介微孔复合材料Beta-MCM-41的制备及其正庚烷临氢异构催化性能

摘要/Abstract

摘要： 采用纳米组装法将经NaOH溶液处理后的HBeta沸石与阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）组装制得介微孔复合材料Beta-MCM-41（记作BM-41），将BM-41与NH4Cl进行离子交换，得到氢型复合材料HBeta-MCM-41（记作HBM-41），以HBM-41为载体制得Pt负载量（w）为0.4%的催化剂Pt/HBM-41，并应用于正庚烷临氢异构化反应。利用X射线衍射、N₂吸附-脱附、傅里叶变换红外光谱等手段对样品进行表征。在温度为240 ℃、压力为常压、质量空速为2.46 h^-1 的反应条件下对催化剂进行评价。反应结果表明，在Pt负载量相同的3种催化剂Pt/HBeta，Pt/MCM-41，Pt/HBM-41中，Pt/HBM-41表现出较高的异构化选择性（87.01%）和较高的正庚烷转化率（78.75%），并具有最高的异庚烷收率（68.52%）。这归结于Beta-MCM-41集合了MCM-41二维六方介孔结构优良的扩散性能和Beta沸石优越的酸性质。

关键词: 正庚烷, 临氢异构, 介微孔复合材料, 铂, Beta-MCM-41

Abstract: The meso-microporous composite Beta-MCM-41 (denoted as BM-41) was prepared by nano-assembly of cationic surfactant cetyltrimethylammonium bromide (CTAB) with Beta zeolite treated with NaOH solution，and hydrogen-based composite HBeta-MCM-41(denoted as HBM-41) was prepared by ion-exchange between BM-41 and NH4Cl. The catalyst Pt/HBM-41 with 0.4% Pt loading (w) was prepared with HBM-41 as support, and applied to the hydroisomerization of n-heptane. The samples were characterized by X-ray diffraction, N₂ adsorption-desorption, and Fourier transform infrared spectroscopy. The catalysts were evaluated at 240 ℃, atmospheric pressure and mass space velocity of 2.46 h^-1. The results showed that Pt/HBM-41 exhibited higher isomerization selectivity (87.01%) and higher n-heptane conversion rate (78.75%) in three catalysts with the same Pt loading: Pt/HBeta, Pt/MCM-41, Pt/HBM-41, the yield of isoheptane was the highest (68.52%). This can be attributed to Beta-MCM-41 combining the excellent diffusion properties of the two-dimensional hexagonal mesoporous MCM-41 with the superior acid properties of Beta zeolite.

Key words: n-heptane, hydroisomerization, micro-mesoporous composites, platinum, Beta-MCM-41

高荔石志远吴保玉赵澎赵宁王文静. 介微孔复合材料Beta-MCM-41的制备及其正庚烷临氢异构催化性能[J]. 石油炼制与化工, 2023, 54(10): 92-101.

