Synthesis of molecular sieves of ton framework type

Abstract

A method for preparing TON-based molecules with unique properties is disclosed. This method utilizes a 1,3,4-trimethylimidazolium cation as a structure-directing agent and a combination of silicon and aluminum sources selected from alumina-coated silica and aluminosilicate zeolites. The resulting molecular sieve can be used in methods for dewaxing paraffinic hydrocarbon feedstocks.

Description

Technical Field

[0001] This disclosure relates to an improved method for preparing molecular sieves having a TON framework structure and the use of such molecular sieves in methods for the catalytic conversion of hydrocarbon compounds. Background Technology

[0002] Molecular sieve materials are classified by the Structure Commission of the International Zeolite Association according to the rules of the IUPAC Commission on Zeolite Nomenclature. Based on this classification, zeolites with established framework types and other crystalline microporous materials have been assigned three-letter codes and described in "Atlas of Zeolite Framework Types," 6th Revision, Elsevier (2007).

[0003] One known molecular sieve with an established structure is the material designated as TON, which is a molecular sieve with a unique one-dimensional 10-membered ring channel system. Examples of TON-based molecular sieves include ISI-1, KZ-2, NU-10, Theta-1, and ZSM-22. TON-based materials have significant commercial value due to their activity as catalysts in the dewaxing of paraffinic hydrocarbons.

[0004] According to this disclosure, using 1,3,4-trimethylimidazolium cations as structure-directing agents and aluminosilicate raw materials, it has been found that TON-type molecular sieves can be synthesized by a simpler method and with a shorter heating cycle than previously possible. Using these materials, TON-type molecular sieves with unique morphologies and physicochemical properties can be prepared. Furthermore, TON-type molecular sieves with small crystal sizes can also be produced. Summary of the Invention

[0005] In a first aspect, a method for synthesizing a TON framework-type molecular sieve is provided, the method comprising: (1) forming a reaction mixture comprising: (a) a combined source of silicon and aluminum, wherein the combined source of silicon and aluminum is alumina-coated silica, an aluminosilicate zeolite of the FAU framework type, or a mixture thereof; (b) a structure directing agent (Q) comprising a 1,3,4-trimethylimidazolium cation; (c) a hydroxide ion source; (d) water; and (e) seed crystals; and (2) subjecting the reaction mixture to crystallization conditions sufficient to allow the molecular sieve crystals to form.

[0006] In a second aspect, a TON framework-type molecular sieve in an initially synthesized (as-synthesized) form is provided, the molecular sieve containing 1,3,4-trimethylimidazolium cations in its pores.

[0007] In a third aspect, a process for hydroisomerizing paraffinic hydrocarbon feedstock is provided, the process comprising: contacting the paraffinic hydrocarbon feedstock with hydrogen and a catalyst comprising a molecular sieve of the TON framework type under hydroisomerization conditions, and producing a product having an increased branched hydrocarbon content relative to the hydrocarbon feedstock; wherein the catalyst further comprises 0.01% to 10% by weight of a noble metal. Attached Figure Description

[0008] Figure 1 This is the powder X-ray diffraction (XRD) pattern of the calcined molecular sieve obtained in Example 1.

[0009] Figure 2(A) and 2(B) Exemplary scanning electron micrographs (SEM) images of the product of Example 1 at various magnifications are shown.

[0010] Figure 3 The powder XRD pattern of the calcined molecular sieve obtained in Example 2 is shown.

[0011] Figures 4(A) and 4(B) show exemplary SEM images of the product of Example 2 at various magnifications.

[0012] Figure 5 The image shows the powder XRD pattern of the calcined molecular sieve obtained in Example 3.

[0013] Figures 6(A) and 6(B) show exemplary SEM images of the product of Example 3 at various magnifications.

[0014] Figure 7 The powder XRD pattern of the calcined molecular sieve obtained in Example 4 is shown.

[0015] Figures 8(A) and 8(B) show exemplary SEM images of the product of Example 4 at various magnifications.

[0016] Figure 9 The powder XRD pattern of the calcined molecular sieve obtained in Example 5 is shown.

