DICP SAPO-34分子筛合成实例 解决的基础问题 Si 原子是如何进入分子筛骨架的 如何控制 Si 原子在分子筛骨架中的分布 结构 & 组成 催化 性能 分子筛的 合成与制备 DICP
Al(1Si) Al(1Si) Al(3Si) Al(4Si) Higher Si/Al Stronger acidic sites
XRD spectra of as-synthesized samples DICP
Crystallization curve of SAPO-34 DICP
IR results DICP
Assignment of the IR bands in framework vibration region of the as-synthesized samples Crystalli-zation Time Structure Type Asym. Stretch Sym. T-O Bending P-O-Al (P-O-P) O-P-O Si-O P-O (Al-O) D-6 Rings PO4 (Si,Al)O4 SiO4 Channel 0h Gel 1225 1090 785 730 - 618 570 520 470 365 0.5h 1070 475 1h Crystal 1215 1100 635 530 480 380 1.5h DICP
DICP Relative content curve of template in the as-synthesized samples Influence of crystallization on the composition of solid samples DICP
31P NMR of the gel samples in the first steps of the crystallization process The stirred mixing gel of the raw sources (silica sol, pseudoboehmite, orthophosphoric acid and water) The stirred mixing gel of a. and template (TEA). The b. gel after aging (the initial state of the crystallization). DICP
27AlMAS(a), 31P MAS(b) and 29Si CP/MAS(c) NMR spectra of as-synthesized samples in the earlier stage of crystallization a b c DICP
27Al MAS NMR spectra of calcined and dehydrated samples in the earlier stage of crystallization DICP
Changes of the Al(IV), P(IV) and Si(IV) relative content (a) and relative proportion (b) of the as-synthesized samples with crystallization time (b) relative proportion DICP (a) relative content
DICP SAPO-34晶化机理模型 初始凝 胶 晶粒以 形成 Si(4Al) 方式 生长(2.5h) 晶核 (0h) (0.5h) 相对结晶度 ~80% 重排 聚合 晶粒以 Si(4Al) 方式 生长(2.5h) 初始凝 胶 (0h) 形成 晶核 (0.5h) 晶粒生长 Si 直接参与 ~80%Si 直接进入骨架 Si(nAl) n=0-4 结构形成 (26h) Si 取代P 2Si 取代 Al+P DICP
DICP 4.分子筛的基本性质 基本特点 基本性质 多孔晶体,规整孔道结构 大比表面积 结构多样性 组成多样性 高热稳定性,水热稳定性 离子交换性质 吸附性质 固体酸碱性质 DICP
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DICP 5.分子筛的表征 XRD: 晶相,晶胞参数,晶体结构 电子显微镜:晶貌,组成 吸附-脱附:比表面积,孔径,孔容、 酸碱性等 红外光谱(IR):-OH;酸碱性质;骨架;表面物种 NMR:结构微环境分析;酸碱性质 热重-差热:热稳定性,酸碱性,吸附(脱附)性质,积碳分析 DICP
注意:XRD图随组成也有变化 DICP
去除模板剂前后XRD图有变化 DICP
DICP XRD测定结晶度 一般测定8个主峰即可 Sum of peak heights (unknown) Sum of peak heights (standard) % Crystalinity = 一般测定8个主峰即可 也可用于测定杂晶相对结晶度 DICP
DICP XRD测定Si/Al比 晶粒必须大于0.3微米 组成变化引起晶胞参数变化,XRD呈现规律性 可以测定Si/Al
HZSM-5 %Al=16.5-30.8 DICP
IR法测定Si/Al 组成规律变化会体现在IR光谱中 只对特定体系适用 DICP
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分子筛酸性的测定 酸碱中和(指示剂法) TPD IR 1H-NMR 31P-NMR TPD和IR最常用 DICP
H-MAS-NMR spectrum of HY zeolite DICP
IR spectra of HY zeolite without and with adsorbed pyridine HY+Pyridine (Lewis) (sodalite) (supercage) (B) DICP
Pyridine adsorption on different zeolites samples DICP P.A. Weyrich, W.F. Holderich, Appl. Catal. A 158 (1997)145.
