Synthesis and characterization of ZSM-22 zeolites and their catalytic performance in alkylation reaction
-
摘要: 通过不同合成方法制备聚束状、粗棒状和细棒状ZSM-22分子筛，采用XRD、SEM、BET、MAS NMR、NH3-TPD及Py-FTIR等表征手段对分子筛的形貌、织构、硅铝配位环境及酸性进行研究。以甲苯-甲醇烷基化制备对二甲苯为探针反应，考察不同形貌ZSM-22分子筛催化剂的催化性能。结果表明，不同形貌ZSM-22分子筛的晶胞参数、织构、硅铝配位环境及酸性等存在明显差异。聚束状ZSM-22分子筛由于各束之间的相互作用导致Si（4Si）配位结构发生变化，Al原子的嵌入导致T3和T4比例较高、T2较少，并表现出更多的L酸中心。在380℃反应温度下，聚束状ZSM-22分子筛催化剂在甲苯-甲醇烷基化反应转化率为16.7%时，对二甲苯选择性达到76.1%。Abstract: The ZSM-22 molecular sieves with various morphologies were synthesized by different methods. XRD, SEM, BET, MAS NMR, NH3-TPD and Py-FTIR were used to study the structure, morphology, surface area, Si-Al coordination and acidity of the samples. Furthermore, the toluene-methanol alkylation as probe reaction was used to investigate the effect of ZSM-22 zeolites morphology on catalytic performance. The lattice parameters, surface areas, Si-Al coordination and acidity of all samples are obviously different. As a result, the interaction of each bundle of the bundle-like ZSM-22 zeolites leads to the structure change of Si (4Si) coordination, the increase of T3 and T4 with decrease of T2 location, and thus displays more L acid sites. At 380℃ reaction temperature, the bundle-like ZSM-22 zeolite catalyst shows high selectivity to p-xylene (76.1%) at about 16.7% conversion in the toluene-methanol alkylation.
-
Key words:
- ZSM-22 molecular sieve /
- morphology /
- toluene-methanol alkylation
-
图 1 不同形貌ZSM-22分子筛的SEM照片
Figure 1 SEM images of ZSM-22 samples with different morphologies
图 3 不同形貌ZSM-22分子筛N2吸脱附曲线
Figure 3 N2 adsorption-desorption isotherms of the different ZSM-22 samples
图 4 不同形貌ZSM-22分子筛的29Si MAS NMR谱图
Figure 4 29Si MAS NMR spectra of the different ZSM-22 zeolite samples
图 5 不同形貌ZSM-22分子筛的27Al MAS NMR谱图
Figure 5 27Al MAS NMR spectra of the different ZSM-22 zeolite samples
图 6 不同形貌ZSM-22分子筛的NH3-TPD谱图
Figure 6 NH3-TPD spectra of the different ZSM-22 zeolite samples
图 7 不同形貌ZSM-22催化剂上的甲苯转化率
Figure 7 Conversion of toluene over different ZSM-22 zeolite samples
图 8 不同形貌ZSM-22催化剂上的对二甲苯选择性
Figure 8 Selectivity of para-xylene over different ZSM-22 zeolite samples
表 1 不同ZSM-22分子筛的晶胞参数、相对结晶度及硅铝物质的量比
Table 1 Unit cell parameters, relative crystallinity and SiO2/Al2O3 (mol ratio) of different ZSM-22 zeolite samples
Sample Cell parameter /nm Unit volume V/nm3 Relative crystallinity /% SiO2/Al2O3 (mol ratio) a b c A 1.406 2.125 0.603 1.801 6 98 72.7 B 1.621 2.282 0.796 2.944 5 100 76.5 C 1.853 1.671 0.513 1.588 4 94 68.6 
下载: 导出CSV
表 2 不同ZSM-22分子筛样品的织构性质
Table 2 Textural properties of different ZSM-22 zeolite samples
