Synthesis of ZSM-22/ZSM-23 intergrowth zeolite as the catalyst support for hydroisomerization of n-hexadecane
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摘要: 在二甲胺与二乙胺双模板剂体系中,通过控制二甲胺/二乙胺的摩尔比为24,动态水热合成了ZSM-22/ZSM-23共晶分子筛。采用XRD、FE-SEM、TEM、N2物理吸附、NH3-TPD和吡啶吸附红外等表征手段,考察了ZSM-22/ZSM-23共晶分子筛样品的物理化学性质,并对其负载Pt后在正十六烷加氢异构化反应中的催化性能进行了研究。结果表明,针状的ZSM-22/ZSM-23分子筛具有与ZSM-22和ZSM-23不同的拓扑结构,其Brönsted酸量及中强酸比例较高。对于正十六烷加氢异构化,相比于单一分子筛和机械混合分子筛催化剂,采用共晶分子筛通过浸渍法制备的双功能Pt/ZSM-22/ZSM-23催化剂同时具备Pt/ZSM-22高选择性以及Pt/ZSM-23高转化率的优势,表现出更高的异构体收率,并具有一定的择形效应,异构化产物以单甲基异构体为主。
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关键词:
- ZSM-22/ZSM-23 /
- 共晶分子筛 /
- 正十六烷 /
- 加氢异构
Abstract: ZSM-22/ZSM-23 intergrowth zeolite was successfully synthesized by hydrothermal method with diethylamine and dimethylamine as co-structure directing agents at a dimethylamine/diethylamine molar ratio of 24. The physicochemical properties of ZSM-22/ZSM-23 intergrowth zeolite including the crystallinity, crystal morphology, texture and acidity were determined by XRD, FE-SEM, TEM, N2-physisorption, NH3-TPD, Py-FTIR, and so on; the performance of Pt/ZSM-22/ZSM-23 catalyst prepared by impregnation in the hydroisomerization of n-hexadecane was then investigated. The results indicate that the ZSM-22/ZSM-23 intergrowth zeolite displays the needle-like morphology with the topological structures of both ZSM-22 and ZSM-23, which is rather different from pure ZSM-22 and ZSM-23 and their mechanical mixture. After loading 0.5% Pt, the bi-functional Pt/ZSM-22/ZSM-23 catalyst exhibits excellent performance in the hydroisomerization of n-hexadecane, with a much higher yield of i-C16 products (dominated by mono-branched isomers) than those obtained over Pt supported on ZSM-22 and ZSM-22 and their mechanical mixture.-
Key words:
- ZSM-22/ZSM-23 /
- intergrowth zeolite /
- n-hexadecane /
- hydroisomerization
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Table 1 Effect of gel composition and synthetic conditions on the crystallization products
Entry DMA/DEA SDA/SiO2 OH−/SiO2 H2O/SiO2 Time t/h Product RC/% 1 30 0.93 0.15a 45 72 ZSM-23+ cristobalite − 2 24 0.75 0.15a 45 72 ZSM-22/ZSM-23+ZSM-5 71 3 24 0.75 0.10a 45 66 ZSM-22/ZSM-23 100 4 24 1.00 0.15a 45 72 ZSM-22/ZSM-23+ZSM-5 69 5 18 0.57 0.15a 45 72 ZSM-22+ cristobalite − 6 12 0.39 0.15a 45 72 ZSM-22+ cristobalite − 7 8 0.81 0.15a 45 72 ZSM-22+cristobalite − 8 24 0.75 0.3a 45 72 ZSM-22/ZSM-23+cristobalite 32 9 24 0.75 0.2a 45 72 ZSM-22/ZSM-23+ZSM-5 49 10 24 0.75 0.12a 45 72 ZSM-22/ZSM-23+cristobalite 61 11 24 0.75 0.12a 45 66 ZSM-22/ZSM-23+ cristobalite 79 12 24 0.75 0.08a 45 72 ZSM-22/ZSM-23+amorphous 83 13 24 0.75 0.05a 45 72 amorphous − 14 24 0.75 0.3b 45 72 ZSM-22/ZSM-23+cristobalite − 15 24 0.75 0.2b 45 72 ZSM-22/ZSM-23 73 16 24 0.75 0.15b 45 66 ZSM-22/ZSM-23 87 17 24 0.75 0.10b 45 66 