Cu/CHA NH<sub>3</sub>-SCR催化剂硫中毒及再生研究进展

摘要柴油车NO_x排放成为我国空气治理的核心之一。铜基菱沸石型小孔分子筛催化剂（Cu/CHA）因其低温高活性、高N₂选择性、宽温度窗口和优异的水热稳定性已成为新一代柴油车脱硝催化剂首选。然而Cu/CHA催化剂在使用过程中易受硫氧化物影响，使其低温NO_x性能大幅下降限制其高效利用。针对以上问题，在综述了Cu/CHA催化剂NH₃-SCR反应活性中心及微观反应机理研究现状的基础上，总结了Cu/CHA催化剂NH₃-SCR反应的硫中毒进展，重点阐述了硫氧化物影响下，Cu/CHA催化剂活性中心、骨架及活性变化间的内在规律；同时归纳了Cu/CHA硫中毒后相关再生方法及其研究进展，能够为Cu/CHA催化剂进一步高效利用提供可靠依据及研究方向。

	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
	沈美庆
	李新华
	王晨
	王军

关键词：铜小孔分子筛 NH₃-SCR反应机理硫中毒再生

Abstract： Nowadays, NO_x emission from diesel is one of main focuses in China. Copper based on small-pore molecular sieves (Cu/CHA) owing to high NO_x activity at low temperature, great N₂ selectivity, wide temperature window and excellent hydrothermal stability have become the main SCR catalysts for diesel. However, sulfur is easy to affect Cu/CHA catalysts and will in turn lead to catalysts have inferior SCR performance. Facing to the above problem, this review sums up the research progress relative with mechanism of NH₃-SCR on Cu/CHA, including the active sites and the nature of NH₃-SCR reaction. Subsequently, the effect of sulfur oxides on Cu/CHA catalysts, mainly contains on the variation relationship between active sites, structure and SCR activity, are great concerned. Finally, the method and nature of regeneration on sulfated catalysts are also involved in this review. This review could give solid basis and guideline for efficient utilization of Cu/CHA catalysts.

Keywords： copper； small-pore molecular sieves； H₃-SCR mechanism； sulfur poisoning； regeneration

Received 2020-01-08;

Fund:国家重大专项（2017YFC0211302）；国家自然科学基金青年基金项目（21908207）；山西省青年科学基金项目（201901D211224）。

Corresponding Authors: 王军,E-mail:junwang@tju.edu.cn;王晨,E-mail:chenwang87@nuc.edu.cn。 Email: junwang@tju.edu.cn;chenwang87@nuc.edu.cn

About author: 沈美庆(1966-),男,教授,现从事机动车尾气净化方面的研究。

引用本文:

沈美庆, 李新华, 王晨, 王军.Cu/CHA NH₃-SCR催化剂硫中毒及再生研究进展[J]. 化学工业与工程, 2020,37(5): 7-13

Shen Meiqing, Li Xinhua, Wang Chen, Wang Jun.Progress for Studying on Sulfur Poisoning and Regeneration over Cu/CHA NH₃-SCR Catalysts[J]. Chemcial Industry and Engineering, 2020,37(5): 7-13

