Synthesis of Aluminum-Containing CIT-13 and CIT-15 Molecular Sieves

Abstract

Provided is a method for preparing molecular sieves CIT-13 and CIT-15 in which aluminum is incorporated into the framework structure.

Description

Technical Field

[0001] The present disclosure relates to a method for preparing aluminogermanosilicate molecular sieves CIT-13 and CIT-15.

Background Art

[0002] Molecular sieves are a commercially important class of materials having a characteristic crystal structure with a defined pore structure as indicated by a distinct X-ray diffraction (XRD) pattern and having a specific chemical composition.

[0003] Molecular sieves are classified by the Structure Commission of the International Zeolite Association according to the rules of the IUPAC Commission on Zeolite Nomenclature regarding zeolite nomenclature. According to this classification, framework type zeolites and other crystalline microporous crystalline materials with established structures are assigned unique three-letter codes and are described, for example, in "Atlas of Zeolite Framework Types" (Elsevier, Sixth Revised Edition, 2007).

[0004] * CTH framework type molecular sieves are disordered materials having a two-dimensional pore system with pores bounded by 14- and 10-membered rings. * Examples of CTH framework type molecular sieves include germanosilicate CIT-13, NUD-2, and SAZ-1. Ultra-large pore molecular sieves such as CIT-13 have attracted interest because of their ability to catalyze reactions with larger reactant and product molecules.

[0005] Germanosilicate CIT-13 consists of Si-rich cfi layers crosslinked by a two-dimensional array of Ge-rich double 4-rings (d4r) units. Due to the instability of the Ge-rich d4r units in CIT-13 germanosilicate, different rich chemical properties are brought about depending on the germanium content of the CIT-13 composition. U.S. Patent Application Publication No. 2017 / 0252729 discloses a topotactic conversion from germanosilicate CIT-13 to CIT-15, a molecular sieve material having a one-dimensional pore system with 10-membered ring pores. Molecular sieves with one-dimensional 10-membered ring pores exhibit attractive properties as catalysts or catalyst components for dewaxing hydrocarbon feeds.

[0006] However, germanosilicate molecular sieves such as CIT-13 and CIT-15 do not have sufficient catalytic activity to be practicable for certain hydrocarbon conversion processes. One important synthetic challenge is to incorporate catalytically active sites, such as aluminum atoms, into these molecular sieve frameworks.

[0007] Accordingly, provided herein is a method for introducing aluminum into the frameworks of CIT-13 and CIT-15. SUMMARY OF THE INVENTION

[0008] In one aspect, a method for synthesizing aluminogermanosilicate molecular sieve CIT-13 is provided, the method comprising: (1) (a) an aluminum source, (b) a silicon source, (c) a germanium source, (d) an organic structure directing agent (Q) comprising one or more of 1,2-dimethyl-3-(3-methylbenzyl)imidazolium cation, 1-methyl-3-(3-methylbenzyl)-imidazolium cation, 1,2-dimethyl-3-(3,5-dimethylbenzyl)imidazolium cation, and 1-methyl-3-(3,5-dimethylbenzyl)-imidazolium cation, (e) a fluoride ion source, (f) water, and (g) a seed material, where the seed material is *Prepare a reaction mixture comprising (including a CTH framework type crystalline molecular sieve), and (2) subject this reaction mixture to crystallization conditions sufficient to form crystals of aluminogermanosilicate molecular sieve.