Comparison of Various Acid Characterization Methods + + Method Acid Type Acid Location (Int./Ext.) Acid Amount Acid Strength Major Drawbacks Brønsted Lewis Titration ─ + Accessibility TPD (Bases adsorption) + + ± Diffusion & Non-acidic adsorption IR (hydroxyls) Sample preparation 1H NMR Water adsorption 31P NMR (TMP) + (B) ─ (L) + (L) ─ (B) Volatile, Oxidization & Toxicity 31 P NMR (Phosphine Oxides) (B, L) Weaker basicity Comparison of Various Acid Characterization Methods
NH3-TPD of H-ZSM-5 Zhao et al., J. Phys. Chem. B, 106, 4462 (2002)
1H & 27Al MAS NMR of H-ZSM-5 Spinning Rate = 5.0 kHz
Introducing the Players TMPO (Trimethylphosphine Oxide) Size ca. 0.55 nm TMP (Trimethylphosphine) Size ca. 0.55 nm TBPO (Tributylphosphine Oxide) Size ca. 0.82 nm ZSM-5 (10-MR)
Sample Preparation Procedures TMP Adsorption thermal decomposition of trimethylphosphine silver iodide complex onto the dehydrated H-ZSM-5 at 473 K TMPO (TBPO) Adsorption H-ZSM-5 dehydration 723 K; 24 h add TMPO/TBPO dissolved in CH2Cl2 under N2 glovebox Loaded Sample CH2Cl2 evacuation vessel agitated at RT; 12 h 323 K packing into MAS rotor 31P MAS NMR
Interactions Between Probe Molecules and Brønsted Acid Sites TMP / Brønsted acid site TMPO / Brønsted acid site Ionic Pair Complex Hydrogen Bonded Complex Formation of TMPH+ complex Higher Acidic Strength O-H Bond Strength 31P Chemical Shift (downfield) Lunsford et al., J. Am. Chem. Soc., 107, 1540 (1985) Mueller et al., J. Phys. Chem. B, 102, 2890 (1998)
31P MAS NMR (TMP/H-ZSM-5/26) Assignments -4 ppm: TMPH+/Brønsted acid sites -50 ppm: TMP/Lewis acid sites -62 ppm: Physisorbed TMP CP/MAS Decoupling Without decoupling Spinning Rate = 7 kHz L B Lunsford et al., JACS, 107, 1540 (1985) NOTE: Acid sites with different strengths cannot be differentiated !!
31P MAS NMR (TMPO/H-ZSM-5) Mobile TMPO 150 120 90 60 30 Chemical shift (ppm) HZSM-5/15 HZSM-5/26 HZSM-5/75 (Partially hydrated) * Spinning Rate = 10 kHz TMPO can probes both internal and external acid sites Upto five 31P resonance were observed @ 86, 75, 67, 63 and 53 ppm for TMPO/Brønsted Increasing Si/Al Acidic Strength No Lewis acid sites observed The newly observed 30 ppm peak can be ascribed due to mobile TMPO
Correlation of Results Obtained from TMPO and TBPO (a) TMPO (b) TBPO * 64 69 48 (P) 58 (P) 70 74 Spinning Rate = 10 kHz Adsorption of TMPO and TBPO on Al-MCM-41 (Si/Al = 70; pore size = 2.54 nm) Chemical Shift ( ) c 1 ( 1- c ) 2 ( 2- c ) TMPO 39 69 (30) 64 (25) TBPO 47 74 (27) 70 (23) Mechanism of Acid Site Formation in Al-MCM-41 ? Mueller et al., J. Phys. Chem. B, 102, 2890 (1998) Zhao et al., J. Phys. Chem. B, 106, 4462 (2002)
31P MAS NMR of Crystalline TBPO
TMPO (Internal + External) Acid Properties of H-ZSM-5 Determined by 31P MAS NMR in Conjunction with ICP TMPO (Internal + External) ( )/ppm 86 (47) 75 (36) 67 (28) 63 (24) 53 (14) 43 (4) 30 Sample (Si/Al) H-ZSM-5/15 0.5% (--- , 0.005) 22.4% (0.165, ---) 37.5% (0.258, 0.017) 36.6% (0.242, 0.027) 3.0% (0.021, ---) H-ZSM-5/26 6.9% (0.014, 0.010) 45.4% (0.159, ---) 22.7% (0.067, 0.012) 25.0% (0.063, 0.025) ---- H-ZSM-5/75 3.5% (0.003, 0.002) 69.8% (0.108, ---) (--- , 0.002) 26.7% (0.032, 0.009) TBPO (External) 92 (45) 75 (28) 71 (24) 54 (7) 47 10.5% 35.0% 54.5% 22.3% 25.2% 52.5% 15.4% 17.6% 67.0% (1) refer to chemical shift difference w.r.t. crystalline TMPO (39 ppm) or TBPO (47 ppm). (2) Data in parentheses denote (Int., Ext.) acid concentrations in (0.05) mmol/g cat. (3) Assume 1:1 relation between adsorbate and Brønsted acid site. ICP probides concentrations of Al, Si and P.
