收稿日期: 2024-11-28
网络出版日期: 2025-12-29
基金资助
四川省科技计划项目(2023JDRC0065)
Study on effect of potassium on deNO x performance and hydrothermal stability of Cu-SSZ-13 catalysts
Received date: 2024-11-28
Online published: 2025-12-29
为探究化学中毒与高温水热老化协同作用对Cu-SSZ-13催化剂NH3-SCR性能的影响机制,经发动机台架中毒和高温处理,得到不同样件。结合BET、SEM、NH3-TPD和H2-TPR等表征分析其物化特性与活性演变规律。结果表明:K通过置换骨架位活性Cu2+和B酸位质子,导致活性Cu2+数量和酸量降低,孔道部分堵塞;老化时,K会加剧分子筛骨架坍塌和加速Cu2+→Cu x O y 的转化,进而抑制Al(OH)3再键合,导致其比表面积和氧化还原性性能显著降低。采用固定床反应器进行活性评价发现,K削弱催化剂活性和水热稳定性。中毒后Cu-SSZ-13催化剂(CZ)在200 ℃和500 ℃下NO x 转化率分别从92.84%和89.38%下降到85.64%和83.22%(KCZ-1)。老化后转化率进一步劣化至74.24%和76.02%(KCZ-HT1),较未中毒老化样品(CZ-HT)下降15.7%和10.8%。此外,K的沉积量沿气流方向梯度递减。研究阐明K通过质子置换及活性位竞争等多途径协同劣化催化剂活性和高温水热稳定性的机制,指出D6R位Cu2+对K中毒的敏感性,而老化过程中8MRs位Cu2+稳定性亦受显著影响,为抗中毒催化剂的定向设计提供理论依据。
冯锡 , 吕亮 , 孙睿 , 赖益能 , 杨兰 , 王瑞芳 . 钾对Cu-SSZ-13催化剂脱硝性能及水热稳定性影响的研究[J]. 无机盐工业, 2025 , 57(12) : 123 -130 . DOI: 10.19964/j.issn.1006-4990.2024-0642
To explore the mechanism of the synergistic effect of chemical poisoning and high-temperature hydrothermal aging on the NH3-SCR performance of Cu-SSZ-13 catalysts,various samples were generated by subjecting the catalysts to poisoning and high-temperature treatment on an engine test bench.The physicochemical properties of catalyst coatings at different locations within the monolithic catalyst were investigated by using BET,SEM,NH3-TPD,and H2-TPR.The results revealed that K deposition on the fresh catalyst displaced isolated Cu2+ and protons on framework Brønsted acid sites,leading to a reduction in the number of active Cu2+ ions in the catalyst framework,a decrease in acidity without crystal structure damage,and partial pore blockage.During the high-temperature hydrothermal aging process,the presence of K exacerbated the collapse of the zeolite framework and accelerated the transformation of Cu2+ into Cu x O y species,which in turn inhibited the recombination of Al(OH)3,leading to a significant decrease in specific surface area and redox properties.The deNO x activity of the catalyst was examined by means of a fixed-bed reactor,and it was found that K weakened the activity and undermined the hydrothermal stability of the catalyst.After poisoning,the deNO x efficiency of CZ at 200 ℃ and 500 ℃ was decreased from 92.84% and 89.38% to 85.64% and 83.22%(KCZ-1),respectively.After aging,the deNO x efficiency of KCZ-HT1 at 200 ℃ and 500 ℃ was further deteriorated to 74.24% and 76.02%,a decrease of 15.7% and 10.8% compared to the unpolluted aged sample(CZ-HT).In addition,the deposition of K in the catalyst was decreased along the gas flow direction,and the higher deposition at the front end resulted in poorer stability of the catalyst than at the back end.These findings provided an important basis for optimizing the design of anti-poisoning catalysts.This study clarified the mechanism by which K synergistically deteriorated catalyst activity and high-temperature hydrothermal stability through proton displacement and active site competition,etc,highlighting the sensitivity of D6R site Cu2+ to K poisoning and the significant impact on the stability of 8MRs site Cu2+ during aging,providing a theoretical basis for the targeted design of anti-poisoning catalysts.