[0009] In another aspect, a method for synthesizing aluminogermanosilicate molecular sieve CIT-15 is provided, the method comprising: (1) (a) an aluminum source, (b) a silicon source, (c) a germanium source, (d) an organic structure directing agent (Q) comprising one or more of 1,2-dimethyl-3-(3-methylbenzyl)imidazolium cation, 1-methyl-3-(3-methylbenzyl)-imidazolium cation, 1,2-dimethyl-3-(3,5-dimethylbenzyl)imidazolium cation, and 1-methyl-3-(3,5-dimethylbenzyl)-imidazolium cation, (e) a fluoride ion source, (f) water, and (g) a seed material (the seed material comprising * Prepare a reaction mixture comprising (including a CTH framework type crystalline molecular sieve), (2) subject this reaction mixture to crystallization conditions sufficient to form crystals of aluminogermanosilicate molecular sieve, (3) recover the product of step (2) and calcine to obtain calcined aluminogermanosilicate CIT-13 molecular sieve, (4) treat the calcined aluminogermanosilicate CIT-13 molecular sieve with water under conditions sufficient to degermanify at least a portion of the calcined aluminogermanosilicate CIT-13 molecular sieve to obtain a phyllosilicate comprising interlayer exfoliated cfi layers, (5) recover this phyllosilicate and calcine it under conditions sufficient to convert this phyllosilicate to aluminogermanosilicate CIT-15 molecular sieve. BRIEF DESCRIPTION OF THE DRAWINGS

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Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Figure 7

Mode for Carrying Out the Invention

[0017] Glossary The term "aluminogermanosilicate" means a zeolite having a framework constructed of alumina, germanium, and silica (i.e., a repetition of tetrahedral units of AlO4, GeO4, and SiO4).

[0018] The term "framework type" is used in the sense described in "Atlas of Zeolite Framework Types", by Ch. Baerlocher, L.B. McCusker, and D.H. Olson (Elsevier, Sixth Revized Edition, 2007).

[0019] The term "sol" means a dispersion of colloidal (i.e., particle diameter less than 1 micrometer) solid particles in a liquid.

[0020] The term "SiO2 / Al2O3 molar ratio" may be abbreviated as "SAR".

[0021] Synthesis of Aluminogermanosilicate CIT-13 (Al-CIT-13) Aluminogermanosilicate molecular sieve CIT-13 can be synthesized by (1) preparing a reaction mixture comprising (a) an aluminum source, (b) a silicon source, (c) a germanium source, (d) an organic structure-directing agent comprising one or more of 1,2-dimethyl-3-(3-methylbenzyl)imidazolium cation, 1-methyl-3-(3-methylbenzyl)-imidazolium cation, 1,2-dimethyl-3-(3,5-dimethylbenzyl)imidazolium cation, and 1-methyl-3-(3,5-dimethylbenzyl)-imidazolium cation, (e) a fluoride ion source, (f) water, and (g) a seed material (this seed material comprises * a crystalline molecular sieve of the CTH framework topology), and (2) subjecting this reaction mixture to crystallization conditions sufficient to form crystals of the aluminogermanosilicate molecular sieve.

[0022] This reaction mixture may have a composition within the ranges described in Table 1 with respect to the molar ratios. [Table 1]

[0023] Suitable aluminum sources include hydrated alumina, aluminum hydroxide, alkali metal aluminates, aluminum alkoxides (e.g., aluminum isopropoxide), and water-soluble aluminum salts (e.g., aluminum nitrate).

[0024] Suitable silicon sources include colloidal silica, fumed silica, alkali metal silicates (e.g., sodium silicate), tetraalkyl orthosilicates (e.g., tetraethyl orthosilicate), and precipitated silica.

[0025] Composite sources of aluminum and silicon such as aluminosilicate sols can also be used. Suitable aluminosilicate sols can be obtained from NALCO Water of Ecolab Company. The aluminosilicate sol can be used as a sole or main source of silicon and aluminum. The term "main" means 50 mol% (e.g., more than 75 mol% or more than 90 mol%).

[0026] Suitable germanium sources include germanium oxide, germanium nitrate, and tetraalkoxy germanium compounds (e.g., tetraethoxy germanium).

[0027] In some embodiments, silicon dioxide and germanium oxide are present in the reaction mixture at a SiO2 / GeO2 molar ratio in the range of 1 to 10 (e.g., 3 to 8).