31P NMR Chemical Shift Assignments for Various Catalysts Adsorbed with TMPO and TBPO
Distribution of Acid Sites for Various Catalysts
DICP 6.分子筛的催化性能 分子筛的特点 多孔晶体 组成可调变性 结构可调变性 孔道结构规整 Shape selective effect 比表面积大 High activity 组成可调变性 酸、碱性可调 离子交换性 氧化还原性能 TS-1,?.. 结构可调变性 据反应特点选择分子筛 DICP
Shape-selective effect 规整孔道结构使分子筛具有特殊的催化性能 Reactant shape selectivity Product shape selectivity Reactant shape selectivity and product shape selectivity are strongly depending on crystal size and activity Restricted transition state shape selectivity Restricted transition state shape selectivity is independent of crystal size and activity, but depends on pore and cavity diameters and on zeolite’s structures DICP
Reactant shape selectivity Product shape selectivity DICP
Reactant shape selectivity Dehydration of n- and iso-butanol on Ca-X and Ca-A DICP
Product shape selectivity C5-C11,汽油 ZSM-5 MTG CH3OH SAPO-34 C2-C4,烯烃 MTO 改性ZSM-5 CH3OH + toluene p-xylene DICP
Liquid Phase Alkylation of Naphthalene over Large Pore Zeolites Background PEN PBN 塑料 液晶中间体 --- 中法PICS项目 DICP
T-butylation of Naphthalene with t-butanol Reaction Results reaction time = 2hs No 1-TBN DICP
Restricted transition state shape selectivity Disproportionation of dialkylbenzene over medium pore zeolite (HMd, ZSM-5) 双分子反应,形成中间过渡态需要较大的空间 The activity on various zeolites (ZSM-5, ZSM-4, Mordenite, Y) were correlated with their effective pore size. DICP
DICP 分子筛催化的液相有机反应 酸碱功能 芳烃的亲电取代反应 脂肪族化合物的亲核取代反应 缩合反应 异构化、重排 消去、加成 烷基化 酰化 卤化 脂肪族化合物的亲核取代反应 酯化 缩合反应 异构化、重排 消去、加成 DICP
分子筛催化的液相有机反应 金属功能 氧化反应 酸性-金属双功能 Cat: TS-1, ... DICP
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DICP 重要的分子筛 A : (detergents, desiccation and separation) ; FAU : X (desiccation, purification, separation) and Y (separation, catalysis) ; MOR : (adsorption and catalysis) ; LTL : KL-type zeolite (catalysis: aromatization) ; MFI : Silicalite and ZSM-5 (adsorption and catalysis) ; BEA : Beta-type zeolite (catalysis: cumene) ; MTW : zeolite MCM-22 (catalysis: ethylbenzene, probably cumene ?) ; CHA : SAPO-34 (methanol to olefins or MTO process- demonstration unit ); FER : Ferrierite (skeletal isomerization of n-butenes- demonstration unit) ; AEL and/or TON : SAPO-11 and possibly ZSM-22 (improvement of pour point for petroleum cuts by straight long paraffin isomerization) ; Structures not revealed (for aromatic C8 isomerization) : one is certain (IFP) and the second is possible (UOP). DICP
7. 规整孔道介孔材料 DICP
A New Family of Mesoporous Materials M41S Mobil researchers in 1992, cationic surfactant pore size 1.5-10nm, high surface areas 1200 m2/g low hydrthermal stability, basic condition Liquid crystal template routes MCM-41 MCM-48 MCM-50 Hexagonal (p6m) lamellar Cubic Ia3d
介孔材料的形成机理 DICP 1. 层状机理: 2. 棒状机理: The mechanism for formation of FSM-16 1993年G. D. Stucky 1996年日本Inagaki: The mechanism for formation of FSM-16 pH decreasing S. B. Inagaki,CHEM SOC JPN 69, 1449(1996) A. Monnier etal. Science, 261,1299(1993) 2. 棒状机理: 1994年M. E. Davis DICP C. Chen, etal. Microporous Mater., 4,1(1995)
介孔材料的形成机理 DICP Cooperative Assembly Approach: Q. Huo etal. Nature, 368, 317(1994).