ZSM-22/ZSM-23 78 18 24 0.75 0.10a 45 84 ZSM-5+cristobalite − 19 24 0.75 0.10a 45 78 ZSM-5+ZSM-22/ZSM-23+cristobalite 45 20 24 0.75 0.10a 45 72 ZSM-22/ZSM-23+cristobalite 86 21 24 0.75 0.10a 45 60 ZSM-22/ZSM-23 92 22 24 0.75 0.10a 45 54 ZSM-22/ZSM-23+amorphous 49 23 24 0.75 0.10a 38 66 ZSM-22/ZSM-23+cristobalite 86 24 24 0.75 0.10a 30 66 ZSM-22/ZSM-23+cristobalite 67 note: a: the alkali source was NaOH; b: the alkali source was KOH Table 2 Textural properties of as-prepared zeolites and catalysts
Sample Surface area/(m2·g−1) Pore volume /(cm3·g−1) Average pore width d/nm SBETa SMicrob SExb vTotalc vMicrob ZSM-22/ZSM-23 198 101 97 0.62 0.05 0.51 ZSM-22 161 69 92 0.62 0.03 0.50 ZSM-23 208 109 99 0.51 0.05 0.53 MZSM-22/ZSM-23 209 98 111 0.66 0.05 0.52 Pt/ZSM-22/ZSM-23 203 106 97 0.36 0.05 0.51 Pt/ZSM-22 157 40 117 0.59 0.02 0.46 Pt/ZSM-23 198 109 89 0.30 0.05 0.53 Pt/MZSM-22/ZSM-23 211 111 100 0.42 0.05 0.53 note: a: calculated by multi-BET equation; b: measured by t-plot method, SEx = SBET − SMicro; c: determined at p/p0 = 0.99; d: derived by HK method Table 3 SiO2/Al2O3 ratios, 27Al NMR data and NH3-TPD analysis results of various zeolites
Sample Acidic density/(NH3 mmol·g−1) SiO2/Al2O3a Al(VI) b/% weak medium strong total ZSM-22/ZSM-23 0.13 0.05 0.05 0.24 79 9 ZSM-22 0.11 0.05 0.06 0.22 74 21 ZSM-23 0.18 0.04 0.14 0.35 78 8 MZSM-22/ZSM-23 0.15 0.05 0.10 0.30 74 15 note: a: determined by ICP-AES; b: derived from the 27Al-NMR spectra Table 4 Acidity distribution of as-synthesized zeolites derived from Py-FTIR
Sample Lewis acid, CL/(mmol·g−1) Brönsted acid, CB/(mmol·g−1) 150 °C 300 °C 450 °C 150 °C 300 °C 450 °C ZSM-22/ZSM-23 0.060 0.045 0.025 0.315 0.312 0.283 ZSM-22 0.105 0.063 0.045 0.093 0.087 0.078 ZSM-23 0.025 0.016 0.011 0.434 0.416 0.386 MZSM-22/ZSM-23 0.086 0.066 0.051 0.248 0.232 0.228 Table 5 Product distribution of the n-hexadecane hydroisomerization over different catalysts
Carbon number Product Distributiona /% Pt/ZSM-22/ZSM-23 Pt/ZSM-22 Pt/ZSM-23 Pt/MZSM-22/ZSM-23 ≤4 ≤C4 8.8 10.2 19.7 7.2 5 2M-C4 3.4 2.6 6.0 3.4 n-C5 5.7 6.0 9.3 6.2 6 2M-C5 2.5 1.7 2.7 2.4 3M-C5 1.3 0.8 1.3 1.2 n-C6 4.3 4.7 6.5 5.3 7 2M-C6 2.2 1.4 2.5 2.7 3M-C6 1.4 0.6 1.4 1.6 n-C7 3.8 3.7 6.4 5.5 8 2M-C7 1.8 0.6 2.0 2.2 3M-C7 0.8 0.3 0.9 1.1 n-C8 1.6 2.3 2.7 2.4 9 2M-C8 0.7 0.6 0.6 0.5 n-C9 1 0.8 0.7 0.5 12 n-C12 1.5 1.8 1.8 1.5 13 1.9 3.5 2.0 1.9 16 2M-C15 8.8 16.2 5.1 7.5 3M-C15 8.5 9.7 6.0 7.8 4M-C15 5.9 5.2 3.5 5.6 5M-C15 5.7 6.7 4.0 6.0 6M-C15 3.7 5.5 3.5 4.8 7M-C15 15 12.6 6.8 13.2 DiMe-C14 9.7 2.8 4.7 9.9 note: a: reaction conditions: H2/feed ratio, 300 mL/mL, contact time, 1.12 min, 320 °C and 4.0 MPa -