[0028] The organic structure-directing agent (Q) includes one or more of the 1,2-dimethyl-3-(3-methylbenzyl)imidazolium cation, 1-methyl-3-(3-methylbenzyl)imidazolium cation, 1,2-dimethyl-3-(3,5-dimethylbenzyl)imidazolium cation, and 1-methyl-3-(3,5-dimethylbenzyl)imidazolium cation, which are represented by the following structures (1), (2), (3), and (4) respectively.

Chemical formula

[0029] Suitable sources of Q include hydroxides, chlorides, bromides, and / or other salts of the relevant quaternary ammonium compound(s).

[0030] Suitable sources of fluoride ions include HF, NH4F, and NH4HF2.

[0031] The seed material is * The seed material may comprise any molecular sieve material having a CTH-type framework structure. The seed material may comprise a molecular sieve selected from the group consisting of CIT-13, NUD-2, SAZ-1, and any combination thereof. In some embodiments, the seed material comprises CIT-13. The seed material may be added in an amount of 0.1-10% of the weight of the silica used in the reaction mixture.

[0032] The reaction mixture can be prepared by any conceivable means, but mixing by agitation, preferably stirring, is preferred. The reaction mixture can be prepared in batch, continuous, or semi-continuous mode.

[0033] The reaction mixture can be in the form of a solution, colloidal dispersion, gel, or paste, with a gel being preferred.

[0034] Crystallization of the desired molecular sieves from the reaction mixture may be carried out under static or stirred conditions in a suitable reaction vessel, such as, for example, a polypropylene jar or Teflon-lined or stainless steel autoclave, contained in a convection oven maintained at a temperature of 100-200° C. for a period of time sufficient for crystallization to occur (e.g., about 1 day to 30 days, or 1 day to 15 days). Crystallization is typically carried out under autogenous pressure.

[0035] Once the desired molecular sieve crystals are formed, the solid product can be separated from the reaction mixture by standard mechanical separation techniques such as centrifugation or filtration. The recovered crystals are washed with water and then dried for several seconds to several minutes (e.g., 5 seconds to 10 minutes in the case of rapid drying) or for several hours (e.g., 4 hours to 24 hours in the case of oven drying at 75 °C to 150 °C) to obtain the as-synthesized molecular sieve crystals. The drying step may be carried out under vacuum or at atmospheric pressure.

[0036] As a result of the crystallization process, the recovered as-synthesized crystalline molecular sieve product contains at least a portion of the organic structure-directing agent used in the synthesis within its pore structure.

[0037] This organic structure-directing agent can be removed by calcination, in which case the as-synthesized molecular sieve is heated under an oxidizing atmosphere such as air or oxygen, a neutral atmosphere such as nitrogen or another inert gas, or a reducing atmosphere such as hydrogen. This atmosphere may be dry or may contain water.

[0038] The temperature used for calcination depends on the components in the material being calcined and is generally about 1 to 8 hours at 400 °C to 900 °C. In some cases, the calcination can be carried out up to a temperature of 1200 °C. In applications involving the methods described herein, the calcination is generally carried out at a temperature of 400 °C to 700 °C for about 1 to 8 hours, preferably at a temperature of 400 °C to 650 °C for about 1 to 4 hours.

[0039] In the as-synthesized or calcined form, Al-CIT-13 can have a molar ratio of (SiO2 + GeO2) / Al2O3 in the range of 35 to 500 (e.g., 35 to 250, or 35 to 150, or 50 to 500, or 50 to 250, or 50 to 150). In some embodiments, the molar ratio of SiO2 / GeO2 can be in the range of 3.8 to 6.0 (e.g., 3.8 to 5.4, or 3.8 to 5.0, or 4.0 to 6.0, or 4.0 to 5.0).