[0017] Figure 10 An exemplary SEM image of the product of Example 5 is shown.

[0018] Figure 11 The powder XRD pattern of the calcined molecular sieve obtained in Example 6 is shown.

[0019] Figures 12(A) and 12(B) show exemplary SEM images of the product of Example 6 at various magnifications.

[0020] Figure 13 The graph shows the conversion rate of n-decane on the catalyst of Example 5 as a function of temperature.

[0021] Figure 14 This is a graph showing the relationship between conversion rate and yield of n-decane conversion on the catalyst in Example 5.

[0022] Figure 15 The graph illustrates the distribution of methyl nonane isomers from the conversion of n-decane on the catalyst of Example 5 as a function of conversion.

[0023] Figure 16 The graph shows the conversion rate of n-decane over the catalyst in Example 6 as a function of temperature.

[0024] Figure 17 This is a graph showing the relationship between conversion rate and yield of n-decane conversion on the catalyst in Example 6.

[0025] Figure 18 The graph illustrates the distribution of methyl nonane isomers from the conversion of n-decane on the catalyst of Example 6 as a function of conversion. Detailed Implementation

[0026] definition

[0027] The term “skeleton type” as used in this paper has the meaning described in Baerlocher, LBMcCusker and DHOlson, “Atlas of Zeolite Framework Types” (Elsevier, 6th revision, 2007).

[0028] The term "initial synthesis" refers to molecular sieves in the form of crystallization and before the removal of structure-directing agents.

[0029] The term "Cn" hydrocarbon refers to a hydrocarbon compound with n carbon atoms per molecule. The term "Cn+" hydrocarbon refers to a hydrocarbon compound with n or no more than n carbon atoms per molecule. The term "Cn-" hydrocarbon refers to a hydrocarbon compound with no more than n carbon atoms per molecule.

[0030] The term "SiO2 / Al2O3 molar ratio" can be abbreviated as "SAR".

[0031] Synthesis of molecular sieves

[0032] TON framework type molecular sieves can be synthesized by: (1) forming a reaction mixture comprising: (a) a combined source of silicon and aluminum, wherein the combined source of silicon and aluminum is alumina-coated silica, FAU framework type aluminosilicate zeolite or a mixture thereof; (b) a structure directing agent (Q) comprising 1,3,4-trimethylimidazolium cation; (c) a hydroxide ion source; (d) water; and (e) seed crystals; and (2) subjecting the reaction mixture to crystallization conditions sufficient to allow the molecular sieve crystals to form.

[0033] The mixture may have a composition in the range of molar ratios listed in Table 1:

[0034] Table 1

[0035] Widest Second <![CDATA[SiO2 / Al2O3]]> 30 to 170 35 to 130 <![CDATA[Q / SiO2]]> 0.03 to 0.50 0.04 to 0.30 <![CDATA[OH / SiO2]]> 0.05 to 1.00 0.10 to 0.50 <![CDATA[H2O / SiO2]]> 5 to 100 10 to 50

[0036] Q contains a 1,3,4-trimethylimidazolium cation.

[0037] The alumina-coated silica may have a SiO2 / Al2O3 molar ratio of at least 30 (e.g., 30 to 170, 35 to 100, 50 to 100, 60 to 80, or 100 to 170). This alumina-coated silica may be obtained from Nalco. The FAU framework type aluminosilicate zeolite may be Y zeolite. This aluminosilicate zeolite may have a SiO2 / Al2O3 molar ratio of at least 30 (e.g., 30 to 100, or 60 to 80). Examples of suitable aluminosilicate zeolites include Y zeolites CBV720, CBV760, and CBV780, commercially available from Zeolyst International. A combined source of silicon and aluminum may be used as the sole or primary source of silicon and aluminum in the reaction mixture.

[0038] The reaction mixture may contain a separate silicon source. If present, suitable silicon sources include colloidal silica, precipitated silica, fumed silica, alkali metal silicates, and tetraalkyl orthosilicates.