[1] KIM J, HAN S W, KIM J C, RYOO R. Supporting nickel to replace platinum on zeolite nanosponges for catalytic hydroisomerization of n-dodecane[J]. ACS Catal,2018,8(11):10545−10554. doi: 10.1021/acscatal.8b03301 [2] LEE S W, IHM S K. Characteristics of magnesium-promoted Pt/ZSM-23 catalyst for the hydroisomerization of n-hexadecane[J]. Ind Eng Chem Res,2013,52(44):15359−15365. doi: 10.1021/ie400628q [3] YU D K, FU M L, YUAN Y H, SONG Y B, CHEN J Y, FANG Y W. One-step synthesis of hierarchical-structured ZSM-5 zeolite[J]. J Fuel Chem Technol,2016,44(11):1363−1369. doi: 10.1016/S1872-5813(16)30059-7 [4] ZHANG M, LI C, CHEN X, CHEN Y, LIANG C. Hierarchical ZSM-48-supported nickel catalysts with enhanced hydroisomerization performance of hexadecane[J]. Ind Eng Chem Res,2019,58(43):19855−19861. doi: 10.1021/acs.iecr.9b04415 [5] LV G, WANG C X, WANG P, SUN L, LIU H, QU W, WANG D G, MA H J, TIAN Z J. Pt/ZSM-22 with partially filled micropore channels as excellent shape-selective hydroisomerization catalyst[J]. ChemCatChem,2019,11(5):1431−1436. doi: 10.1002/cctc.201801695 [6] LIU P, REN J, SUN Y H. Influence of template on Si distribution of SAPO-11 and their performance for n-paraffin isomerization[J]. Microporous Mesoporous Mater,2008,114(1/3):365−372. doi: 10.1016/j.micromeso.2008.01.022 [7] YUNFENG H, XIANGSHENG W, XINWEN G, SILUE L, SHENG H, HAIBO S, LIANG B. Effects of channel structure and acidity of molecular sieves in hydroisomerization of n-octane over bi-functional catalysts[J]. Catal Lett,2005,100(1/2):59−65. doi: 10.1007/s10562-004-3086-9 [8] SHI J, WANG Y, YANG W, TANG Y, XIE Z. Recent advances of pore system construction in zeolite-catalyzed chemical industry processes[J]. Chem Soc Rev,2015,44(24):8877−8903. doi: 10.1039/C5CS00626K [9] CHEN Y J, LI C, CHEN X, LIU Y, LIANG C H. Synthesis of ZSM-23 zeolite with dual structure directing agents for hydroisomerization of n-hexadecane[J]. Microporous Mesoporous Mater,2018,268:216−224. doi: 10.1016/j.micromeso.2018.04.033 [10] ZHENG J J, ZHANG X W, ZHANG Y, MA J H, LI R F. Structural effects of hierarchical pores in zeolite composite[J]. Microporous Mesoporous Mater,2009,122(1/3):264−269. doi: 10.1016/j.micromeso.2009.03.009 [11] OHSUNA T, TERASAKI O, NAKAGAWA Y, ZONES S I, HIRAGA K. Electron microscopic study of intergrowth of MFL and MEL: Crystal faults B-MEL[J]. J Phy Chem B,1997,101(48):9881−9885. doi: 10.1021/jp971448y [12] CLAUDE M C, VANBUTSELE G, MARTENS J A. Dimethyl branching of long n-alkanes in the range from decane to tetracosane on Pt/H-ZSM-22 bifunctional catalyst[J]. J Catal,2001,203(1):213−231. doi: 10.1006/jcat.2001.3325 [13] CHEN Y, LI C, WANG L, ZHANG M, LIANG C. Seed-assisted synthesis of ZSM-23 zeolites in the absence of alkali metal ions[J]. Microporous Mesoporous Mater,2017,252:146−153. doi: 10.1016/j.micromeso.2017.06.013 [14] ROLLMANN L D, SCHLENKER J L, LAWTON S L, KENNEDY C L, KENNEDY G J, DOREN D J. On the role of small amines in zeolite synthesis[J]. J Phy Chem B,1999,103(34):7175−7183. doi: 