[0040] As shown in U.S. Patent Application Publication No. 2016 / 0346771, molecular sieve CIT-13 can be described as having a powder XRD pattern showing at least five of the characteristic peaks at 6.45 (±0.2), 7.18 (±0.2), 12.85 (±0.2), 18.26 (±0.2), 18.36 (±0.2), 18.63 (±0.2), 20.78 (±0.2), 21.55 (±0.2), 23.36 (±0.2), 24.55 (±0.2), 26.01 (±0.2), and 26.68 (±0.2)° 2θ. In some embodiments, the molecular sieve can show six, seven, eight, nine, or ten of these characteristic peaks. The powder XRD pattern shown was determined by standard techniques. The radiation was copper Kα / doublet. Slight variations in the diffraction pattern values in the tables or figures can also be due to variations in the organic compounds used in the preparation and variations in the silica-to-alumina molar ratio between samples. Despite these slight perturbations, the basic crystal structure in the as-prepared or post-calcined state remains substantially unchanged.

[0041] Synthesis of Aluminogermanosilicate CIT-15 (Al-CIT-15) Optionally, the calcined Al-CIT-13 prepared as described herein can be converted to an aluminogermanosilicate CIT-15 molecular sieve (Al-CIT-15).

[0042] The Al-CIT-13 molecular sieve can be treated with water to at least partially degermanate the molecular sieve to produce a phyllosilicate.

[0043] Preferably, the water does not contain inorganic acids, organic acids, or their salts. Examples of inorganic acids include hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. Examples of organic acids include oxalic acid, formic acid, acetic acid, and propionic acid. Preferably, the water does not contain inorganic bases, organic bases, or their salts. Examples of inorganic bases include ammonia, as well as hydroxides and carbonates of alkali or alkaline earth metals. Examples of organic bases include organic amines. Since acids or bases can dealuminate the CIT-13 molecular sieve and can adversely affect the catalytic activity of the resulting product, it is important to use water for dealumination.

[0044] The resulting phyllosilicate can be described as a two-dimensional material containing silicon-rich cfi layers resulting from the interlayer exfoliation of CIT-13, but the germanium-rich d4r units are removed by hydrolysis, along with which the corresponding surface silanol (Si-OH) groups are introduced. The resulting phyllosilicate can also be described as an aluminogermanosilicate composition essentially consisting of (the) siloxylated silicon-rich cfi layers of the CIT-13 framework. While not intending to be bound by any theory, the transformations described herein generally maintain the structure of these silicon-rich cfi layers, and it is believed that the way these silicon-rich cfi layers are bonded to each other is different between the starting material and the final product.

[0045] These phyllosilicates can be characterized by the main peaks of the powder XRD pattern in the range of about 6.9 to about 9° 2θ, for example 7.0 (±0.2) to 8.1 (±0.2)° 2θ. This main peak is at a higher angle than the corresponding main peak of the Al-CIT-13 molecular sieve from which it is derived. This shift to a higher 2θ angle in the phyllosilicate is consistent with the removal of the d4r building unit and the denser packing of the silicon-rich cfi layer. Some variation can be observed in the absolute position of this main peak. This can be explained when it is understood that the peaks are due to the individual layers being stacked (i.e., each layer is insufficient to provide a diffraction pattern) and the diffraction pattern can only be seen by stacking multiple phyllosilicate layers. In this case, the stacking seems to be extremely sensitive to trace amounts of inserted impurities (such as water) that may be present between the phyllosilicate layers, which affects the packing and thus the position of the diffraction peaks. Additionally, or alternatively, different levels of silanol pendants can affect the stacking distance. In either case, the d-spacing of the stacked layers is in the range of 10.5 angstroms to 11.5 angstroms.

[0046] The phyllosilicates can have an SiO2 / GeO2 molar ratio of at least 25 (for example, 25 to 200, or 25 to 100, or 25 to 80, or 25 to 60, or 50 to 200, or 50 to 100, or 50 to 80, or 50 to 60). Additionally, or alternatively, the phyllosilicates can have an SiO2 / Al2O3 molar ratio of at least 50 (for example, 50 to 1000, or 50 to 800, or 100 to 1000, or 100 to 800, or 200 to 1000, or 225 to 800).

[0047] The Al-CIT-13 molecular sieve may be treated with water at a temperature in the range of about 20°C to 180°C (for example, 50°C to 100°C, or 60°C to 100°C, or 70°C to 100°C, or 80°C to 100°C, or 90°C to 100°C).