参考文献

[1] Maxwell I., Stork W. Hydrocarbon processing with zeolites[J]. Studies in Surface Science and Catalysis, 2001, 137:747-819
[2] Miller S. J. New molecular sieve process for lube dewaxing by wax isomerization[J]. Microporous Materials, 1994, 2(5): 439-449
[3] Matsuda T., Watanabe K., Sakagami H., et al. Catalytic properties of H2-reduced MoO3 and Pt/zeolites for the isomerization of pentane, hexane, and heptane[J]. Applied Catalysis A: General, 2003, 242(2): 267-274
[4] Weitkamp J. The influence of chain length in hydrocracking and hydroisomerization of n-alkanes [M]. 1975.
[5] Weitkamp J., Jacobs P. A., Martens J. A. Isomerization and hydrocracking of C9 through C16 n-alkanes on Pt/HZSM-5 zeolite[J]. Applied catalysis, 1983, 8(1): 123-141
[6] Martens J. A., Jacobs P. A., Weitkamp J. Attempts to rationalize the distribution of hydrocracked products. I qualitative description of the primary hydrocracking modes of long chain paraffins in open zeolites[J]. Applied Catalysis, 1986, 20(1): 239-281
[7] Kresge C. T., Leonowicz M. E., Roth W. J., et al. Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism[J]. Nature, 1992, 359(6397): 710-712
[8] Dautzenberg F. M., Angevine P. J. Encouraging innovation in catalysis[J]. Catalysis Today, 2004, 93(9): 3-16
[9] Allain J. F., Magnoux P., Schulz P., et al. Hydroisomerization of n-hexane over platinum mazzite and platinum mordenite catalysts kinetics and mechanism[J]. Applied Catalysis A General, 1997, 152(2): 221-235
[10] Ribeiro F., Marcilly C., Guisnet M. Hydroisomerization of n-hexane on platinum zeolites : I. Kinetic study of the reaction on platinum/Y-zeolite catalysts: Influence of the platinum content[J]. Journal of Catalysis, 1982, 78(2): 267-274
[11] Guisnet M., Alvarez F., Giannetto G., et al. Hydroisomerization and hydrocracking of n-heptane on Pth zeolites. Effect of the porosity and of the distribution of metallic and acid sites[J]. Catalysis Today, 1987, 1(4): 415-433
[12] Perez-Pariente J., Martens J. A., Jacobs P. A. Factors affecting the synthesis efficiency of zeolite Beta from aluminosilicate gels containing alkali and tetraethylammonium ions[J]. Zeolites, 1988, 8(1): 46-53
[13] Wang S., Dou T., Li Y., et al. A novel method for the preparation of MOR/MCM-41 composite molecular sieve[J]. Catalysis Communications, 2005, 6(1): 87-91
[14] Zhang H., Li Y. Preparation and characterization of Beta/MCM-41composite zeolite with a stepwise-distributed pore structure[J]. Powder Technology, 2008, 183(1): 73-78
[15] Ivanova I. I., Knyazeva E. E. Micro-mesoporous materials obtained by zeolite recrystallization: synthesis, characterization and catalytic applications[J]. Chemical Society Reviews, 2013, 42(9): 3671-3688
[16] Xu H., Guan J., Wu S., et al. Synthesis of Beta/MCM-41 composite molecular sieve with high hydrothermal stability in static and stirred condition[J]. Journal of Colloid & Interface Science, 2009, 329(2): 346-350
[17] Inagaki S., Ogura M., Inami T., et al. Synthesis of MCM-41-type mesoporous materials using filtrate of alkaline dissolution of ZSM-5 zeolite[J]. Microporous and Mesoporous Materials, 2004, 74(1): 163-170
[18] Beck J. S., Vartuli J. C., Roth W. J., et al. A new family of mesoporous molecular sieves prepared with liquid crystal templates[J]. Journal of the American Chemical Society, 1992, 114(27): 10834-10843
[19] Cychosz K. A., Guillet-Nicolas R., García-Martínez J., et al. Recent advances in the textural characterization of hierarchically structured nanoporous materials[J]. Chemical Society Reviews, 2017, 46(2): 389
[20] Camblor M. A., Corma A., Valencia S. Characterization of nanocrystalline zeolite Beta[J]. Microporous & Mesoporous Materials, 1998, 25(1-3): 59-74
[21] Umamaheswari V., Palanichamy M., Murugesan V. Isopropylation of m-Cresol over Mesoporous Al-MCM-41 Molecular Sieves[J]. Journal of Catalysis, 2002, 210(2): 367-374
[22] Perez-Pariente J., Martens J. A., Jacobs P. A. Crystallization mechanism of zeolite beta from (TEA)2O, Na2 O and K2O containing aluminosilicate gels[J]. Applied Catalysis, 1987, 31(1): 35-64
[23] Lopez T., Navarrete J., Gomez R., et al. Preparation of sol-gel sulfated ZrO2 SiO2 and characterization of its surface acidity[J]. Applied Catalysis A General, 1995, 125(2): 217-232
[24] Wang J. A., Bokhimi X., Novaro O., et al. Effects of structural defects and acid-basic properties on the activity and selectivity of isopropanol decomposition on nanocrystallite sol-gel alumina catalyst[J]. Journal of Molecular Catalysis A Chemical, 1999, 137(1-3): 239-252
[25] Srinivas D., Srivastava R., Ratnasamy P. Transesterifications over titanosilicate molecular sieves[J]. Catalysis Today, 2004, 96(3): 127-133