10.1021/jp991913m [15] LATEEF S A, BAKARE I A, MAYORAL A, SEBASTIAN V, MURAZA O. Selective catalytic cracking of n-hexane to olefins over SSZ-54 fabricated by facile and novel dual templating method[J]. Fuel,2018,227:48−58. doi: 10.1016/j.fuel.2018.03.161 [16] WANG B, TIAN Z, LI P, WANG L, XU Y, QU W, MA H, XU Z, LIN L. Synthesis of ZSM-23/ZSM-22 intergrowth zeolite with a novel dual-template strategy[J]. Mater Res Bull,2009,44(12):2258−2261. doi: 10.1016/j.materresbull.2009.07.017 [17] BURTON A W, ZONES S I, REA T, CHAN I Y. Preparation and characterization of SSZ-54: A family of MTT/TON intergrowth materials[J]. Microporous Mesoporous Mater,2010,132(1-2):54−59. doi: 10.1016/j.micromeso.2009.10.023 [18] MUNUSAMY K, DAS R K, GHOSH S, KUMAR S A K, PAI S, NEWALKAR B L. Synthesis, characterization and hydroisomerization activity of ZSM-22/23 intergrowth zeolite[J]. Microporous Mesoporous Mater,2018,266:141−148. doi: 10.1016/j.micromeso.2018.02.044 [19] ZHANG M, WANG L, CHEN Y, ZHANG Q, LIANG C. Creating mesopores in ZSM-48 zeolite by alkali treatment: Enhanced catalyst for hydroisomerization of hexadecane[J]. J Energy Chem,2016,25(3):539−544. doi: 10.1016/j.jechem.2016.01.014 [20] CHI K, ZHAO Z, TIAN Z, HU S, YAN L, LI T, WANG B, MENG X, GAO S, TAN M, LIU Y. Hydroisomerization performance of platinum supported on ZSM-22/ZSM-23 intergrowth zeolite catalyst[J]. Pet Sci,2013,10(2):242−250. doi: 10.1007/s12182-013-0273-6 [21] ZHANG M, CHEN Y, WANG L, ZHANG Q, TSANG C W, LIANG C. Shape selectivity in hydroisomerization of hexadecane over Pt supported on 10-ring zeolites: ZSM-22, ZSM-23, ZSM-35, and ZSM-48[J]. Ind Eng Chem Res,2016,55(21):6069−6078. doi: 10.1021/acs.iecr.6b01163 [22] ABOUL-FOTOUH S M K, ALI L I, NAGHMASH M A, ABOUL-GHEIT N A K. Effect of the Si/Al ratio of HZSM-5 zeolite on the production of dimethyl ether before and after ultrasonication[J]. J Fuel Chem Technol,2017,45(5):581−588. doi: 10.1016/S1872-5813(17)30030-0 [23] WANG C, ZHANG L, HUANG X, ZHU Y, LI G K, GU Q, CHEN J, MA L, LI X, HE Q, XU J, SUN Q, SONG C, PENG M, SUN J, MA D. Maximizing sinusoidal channels of HZSM-5 for high shape-selectivity to p-xylene[J]. Nat Commun,2019,10(1):4348. doi: 10.1038/s41467-019-12285-4 [24] LI H R, LIU C L, WANG Y, ZHENG J J, FAN B B, LI R F. Synthesis, characterization and n-hexane hydroisomerization performances of Pt supported on alkali treated ZSM-22 and ZSM-48[J]. RSC Adv,2018,8(51):28909−28917. doi: 10.1039/C8RA04858D [25] WANG B C, TIAN Z J, LI P, WANG L, XU Y P, QU W, HE Y L, MA H J, XU Z S, LIN L W. A novel approach to synthesize ZSM-23 zeolite involving N, N-dimethylformamide[J]. Microporous Mesoporous Mater,2010,134(1/3):203−209. doi: 10.1016/j.micromeso.2010.06.001 [26] MAZUREK M, BENKER N, ROTH C, FUESS H. Binary mixtures of carbon supported Pt and Ru catalysts for