Sample BET surface area A/(m2·g-1) micropore external total A 157.9 49.8 207.7 B 129.6 84.9 214.5 C 153.9 88.2 242.1
下载: 导出CSV
表 3 不同ZSM-22分子筛样品的Py-FTIR表征
Table 3 Acidity properties of different samples by Py-FTIR result
Sample Acidity /(μmolPy·g-1) Distribution of acid sites 200 350 total L B L B L B L200/B200 L350/B350 Ltotal/Btotal A 83.7 34.6 82.9 28.0 166.6 62.6 2.42 2.96 2.66 B 33.3 18.1 22.8 17.3 56.1 35.4 1.84 1.32 1.58 C 70.0 61.0 55.5 58.6 125.5 119.6 1.15 0.95 1.05
下载: 导出CSV
-
[1] KOKOTAILO G T, SCHLENKER J L, DWYER F G, VALYOCSIK E W.The framework topology of ZSM-22:A high silica zeolite[J].Zeolite, 1985, 5(6):349-351. doi: 10.1016/0144-2449(85)90122-8 [2] SIMON M W, SUIB S L, OYOUNG C L.Synthesis and characterization of ZSM-22 zeolites and their catalytic behavior in 1-butene isomerization reactions[J].J Catal, 1994, 147(2):484-493. doi: 10.1006/jcat.1994.1165 [3] 柴志波, 吕恩静, 张怀科, 任杰.乙醇对Pt/SAPO-11和Pt/ZSM-22催化剂烷烃异构化性能的影响[J].燃料化学学报, 2014, 42(2):208-211. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18356.shtmlCHAI Zhi-bo, LV En-jing, ZHANG Huai-ke, REN Jie.Effect of ethanol on the isomerization of n-heptane over Pt/SAPO-11 and Pt/ZSM-22 catalysts[J].J Fuel Chem Technol, 2014, 42(2):208-211. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18356.shtml [4] LIU S Y, REN J, ZHU S J, ZHANG H K, LÜ E J, XU J, LI Y W.Synthesis and characterization of the Fe-substituted ZSM-22 zeolite catalyst with high n-dodecane isomerizaton performance[J].J Catal, 2015, 330:485-496. doi: 10.1016/j.jcat.2015.07.027 [5] MURAZA O, ABDUL L A, TAGO T, NANDIYANTO A B D, KONNO H, NAKASAKA Y, YAMAN Z H, MASUDA T.Microwave-assisted hydrothermal synthesis of submicron ZSM-22 zeolite and their applications in light olefin production[J].Microporous Mesoporous Mater, 2015, 206:136-143. doi: 10.1016/j.micromeso.2014.12.025 [6] KUMAR R, RATNASAMY P.Isomerization and formation of xylenes over ZSM-22 and ZSM-23 zeolites[J].J Catal, 1989, 116(2):440-448. doi: 10.1016/0021-9517(89)90110-3 [7] 尹丽颖, 刘靖, 谭涓, 尹建波, 吴卓.ZSM-22催化甲苯甲醇烷基化反应的研究[J].工业催化, 2009, 17(1):48-53. http://www.cnki.com.cn/Article/CJFDTOTAL-GYCH200901017.htmYIN Li-ying, LIU jing, TAN juan, YIN Jian-bo, WU Zhuo.Methylation of toluene with methanol over ZSM-22 zeolite catalysts[J].Ind Catal, 2009, 17(1):48-53. http://www.cnki.com.cn/Article/CJFDTOTAL-GYCH200901017.htm [8] CHEN X X, YAN W F, SHEN W L, Yu J H, CAO X J, XU R R.Morphology control of self-stacked silicalite-1 crystals using microwave-assisted solvothermal synthesis[J].Microporous Mesoporous Mater, 2007, 104(1/3):296-304. [9] 杨爱梅, 田海锋, 查飞, 常玥.不同形貌HZSM-5的合成及其在催化二氧化碳加氢制备二甲醚中的应用[J].