Synthesis of Silicalite-1 hollow sphere catalyst and its application for Beckmann rearrangement reaction
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摘要: 以碳微球作为硬模板、纳米Silicalite-1分子筛作为壳层，采用水热法合成了Silicalite-1空心球材料。采用XRD、SEM、FT-IR、N2吸附、29Si MAS NMR、TG、XPS等技术对催化剂的物相、形貌和性能等进行表征，发现该空心材料具有较高的结晶度、发达的多级孔道结构和丰富的表面羟基。与传统方法制备的Silicalite-1分子筛催化剂相比，Silicalite-1空心材料在环己酮肟Beckmann重排反应中表现出优异的催化性能，使环己酮肟的转化率达99%、己内酰胺的选择性达94%，同时催化剂保持极佳的稳定性。研究表明，Silicalite-1空心材料中具有的大量巢式硅羟基和末端硅羟基是Beckmann重排反应的主要活性位，且可通过简单焙烧再生实现羟基活性位的完全恢复。
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关键词:
- Silicalite-1 /
- 空心材料 /
- 碳微球 /
- 硬模板法 /
- Beckmann重排
Abstract: Silicalite-1 zeolite hollow sphere structured material was hydrothermally synthesized via the aid of carbon microspheres as hard-template. The morphology, structure, textural and physicochemical properties of the material were characterized with XRD, SEM, FT-IR, N2 adsorption-desorption isotherm, 29Si MAS NMR, TG, and XPS techniques. It was suggested that the obtained Silicalite-1 hollow spheres were highly crystallized with developed multiple channel structure and abundant surface hydroxyl groups, which endowed the material with excellent catalytic properties in Beckmann rearrangement reaction of cyclohexanone-oxime. Compared with the Silicalite-1 catalyst prepared from conventional method, the Silicalite-1 hollow sphere catalyst showed much higher activity to the conversion of cyclohexanone-oxime (99%) and selectivity of caprolactam (94%), with excellent stability at the same time. The abundant nest silanols and terminal silanols in Silicalite-1 hollow sphere were main active sites for Beckmann rearrangement reaction, and could be easily recovered from the deactivated catalysts by calcination.-
Key words:
- Silicalite-1 /
- hollow sphere /
- carbon microspheres /
- hard-template /
- Beckmann rearrangement
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图 1 碳微球在酸处理前 (a) 与处理后 (b) 的XPS O 1s谱图
Figure 1 O 1s XPS spectra of carbon microspheres before (a) and after (b) the acid pre-treatment
图 2 所合成不同阶段样品的SEM照片
Figure 2 SEM images of samples obtained from different synthesis stages
(a): carbon microspheres; (b): core-shell structured sample C@Sil; (c): crushed Silicalite-1 hollow sphere Sil-HS;(d): surface of Sil-HS; (e): sample Sil-100; (f): sample Sil-5000
图 3 三种Silicalite-1分子筛的XRD谱图
Figure 3 XRD patterns of the Silicalite-1 of Sil-HS (a), Sil-100 (b) and Sil-5000 (c)
图 4 Sil-HS与Sil-100的N2吸脱附曲线 (a) 和Sil-HS的孔径分布图 (b)
Figure 4 N2 adsorption and desorption curves of Sil-HS and Sil-100 (a) and pore size distribution of Sil-HS (b)
图 5 三种Silicalite-1样品的29Si MAS NMR谱图
Figure 5 29Si MAS NMR spectra of Sil-HS (a), Sil-100 (b) and Sil-5000 (c)
图 6 三种Silicalite-1样品的FT-IR谱图
Figure 6 FT-IR spectra of the Silicalite-1 samples Sil-HS (a), Sil-100 (b) and Sil-5000 (c)
图 7 分子筛中硅羟基结构示意图
Figure 7 Structures of several silicon hydroxyls in zeolite, terminal silanols (a), vicinal silanols (b) and nest silanols (c)
图 8 三种Silicalite-1催化剂上环己酮肟转化率随时间的变化