[0039] The hydroxide ion source can be an alkali metal hydroxide. The alkali metal can be lithium, sodium, potassium, or a mixture thereof. However, this component can be omitted as long as the basicity is maintained. A structure directing agent can be used to provide hydroxide ions. If present, the molar ratio of alkali metal cations to SiO2 can be in the range of 0.05 to 1.00 (e.g., 0.05 to 0.50).

[0040] The structure-directing agent (Q) comprises a 1,3,4-trimethylimidazolium cation represented by the following structure (1):

[0041]

[0042] Suitable sources of Q include hydroxides, chlorides, bromides, and / or other salts of quaternary ammonium compounds.

[0043] The reaction mixture also contains seed crystals, typically TON-based molecular sieve seed crystals, ideally in an amount from 0.01 wt ppm to 10,000 wt ppm (e.g., 100 wt ppm to 5,000 wt ppm) of the reaction mixture. Seed crystals can help improve selectivity for TON and / or shorten the crystallization process.

[0044] The molecular sieve required for crystallization from the above reaction mixture can be carried out under static, tumbling, or stirred conditions in a suitable reactor vessel (such as, for example, a polypropylene tank or a PTFE-lined or stainless steel autoclave) at a temperature of 120°C to 200°C (e.g., 135°C to 180°C) for a duration sufficient for crystallization to occur at the temperature used, for example, about 1 to 10 days (e.g., 2 to 7 days). Crystallization is typically carried out under pressure in an autoclave, subjecting the reaction mixture to autogenous pressure.

[0045] Once the desired molecular sieve crystals have formed, the solid product can be separated from the reaction mixture using standard mechanical separation techniques such as centrifugation or filtration. The recovered crystals are washed with water and then dried for seconds to minutes (e.g., 5 seconds to 10 minutes for rapid drying) or hours (e.g., 4 hours to 24 hours for oven drying at 75°C to 150°C) to obtain the initially synthesized molecular sieve crystals. The drying step can be carried out under vacuum or at atmospheric pressure.

[0046] As a result of the crystallization process, the recovered crystalline molecular sieve product contains at least a portion of the structure-directing agent used in the synthesis within its pores.

[0047] The initially synthesized molecular sieve can be subjected to heat treatment, ozone treatment, or other treatments to remove some or all of the structure-directing agent used in its synthesis. Removal of the structure-directing agent can be carried out using heat treatment (e.g., calcination), wherein the initially synthesized material is heated in an atmosphere selected from air, nitrogen, or mixtures thereof at a temperature sufficient to remove some or all of the structure-directing agent. While pressures below atmospheric pressure can be used for heat treatment, atmospheric pressure is preferred for convenience. This heat treatment can be carried out at a temperature of at least 370°C (e.g., 400°C to 700°C), for at least one minute, and typically not longer than 20 hours (e.g., 1 to 8 hours).

[0048] TON-type molecular sieves (in which some or all of the structure-directing agents are removed) can be combined with a hydride metal component. This hydride metal component can be selected from molybdenum, tungsten, rhenium, nickel, cobalt, chromium, manganese, or noble metals such as platinum or palladium, where the hydrogenation-dehydrogenation function is to be performed. Such hydride metal components can be incorporated into the composition through one or more of the following processes: co-crystallization; ion exchange into the composition; impregnation into the composition; or physical mixing with the composition. The amount of metal can range from 0.001 wt% to 20 wt% (0.01 wt% to 10 wt%, or 0.5 wt% to 2.0 wt%) of the catalyst.

[0049] Once a molecular sieve is synthesized, it can be formulated into a catalyst composition by combining it with another material resistant to the temperature and other conditions used in the organic conversion process. Such resistant materials can be selected from active materials, inactive materials, synthetic zeolites, naturally occurring zeolites, inorganic materials, or mixtures thereof. Examples of such resistant materials include clay, silica, titanium dioxide, metal oxides (such as alumina), or mixtures thereof. The inorganic material can be naturally occurring or in the form of a gel-like precipitate or gel comprising a mixture of silica and metal oxides. The use of a resistant material in combination with a molecular sieve (i.e., in combination with the molecular sieve or during the synthesis of the initially synthesized material in which its crystals are active) often alters the conversion and / or selectivity of the catalyst in certain organic conversion processes. Inactive resistant materials are suitable as diluents to control the conversion in a given process, allowing the product to be obtained in an economical and orderly manner without the need for other means of controlling the reaction rate. These materials can be incorporated into naturally occurring clays (e.g., bentonite and kaolin) to improve the crushing strength of the catalyst under commercial operating conditions. Inactive resistant materials (i.e., clay, oxides, etc.) act as binders for the catalyst. Catalysts with good crushing strength may be beneficial because it is necessary to prevent the catalyst from decomposing into powdery material in commercial use.