PEM fuel cells[J]. Fuel Cells,2006,6(3/4):208−213. doi: 10.1002/fuce.200600012 [27] LATEEF S A, BAKARE I A, MURAZA O. Microwave assisted synthesis of MTT-TON intergrowth crystals for the catalytic conversion of naphtha to olefins[J]. Microporous Mesoporous Mater,2018,260:253−259. doi: 10.1016/j.micromeso.2017.10.023 [28] CHEN Z, LIU S, WANG H, NING Q, ZHANG H, YUN Y, REN J, LI Y W. Synthesis and characterization of bundle-shaped ZSM-22 zeolite via the oriented fusion of nanorods and its enhanced isomerization performance[J]. J Catal,2018,361:177−185. doi: 10.1016/j.jcat.2018.02.019 [29] CHEN Y, LI C, CHEN X, LIU Y, TSANG C-W, LIANG C. Synthesis and characterization of iron-substituted ZSM-23 zeolite catalysts with highly selective hydroisomerization of n-hexadecane[J]. Ind Eng Chem Res,2018,57(41):13721−13730. doi: 10.1021/acs.iecr.8b03806 [30] BLEKEN F L, BARBERA K, BONINO F, OLSBYE U, LILLERUD K P, BORDIGA S, BEATO P, JANSSENS T V W, SVELLE S. Catalyst deactivation by coke formation in microporous and desilicated zeolite H-ZSM-5 during the conversion of methanol to hydrocarbons[J]. J Catal,2013,307:62−73. doi: 10.1016/j.jcat.2013.07.004 [31] MURAZA O, BAKARE I A, TAGO T, KONNO H, TANIGUCHI T, AL-AMER A M, YAMANI Z H, NAKASAKA Y, MASUDA T. Selective catalytic cracking of n-hexane to propylene over hierarchical MTT zeolite[J]. Fuel,2014,135:105−111. doi: 10.1016/j.fuel.2014.06.045 [32] MOELLER K, BEIN T. Crystallization and porosity of ZSM-23[J]. Microporous Mesoporous Mater,2011,143(2/3):253−262. doi: 10.1016/j.micromeso.2010.12.019 [33] CLAUDE M C, MARTENS J A. Monomethyl-branching of long n-alkanes in the range from decane to tetracosane on Pt/H-ZSM-22 bifunctional catalyst[J]. J Catal,2000,190(1):39−48. doi: 10.1006/jcat.1999.2714 [34] ZHANG F, LIU Y, SUN Q, DAI Z, GIES H, WU Q, PAN S, BIAN C, TIAN Z, MENG X, ZHANG Y, ZOU X, YI X, ZHENG A, WANG L, XIAO F S. Design and preparation of efficient hydroisomerization catalysts by the formation of stable SAPO-11 molecular sieve nanosheets with 10-20 nm thickness and partially blocked acidic sites[J]. Chem Commun,2017,53(36):4942−4945. doi: 10.1039/C7CC01519D [35] WU T, YUAN G M, CHEN S L, XUE Y, LI S J. Synthesis of ZSM-5 and its application in butylene catalytic cracking[J]. J Fuel Chem Technol,2017,45(2):182−188. doi: 10.1016/S1872-5813(17)30013-0 [36] XU H, ZHANG J, WU Q M, CHEN W, LEI C, ZHU Q Y, HAN S C, FEI J H, ZHENG A M, ZHU L F, MENG X J, MAURER S, DAI D, PARVULESCU A N, MULLER U, XIAO F S. Direct synthesis of aluminosilicate SSZ-39 zeolite using colloidal silica as a starting source[J]. ACS Appl Mater Interfaces,2019,11(26):23112−23117. doi: 10.1021/acsami.9b03048 [37] DANILINA N, KRUMEICH F, CASTELANELLI S A, VAN BOKHOVEN J A. Where are the active sites in zeolites? origin of aluminum zoning in ZSM-5[J]. J Phys Chem