精细化工, 2015, 32(4):416-421. http://www.cnki.com.cn/Article/CJFDTOTAL-JXHG201504012.htmYANG Ai-mei, TIAN Hai-feng, ZHA Fei, CHANG Yue.Preparation of different morphology HZSM-5 and its application in catalytic synthesis of dimethyl ether from CO2 hydrogenation[J].Fine Chem, 2015, 32(4):416-421. http://www.cnki.com.cn/Article/CJFDTOTAL-JXHG201504012.htm [10] 宋孟璐, 董贺新, 韩丽, 陈宜俍, 詹予忠.醇对水热合成SAPO-56分子筛的影响[J].应用化工, 2015, 44(9):1577-1585. http://www.cnki.com.cn/Article/CJFDTOTAL-SXHG201509001.htmSONG Meng-lu, DONG He-xin, HAN Li, CHEN Yi-liang, ZHAN Yu-zhong.Influence of various alcohol on the hydrothermal synthesis of SAPO-56 molecular sieve[J].Appl Chem Ind, 2015, 44(9):1577-1585. http://www.cnki.com.cn/Article/CJFDTOTAL-SXHG201509001.htm [11] WANG Z M, TIAN Z J, WEN G D, TENG F, XU Y P, XU Z S, LIN L W.Synthesis and characterization of SAPO-11 molecular sieves from alcoholic systems[J].React Kinet Catal Lett, 2006, 88(1):81-88. doi: 10.1007/s11144-006-0113-4 [12] 李静, 刘粟侥, 张怀科, 吕恩静, 任鹏举, 任杰.特殊形貌类雪花状ZSM-5分子筛的合成、表征及甲醇制烯烃催化性能[J].催化学报, 2016, 37(2):308-315. doi: 10.1016/S1872-2067(15)60979-2LI Jing, LIU Su-yao, ZHANG Huai-ke, LV En-jing, REN Peng-ju, REN Jie.Synthesis and characterization of an unusual snowflake-shaped ZSM-5 zeolite with high catalytic performance in the methanol to olefin reaction[J].Chin J Catal, 2016, 37(2):308-315. doi: 10.1016/S1872-2067(15)60979-2 [13] KALITA B, TALUKDAR A K.An effcient synthwsis of nanocrystalline MFI zeolite using different silica sources:A green approach[J].Mate Res Bull, 2009, 44(2):254-258. doi: 10.1016/j.materresbull.2008.06.014 [14] MINTOVA S, VALTCHEV V.Effect of the silica source on the formation of nanosized silicalite-1:An in situ dynamic light scattering study[J].Microporous Mesoporous Mater, 2002, 55(2):171-179. doi: 10.1016/S1387-1811(02)00401-8 [15] TREACY M M J, HIGGINS J B.Collection of Simulated XRD Powder Patterns for Zeolites[M].International Zeolite Association, 2007, 430. [16] GREGG S J, SING K S W.Adsirption, Surface Area and Porosity[M].Academic Press, London, 1982, 154. [17] DEREWINSKI M, SARV P, MIFSUD A.Thermal stability and siting of aluminum in isostructural ZSM-22 and Theta-1 zeolite[J].Catal Today, 2006, 114(2/3):197-204. [18] WANG G, LIU Q J, SU W G, LI X J, JIANG Z X, FANG X C, HAN C R, LI C, Hydroisomerization activity and selectivity of n-dodecane over modified Pt/ZSM-22 catalysts[J].Appl Catal A:Gen, 2008, 335(1):20-27. doi: 10.1016/j.apcata.2007.11.002 [19] LIU S Y, REN J, ZHANG H K, LV E J, YANG Y, LI Y-W.Synthesis, characterization and isomerization performance of micro/mesoporous materials based on H-ZSM-22 zeolite[J].J Catal, 2016, 335:11-23. doi: 10.1016/j.jcat.2015.12.009 [20] 聂轶苗, 夏茂辉, 白丽梅, 刘淑贤, 张晋霞, 牛福生.