Figure 8 Conversion of cyclohexanone-oxime (CHO) with time on stream over different Silicalite-1 catalysts
(a): Sil-HS; (b): Sil-100; (c): Sil-5000; reaction condition: 350 ℃, WHSV of CHO 4 h-1
图 9 三种催化剂失活后C 1s XPS谱图
Figure 9 C 1s XPS spectra of the deactivated catalysts of Sil-HS (a), Sil-100 (b) and Sil-5000 (c)
图 10 反应前后Sil-HS催化剂的FT-IR谱图
Figure 10 FT-IR spectra of Sil-HS
a: fresh catalyst; b: used catalyst; c: re-activated catalyst
表 1 三种催化剂的结构参数
Table 1 Textural parameters of three different Silicalite-1 samples
Sample Crystallinity /% ABETa/(m2·g-1) Aexternalb/(m2·g-1) vtotal/(cm3·g-1) vmicro/(cm3·g-1) vmeso/(cm3·g-1) Sil-HS 85 354 80 0.26 0.12 0.14 Sil-100 75 340 75 0.37 0.12 0.25 Sil-5000 100 394 51 0.22 0.13 0.09 a: determined from BET method; b: obtained from t-plot method 
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表 2 三种催化剂的Q3占比及单胞内的硅羟基数量
Table 2 Q3 proportion and the number of silanol groups per unit cell of the catalysts
Catalyst Sil-HS Sil-100 Sil-5000 Q3/(Q3+Q4) 1.51% 0.63% 0.53% Si-OHa/unit cell 1.45 0.60 0.51 a: Si-OH /unit cell=96 Q3/(Q3+Q4)[37]
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表 3 环己酮肟Beckmann重排反应中不同催化剂上的产物分布a
Table 3 Production distribution over three Silicalite-1 catalysts in Beckmann rearrangement reaction of cyclohexanone-oxime a
Catalyst CHO conversion x/% Product selectivity s/%b CL HEN CH (CHA) CHE others Sil-HS 97.9 94.2 0.9 1.7 1.9 1.3 Sil-100 86.0 91.3 1.2 3.4 1.3 2.8 Sil-5000 35.3 86.4 1.3 6.2 1.0 5.1 a: reaction conditions: 1 atm, 350 ℃, WHSV of CHO 4 h-1, 0.2 g/mL CHO in methanol solvent, N2 flow rate 30 mL/min，conversion and selectivity were obtained at 180 min of process time;
b: CHO=cyclohexanone-oxime, CL=ε-caprolactam, HEN=5-hexenenitrile, CH=cyclohexanone, CHA=cyclohexanol, CHE=cyclohex-2-enone
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表 4 三种失活催化剂上积炭物种及氧物种含量比较
Table 4 Carbon and oxygen species on the deactivated catalysts
Catalyst Total cokea w/% Coking ratea w/(%·h-1) Ratio of C, O, Sib(mol ratio) Distribution of C speciesb (wmol/%) C/O C/ Si C1 C2 C3 Sil-HS 6.72 0.132 0.48 1.42 43.0 50.8 6.2 Sil-100 2.36 0.262 0.25 0.66 51.1 42.4 6.5 Sil-5000 6.74 0.749 2.06 6.06 43.0 39.8 17.2 a: determined from TG; b: determined from XPS
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[1] LI Y, SHI J.Hollow-structured mesoporous materials:Chemical synthesis, functionalization and applications[J].Adv Mater, 2014, 26(20):3176-3205. doi: 10.1002/adma.v26.20 [2] FUJI M, TAKAI C, RIVERA VIRTUDAZO R V.Development of new templating approach for hollow nanoparticles and their applications[J].Adv Powder Technol, 2014, 25(1):91-100. doi: 10.1016/j.apt.2013.12.002 [3] OKAMOTO M.Synthesis of core-shell structured porous materials and applications as catalysts and precursors for hollow porous materials[J].Bull Jpn Petro Inst, 2013, 56(4):198-205. doi: 10.1627/jpi.56.198 [4] 金炜阳, 程党国, 陈丰秋, 詹晓力.分子筛膜包覆型催化剂的制备和应用[J].