| [1] | 赖慧龙,于飞,杨冬霞,等.基于不同Cu-CHA催化剂方案的NH3-SCR性能及氨存储特性研究[J].无机盐工业,2024,56(12):159-166. |
| LAI Huilong, YU Fei, YANG Dongxia,et al.Research on NH3-SCR performance and ammonia storage characteristics based on different Cu-CHA catalyst schemes[J].Inorganic Chemicals Industry,2024,56(12):159-166. | |
| [2] | 谭仁俊,罗仕忠,王涛,等.不同元素掺杂锰基催化剂的NH3-SCR反应性能研究[J].无机盐工业,2023,55(7):115-121. |
| TAN Renjun, LUO Shizhong, WANG Tao,et al.Study on NH3-SCR performance of manganese based catalysts doped with different elements[J].Inorganic Chemicals Industry,2023,55(7):115-121. | |
| [3] | SHI Zhiwei, PENG Qingguo, Jiaqiang E,et al.Mechanism,performance and modification methods for NH3-SCR catalysts:A revi- ew[J].Fuel,2023,331:125885. |
| [4] | LIN Qingjin, XU Shuhao, ZHAO Hongyan,et al.Highlights on key roles of Y on the hydrothermal stability at 900 ℃ of Cu/SSZ-39 for NH3-SCR[J].ACS Catalysis,2022,12(22):14026-14039. |
| [5] | SHAN Yulong, DU Jinpeng, ZHANG Yan,et al.Selective catalytic reduction of NO x with NH3:Opportunities and challenges of Cu-based small-pore zeolites[J].National Science Review,2021,8(10):nwab010. |
| [6] | KWAK J H, ZHU Haiyang, LEE J H,et al.Two different cationic positions in Cu-SSZ-13?[J].Chemical Communications,2012,48(39):4758-4760. |
| [7] | SONG J, WANG Yilin, WALTER E D,et al.Toward rational design of Cu/SSZ-13 selective catalytic reduction catalysts:Implications from atomic-level understanding of hydrothermal stability[J].ACS Catalysis,2017,7(12):8214-8227. |
| [8] | MA Lei, CHENG Yisun, CAVATAIO G,et al.Characterization of commercial Cu-SSZ-13 and Cu-SAPO-34 catalysts with hydrothermal treatment for NH3-SCR of NO x in diesel exhaust[J].Chemical Engineering Journal,2013,225:323-330. |
| [9] | 李昊,邓志权,李国波,等.移动源分子筛脱硝催化剂研究进展[J].中国材料进展,2024,43(9):773-785,772. |
| LI Hao, DENG Zhiquan, LI Guobo,et al.Research progress of mobile source molecular sieve denitrification catalyst[J].Materials China,2024,43(9):773-785,772. | |
| [10] | JIANG Han, GUAN Bin, PENG Xuesong,et al.Effect of sulfur poisoning on the performance and active sites of Cu/SSZ-13 catalyst[J].Chemical Engineering Science,2020,226:115855. |
| [11] | SONG Kunli, ZHAO Shuqi, LI Zhenguo,et al.Zinc and phosphorus poisoning tolerance of Cu-SSZ-13 and Ce-Cu-SSZ-13 in the catalytic reduction of nitrogen oxides[J].Journal of Colloid and Interface Science,2023,629:243-255. |
| [12] | GUO Jiangfeng, WANG Aiyong, LIN He.Effect of phosphorus poisoning on the hydrothermal stability of Cu/CHA and Cu/LTA towards NH3-SCR[J].Microporous and Mesoporous Materials,2022,346:112313. |
| [13] | JOUINI H, MEJRI I, MARTINEZ-ORTIGOSA J,et al.Alkali poisoning of Fe-Cu-ZSM-5 catalyst for the selective catalytic reduction of NO with NH3 [J].Research on Chemical Intermediates,2022,48(8):3415-3428. |
| [14] | FAN Chi, CHEN Zhen, PANG Lei,et al.Steam and alkali resistant Cu-SSZ-13 catalyst for the selective catalytic reduction of NO x in diesel exhaust[J].Chemical Engineering Journal,2018,334:344-354. |
| [15] | HAN Shuai, YE Qing, CHENG Shuiyuan,et al.Effect of the hydrothermal aging temperature and Cu/Al ratio on the hydrothermal stability of CuSSZ-13 catalysts for NH3-SCR[J].Catalysis Science & Technology,2017,7(3):703-717. |
| [16] | ZHANG Tao, LI Jianmei, LIU Jian,et al.High activity and wide temperature window of Fe-Cu-SSZ-13 in the selective catalytic reduction of NO with ammonia[J].AIChE Journal,2015,61(11):3825-3837. |
| [17] | WANG Can, WANG Chen, WANG Jun,et al.Effects of Na+ on Cu/SAPO-34 for ammonia selective catalytic reduction[J].Journal of Environmental Sciences,2018,70:20-28. |
| [18] | KIM Y J, LEE J K, MIN K M,et al.Hydrothermal stability of Cu-SSZ-13 for reducing NO x by NH3 [J].Journal of Catalysis,2014,311:447-457. |
| [19] | YONG Xin, ZHANG Cuijuan, WEI Miao,et al.Promotion of the performance of Cu-SSZ-13 for selective catalytic reduction of NO x by ammonia in the presence of SO2 during high temperature hydrothermal aging[J].Journal of Catalysis,2021,394:228- 235. |
| [20] | BULáNEK R, WICHTERLOVá B, SOBAL??K Z,et al.Reducibility and oxidation activity of Cu ions in zeolites Effect of Cu ion coordination and zeolite framework composition[J].Applied Catalysis B:Environmental,2001,31(1):13-25. |
| [21] | ZHAO Zhenchao, YU Rui, ZHAO Rongrong,et al.Cu-exchanged Al-rich SSZ-13 zeolite from organotemplate-free synthesis as NH3-SCR catalyst:Effects of Na+ ions on the activity and hydrothermal stability[J].Applied Catalysis B:Environmental,2017,217:421-428. |
| [22] | FICKEL D W, LOBO R F.Copper coordination in Cu-SSZ-13 and Cu-SSZ-16 investigated by variable-temperature XRD[J].The Journal of Physical Chemistry C,2010,114(3):1633-1640. |
| [23] | HAN Jinfeng, LI Junyan, BAI Yang,et al.Cocrystallized zeolite interface boosting the hydrothermal stability of Cu-CHA/OFF-ERI catalysts[J].CCS Chemistry,2025,7(3):681-690. |
| [24] | SU Wenkang, LI Zhenguo, PENG Yue,et al.Correlation of the changes in the framework and active Cu sites for typical Cu/CHA zeolites(SSZ-13 and SAPO-34) during hydrothermal aging[J].Physical Chemistry Chemical Physics,2015,17(43):29142-29149. |
| [25] | GAO Feng, WALTER E D, WASHTON N M,et al.Synthesis and evaluation of Cu/SAPO-34 catalysts for NH3-SCR 2:Solid-state ion exchange and one-pot synthesis[J].Applied Catalysis B:Environmental,2015,162:501-514. |
| [26] | ZHENG Chaohe, ZHAO Haibo.The microscopic oxidation mechanism of NH3 on CuO(111):A first-principles study[J].Fuel Processing Technology,2021,213:106712. |
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