DICP microporous pore size <1.1 nm zeolites pore size 2-6 nm MCM-41 Applications: catalysis, separation, adsorption, sensor, nanodevice and fabrication of nanostructured materials advantage in the mass diffusion and transport because of their interconnecting networks Bicontinuous helix 3D cubic mesostructure Ia3d, MCM-48 DICP J. Thomas, O. Terasaki et al., Acc. Chem. Res. 2001, 34, 583-594
DICP Cubic Caged Mesoporous Silica SBA-1 low temperature synthesis,-5°C, acid synthesis, large head group surfactant, C16H33N(Et)3Br well defined morphology an epitaxial phase transformation DICP Q. Huo etal. Nature, 368, 317(1994). O. Terasaki, T. Tatsumi, JACS, 2002, 123, 12089
DICP Large Pore Cubic Caged SBA-16 XRD patterns 3D caged structure, cubic Im3m triblock copolymer with long EO chains F127, EO106PO70EO106,F108, F98, Brij 700, acid synthesis, highly ordered 110 111 8.0 nm 100 N2 sorption isotherms XRD patterns Cell parameter a = 13.3 nm Window size 2.3 nm Cavity surface Sphere diameter d = 9.5 nm XRD patterns DICP O. Terasaki, D. Zhao et al. Nature 408, 449(2000) Structure model D. Zhao, et al. J. Am. Chem. Soc. 1998, 120, 6024
DICP Mesoporous Silica MCM-48 and Carbons CMK-4 R. Ryoo et al., J. Phys. Chem. B, 103, 7743, 1999. S. Jun, S. H. Joo, R. Ryoo, et al., J. Am. Chem. Soc., 122(43); 10712-10713, 2000. S. Joo, R. Ryoo et al., Microporous Mesoporous Mater., 44-45, 153-158, 2001.
DICP Mesoporous Silica SBA-15 TEM images o block copolymer templating acidic synthesis condition large pore size (4.6 ~ 40 nm) thermally and hydrothermally stable highly ordered thick silica wall, microporous walls high surface areas ( ~ 1000 m2/g) pore volume (1.0—2.5 cm3/g) N2 sorption isotherms TEM images initial parts of plots DICP D. Zhao, et al. J. Am. Chem. Soc. 1998, 120, 6024 XRD patterns N2 sorption isotherms S.-H. Joo, R. Ryoo, M. Jaroniec, J. Phys. Chem. B 2002, 106, 4640 D. Zhao, Science, 1998, 279, 548
Synthesis of Mesoporous Materials Surfactant + Inorganic source hydrothermal pH, media Synthetic Characters for Mesoporous Materials: 1. low temperature , -5°C~RT, <150 ° C 2. fast formation rate < 1 min 3. composition is variable, tetrahedron, octahedron 4. non-aqueous synthesis, surfactant templating 5. morphology control Structure characters: 1. non-perfect crystal, long range order (no code) 2. amorphous inorganic walls 3. weck interaction (H-bonding, ligand, van der Waals) 4. hydrothermally unstable
Synthesis Routes to Mesoporous Materials MCM-41 (p6m), MCM-48 (Ia3d), MCM-50 (L), SBA-6 (Pm3n), SBA-8 (cmm), FUD-2(Fd3m) Non-silica oxide mesostructures, e.g. W, Mo SBA-3 (p6m), SBA-1 (pm3n), SBA-2 (P63/mmc), MHS, MUX, worm-like dirordered mesopore Hexagonal , cubic mesostructures, Nb, Ta f, I+…X…H+S S= nonionic surfactant, block copolymers SBA-15 (p6m), SBA-16 (Im3m), SBA-12 (P63/mmc), SBA-11(Pm3m), FDU-1(Im3m), FDU-4, 5 SBA-13, 14 Q. Huo etal. Nature, 368, 317(1994). S.A. Bagshaw, etal. Science, 269, 1242(1995) J. Y. Ying, ANGEW CHEM INT EDIT 38, 56(1999) D. Zhao, Science, 1998, 279, 548
