铁钨复合氧化物用于NH<sub>3</sub>选择性催化还原NO

摘要

采用共沉淀法制备铁钨复合氧化物催化剂,用于NH₃选择性催化还原NO,考察了Fe/W物质的量之比、反应空速、SO₂和H₂O对催化剂脱硝活性的影响,同时运用SEM、XRD、BET、NH₃-TPD等表征手段对催化剂的微观形貌、晶型、比表面积、孔结构参数及表面酸性进行了分析。实验结果表明当n(Fe):n(W)=4:1时,催化剂的反应活性最佳,其在300~400 ℃温度范围内及GHSV=75 000 h^-1 条件下NO转化率仍保持在90%以上,同时其也显示出较强的抗SO₂和H₂O中毒性能。通过表征发现Fe与W之间强烈的相互作用,较大的比表面积和催化剂较强的酸性是催化剂催化活性较好的主要原因。

	Service

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	Email Alert
	RSS
	作者相关文章
	戎雪佳
	李永红
	李晓良

关键词：铁钨复合氧化物催化剂；选择性催化还原；脱硝

Abstract：

Iron-Tungsten mixed oxide catalyst was prepared by the co-precipitation method and used for the selective catalytic reduction of NO with NH₃.The effects of molar ratios of Fe/W, space velocity, SO₂ and H₂O on the NO conversion were investigated. The characterization means of SEM, XRD, BET and NH₃-TPD were also applied to analyze the physicochemical properties of the catalyst. Among all the iron-tungsten mixed oxides, the catalyst with the Fe/W molar ratio of 4:1 exhibited the best catalytic activity with above 90% NO conversion in the temperature range from 300 ℃ to 400 ℃ under the space velocity of 75 000 h^-1. The Fe₄WO_x catalyst also showed high tolerance to SO₂ and H₂O in the test condition. The characterization result showed that the strong interaction between Fe and W, the large specific surface, and the strong acidity were the main reasons for the iron-tungsten mixed oxide catalyst to acquire the high catalytic activity.

Keywords： iron-tungsten mixed oxide catalyst； selective catalytic reduction； denitration

Received 2014-05-06;

Fund:

教育部创新团队发展计划(IRT0936)。

Corresponding Authors: 李永红,E-mail:yhli@tju.edu.cn。 Email: yhli@tju.edu.cn

About author: 戎雪佳(1988-),女,硕士研究生,从事脱硝催化剂的研究。

引用本文:

戎雪佳, 李永红, 李晓良.铁钨复合氧化物用于NH₃选择性催化还原NO[J]. 化学工业与工程, 2015,32(4): 19-23,62

Rong Xuejia, Li Yonghong, Li Xiaoliang.Iron-Tungsten Mixed Oxide Catalyst for the Selective Catalytic Reduction of NO with NH₃[J]. Chemcial Industry and Engineering, 2015,32(4): 19-23,62