[0050] Naturally occurring clays that can be combined with molecular sieves include montmorillonite and the kaolin family (which includes sub-bentonite), as well as kaolinite commonly known as Dixie, McNamee, Ga, and Florida clays, or other clays whose main mineral components are halloysite, kaolinite, dickite, nacre, or anauxite. These clays can be used in their original, unprocessed state, or after initial calcination, acid treatment, or chemical modification.

[0051] Binders used for bonding with molecular sieves also include inorganic oxides selected from silica, zirconium oxide, titanium dioxide, magnesium oxide, beryllium oxide, aluminum oxide, or mixtures thereof.

[0052] In addition to the aforementioned materials, molecular sieves can also be combined with porous matrix materials such as silica-alumina, silica-magnesium oxide, silica-zirconia, silica-thorium oxide, silica-beryllium oxide, silica-titanium dioxide, and ternary compositions such as silica-alumina-thorium oxide, silica-alumina-zirconia, silica-alumina-magnesium oxide, and silica-magnesium oxide-zirconia.

[0053] The relative proportions of molecular sieves and inorganic oxide matrices can vary widely, with the molecular sieve content ranging from 1 wt% to 95 wt% (e.g., 20 wt% to 90 wt%) of the composite material.

[0054] Catalysts are used in conventional ways, such as in the form of spheres or extrusions.

[0055] Characterization of molecular sieves

[0056] The molecular sieve, in its anhydrous form during initial synthesis, can have a chemical composition in the range of molar ratios listed in Table 2:

[0057] Table 2

[0058] Widest Second <![CDATA[SiO2 / Al2O3]]> 30 to 100 35 to 80 <![CDATA[Q / SiO2]]> >0 to ≤0.1 >0 to ≤0.1

[0059] Q contains a 1,3,4-trimethylimidazolium cation.

[0060] The TON framework-type molecular sieves prepared as described herein can have small crystal sizes. This crystal size is based on individual crystals (including twins) but excludes crystal aggregates. Crystal size is the length of the longest diagonal of a three-dimensional crystal. Direct measurement of crystal size can be performed using microscopic methods such as SEM and TEM. For example, SEM measurements involve examining the morphology of the material at high magnification (typically 1000x to 10,000x). This SEM method can be performed by distributing a representative portion of the molecular sieve powder onto a suitable mount, such that the individual particles are reasonably uniformly distributed across the entire field of view at magnification of 1000x to 10,000x. From this population, statistically significant random samples of individual crystals (e.g., 50 to 200) are examined, and the longest diagonal of each individual crystal is measured and recorded. (Particles that are clearly large polycrystalline aggregates should not be included in the measurements.) Based on these measurements, the arithmetic mean of the sample crystal sizes is calculated.

[0061] The TON framework-type molecular sieves synthesized as described herein were characterized by their powder X-ray diffraction (XRD) patterns. Powder XRD patterns representing TON framework-type molecular sieves can be found in MMJ Treacy and JB Higgins, “Collection of Simulated XRD Powder Patterns for Zeolites” (Elsevier, 5th revised edition, 2007).

[0062] The X-ray diffraction data reported in this paper were collected using standard techniques with copper K-α radiation. Minor variations in the diffraction patterns may be due to changes in the molar ratio of the framework material in a particular sample, resulting from alterations in the lattice constant. Additionally, sufficiently small crystals will affect the shape and intensity of the peaks, leading to significant peak broadening. Minor variations in the diffraction pattern may also be caused by variations in the organic compounds used in the preparation. Calcination may also cause minor shifts in the XRD pattern. Despite these minor perturbations, the basic crystal structure remains unchanged.