[1] Montenegro G, Onorati A. Urea-SCR technology for deNO_x after treatment of diesel exhausts[EB/OL]. 2014
[2] Cheng Y, Montreuil C N, Cavataio G, et al. Sulfur tolerance and DeSO_x studies on diesel SCR catalysts[J]. SAE International Journal of Fuels and Lubricants, 2008, 1(1):471-476
[3] Gao F, Kwak J H, Szanyi J, et al. Current understanding of Cu-exchanged Chabazite molecular sieves for use as commercial diesel engine DeNO_x catalysts[J]. Topics in Catalysis, 2013, 56(15/17):1441-1459
[4] Xue J, Wang X, Qi G, et al. Characterization of copper species over Cu/SAPO-34 in selective catalytic reduction of NO_x with ammonia:Relationships between active Cu sites and de-NO_x performance at low temperature[J]. Journal of Catalysis, 2013, 297:56-64
[5] Wang J, Shao L, Wang C, et al. Controllable preparation of various crystal size and nature of intra-crystalline diffusion in Cu/SSZ-13 NH₃-SCR catalysts[J]. Journal of Catalysis, 2018, 367:221-228
[6] Wang D, Zhang L, Kamasamudram K, et al. In situ-DRIFTS study of selective catalytic reduction of NO_x by NH₃ over Cu-exchanged SAPO-34[J]. ACS Catalysis, 2013, 3(5):871-881
[7] Su W, Chang H, Peng Y, et al. Reaction pathway investigation on the selective catalytic reduction of NO with NH₃ over Cu/SSZ-13 at low temperatures[J]. Environmental Science & Technology, 2015, 49(1):467-473
[8] Yu T, Hao T, Fan D, et al. Recent NH₃-SCR mechanism research over Cu/SAPO-34 catalyst[J]. The Journal of Physical Chemistry C, 2014, 118(13):6565-6575
[9] Gao F, Wang Y, Szanyi J, et al. Selective catalytic reduction over Cu/SSZ-13:Linking homo-and heterogeneous catalysis[J]. J Am Chem Soc, 2017, 139:4935-4942
[10] Christopher P, Ishant K, Atish P A, et al. Dynamic multinuclear sites formed by mobilized copper ions in NO_x selective catalytic reduction[J]. Science, 2017, 357:898-903
[11] Wang J, Huang Y, Yu T, et al. The migration of Cu species over Cu-SAPO-34 and its effect on NH₃ oxidation at high temperature[J]. Catalysis Science & Technology, 2014, 4(9):3004-3012
[12] Leistner K, Mihai O, Wijayanti K, et al. Comparison of Cu/BEA, Cu/SSZ-13 and Cu/SAPO-34 for ammonia-SCR reactions[J]. Catalysis Today, 2015, 258:49-55
[13] Wang C, Wang J, Wang J, et al. The role of impregnated sodium ions in Cu/SSZ-13 NH₃-SCR catalysts[J]. Catalysts, 2018, 8:593-607
[14] Shen M, Wen H, Hao T, et al. Deactivation mechanism of SO₂ on Cu/SAPO-34 NH₃-SCR catalysts:Structure and active Cu²⁺[J]. Catalysis Science & Technology, 2015, 5(3):1741-1749
[15] Brookshear D, Nam J, Nguyen K, et al. Impact of sulfation and desulfation on NO_x reduction using Cu-chabazite SCR catalysts[J]. Catalysis Today, 2015, 258:359-366
[16] Wijayanti K, Andonova S, Kumar A, et al. Impact of sulfur oxide on NH₃-SCR over Cu-SAPO-34[J]. Applied Catalysis B:Environmental, 2015, 166/167:568-579
[17] Jangjou Y, Quan D, Gu Y, et al. Nature of Cu active centers in Cu-SSZ-13 and their responses to SO₂ exposure[J]. ACS Catalysis, 2018, 8(2):1325-1337
[18] Luo J, Wang D, Kumar A, et al. Identification of two types of Cu sites in Cu/SSZ-13 and their unique responses to hydrothermal aging and sulfur poisoning[J]. Catalysis Today, 2016, 267:3-9
[19] Wang C, Wang J, Wang J, et al. The effect of sulfate species on the activity of NH₃-SCR over Cu/SAPO-34[J]. Applied Catalysis B:Environmental, 2017, 204:239-249
[20] Wijayanti K, Xie K, Kumar A, et al. Effect of gas compositions on SO₂ poisoning over Cu/SSZ-13 used for NH₃-SCR[J]. Applied Catalysis B:Environmental, 2017, 219:142-154
[21] Shen M, Zhang Y, Wang J, et al. Nature of SO₃ poisoning on Cu/SAPO-34 SCR catalysts[J]. Journal of Catalysis, 2018, 358:277-286
[22] Su W, Li Z, Zhang Y, et al. Identification of sulfate species and their influence on SCR performance of Cu/CHA catalyst[J]. Catalysis Science & Technology, 2017, 7(7):1523-1528
[23] Wang C, Hou Y, Yan W, et al. The role of SO₃ poisoning in CU/SSZ-13 NH₃-SCR catalysts[J]. Catalysts, 2019, 9:741-754
[24] Hammershøi P S, Jangjou Y, Epling W S, et al. Reversible and irreversible deactivation of Cu-CHA NH₃-SCRcatalysts by SO₂ and SO₃[J]. Applied Catalysis B:Environmental, 2018, 226:38-45
[25] Dahlin S, Lantto C, Englund J, et al. Chemical aging of Cu-SSZ-13 SCR catalysts for heavy-duty vehicles-Influence of sulfur dioxide[J]. Catalysis Today, 2019, 320:72-83
[26] Wijayanti K, Leistner K, Chand S, et al. Deactivation of Cu-SSZ-13 by SO₂ exposure under SCR conditions[J]. Catalysis Science & Technology, 2015, 6(8):2565-2579
[27] Zhang L, Wang D, Liu Y, et al. SO₂ poisoning impact on the NH₃-SCR reaction over a commercial Cu-SAPO-34 SCR catalyst[J]. Applied Catalysis B:Environmental, 2014, 156/157:371-377
[28] Hammershøi P S, Vennestrøm P N R, Falsig H, et al. Importance of the Cu oxidation state for the SO^-₂ poisoning of a Cu-SAPO-34 catalyst in the NH₃-SCR reaction[J]. Applied Catalysis B:Environmental, 2018, 236:377-383
[29] Shen M, Li X, Wang J, et al. Nature identification of Cu active sites in sulfur-fouled Cu/SAPO-34 regeneration[J]. Ind Eng Chem Res, 2018, 57(10):3501-3509
[30] Kumar A, Smith M A, Kamasamudram K, et al. Impact of different forms of feed sulfur on small-pore Cu-zeolite SCR catalyst[J]. Catalysis Today, 2014, 231:75-82
[31] Shen M, Wang Z, Li X, et al. Effects of regeneration conditions on sulfated CuSSZ-13 catalyst for NH₃-SCR[J]. Korean J Chem Eng, 2019, 36(8):1249-1257
[32] Ando R, Banno Y, Nagata M. Detailed mechanism of S poisoning and de-sulfation treatment of Cu-SCR catalyst[J]. SAE Technical Paper Series, 2017, doi:10.4271/2017-01-0944
[33] Kumar A, Smith M A, Kamasamudram K, et al. Chemical deSO_<i>x: An effective way to recover Cu-zeolite SCR catalysts from sulfur poisoning[J]. Catalysis Today, 2016, 267:10-16