Fe和Cu分子筛催化剂同时催化NOx还原和N2O分解

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Abstract Fe-Beta and Cu-SSZ-13 catalysts were prepared by ion-exchange method, and composite catalysts were prepared using different mixing methods. Performance of the catalysts in catalyzing NO_x reduction and N₂O decomposition at the same time was investigated. Fe_0.4Cu_0.1catalyst, which was composed of Fe-Beta in the top layer and Cu-SSZ-13 in the bottom layer with mass ratio of 4:1, performed the best in catalyzing the removal of NO_x and N₂O simultaneously and broadening the reactive temperature window. Effects of inlet gas composition on the conversion of NO_x, N₂O, and NH₃ were investigated. Physicochemical characteristics of the catalysts were characterized by N₂ adsorption-desorption, XRD, NH₃-TPD, UV-Vis DRS and H₂-TPR techniques. The results showed that Cu-SSZ-13 and Fe-Beta had superior performance in catalyzing NO_x reduction and N₂O decomposition, respectively. In the tested temperature range, NO_x was reduced by NH₃ while N₂O was decomposed over Fe_0.4Cu_0.1 when [NH₃]/[NO_x] was 1. NO_x and N₂O conversion reached 93.4% and 100%, respectively at 450℃. Oxidation of NH₃ by O₂ at high temperatures (>350℃) leads to decrease in NO_x conversion with increasing temperature. And the formation of oxygen species from the decomposition of N₂O at high temperatures (≥350℃) explains the efficient NO_x reduction without O₂ in the inlet gas. The presence of 2%H₂O in the inlet gas hardly affected the reduction of NO_x and oxidation of NH₃ over Fe_0.4Cu_0.1 at high temperature (450℃), but did show reversible inhibitory effects on the conversion of N₂O. Abundant isolated Cu²⁺ ions were detected over Cu-SSZ-13, providing sufficient active centers for the NH₃-SCR reaction. Both isolated Fe³⁺ ions and Fe_xO_y species, which can catalyze NO oxidation and N₂O decomposition, respectively, were detected over Fe-Beta. Using the top-Fe-bottom-Cu composite catalyst, NO oxidation occurs over Fe-Beta, which consumes oxygen species formed from N₂O decomposition and thus promotes the conversion of N₂O at low temperatures (≤450℃). However, the promotion effect of NO oxidation on NO_x reduction was insignificant since NO_x conversion was rather high in the temperature range for effective N₂O decomposition.

Key words： NO_x reduction N₂O decomposition Fe-Beta Cu-SSZ-13 composite catalyst

Received: 09 February 2024

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X511

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	Articles by authors
	SI Qing-yu
	FAN Xing
	ZHANG Wei-hang
	MIAO Jing-wen
	LIU Ruo-wen

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SI Qing-yu,FAN Xing,ZHANG Wei-hang等. Simultaneous reduction of NO_x and decomposition of N₂O over Fe and Cu zeolite catalysts[J]. CHINA ENVIRONMENTAL SCIENCECE, 2024, 44(9): 4826-4834.

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http://www.zghjkx.com.cn/EN/ OR http://www.zghjkx.com.cn/EN/Y2024/V44/I9/4826

