中国汽车技术研究中心有限公司,移动源污染排放控制技术国家工程实验室,天津 300300
National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology & Research Center Co. Ltd., Tianjin 300300, China
O(g)含量的变化对催化剂的物理化学结构的影响较小。在高温水热老化过程中,温度对催化性能劣化的影响大于水蒸汽含量,是催化剂失活的主要原因。
Aiming at the hydrothermal deactivation of Cu/ZSM-5 catalysts under high temperature, they were synthesized by impregnation method and then the hydrothermal aging treatment of these catalysts were carried out under different temperatures and water vapor contents. The physicochemical properties of the catalysts were characterized by BET, SEM, XRD, H
-TPR and XPS. The NH
-SCR performance and hydrothermal deactivation mechanism of the Cu/ZSM-5 catalysts under different hydrothermal aging conditions were studied. The results showed that the NH
-SCR performance of each Cu/ZSM-5 catalyst was reduced after hydrothermal treatment. With the increase of temperature of hydrothermal aging, the zeolite supports of Cu/ZSM-5 collapsed, the specific surface area decreased and the pore volume increased while the MFI structure of Cu/ZSM-5 remained unchanged, even the isolated active Cu
in it decreased and partly transformed to CuO microcrystal. However, the change in water vapor content had slight effect on the physicochemical structure of the catalyst. High temperature hydrothermal deactivation study found that the effect of temperature on catalytic performance degradation was greater than that of water vapor contents. High temperature was the main reason for catalyst deactivation.
.
不同条件下水热老化Cu/ZSM-5催化剂XRD图谱
X-ray diffraction patterns of Cu/ZSM-5 with different conditions of hydrothermal aging
-TPR of Cu/ZSM-5 with different conditions of hydrothermal aging
不同条件水热老化Cu/ZSM-5催化剂SEM图
SEM images of Cu/ZSM-5 with different conditions of hydrothermal aging
不同条件水热老化Cu/ZSM-5催化剂XPS图谱
XPS spectra of Cu/ZSM-5 with different conditions of hydrothermal aging
[1] | FAHAMI A R, NOVA I, TRONCONI E. A kinetic modeling study of NO oxidation over a commercial Cu-CHA SCR catalyst for diesel exhaust aftertreatment[J]. Catalysis Today, 2017, 297(15): 10-16. |
[2] | KARAMITROS D, KOLTSAKIS G. Model-based optimization of catalyst zoning on SCR-coated particulate filters[J]. Chemical Engineering Science, 2017, 173(14): 514-524. |
[3] | FICKEL D W, D′ADDIO E, LAUTERBACH J A, et al. The ammonia selective catalytic reduction activity of copper-exchanged small-pore zeolites[J]. Applied Catalysis B: Environmental, 2011, 102(3/4): 441-448. |
[4] | KWAK J H, TONKYN R G, KIM D H, et al. Excellent activity and selectivity of Cu-SSZ-13 in the selective catalytic reduction of NOx with NH3[J]. Journal of Catalysis, 2010, 275(2): 187-190. doi: 10.1016/j.jcat.2010.07.031 |
[5] | FICKEL D W, FEDEYKO J M, LOBO R F. Copper coordination in Cu-SSZ-13 and Cu-SSZ-16 investigated by variable-temperature XRD[J]. Journal of Physical Chemistry C, 2010, 114(3): 1633-1640. doi: 10.1021/jp9105025 |
[6] | WILKEN N, KAMASAMUDRAM K, CURRIER N W. Heat of adsorption for NH3, NO2 and NO on Cu-Beta zeolite using microcalorimeter for NH3 SCR applications[J]. Catalysis Today, 2010, 151(3/4): 237-243. |
[7] | 张惠, 王喜芹, 栾志强, 等. 铜-胺改性ZSM-5吸附剂的制备及其对NOx的净化机理[J]. 环境工程学报, 2013, 7(12): 4887-4890. |
[8] | 李富霞, 任晓光, 李鹏, 等. 焙烧条件对CuO/ZSM-5催化剂脱硫脱硝性能的影响[J]. 环境工程学报, 2013, 7(8): 3117-3122. |
[9] | 石晓燕, 刘福东, 单文坡, 等. 水热老化对不同方法制备的Fe-ZSM-5用于NH3选择性催化还原NOx的影响[J]. 催化学报, 2012, 33(3): 454-464. |
[10] | GOMEZ S A, CAMPERO A, MARTINEZ-HERNANDEZ A. Changes in Cu2+ environment upon wet deactivation of Cu-ZSM-5 deNOx catalysts[J]. Applied Catalysis A: General, 2000, 197(1): 157-164. doi: 10.1016/S0926-860X(99)00546-3 |
[11] | PARK J H, PARK H J, BAIK J H. Hydrothermal stability of Cu-ZSM-5 catalyst in reducing NO by NH3 for the urea selective catalytic reduction process[J]. Journal of Catalysis, 2006, 240(1): 47-57. doi: 10.1016/j.jcat.2006.03.001 |
[12] | 任爱玲, 刘卉, 张硕, 等. Ce-Mn/ZSM-5催化剂的制备及其低温脱硝性能分析[J]. 现代化工, 2018, 38(6): 73-77. |
[13] | 杨晓初, 肖海平, 万震天, 等. 煅烧温度影响MNOx/ZSM-5催化NO氧化性能研究[J]. 热能动力工程, 2018, 33(4): 56-62. |