硅铝酸盐类矿物晶体的27Al、29Si固体高分辨率核磁共振谱图解析方法[J].硅酸盐通报, 2012, 31(5):1200-1203.NIE Yi-miao, XIA Mao-hui, BAI Li-mei, LIU Shu-xian, ZHANG Jin-xia, NIU Fu-sheng.27Al and 29Si-MAR spectrogram analysis of metasilicate (aluminosilicate) crystal[J].Bull Chin Ceram Soc, 2012, 31(5):1200-1203. [21] 高雄厚, 张忠东, 王晋军, 王智峰, 毛学文, 沈师孔.晶化温度对MCM-41结晶度、酸性和骨架铝结构的影响[J].分子催化, 1999, 13(2):127-131. http://www.cnki.com.cn/Article/CJFDTOTAL-FZCH902.008.htmGAO Xiong-hou, ZHANG Zhong-dong, WANG Jin-jun, WANG Zhi-feng, MAO Xue-wen, SHEN Shi-kong.Effect of crystallization temperature on structure and performance of MCM-41[J].J Mol Catal, 1999, 13(2):127-131. http://www.cnki.com.cn/Article/CJFDTOTAL-FZCH902.008.htm [22] BLASCO T, CORMA A, MAITÍNEZ T J.Hydrothermal stabilization of ZSM-5 catalytic-cracking additives by phosphorus addition[J].J Catal, 2006, 237(2):267-277. doi: 10.1016/j.jcat.2005.11.011 [23] VOS A M, ROZANSKA X, SCHOONHEYDT R A, VAN S R A, HUTSCHKA F, HAFNER J.A theoretical study of the alkylation reaction of toluene with methanol catalyzed by acidic mordenite[J].J Am Chem Soc, 2001, 123(12):2799-2809. doi: 10.1021/ja001981i [24] YASHIMA T, AHMAD H, YAMAZAKI K, KATSUTA M, HARA N.Alkylation of synthetic zeolites I.Alkylation of toluene with methanol[J].J Catal, 1970, 16(3):273-280. doi: 10.1016/0021-9517(70)90223-X [25] BORGNA A, SEPÚLVEDA J, MAGNI S I, APESTEGUÍA C R.Active sites in the alkylation of toluene with methanol:A study by selective acid-base poisoning[J].Appl Catal, 2004, 276(1/2):207-215. [26] NAMBA S, KIM J H, YASHIMA T.Para-selectivity of zeolites and metallosilicates MFI structure[J].Stud Sci Catal, 1994, 83:279-286. doi: 10.1016/S0167-2991(08)63267-X [27] 张志萍, 赵岩, 吴宏宇, 谭伟, 王祥生, 郭新闻.改性纳米HZSM-5催化剂上甲苯与甲醇的烷基化反应[J].催化学报, 2011, 32(7):1280-1286. http://www.cnki.com.cn/Article/CJFDTOTAL-CHUA201107028.htmZHANG Zhi-ping, ZHAO yan, WU Hong-yu, TAN Wei, WANG Xiang-sheng, GUO Xin-wen.Shape-selective alkylation of toluene with methanol over modified nano-scale HZSM-5 zeolite[J].Chin J Catal, 2011, 32(7):1280-1286. http://www.cnki.com.cn/Article/CJFDTOTAL-CHUA201107028.htm [28] TAN W, LIU M, ZHAO Y, HOU K K, WU H Y, ZHANG A F, LIU H O, WANG Y R, SONG C S, GUO X W.Para-selective methylation of toluene with methanol over nano-sized ZSM-5 catalysts:Synergistic effects of surface modifications with SiO2, P2O5 and MgO[J].Microporous Mesoporous Mater, 2014, 196:18-30. doi: 10.1016/j.micromeso.2014.04.050 [29] 丁春华, 王祥生, 郭新闻.氧化物改性MCM-22上甲苯与甲醇的烷基化性能研究[J].