[0063] Hydroisomerization of paraffinic hydrocarbon feedstock

[0064] The molecular sieve of the present invention is suitable for use as a catalyst for hydroisomerizing paraffinic hydrocarbon feedstocks. When the paraffinic hydrocarbon feedstocks are contacted with hydrogen under hydroisomerization conditions in the presence of the catalyst, products with an increased number of branched hydrocarbons relative to the hydrocarbon feedstocks are produced.

[0065] Hydroisomerization conditions include temperatures ranging from 200°C to 450°C (e.g., 250°C to 400°C), pressures ranging from 0.5 MPa to 20 MPa (e.g., 1 MPa to 15 MPa), and time ranging from 0.1 to 10 h. -1 (e.g., 0.5 to 5 hours) -1 The liquid hourly space velocity (LHSV) ranged from 35.6 to 1781 Nm. 3 / m 3 (e.g., 890 to 1424 Nm) 3 / m 3 The hydrogen circulation rate.

[0066] If the hydrocarbon feedstock includes n-C8+ hydrocarbons (e.g., n-C10+ or ​​n-C15+ hydrocarbons), then the hydrocarbon feedstock is not limited to a specific type. More specifically, examples of such hydrocarbon feedstocks include relatively light distillation fractions, such as kerosene and jet fuel; and high-boiling-point feedstocks, such as fuel or wax fractions derived from any type of crude oil, atmospheric residue, vacuum residue, vacuum distillation residue, recycled feedstocks, synthetic crude oils (e.g., shale oil, tar, etc.), gas oil, vacuum gas oil, foot oil, Fischer-Tropsch synthetic oils; and other heavy oils.

[0067] Example

[0068] The following illustrative examples are intended to be non-limiting.

[0069] Example 1

[0070] In a 23 mL polytetrafluoroethylene autoclave, 3.96 g of an aqueous solution of 1,3,4-trimethylimidazolium hydroxide (0.98 mmol OH) was added. – Mix 1.0 g of CBV780 Y zeolite (SAR = 80) with 5.21 g of deionized water. Then, add 1.0 g of CBV780 Y zeolite, followed by TON zeolite seed crystals, and mix thoroughly. Heat the mixture in a sealed autoclave at 170 °C for 3 days at 43 rpm. Recover the material by filtration, wash with plenty of water, and finally air dry at 85 °C.

[0071] The material was calcined in air by placing a thin bed of material in a calcining pan and heating it in a muffle furnace from room temperature to 120°C at a rate of 1°C / min and holding it at 120°C for 2 hours. Then, the temperature was ramped up to 540°C at a rate of 1°C / min and held at 540°C for 5 hours. The temperature was again ramped up to 595°C at a rate of 1°C / min and held at 595°C for 5 hours. The material was then allowed to cool to room temperature.

[0072] Powder XRD patterns of calcined materials Figure 1 The image shows that the material is a TON framework zeolite. Figures 2(A) and 2(B) show exemplary SEM images of the product at various magnifications. As shown, the crystals have a columnar morphology with an average length greater than 1 μm, an average width of about 0.5 μm, and an average thickness of less than 0.1 μm.

[0073] Example 2

[0074] In a 23 mL polytetrafluoroethylene autoclave, 0.72 g of an aqueous solution of 1,3,4-trimethylimidazolium hydroxide (0.98 mmol OH) was added. – A mixture of 0.17 g LiOH·H₂O and 7.22 g deionized water was prepared. Then, 4.0 g of alumina-coated silica (SAR = 100, 26.5% solids, Nalco) was added, followed by zeolite TON seed crystals, and the mixture was thoroughly mixed. The mixture was then heated in a sealed autoclave at 170 °C at 43 rpm for 3 days. The material was recovered by filtration and washed with copious amounts of water, and finally dried in air at 85 °C.

[0075] The initially synthesized material was calcined according to the method described in Example 1.

[0076] Powder XRD patterns of calcined materials Figure 3The image shows that the material is a TON framework zeolite. Figures 4(A) and 4(B) show exemplary SEM images of the product at various magnifications. As shown, the crystals are in the form of needle bundles with an average length greater than 1 μm and an average thickness less than 0.1 nm.