化学进展, 2011, 23(10):2021-2030. http://www.cnki.com.cn/Article/CJFDTOTAL-HXJZ201110005.htmJIN Wei-yang, CHENG Dang-guo, CHEN Feng-qiu, ZHAN Xiao-li.Synthesis and application of zeolite membrane encapsulated catalysts[J].Prog Chem, 2011, 23(10):2021-2030. http://www.cnki.com.cn/Article/CJFDTOTAL-HXJZ201110005.htm [5] WANG X D, TANG Y, WANG Y J, GAO Z, YANG W L, FU S K.Fabrication of hollow zeolite spheres[J].Chem Commun, 2000, 21:2161-2162. https://www.researchgate.net/profile/Wuli_Yang/publication/244539605_Fabrication_of_hollow_zeolite_spheres/links/0c96052ca2be9a1f38000000.pdf [6] LAI Z, BONILLA G, DIAZ I, NERY J G, SUJAOTI K, AMAT M A, KOKKOLI E, TERASAKI O, THOMPSON R W, TSAPATSIS M, VLACHOS D G.Microstructural optimization of a zeolite membrane for organic vapor separation[J].Science, 2003, 300(5618):456-460. [7] YU G, SUN B, PEI Y, XIE S, YAN S, QIAO M, FAN K, ZHANG X, ZONG B.FexOy@C spheres as an excellent catalyst for Fischer-Tropsch synthesis[J].J Am Chem Soc, 2010, 132(3):935-937. doi: 10.1021/ja906370b [8] KHAN E A, HU E, LAI Z.Preparation of metal oxide/zeolite core-shell nanostructures[J].Microporous Mesoporous Mater, 2009, 118(1/3):210-217. [9] WANG X D, ZHANG B Q, LIU X F, LIN J Y S.Synthesis of b-oriented TS-1 films on chitosan-modifiedα-Al2O3 substrates[J].Adv Mater, 2006, 18(24):3261-3265. doi: 10.1002/(ISSN)1521-4095 [10] WANG X, YAN J, HUANG W.Synthesis of b-oriented TS-1 zeolite membranes with high performance in the oxyfunctionalization of n-hexane[J].Thin Solid Films, 2013, 534:40-44. doi: 10.1016/j.tsf.2013.01.075 [11] PENG H, XU L, WU H, WANG Z, LIU Y, LI X, HE M, WU P.Synthesis and formation mechanism of TS-1@mesosilica core-shell materials templated by triblock copolymer surfactant[J].Microporous Mesoporous Mater, 2012, 153:8-17. doi: 10.1016/j.micromeso.2011.11.055 [12] CHU N, WANG J, ZHANG Y, YANG J, LU J, YIN D.Nestlike hollow hierarchical MCM-22 microspheres:Synthesis and exceptional catalytic properties[J].Chem Mater, 2010, 22(9):2757-2763. doi: 10.1021/cm903645p [13] GARCÍA-MARTÍNEZ J, CAZORLA-AMORÓ S D, LINARES-SOLANO A, LIN Y S.Synthesis and characterisation of MFI-type zeolites supported on carbon materials[J].Microporous Mesoporous Mater, 2001, 42(2/3):255-268. [14] VALTCHEV V, MINTOVA S.Layer-by-layer preparation of zeolite coatings of nanosized crystals[J].Microporous Mesoporous Mater, 2001, 43(1):41-49. doi: 10.1016/S1387-1811(00)00345-0 [15] CARUSO F, CARUSO R A, MOHWALD H.Nanoengineering of inorganic and hybrid hollow spheres by colloidal templating[J].Science, 1998, 282(5391):1111-1114. doi: 10.1126/science.282.5391.1111 [16] VALTCHEV V.Silicalite-1 hollow spheres and bodies with a regular system of macrocavities[J].Chem Mater, 2002, 14(10):4371-4377. doi: 10.1021/cm020579v [17] VALTCHEV V.Core-shell polystyrene/zeolite a microbeads[J].Chem Mater, 2002, 14(3):956-958. doi: 10.1021/cm010927d [18] JI Y J, ZHANG B, XU L, WU H, PENG H, CHEN L, LIU Y, WU P.Core/shell-structured Al-MWW@B-MWW zeolites for shape-selective toluene disproportionation to para-xylene[J].J Catal, 2011, 283(2):168-177. doi: 10.1016/j.jcat.2011.08.007 [19] LV Y, QIAN X, TU B, ZHAO D.Generalized synthesis of