[1] Ma L, Li J, Ke R, et al. Catalytic performance, characterization, and mechanism study of Fe₂(SO₄)₃/TiO₂ catalyst for selective catalytic reduction of NO_x by ammonia[J]. The Journal of Physical Chemistry, 2011, 115(15): 7 603-7 612
[2] Phil H H, Reddy M P, Kumar P A, et al. SO₂ resistant antimony promoted V₂O₅/TiO₂ catalyst for NH₃-SCR of NO_x at low temperatures[J]. Applied Catalysis B: Environmental, 2008, 78(3/4): 301-308
[3] Zhang X, Li X, Wu J, et al. Selective catalytic reduction of NO by ammonia on V₂O₅/TiO₂ catalyst prepared by sol-gel method[J]. Catalysis Letters, 2009, 130(1/2): 235-238
[4] Mutin P H, Popa A F, Vioux A, et al. Nonhydrolytic vanadia-titania xerogels: Synthesis, characterization, and behavior in the selective catalytic reduction of NO by NH₃[J]. Applied Catalysis B, 2006, 69(1): 49-57
[5] Shu Y, Sun H, Quan X, et al. Enhancement of catalytic activity over the iron-modified Ce/TiO₂ catalyst for selective catalytic reduction of NO_x with ammonia[J]. The Journal of Physical Chemistry C, 2012, 116(48): 25 319-25 327
[6] Wu Z, Jiang B, Liu Y. Effect of transition metals addition on the catalyst of manganese/titania for low-temperature selective catalytic reduction of nitric oxide with ammonia[J]. Applied Catalysis B: Environmental, 2008, 79(4): 347-355
[7] Yang S, Li J, Wang C, et al. Fe-Ti spinel for the selective catalytic reduction of NO with NH₃: Mechanism and structure-activity relationship[J]. Applied Catalysis B: Environmental, 2012, 117: 73-80
[8] Santhosh Kumar M, Schwidder M, Grünert W, et al. Selective reduction of NO with Fe-ZSM-5 catalysts of low Fe content: Part II. Assessing the function of different Fe sites by spectroscopic in situ studies[J]. Journal of Catalysis, 2006, 239(1): 173-186
[9] Nova I, Lietti L, Tronconi E, et al. Dynamics of SCR reaction over a TiO₂-supported vanadia-tungsta commercial catalyst[J]. Catalysis Today, 2000, 60(1/2): 73-82
[10] Chen J, Yang R. Role of WO₃ in mixed V₂O₅-WO₃/TiO₂ catalysts for selective catalytic reduction of nitric-oxide with ammonia[J]. Applied Catalysis A: General, 1992, 80(1): 135-148
[11] 吴碧君, 肖萍, 刘晓勤. MnOx-WO₃/TiO₂ NH₃选择性还原NO_x的催化性能与动力学[J]. 化工学报, 2011, 62(4): 940-946 Wu Bijun, Xiao Ping, Liu Xiaoqin. Performance and kinetic study on selective catalytic reduction of NO_x with NH₃ of MnOx-WO₃/TiO₂ catalyst[J]. CIESC Journal, 2011, 62(4): 940-946(in Chinese)
[12] 邓珊珊, 李永红, 阿荣塔娜, 等. MnOx-SnO₂/TiO₂型催化剂低温 NH₃选择性催化还原 NO[J]. 化工进展, 2013, 32(10): 2 403-2 408 Deng Shanshan, Li Yonghong, A Rongtana, et al. Low-Temperature selective catalytic reduction of NO with NH₃ over manganese and tin oxides supported on titania[J]. Chemical Industry and Engineering Progress, 2013, 32(10): 2 403-2 408(in Chinese)
[13] Chen L, Horiuchi T, Mori T. On the promotional effect of Sn in Co-Sn/Al₂O₃ catalyst for NO selective reduction[J]. Catalysis Letters, 2001, 72(1/2): 71-75
[14] Wu Z, Jin R, Liu Y, et al. Ceria modified MnO_x/TiO₂ as a superior catalyst for NO reduction with NH₃ at low-temperature[J]. Catalysis Communications, 2008, 9(13): 2 217-2 220
[15] Xu W, He H, Yu Y. Deactivation of a Ce/TiO₂ catalyst by SO₂ in the selective catalytic reduction of NO by NH₃[J]. The Journal of Physical Chemistry C, 2009, 113(11): 4 426-4 432
[16] Gao X, Jiang Y, Zhong Y, et al. The activity and characterization of CeO₂-TiO₂ catalysts prepared by the sol-gel method for selective catalytic reduction of NO with NH₃[J]. Journal Hazard Mater, 2010, 174(1): 734-739
[17] Liu F, He H, Zhang C, et al. Selective catalytic reduction of NO with NH₃ over iron titanate catalyst: Catalytic performance and characterization[J].Applied Catalysis B, 2010, 96(3): 408-420
[18] 熊志波, 路春美. 铁铈复合氧化物催化剂SCR脱硝的改性研究[J]. 燃料化学学报, 2013, 41(3): 361-367 Xiong Zhibo, Lu Chunmei. Study on the modification of iron-cerium mixed oxide catalyst for selective catalytic reduction of NO[J]. Journal of Fuel Chemistry and Technology, 2013, 41(3): 361-367(in Chinese)