[26] Chen L. F., Nore?a L. E., Navarrete J., et al. Improvement of surface acidity and structural regularity of Zr-modified mesoporous MCM-41[J]. Materials Chemistry and Physics, 2006, 97(2): 236-242
[27] Liu D., Hu S., Lau R., et al. Hydroconversion of n-heptane over Pt/Al-MCM-41 mesoporous molecular sieves[J]. Chemical Engineering Journal, 2009, 151(1-3): 308-318
[28] Liu D., Quek X. Y., Hu S., et al. Mesostructured TUD-1 supported molybdophosphoric acid (HPMo/TUD-1) catalysts for n-heptane hydroisomerization[J]. Catalysis Today, 2009, 147(9): S51-S57
[29] Guo W., Huang L., Deng P., et al. Characterization of Beta/MCM-41 composite molecular sieve compared with the mechanical mixture[J]. Microporous & Mesoporous Materials, 2001, 44(01): 427-434
[30] Steijns M., Froment G. F. Hydroisomerization and hydrocracking. 3. Kinetic analysis of rate data for n-decane and n-dodecane[J]. Industrial & Engineering Chemistry Product Research & Development, 1981, 20(4):660-668
[31] Weitkamp J. Isomerization of long-chain n-alkanes on a Pt/CaY zeolite catalyst[J]. Industrial & Engineering Chemistry Research, 1982, 21(4):550-558
[32] Maloncy M. L., Maschmeyer T., Jansen J. C. Technical and economical evaluation of a zeolite membrane based heptane hydroisomerization process[J]. Chemical Engineering Journal, 2005, 106(3): 187-195
[33] Wang Z. B., Kamo A., Yoneda T., et al. Isomerization of n -heptane over Pt-loaded zeolite β catalysts[J]. Applied Catalysis A General, 1997, 159(1-2): 119-132
[34] Aerts A., Huybrechts W., Kremer S. P., et al. n-Alkane hydroconversion on Zeogrid and colloidal ZSM-5 assembled from aluminosilicate nanoslabs of MFI framework type[J]. Chemical Communications, 2003, 9(15): 1888-1889
[35] Sie S. H. Progress of quantitative micro-PIXE applications in geology and mineralogy[J]. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1993, 75(1): 403-410
[36] Patrigeon A., Benazzi E., Travers C., et al. Influence of the zeolite structure and acidity on the hydroisomerization of n-heptane[J]. Catalysis Today, 2001, 65(2): 149-155
[37] Lugstein A., Jentys A., Vinek H. Hydroconversion of n-heptane over bifunctional HZSM-5 zeolites influence of the metal concentration and distribution on the activity and selectivity[J]. Applied Catalysis A General, 1998, 166(166): 29-38
[38] Gopal S., Smirniotis P. G. Factors affecting isomer yield for n-heptane hydroisomerization over as-synthesized and dealuminated zeolite catalysts loaded with platinum[J]. Journal of Catalysis, 2004, 225(2): 278-287
[39] Maesen T. L. M., Schenk M., Vlugt T. J. H., et al. Differences between MFI- and MEL-Type Zeolites in Paraffin Hydrocracking[J]. Journal of Catalysis, 2001, 203(2): 281-291
[40] Hu Y., Wang X., Guo X., et al. Effects of channel structure and acidity of molecular sieves in hydroisomerization of n-octane over bi-functional catalysts[J]. Catalysis Letters, 2005, 100(1-2): 59-65
[41] Roldán R., Romero F. J., Jiménez-Sanchidrián C., et al. Influence of acidity and pore geometry on the product distribution in the hydroisomerization of light paraffins on zeolites[J]. Applied Catalysis A General, 2005, 288(1): 104-115
[42] Pérez-Ramírez J., Verboekend D., Bonilla A., et al. Zeolite Catalysts with Tunable Hierarchy Factor by Pore‐Growth Moderators[J]. Advanced Functional Materials, 2009, 19(24): 3972-3979
[43] Guo L., Bao X., Fan Y., et al. Impact of cationic surfactant chain length during SAPO-11 molecular sieve synthesis on structure, acidity, and n-octane isomerization to di-methyl hexanes[J]. Journal of Catalysis, 2012, 294(10): 161-170
[44] Yadav R., Sakthivel A. Silicoaluminophosphate molecular sieves as potential catalysts for hydroisomerization of alkanes and alkenes[J]. Applied Catalysis A General, 2014, 481(25): 143-160
[45] Bi Y., Xia G., Huang W., et al. Hydroisomerization of long chain n-paraffins: the role for the acidity of zeolite[J]. Rsc Advances, 2015, 5(120): 99201-99206
[46] Zhang W., Smirniotis P. G. Effect of Zeolite Structure and Acidity on the Product Selectivity and Reaction Mechanism for n-Octane Hydroisomerization and Hydrocracking[J]. Journal of Catalysis, 1999, 182(2): 400-416
[47] Talebi G., Sohrabi M., Royaee S. J., et al. Synthesis and activity measurement of the some bifunctional platinum loaded Beta zeolite catalysts for n-heptane hydroisomerization[J]. Journal of Industrial & Engineering Chemistry, 2008, 14(5): 614-621
[48] Yang X., Wang J. A., Chen L., et al. Heteropolyacid grafted Pt/Si-MCM-41 catalyst for C7 skeletal isomerization[J]. Catalysis Communications, 2012, 28(28): 202-206
[49] Liu P., Ren J., Sun Y. Influence of template on Si distribution of SAPO-11 and their performance for n-paraffin isomerization[J]. Microporous & Mesoporous Materials, 2008, 114(1-3): 365-372