10562-009-0146-1 [28] ZIELINSKI J, ZGLINICKA I, ZNAK L, KASZKUR Z. Reduction of Fe2O3 with hydrogen[J]. Appl Catal A:Gen, 2010, 381(1/2):191-196. [29] RIEDEL T, CLAEYS M, SCHULZ H, SCHAUB G, NAM S S, JUN KW, CHOI M J, KISHAN G, LEE K W. Comparative study of Fischer-Tropsch synthesis with H2/CO and H2/CO2, syngas using Fe-and Co-based catalysts[J]. Appl Catal A:Gen, 1999, 186(1/2):201-213. https://www.researchgate.net/publication/324519882_Study_of_CO_Hydrogenation_Reaction_on_Cobalt_Titania_Catalyst [30] LOGDBERG S, TRISTANTINI D W. Hydrocarbon production via Fischer-Tropsch synthesis from H2-poor syngas over different Fe-Co/Al2O3 bimetallic catalysts[J]. Appl Catal B:Environ, 2009, 89:167-182. doi: 10.1016/j.apcatb.2008.11.037 [31] BAO A, LI J L, ZHANG Y H. Effect of barium on reducibility and activity for cobalt-based Fischer-Tropsch synthesis catalysts[J]. J Nat Gas Chem, 2010, 19:622-627. doi: 10.1016/S1003-9953(09)60120-1 [32] WILLIAMS M F, FONFÉ B, SIEVERS C. Hydrogenation of tetralin on silica-alumina-supported Pt catalysts I. Physicochemical characterization of the catalytic materials[J]. J Catal, 2007, 251(2):485-496. doi: 10.1016/j.jcat.2007.06.009 [33] JAGTAP N, UMBARKAR S B, MIQUEL P, GRANGER P, DONGARE M K. Support modification to improve the sulphur tolerance of Ag/Al2O3, for SCR of MOx, with propene under lean-burn conditions[J]. Appl Catal B:Environ, 2009, 90(3/4):416-425. https://es.scribd.com/doc/210773456/All-Questions-Word-Count [34] KANTCHEVA M, VAKKASOGLU A S. Cobalt supported on zirconia and sulfated zirconia I.:FT-IR spectroscopic characterization of the MOx species formed upon NO adsorption and NO/O2 coadsorption[J]. J Catal, 2004, 223(2):352-363. doi: 10.1016/j.jcat.2004.02.007 [35] KANTCHEVA M, VAKKASOGLU A S. Cobalt supported on zirconia and sulfated zirconia:Ⅱ. Reactivity of adsorbed MOx, compounds toward methane[J]. J Catal, 2004, 223(2):364-371. doi: 10.1016/j.jcat.2004.02.006 [36] LI N, WANG A Q, ZHENG M Y, WANG X D, CHENG R H, ZHANG T. Probing into the catalytic nature of Co/sulfated zirconia for selective reduction of NO with methane[J]. J Catal, 2004, 225(2):307-315. doi: 10.1016/j.jcat.2004.04.026 [37] SULTANA A, HANEDA M, FUJITANI T, HAMADA H. Influence of Al2O3, support on the activity of Ag/Al2O3, catalysts for SCR of NO with decane[J]. Catal Lett, 2007, 114(1/2):96-102. [38] 杨溪, 苏亚欣, 钱文燕, 袁旻昊, 周皞, 邓文义, 赵兵涛. Fe-Ag/Al2O3催化丙烯还原NO的实验研究[J].燃料化学学报, 2017, 45(11):1365-1375. doi: 10.3969/j.issn.0253-2409.2017.11.012YANG Xi, SU Ya-xin, QIAN Wen-yan, YUAN Min-hao, ZHOU Hao, DENG Wen-yi, ZHAO Bing-tao. Experimental study on selective catalytic reduction of NO by C3H6 over Fe-Ag/Al2O3 catalysts[J]. J Fuel Chem Technol, 2017, 45(11):1365-1375. doi: 10.3969/j.issn.0253-2409.2017.11.012 [39] CHEN Z, YANG Q, LI H, LI X H, WANG L, TSANG S C. Cr-MnOx mixed-oxide catalysts for selective catalytic reduction of MOx with NH3 at low temperature[J]. J Catal, 2010, 276(1):56-65. doi: 10.1016/j.jcat.2010.08.016 -
点击查看大图
图(8) / 表(2)
计量
- 文章访问数: 104
- HTML全文浏览量: 84
- PDF下载量: 6
- 被引次数: 0