[14] | 杜蒙蒙, 温正城, 康普滋, 等. ZSM-5负载Ce-Co催化氧化NO的机理研究[J]. 热能动力工程, 2018, 33(3): 93-99. |
[15] | SHI X Y, HE H, XIE L J. The effect of Fe species distribution and acidity of Fe-ZSM-5 on the hydrothermal stability and SO2 and hydrocarbons durability in NH3-SCR reaction[J]. Chinese Journal of Catalysis, 2015, 36(4): 649-656. doi: 10.1016/S1872-2067(14)60268-0 |
[16] | 宋守强, 李明罡, 李黎声, 等. 磷改性ZSM-5分子筛的水热稳定性[J]. 石油学报(石油加工), 2014, 30(2): 194-203. doi: 10.3969/j.issn.1001-8719.2014.02.002 |
[17] | DING J, XUE T, WU H H, et al. One-step post-synthesis treatment for preparing hydrothermally stable hierarchically porous ZSM-5[J]. Chinese Journal of Catalysis, 2017, 38(1): 48-57. doi: 10.1016/S1872-2067(16)62549-4 |
[18] | IWASAKI M, YAMAZAKI K, BANNO K, et al. Characterization of Fe/ZSM-5 DeNOx catalysts prepared by different methods: Relationships between active Fe sites and NH3-SCR performance[J]. Journal of Catalysis, 2008, 260(2): 205-216. doi: 10.1016/j.jcat.2008.10.009 |
[19] | 李振国, 马杰, 刘双喜, 等. 黏结剂对柴油车用V2O5-WO3/TiO2催化剂选择性催化还原性能的影响[J]. 工业催化, 2011, 19(11): 60-63. doi: 10.3969/j.issn.1008-1143.2011.11.011 |
[20] | 李振国, 马杰, 王务林, 等. 制备条件对柴油车用V2O5-WO3/TiO2催化剂催化性能的影响[J]. 工业催化, 2011, 19(5): 30-33. doi: 10.3969/j.issn.1008-1143.2011.05.006 |
[21] | BEUTEL T, SARKANY J, LEI G D, et al. Redox chemistry of Cu/ZSM-5[J]. Journal of Physical Chemistry, 1996, 100(2): 845-851. doi: 10.1021/jp952455u |
[22] | PRALIAUD H, MIKHAILENKO S, CHAJAR Z, et al. Surface and bulk properties of Cu-ZSM-5 and Cu/Al2O3 solids during redox treatments. Correlation with the selective reduction of nitric oxide by hydrocarbons[J]. Applied Catalysis B: Environmental, 1998, 16(4): 359-374. doi: 10.1016/S0926-3373(97)00093-3 |
[23] | RICHTER M, FAIT M J G, ECKELT R, et al. Oxidative gas phase carbonylation of methanol to dimethyl carbonate over chloride-free Cu-impregnated zeolite Y catalysts at elevated pressure[J]. Applied Catalysis B: Environmental, 2006, 73(3/4): 269-281. |
[24] | SULTANA A, NANBA T, HANEDA M, et al. Influence of co-cations on the formation of Cu+ species in Cu/ZSM-5 and its effect on selective catalytic reduction of NOx with NH3[J]. Applied Catalysis B: Environmental, 2010, 101(1/2): 61-67. |
[25] | NANBA T, MASUKAWA S, OGATA A, et al. Active sites of Cu-ZSM-5 for the decomposition of acrylonitrile[J]. Applied Catalysis B: Environmental, 2005, 61(3/4): 288-296. |
[26] | RICHTER M, FAIT M J G, ECKELT R, et al. Gas-phase carbonylation of methanol to dimethyl carbonate on chloride-free Cu-precipitated zeolite Y at normal pressure[J]. Journal of Catalysis, 2007, 245(1): 11-24. doi: 10.1016/j.jcat.2006.09.009 |
[27] | KEFIROV R, PENKOVA A, HADJIIVANOV K, et al. Stabilization of Cu+ ions in BEA zeolite: Study by FTIR spectroscopy of adsorbed CO and TPR[J]. Microporous and Mesoporous Materials, 2008, 116(1/2/3): 180-187. |
[28] | RUTKOWSKA M, PACIA I, BAS?G S, et al. Catalytic performance of commercial Cu-ZSM-5 zeolite modified by desilication in NH3-SCR and NH3-SCO processes[J]. Microporous and Mesoporous Materials, 2017, 246: 193-206. doi: 10.1016/j.micromeso.2017.03.017 |
[29] | 吕刚, 范啸天, 宋崇林, 等. Cu/ZSM-5催化剂制备及SCR催化性能研究[J]. 工程热物理学报, 2015, 36(10): 2276-2281. |
[30] | LI Z G, CHEN X Y, LI J H, et al. Synthesis and evaluation of mesopore structured ZSM-5 and a CuZSM-5 catalyst for NH3-SCR reaction: Studies of simulated exhaust and engine bench testing[J]. RSC Advances, 2016, 6: 102570-102581. doi: 10.1039/C6RA20237C |
[31] | SARMA D D, RAO C N R. XPES studies of oxides of second- and third-row transition metals including rare earths[J]. Journal of Electron Spectroscopy and Related Phenomena, 1980, 20(1): 25-45. doi: 10.1016/0368-2048(80)85003-1 |
[32] | WANG L, GAUDET J R, LI W, et al. Migration of Cu species in Cu/SAPO-34 during hydrothermal aging[J]. Journal of Catalysis, 2013, 306: 68-77. doi: 10.1016/j.jcat.2013.06.010 |
[33] | 郑昌坤, 韩帅, 叶青. 铜源对Cu/ZSM-5催化剂氨选择性催化还原NO的影响[J]. 化学工程, 2018, 46(9): 23-27. doi: 10.3969/j.issn.1005-9954.2018.09.005 |