core-shell structured nano-zeolite@ordered mesoporous silica composites[J].Catal Today, 2013, 204:2-7. doi: 10.1016/j.cattod.2012.09.031 [20] CHAMNANKID B, WITOON T, KONGKACHUICHAY P, CHAREONPANICH M.One-pot synthesis of core-shell silica-aluminosilicate composites:Effect of pH and chitosan addition[J].Colloids Surf A, 2011, 380(1/3):319-326. [21] DONG A, WANG Y, TANG Y, REN N, ZHANG Y, GAO Z.Hollow zeolite capsules:A novel approach for fabrication and guest encapsulation[J].Chem Mater, 2002, 14(8):3217-3219. doi: 10.1021/cm025577p [22] KIM J, PARK W, RYOO R.Surfactant-directed zeolite nanosheets:A high-performance catalyst for gas-phase beckmann rearrangement[J].ACS Catal, 2011, 1(4):337-341. doi: 10.1021/cs100160g [23] TAKAHASHI T, NISHI M, TAGAWA Y, KAI T.Catalyst deactivation of high-silica HZSM-5 in the Beckmann rearrangement reaction of cyclohexanone oxime[J].Microporous Mater, 1995, 3(s 4/5):467-471. [24] KUMAR R, CHOWDHURY B.Comprehensive study for vapor phase beckmann rearrangement reaction over zeolite systems[J].Ind Eng Chem Res, 2014, 53(43):16587-16599. doi: 10.1021/ie503170n [25] 李倩, 严罗一, 夏定, 申永存.贝克曼重排反应研究进展[J].有机化学, 2011, 31(12):2034-2042. http://www.cnki.com.cn/Article/CJFDTOTAL-YJHU201112010.htmLI Qian, YAN Luo-yi, XIA Ding, SHEN Yong-cun.Research progress of Beckmann rearrangement[J].Chin J Org Chem, 2011, 31(12):2034-2042. http://www.cnki.com.cn/Article/CJFDTOTAL-YJHU201112010.htm [26] LI W C, LU A H, PALKOVITS R, SCHMIDT W, SPLIETHOFF B, SCHVTH F.Hierarchically structured monolithic silicalite-1 consisting of crystallized nanoparticles and its performance in the beckmann rearrangement of cyclohexanone oxime[J].J Am Chem Soc, 2005, 127(36):12595-12600. doi: 10.1021/ja052693v [27] HEITMANN G P, DAHLHOFF G, HOLDERICH W F.Catalytically active sites for the beckmann rearrangement of cyclohexanone oxime to epsilon-caprolactam[J].J Catal, 1999, 186(1):12-19. doi: 10.1006/jcat.1999.2552 [28] YIN C, NI R, BAO X, CHEN Y.Synthesis of hierarchical porous silicalite-1 and its catalytic performance in Beckmann rearrangement[J].Microporous Mesoporous Mater, 2015, 202:133-137. doi: 10.1016/j.micromeso.2014.08.047 [29] SONG H, XING C, LI B, SHEN W.Spherical carbon with SO3H groups as an efficient solid acid catalyst for 2, 4, 5-triphenyl-imidazole synthesis[J].Chem Select, 2016, 1(2):301-308. [30] BERENGUER-MURCIAÁ, GARCÍA-MARTÍNEZ J, CAZORLA-AMORÓ S D, LINARES-SOLANO Á, FUERTES A B.Silicalite-1 membranes supported on porous carbon discs[J].Microporous Mesoporous Mater, 2003, 59(2/3):147-159. [31] LI Q, HEDLUND J, STERTE J, CREASER D, BONS A J.Synthesis and characterization of zoned MFI films by seeded growth[J].Microporous Mesoporous Mater, 2002, 56(3):291-302. doi: 10.1016/S1387-1811(02)00503-6 [32] KULKARNI S B S V P, KOTASTHANE A N BORADE R B, RATNASAMY P.Studies in the synthesis of ZSM-5 zeolites[J].Zeolites, 1982, 2(4):313-318. doi: 10.1016/S0144-2449(82)80077-8 [33] SUGIMOTO M K H, TAKATSU K, KAWATA N.Correlation between the crystal size and catalytic properties of ZSM-5 