[0048] The Al-CIT-13 molecular sieve may be treated with water for a time in the range of 30 minutes to 72 hours (e.g., 6 to 36 hours, or 18 to 30 hours).

[0049] The weight ratio of water to Al-CIT-13 during the treatment can be in the range of 2:1 to 500:1 or more (e.g., 5:1 to 500:1, or 10:1 to 500:1, or 50:1 to 500:1, 100:1 to 500, or 2:1 to 300:1, or 5:1 to 300:1, or 10:1 to 300:1, or 50:1 to 300:1, or 100:1 to 300:1).

[0050] After treating Al-CIT-13 with water, the resulting phyllosilicate may be separated from the suspension. There are no specific restrictions regarding the appropriate separation method, and any solid-liquid separation technique can be considered. Suitable separation methods include filtration such as suction filtration or pressure filtration, centrifugation, and rapid drying such as spray drying or spray granulation.

[0051] The recovered phyllosilicate can be subjected to a washing step and / or drying.

[0052] Any conceivable cleaning agent can be used. Cleaning agents that may be used include water, alcohol (e.g., methanol, ethanol, propanol), or mixtures thereof. Water, or a mixture of water and at least one alcohol, preferably water and ethanol, is preferred, and water is particularly preferred as the cleaning agent. When applying the cleaning, it is preferred to continue the cleaning process until the cleaning water has a conductivity of up to 1000 mS / cm (e.g., up to 850 mS / cm, or up to 700 mS / cm).

[0053] Suitable drying methods include drying in a conventional oven as either a batch or continuous drying process, rapid drying such as spray drying or spray granulation, flash drying, or microwave drying. The drying may be carried out at a temperature within the range of about 20°C to 200°C (for example, 80°C to 190°C, or 100°C to 180°C) in a suitable atmosphere such as industrial nitrogen, air, lean air, or vacuum.

[0054] The phyllosilicate is capable of topotactic [(re)organization and (re)construction] to form CIT-15.

[0055] After treating Al-CIT-13 with water, the resulting phyllosilicate is subjected to calcination. During calcination, the phyllosilicate can form an aluminogermanosilicate CIT-15 molecular sieve via topotactic reorganization.

[0056] Topotactic reorganization can occur by a layered material containing terminal silanol groups such as the currently produced phyllosilicate. Upon calcination, these terminal silanol groups condense, releasing water and forming Si-O-Si bonds. Without intending to be bound by any theory, the conversion from phyllosilicate to CIT-15 is thought to operate by this mechanism.

[0057] The calcination step may be carried out at various temperatures and durations. The normal peak calcination temperature often falls within the range of 350°C to 925°C or higher (for example, 400°C to 650°C).

[0058] The calcination step may be carried out for a period that may range from 30 minutes to 48 hours (for example, 1 to 24 hours, or 1 to 12 hours, or 2 to 10 hours, or 3 to 8 hours, or 4 to 6 hours).

[0059] The calcination step may be carried out in a calcination gas stream comprising an inert gas (e.g., nitrogen), oxygen, air, or any mixture or combination thereof. In some embodiments, the calcination gas stream may comprise air, while in other embodiments, the calcination gas stream may comprise a mixture of air and nitrogen. Further, in certain embodiments, the calcination gas stream may be an inert gas such as nitrogen and / or argon.

[0060] The calcination step may be carried out in any number of well-known apparatuses including, for example, a rotary calciner, a fluidized bed calciner, a batch oven, and the like.

[0061] As shown in U.S. Patent Application Publication No. 2017 / 0252729, molecular sieve CIT-15 may be described as having a powder XRD pattern showing at least five of the characteristic peaks at 8.15 (±0.2), 10.13 (±0.2), 12.80 (±0.2), 16.25 (±0.2), 19.03 (±0.2), 19.97 (±0.2), 20.33 (±0.2), 23.79 (±0.2), 23.91 (±0.2), 24.10 (±0.2), 24.63 (±0.2), 25.77 (±0.2), 26.41 (±0.2), 27.75 (±0.2), 34.7 (±0.2), and 37.78 (±0.2) °2θ. In another embodiment, the molecular sieve may show six, seven, eight, nine, or ten of these characteristic peaks.