C,2010,114(14):6640−6645. doi: 10.1021/jp1006044 [38] ZHANG Y, LIU Y, SUN L, ZHANG L, XU J, DENG F, GONG Y. Synthesis of EU-1/ZSM-48 Co-crystalline zeolites from high-silica EU-1 seeds: tailoring phase proportions and promoting long crystalline-phase stability[J]. Chem Eur J,2018,24(25):6595−6605. doi: 10.1002/chem.201705805 [39] DANISI R M, SCHMIDT J E, PAIONI A L, HOUBEN K, POPLAWSKY J D, BALDUS M, WECKHUYSEN B M, VOGT E T C. Revealing long- and short-range structural modifications within phosphorus-treated HZSM-5 zeolites by atom probe tomography, nuclear magnetic resonance and powder X-ray diffraction[J]. Phys Chem Chem Phys,2018,20(44):27766−27777. doi: 10.1039/C8CP03828G [40] YANG Z C, LIU Y Q, LIU D D, MENG X T, LIU C G. Hydroisomerization of n-octane over bimetallic Ni-Cu/SAPO-11 catalysts[J]. Appl Catal A: Gen,2017,543:274−282. doi: 10.1016/j.apcata.2017.06.028 [41] TIAN S S, CHEN J X. Hydroisomerization of n-dodecane on a new kind of bifunctional catalyst: Nickel phosphide supported on SAPO-11 molecular sieve[J]. Fuel Process Technol,2014,122:120−128. doi: 10.1016/j.fuproc.2014.01.031 [42] GAO S B, ZHAO Z, LU X F, CHI K B, DUAN A J, LIU Y F, MENG X B, TAN M- W, YU H Y, SHEN Y G, LI M C. Hydrocracking diversity in n-dodecane isomerization on Pt/ZSM-22 and Pt/ZSM-23 catalysts and their catalytic performance for hydrodewaxing of lube base oil[J]. Pet Sci,2020,17(6):1752−1763. doi: 10.1007/s12182-020-00500-7 [43] MILLER S J, LACHEEN H S, CHEN C Y. Determining the strength of Bronsted acid sites for hydrodewaxing over shape-selective catalysts[J]. Ind Eng Chem Res,2016,55(24):6760−6767. doi: 10.1021/acs.iecr.6b01081 [44] TEKETEL S, SKISTAD W, BENARD S, OLSBYE U, LILLERUD K P, BEATO P, SVELLE S. Shape selectivity in the conversion of methanol to hydrocarbons: The catalytic performance of one-dimensional 10-ring zeolites: ZSM-22, ZSM-23, ZSM-48, and EU-1[J]. ACS Catal,2012,2(1):26−37. doi: 10.1021/cs200517u [45] HENGSAWAD T, SRIMINGKWANCHAI C, BUTNARK S, RESASCO D E, JONGPATIWUT S. Effect of metal-acid balance on hydroprocessed renewable jet fuel synthesis from hydrocracking and hydroisomerization of biohydrogenated diesel over Pt-supported catalysts[J]. Ind Eng Chem Res,2018,57(5):1429−1440. doi: 10.1021/acs.iecr.7b04711 [46] HUYBRECHTS W, THYBAUT J, DEWAELE B, VANBUTSELE G, HOUTHOOFD K, BERTINCHAMPS F, DENAYER J, GAIGNEAUX E, MARIN G, BARON G. Bifunctional catalytic isomerization of decane over MTT-type aluminosilicate zeolite crystals with siliceous rim[J]. J Catal,2006,239(2):451−459. doi: 10.1016/j.jcat.2006.02.020 [47] CHOUDHURY I R, HAYASAKA K, THYBAUT J W, NARASIMHAN C S L, DENAYER J F, MARTENS J A, MARIN G B. Pt/H-ZSM-22 hydroisomerization catalysts optimization guided by single-event microkinetic modeling[J]. J Catal,2012,290:165−176. doi: 10.1016/j.jcat.2012.03.015