石油学报, 2007, 23(5):38-42. http://www.cnki.com.cn/Article/CJFDTOTAL-SXJG200705008.htmDING Chun-hua, WANG Xiang-sheng, GUO Xin-wen.Study on alkylation of toluene with methanol over oxide modified MCM-22 zeolite[J].Acta Pet Sin, 2007, 23(5):38-42. http://www.cnki.com.cn/Article/CJFDTOTAL-SXJG200705008.htm [30] DING C H, WANG X S, GUO X W, ZHANG S G.Characterization and catalytic alkylation of hydrothermally dealuminated nanoscale ZSM-5 zeolite catalyst[J].Catal Commun, 2007, 9(4):487-493. [31] 丁春华, 王祥生, 郭新闻.水热处理对MCM-22催化剂酸性、孔结构及甲苯/甲醇烷基化性能的影响[J].高等学校化学学报, 2007, 28(5):922-927. http://www.cnki.com.cn/Article/CJFDTOTAL-GDXH200705030.htmDING Chun-hua, WANG Xiang-sheng, GUO Xin-wen.Effect of hydrothermal treatnent of MCM-22 catalyst on the acidity, pore structure and a lkylation properties of toluene with methanol[J].Chem J Chin Univ, 2007, 28(5):922-927. http://www.cnki.com.cn/Article/CJFDTOTAL-GDXH200705030.htm [32] ZHAO Y, TAN W, WU H Y, ZHANG A F, LIN M, LI G M, WANG X S, SONG C S, GUO X W.Effect of Pt on stability of nano-scale ZSM-5 catalyst for toluene alkylation with methanol into p-xylene[J].Catal Today, 2011, 160(1):179-183. doi: 10.1016/j.cattod.2010.05.036 [33] 周健, 刘志成, 李丽媛, 王仰东, 高焕新, 杨为民, 谢在库, 唐颐.多级孔ZSM-5分子筛:丰富的外表面酸中心和良好的二甲苯异构化催化性能[J].催化学报, 2013, 34(7):1429-1433. doi: 10.1016/S1872-2067(12)60602-0ZHOU Jian, LIU Zhi-cheng, LI Li-yuan, WANG Yang-dong, GAO Huan-xin, YANG Wei-min, XIE Zai-ku, TANG Yi.Hieraichical mesoporous ZSM-5 zeolite with increased external surface acid sites and high catalytic performance in o-xylene isomerization[J].Chin J Catal, 2013, 34(7):1429-1433. doi: 10.1016/S1872-2067(12)60602-0 [34] KIM J H, NAMBA S, YASHIMA T.Para-selectivity of zeolites with MFI structure difference between disproportionation and alkylation[J].Appl Catal, 1992, 83(1):51-58. doi: 10.1016/0926-860X(92)80025-8 [35] ČEJKA J, ŽILKOVÁN, WICHTERLOVÁB, EDER-MIRTH G, LERCHER J A.Decisive role of transport rate of products for zeolite para-selectivity:Effect of coke deposition and external surface silylation on activity and selectivity of HZSM-5 in alkylation of toluene[J].Zeolites, 1996, 17(3):265-271. doi: 10.1016/0144-2449(96)00006-1 [36] WEI J.A mathematical theory of enhanced para-xylene selectivity in molecular sieve catalysts[J].J Catal, 1982, 76(2):433-439. doi: 10.1016/0021-9517(82)90272-X [37] CHEN N Y, KAEDING W W, DWTER F G.Para-directed aromatic reactions over shape-selective molecular sieve zeolite catalysts[J].J Am Chem Soc, 1979, 101(22):6783-6784. doi: 10.1021/ja00516a065 -
点击查看大图
图(8) / 表(3)
计量
- 文章访问数: 230
- HTML全文浏览量: 43
- PDF下载量: 26
- 被引次数: 0