[0062] The present Al-CIT-15 molecular sieve may have an SiO2 / GeO2 molar ratio of at least 25 (e.g., 25 to 100, or 25 to 80, or 25 to 60, or 40 to 100, or 40 to 80, or 40 to 60). Further, or alternatively, the Al-CIT-15 molecular sieve may have an SiO2 / Al2O3 molar ratio of at least 50 (e.g., 50 to 500, or 50 to 200, or 100 to 500, or 100 to 200).

Examples

[0063] The following exemplary examples are to be considered non-limiting.

[0064] Example 1 Synthesis of Al-CIT-13 9.9 g of a 1,2-dimethyl-3-(3-methylbenzyl)imidazolium hydroxide (Q-OH) solution (19.4% solution) was added to a 23 mL Teflon liner. 0.37 g of germanium oxide was added and the mixture was stirred until clear. 2.75 g of NALCO aqueous aluminosilicate sol (SAR = 131; 31.2% silica-alumina solids in water) was added. Excess water was evaporated by gently blowing a nitrogen stream over the top of the liner to appropriately adjust the water content. Then, 0.37 g of hydrofluoric acid (48%) was added. Finally, 0.03 g of seed crystals of germanosilicate CIT-13 were added.

[0065] The final molar ratio of the gel was as follows: 1 SiO2:0.0076 Al2O3:0.25 GeO2:0.625 Q-OH:0.625 HF:12.5 H2O.

[0066] The liner was transferred to a stainless steel autoclave, and the autoclave was placed in an oven at 160 °C and rotated at 43 rpm for 14 days. The solid product was washed with an excess amount of deionized water and dried in an oven at 95 °C.

[0067] The dried product was analyzed by powder XRD and SEM. The powder X-ray diffraction pattern of the product is shown in Figure 1, indicating that the product contains a high-purity CIT-13 phase. The SEM image is shown in Figure 2, indicating a uniform crystal region.

[0068] Measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES) showed that the as-synthesized product had a SiO2 / Al2O3 molar ratio of 130 and a SiO2 / GeO2 molar ratio of 5.

[0069] Example 2 Calcination of Al-CIT-13 The as-synthesized product of Example 1 was calcined in a muffle furnace under a flowing air stream heated to 550 °C at a rate of 1 °C / min, held at 550 °C for 5 hours, cooled, and then analyzed by powder XRD. The powder XRD pattern showed that this material remained stable after calcination.

[0070] The calcined product had a molar ratio of SiO2 / Al2O3 of 133 and a molar ratio of SiO2 / GeO2 of 5 as measured by ICP-AES.

[0071] Using N2 as the adsorbate, the calcined product was subjected to pore volume analysis by the t-plot method. This material showed a pore volume of 0.15 cm 3 / g.

[0072] Example 3 Synthesis of Al-CIT-13 8.35 g of a 1,2-dimethyl-3-(3-methylbenzyl)imidazolium hydroxide (Q-OH) solution (19.4 wt%) was added to a 23 mL Teflon® liner, followed by 0.31 g of germanium oxide, and the mixture was stirred until clear. Then, 0.05 g of aluminum isopropoxide was added, followed by 2.50 g of tetraethyl orthosilicate. By gently blowing a nitrogen stream over the top of the liner, an appropriate amount of ethanol, isopropanol, and water was evaporated. Once the correct molar ratio was achieved, 0.31 g of HF (48 wt% solution) was added and the mixture was homogenized with a spatula. Then, 0.02 g of the germanosilicate CIT-13 seed crystals was added and the mixture was homogenized with a spatula. The molar ratio of the gel was 1 SiO2:0.01 Al2O3:0.25 GeO2:0.625 Q-OH:0.625 HF:12.5 H2O.