zeolite[J].Zeolites, 1987, 7(6):503-507. doi: 10.1016/0144-2449(87)90087-X [34] OUTIRITE M, LAGRENÉE M, LEBRINI M, TRAISNEL M, JAMA C, VEZIN H, BENTISS F.Ac impedance, X-ray photoelectron spectroscopy and density functional theory studies of 3, 5-bis (n-pyridyl)-1, 2, 4-oxadiazoles as efficient corrosion inhibitors for carbon steel surface in hydrochloric acid solution[J].Electrochim Acta, 2010, 55(5):1670-1681. doi: 10.1016/j.electacta.2009.10.048 [35] BOUMHARA K, TABYAOUI M, JAMA C, BENTISS F.Artemisia Mesatlantica essential oil as green inhibitor for carbon steel corrosion in 1M HCl solution:Electrochemical and XPS investigations[J].J Ind Eng Chem, 2015, 29:146-155. doi: 10.1016/j.jiec.2015.03.028 [36] HUNGER M, KÄRGER J, PFEIFER H, CARO J, ZIBROWIUS B, BVLOW M, MOSTOWICZ R.Investigation of internal silanol groups as structural defects in ZSM-5-type zeolites[J].J Chem Soc Faraday Trans, 1987, 83(1):3459-3468. [37] KUHN J, MOTEGH M, GROSS J, KAPTEIJN F.Detemplation of[B]MFI zeolite crystals by ozonication[J].Microporous Mesoporous Mater, 2009, 120(1/2):35-38. [38] YAMAGISHI K, NAMBA S, YASHIMA T.Defect sites in highly siliceous HZSM-5 zeolites:A study performed by alumination and IR spectroscopy[J].J Phy Chem, 1991, 95(2):872-877. doi: 10.1021/j100155a071 [39] BARBERA K, BONINO F, BORDIGA S, JANSSENS T V W, BEATO P.Structure-deactivation relationship for ZSM-5 catalysts governed by framework defects[J].J Catal, 2011, 280(2):196-205. doi: 10.1016/j.jcat.2011.03.016 [40] VASCHETTO E G, CASUSCELLI S G, EIMER G A.Improvements in the Beckmann rearrangement process by using highly selective mesoporous catalysts[J].Microporous Mesoporous Mater, 2016, 221:175-181. doi: 10.1016/j.micromeso.2015.09.038 [41] IZUMI Y, ICHIHASHI H, SHIMAZU Y, KITAMURA M, SATO H.Development and industrialization of the vapor-phase beckmann rearrangement process[J].Bull Chem Soc Jpn, 2007, 80(7):1280-1287. doi: 10.1246/bcsj.80.1280 [42] ICHIHASHI H, SATO H.The development of new heterogeneous catalytic processes for the production of ε-caprolactam[J].Appl Catal A:Gen, 2001, 221(1/2):359-366. [43] SINGH P S, BANDYOPADHYAY R, HEGDE S G, RAO B S.Vapor phase Beckmann rearrangement of cyclohexanone oxime over SAPO-11 molecular sieve[J].Appl Catal A:Gen, 1996, 136:249-263. doi: 10.1016/0926-860X(95)00303-7 [44] RÖSELER J, HEITMANN G, HÖLDERICH W F.Vapor-phase Beckmann using B-MFI zeolites[J].Appl Catal A:Gen, 1996, 144:319-333. doi: 10.1016/0926-860X(96)00127-5 [45] KO A N, HUNG C C, CHEN C W, OUYANG K H.Mesoporous molecular sieve Al-MCM-41 as a novel catalyst for vapor-phase Beckmann rearrangement of cyclohexanone oxime[J].Catal Lett, 2001, 71(3/4):219-224. doi: 10.1023/A:1009038701442 [46] KELEMEN S R, M.AFEWORKI A, GORBATY M L, COHEN A D.Characterization of organically bound oxygen forms in lignites, peats, and pyrolyzed peats by X-ray photoelectron spectroscopy (XPS) and solid-state 13C NMR methods[J].Energy Fuels, 2002, 16(6):1450-1462. doi: 10.1021/ef020050k -
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