[1] Saramok M, Szymaszek A, Inger M, et al. Modified zeolite catalyst for a NO_x selective catalytic reduction process in nitric acid plants [J]. Catalysts, 2021,11(4):450.
[2] Konsolakis M. Recent advances on nitrous oxide (N₂O) decomposition over non-noble-metal oxide catalysts: Catalytic performance, mechanistic considerations, and surface chemistry aspects [J]. ACS Catalysis, 2015,5(11):6397-6421.
[3] GB 26131-2010硝酸工业污染物排放标准[S]. GB 26131-2010 Emission standards of pollutants for nitric acid industry [S].
[4] 中华人民共和国科学技术部.科技部等九部门关于印发《科技支撑碳达峰碳中和实施方案(2022-2030年)》的通知[EB/OL]. https://www.gov.cn/zhengce/zhengceku/2022-08/18/content_5705865.htm, 2022-06-24. Ministry of Science and Technology of the People’s Republic of China. Implementation Program for Science and Technology-Supported Carbon Cap and Carbon Neutrality (2022-2030) [EB/OL]. https://www.gov.cn/zhengce/zhengceku/2022-08/18/content_5705865.htm, 2022-06-24.
[5] Xiao G, Guo Z, Lin B, et al. Cu-VWT catalysts for synergistic elimination of NO_x and volatile organic compounds from coal-fired flue gas [J]. Environmental Science & Technology, 2022,56(14): 10095-10104.
[6] 郑乐辰,李祥如,王靖霏,等.柴油车尾气SCR脱硝催化剂研究进展[J]. 化学试剂, 2023,45(11):88-97. Zheng L C, Li X R, Wang J F, et al. Review on SCR DeNO_x catalysts for diesel vehicle exhaust [J]. Chemical Reagents, 2023,45(11):88-97.
[7] Isupova L A, Ivanova Y A. Removal of nitrous oxide in nitric acid production [J]. Kinetics and Catalysis, 2019,60:744-760.
[8] Liang X L, Tang H L, Yang F F, et al. Ammonia-steam treated FeZSM-5 for direct N₂O decomposition [J]. Microporous and Mesoporous Materials, 2019,290:109655.
[9] Cheng J, Zheng D, Yu G, et al. N₂O catalytic decomposition and NH₃-SCR coupling reactions over Fe-SSZ-13catalyst: Mechanisms and interactions unraveling via experiments and DFT calculations [J]. ACS Catalysis, 2023,13(2):934-947.
[10] Wang A, Wang Y, Walter E D, et al. Catalytic N₂O decomposition and reduction by NH₃ over Fe-Beta and Fe-SSZ-13catalysts [J]. Journal of Catalysis, 2018,358:199-210.
[11] 李佳,樊星,陈莉,等.硝酸生产尾气中NO_x和N₂O联合脱除技术研究进展[J]. 化工进展, 2023,42(7):3770-3779. Li J, Fan X, Chen L, et al. Research progress of simultaneous removal of NO_x and N₂O from the tail gas of nitric acid production [J]. Chemical Industry and Engineering Progress, 2023,42(7):3770-3779.
[12] Guo J, Yang W, Zhang Y, et al. A multiple-active-site Cu-SSZ-13for NH₃-SCO: Influence of Si/Al ratio on the catalytic performance [J]. Catalysis Communications, 2020,135:105751.
[13] Li H, Zhao S, Zhang W, et al. Efficient esterification over hierarchical Zr-Beta zeolite synthesized via liquid-state ion-exchange strategy [J]. Fuel, 2023,342:127786.
[14] Zhang T, Chang H, You Y, et al. Excellent activity and selectivity of one-pot synthesized Cu-SSZ-13catalyst in the selective catalytic oxidation of ammonia to nitrogen [J]. Environmental Science & Technology, 2018,52(8):4802-4808.
[15] Leistner K, Xie K, Kumar A, et al. Ammonia desorption peaks can be assigned to different copper sites in Cu/SSZ-13[J]. Catalysis Letters, 2017,147:1882-1890.
[16] Zhu N, Lian Z, Zhang Y, et al. Improvement of low-temperature catalytic activity over hierarchical Fe-Beta catalysts for selective catalytic reduction of NO_x with NH₃ [J]. Chinese Chemical Letters, 2019,30(4):867-870.
[17] Wang P, Jin M, Yu D, et al. Evolution mechanism of N₂O for the selective catalytic reduction of NO_x by NH₃ over Cu-SSZ-13 assisted Fe-BEA catalysts [J]. Catalysis Letters, 2021,151:3381-3395.
[18] Gao F, Walter E D, Karp E M, et al. Structure-activity relationships in NH₃-SCR over Cu-SSZ-13as probed by reaction kinetics and EPR studies [J]. Journal of Catalysis, 2013,300:20-29.
[19] Zhang T, Qiu Y, Liu G H, et al. Nature of active Fe species and reaction mechanism over high-efficiency Fe/CHA catalysts in catalytic decomposition of N₂O [J]. Journal of Catalysis, 2020,392:322-335.
[20] Zhang Y B, Wang P, Zhao H Y, et al. The promoting mechanism of Ce on the hydrothermal stability of Fe-Beta catalyst for NH₃-SCR reaction [J]. Microporous and Mesoporous Materials, 2022,338:111937.
[21] Colombo M, Nova I, Tronconi E, et al. NO/NO₂/N₂O-NH₃SCR reactions over a commercial Fe-zeolite catalyst for diesel exhaust aftertreatment: Intrinsic kinetics and monolith converter modelling [J]. Applied Catalysis B: Environmental, 2012,111-112:106-118.
[22] 姚小江,张雷,孔婷婷,等.低温氨-选择性催化还原氮氧化物催化剂的研究进展[J]. 工业催化, 2016,24(6):1-9. Yao X J, Zhang L, Kong T T, et al. Research progress in selective catalytic reduction of nitrogen oxides by ammonia at low temperature [J]. Industrial Catalysis, 2016,24(6):1-9.
[23] Yu D, Wang P, Li X J, et al. Study on the role of Fe species and acid sites in NH₃-SCR over the Fe-based zeolites [J]. Fuel, 2023,336:126759.
[24] Liu Q, Bian C, Jin Y F, et al. Influence of calcination temperature on the evolution of Fe species over Fe-SSZ-13catalyst for the NH₃-SCR of NO [J]. Catalysis Today, 2022,388-389:158-167.
[25] Zhang T, Qin X, Peng Y, et al. Effect of Fe precursors on the catalytic activity of Fe/SAPO-34 catalysts for N₂O decomposition [J]. Catalysis Communications, 2019,128:105706.