[0073] The liner was then placed in a stainless-steel autoclave and synthesized in an oven at 160 °C for 14 days while rotating at 43 rpm. The solid product was washed with an excess of deionized water and dried in an oven at 95 °C.

[0074] The recovered product was identified as CIT-13 by powder XRD.

[0075] Example 4 Synthesis of Al-CIT-13 9.09 g of a 1,2-dimethyl-3-(3-methylbenzyl)imidazolium hydroxide (Q-OH) solution (19.4 wt%) was added to a 23 mL Teflon® liner, followed by 0.34 g of germanium oxide, and the mixture was stirred until clear. Then, 0.04 g of Reheis F2000 aluminum hydroxide (50% Al2O3) was added, followed by 2.75 g of tetraethyl orthosilicate. By gently blowing a stream of nitrogen over the top of the liner, an appropriate amount of ethanol and water were evaporated. Once the correct molar ratio was achieved, 0.34 g of HF (48 wt% solution) was added and the mixture was homogenized with a spatula. Then, 0.02 g of seed crystals of germanosilicate CIT-13 were added and the mixture was homogenized with a spatula. The molar ratio of the gel was 1 SiO2:0.01 Al2O3:0.25 GeO2:0.625 Q-OH:0.625 HF 12.5H2O.

[0076] The liner was then placed in a stainless steel autoclave and synthesized in an oven at 160 °C for 14 days while rotating at 43 rpm. The solid product was washed with an excess of water and dried in an oven at 95 °C.

[0077] The recovered product was identified as CIT-13 by powder XRD.

[0078] Example 5 Synthesis of Al-CIT-15 0.1 g of a calcined Al-CIT-13 sample from Example 2 was added to 25 g of deionized water in a Teflon-lined FEP bottle. A magnetic stir bar was added and the mixture was stirred in an oil bath at 95 °C for 24 hours. The mixture was then centrifuged at 15,000 rpm and the liquid was decanted. The solid product was dried overnight at room temperature in a vacuum oven.

[0079] Next, the dried product was calcined as in Example 2.

[0080] The calcined product was analyzed by powder XRD and SEM. The powder X-ray diffraction pattern of the product is shown in Figure 3, indicating that the product contains a high-purity CIT-15 phase. The SEM image is shown in Figure 4, indicating a uniform crystal region.

[0081] The calcined product had a molar ratio of SiO2 / Al2O3 of 132 and a molar ratio of SiO2 / GeO2 of 51 as measured by ICP-AES.

[0082] Using N2 as the adsorbate, the calcined product was subjected to pore volume analysis by the t-plot method. The molecular sieve showed a pore volume of 0.03 cm 3 / g.

[0083] The acidic site density of the calcined product was characterized by temperature-programmed desorption using n-propylamine and found to be 28 μmol H + / g.

[0084] Example 6 Preparation of Catalyst Al-CIT-15 prepared according to Example 5 was ion-exchanged in an aqueous palladium nitrate solution at a pH of about 10 with the addition of 0.5 wt% Pd. The Pd-exchanged zeolite was washed with deionized water until the conductivity was less than 50 μS / cm and dried. Then, the zeolite was calcined in air at 482 °C for 3 hours.

[0085] Example 7 Hydroconversion Rate of n-Decane For the catalyst test, 0.5 g of the Pd catalyst of Example 6 (weight of the dehydrated sample measured by thermogravimetric analysis at 600 °C) was filled in the center of a 23-inch long × 0.25-inch outer diameter stainless steel reaction tube filled with random upstream of the catalyst to preheat the raw materials (total pressure 1200 psig; downflow hydrogen rate 12.5 mL / min when measured at 1 atm and 25 °C; and downflow liquid feed rate 1 mL / hour). First, the catalyst was reduced in flowing hydrogen at 315 °C for 1 hour. The reaction was carried out at a temperature of 500 °F to 650 °F. The products were analyzed by on-line capillary gas chromatography (GC) approximately once every 60 minutes. The raw data from the GC was collected by an automatic data collection / processing system, and the hydrocarbon conversion rate was calculated from the raw data. The conversion rate is defined as the amount (mol%) of n-decane reacting to produce other products (including iso-C10). The yield of iso-C10 is expressed as the mole percent of products other than n-decane. The yield of cracked products (less than C10) is expressed as the mole percent of n-decane converted to cracked products. The results are shown in Figures 5 to 7. These results indicate that Al-CIT-15 functions well for isomerization.