8. 分子筛研究的几个热点方向 DICP
DICP Sessions in 13-IZC Mineralogy of natural zeolite Zeolite nucleation and growth New methods of zeolite synthesis Isomorphous substitutions Synthesis of new materials Fundamentals of micelle templating New mesoporous molecular sieves Syntheses with non-ionic surfactants Crystal structure determination Host-guest chemistry Post-synthesis modification In-situ spectroscopy and catalysis Frameworks and acid sites Frameworks, cations, clusters Modelling and theoretical studiesA Modelling and theoretical studies B Principles of adsorption Adsorption and separation process Diffusion: fundamental approach Zeolite membranes and films Nanocomposite fundamentals and applications Advanced materials Micro- and mesoporous materials in fine chemistry New routes to hydrocarbon activation Conversion of aromatics Catalysis for oil refining Selective oxidation and sulfur resistance Confinement and physical chemistry for catalysis New approaches to catalyst preparation Environmental catalysis Environment-friendly applications of zeolites Zeolite minerals and health sciences DICP
DICP 几个热点方向 传统分子筛研究仍持续保持活力 Avelino Corma, Maria J. Diaz-Cabanas, Joaquin Martinez-Triguero, Fernando Rey & Jordi Rius,A large-cavity zeolite with wide pore indows and potential as an oil refining catalyst,Nature,514-517(418), 2002 DICP
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介孔分子筛 目前仍没有能够耐受800oC长期水热处理的材料 催化应用背景之一是用于重质油的加工 DICP
规整孔道结构的碳分子筛 Zhixin Ma, Takashi Kyotani* and Akira Tomita, Preparation of a high surface area microporous carbon having the structural regularity of Y zeolite, Chem. Commun., 2000, 2365–2366 DICP
DICP 孔道规整的无机-有机复合材料 国际进展 NATURE, VOL 416, p304-307, 21 MARCH 2002 An ordered mesoporous organosilica hybrid material with a crystal-like wall structure Shinji Inagaki, Shiyou Guan, Tetsu Ohsuna, Osamu Terasaki DICP
Structural models of mesoporous benzene±silica Structural models of mesoporous benzene±silica. A, B, Images of the layered arrangement of SiO1.5-C6H4-SiO1.5 units in the walls. The structure was optimized by minimizing the three-dimensional periodic lattice using the force field COMPASS. C, D, Images of the hexagonal lattice constructed with the layered pore-wall structure. The structure was also minimized by using the force field COMPASS. Atoms are represented as a stick model. Silicon, orange; oxygen, red; carbon, white; hydrogen, yellow. DICP
DICP SCIENCE, VOL 291, p1021-1023, 9 FEBRUARY 2001 Interwoven Metal-Organic Framework on a Periodic Minimal Surface with Extra-Large Pores Banglin Chen, M. Eddaoudi, S. T. Hyde, M. O’Keeffe, O. M. Yaghi SCIENCE, VOL 295,p469-472, 18 JANUARY 2002 Systematic Design of Pore Size and Functionality in Isoreticular MOFs and Their Application in Methane Storage M. Eddaoudi, J. Kim, N. Rosi, D. Vodak, J. Wachter, M. O’Keeffe, O. M. Yaghi1 DICP
Thank you DICP