Claims

1. 1. A method for synthesizing aluminogermanosilicate molecular sieve CIT-13, said method comprising: （１） (a) an aluminum source; (b) a silicon source; (c) a germanium source; (d) an organic structure directing agent (Q) containing one or more of a 1,2-dimethyl-3-(3-methylbenzyl)imidazolium cation, a 1-methyl-3-(3-methylbenzyl)-imidazolium cation, a 1,2-dimethyl-3-(3,5-dimethylbenzyl)imidazolium cation, and a 1-methyl-3-(3,5-dimethylbenzyl)-imidazolium cation; (e) a source of fluoride ions; (f) water, and (g) ＊ preparing a reaction mixture containing a seed material comprising a crystalline molecular sieve of the CTH framework type; both the aluminum source and the silicon source are aluminosilicate sols; (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the aluminogermanosilicate molecular sieve; The synthesis method comprising:

2. 2. The process of claim 1, wherein the reaction mixture has the following composition, in terms of molar ratios: Table 1

3. 2. The process of claim 1, wherein the reaction mixture has the following composition, in terms of molar ratios: Table 2

4. 10. The method of claim 1, wherein the germanium source is selected from the group consisting of germanium oxide, germanium nitrate, tetraalkoxygermanium compounds, and any combination thereof.

5. The silicon source and the germanium source are in the range of 1 to 10 SiO ２ / GeO ２ 2. The method of claim 1, wherein the hydroxyl group is present in a molar ratio of:

6. 10. The method of claim 1, wherein the seed material comprises a molecular sieve selected from the group consisting of CIT-13, NUD-2, SAZ-1, and any combination thereof.

7. 10. The method of claim 1, wherein the seed material is present in an amount of 0.1 to 10% of the weight of silica in the reaction mixture.

8. 10. The method of claim 1, wherein the crystallization conditions comprise a temperature of from 100°C to 200°C and a crystallization time of from about 1 day to 21 days.

9. 1. A method for synthesizing aluminogermanosilicate molecular sieve CIT-15, said method comprising: （１） (a) an aluminum source; (b) a silicon source; (c) a germanium source; (d) an organic structure directing agent (Q) containing one or more of a 1,2-dimethyl-3-(3-methylbenzyl)imidazolium cation, a 1-methyl-3-(3-methylbenzyl)-imidazolium cation, a 1,2-dimethyl-3-(3,5-dimethylbenzyl)imidazolium cation, and a 1-methyl-3-(3,5-dimethylbenzyl)-imidazolium cation; (e) a source of fluoride ions; (f) water, and (g) ＊ preparing a reaction mixture containing a seed material comprising a crystalline molecular sieve of the CTH framework type; both the aluminum source and the silicon source are aluminosilicate sols; (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the aluminogermanosilicate molecular sieve; (3) recovering and calcining the product of step (2) to obtain calcined aluminogermanosilicate CIT-13 molecular sieve; (4) treating the calcined aluminogermanosilicate CIT-13 molecular sieve with water under conditions sufficient to degermanate at least a portion of the calcined aluminogermanosilicate CIT-13 molecular sieve to provide a phyllosilicate comprising exfoliated cfi layers; (5) recovering the phyllosilicate and calcining it under conditions sufficient to convert the phyllosilicate to an aluminogermanosilicate CIT-15 molecular sieve. The synthesis method comprising the steps of:

10. 10. The method of claim 9, wherein the treating according to step (4) is carried out at a temperature of from 50°C to 180°C.

11. 10. The method of claim 9, wherein said treating according to step (4) is carried out for a time period of from 30 minutes to 72 hours.

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