[0077] Example 3

[0078] In a 23 mL polytetrafluoroethylene autoclave, 0.72 g of an aqueous solution of 1,3,4-trimethylimidazolium hydroxide (0.98 mmol OH) was added. - The mixture was prepared by mixing 0.096 g of LiOH·H₂O, 1.76 g of 1 MkOH, and 5.54 g of deionized water. Then, 4.0 g of alumina-coated silica (SAR = 100, 26.5% solids, Nalco) was added, followed by zeolite TON seed crystals, and the mixture was thoroughly mixed. The mixture was then heated in a sealed autoclave at 170 °C with a rotation speed of 43 rpm for 3 days. The material was recovered by filtration and washed with copious amounts of water, and finally dried in air at 85 °C.

[0079] The initially synthesized material was calcined according to the method described in Example 1.

[0080] Powder XRD patterns of calcined materials Figure 5 The image shows that the material is a TON framework zeolite. Figures 6(A) and 6(B) show exemplary SEM images of the product at various magnifications. As shown, the crystals are in the form of columnar bundled needles with an average length greater than 1 μm, an average width of about 0.1 μm, and an average thickness of less than 100 nm.

[0081] Example 4

[0082] In a 23 mL polytetrafluoroethylene autoclave, 1.91 g of an aqueous solution of 1,3,4-trimethylimidazolium hydroxide (0.98 mmol OH) was added. – Mix 0.085 g of LiOH·H2O and 3.42 g of deionized water. Then, add 1.0 g of CBV780 Y zeolite (SAR = 80), followed by zeolite TON seed crystals, and mix thoroughly. Heat in a sealed autoclave at 150 °C for 3 days at 43 rpm. Recover the material by filtration, wash with plenty of water, and finally air dry at 85 °C.

[0083] The initially synthesized material was calcined according to the method described in Example 1.

[0084] Powder XRD patterns of calcined materials Figure 7The image shows that the material is a TON framework zeolite. Figures 8(A) and 8(B) show exemplary SEM images of the product at various magnifications. As shown, the crystals are in the form of irregularly shaped flakes with an average size of less than 1 μm × 1 μm and an average thickness of less than 50 nm.

[0085] Example 5

[0086] In a 125 mL polytetrafluoroethylene autoclave, 5.38 g of an aqueous solution of 1,3,4-trimethylimidazolium hydroxide (0.88 mmol OH) was added. – Mix 27.24 g of 1M KOH and 21.2 g of deionized water. Then, add 21.0 g of alumina-coated silica (SAR = 35; 24.5% solids, Nalco), followed by 7.02 g of... AS-30 colloidal silica was then added, followed by the addition of zeolite TON seed crystals, and thoroughly mixed. The mixture was then heated in a sealed autoclave at 175°C with a rotation speed of 43 rpm for 2 days. The material was recovered by filtration, washed with copious amounts of water, and finally air-dried at 85°C.

[0087] The initially synthesized material was calcined according to the method described in Example 1.

[0088] Powder XRD patterns of calcined materials Figure 9 The diagram shows that the material is a TON skeleton zeolite. Figure 10 An exemplary SEM image of the product is shown. As shown, the crystals are in the form of a bundle of small crystal-sized fibrous needles.

[0089] The calcined material was then converted to ammonium form by heating in an ammonium nitrate solution (typically, at 85°C for at least 3 hours in a solution of 1 g NH4NO3 / 1 g zeolite in 10 mL H2O). The material was then filtered. This process was repeated twice, for a total of three exchanges. Finally, the material was washed with deionized water until the conductivity was less than 100 μS / cm and dried in air at 85°C.

[0090] The density of acid sites was characterized using temperature-programmed desorption (TPD) with n-propylamine and determined to be 522 μmol H₂. + / g.

[0091] The nitrogen micropore volume was measured to be 0.095 cm³. 3 / g(t-plot analysis) and the BET surface area is 232.6m². 2 / g.

[0092] The SAR of this material was determined to be 44.7 according to inductively coupled plasma mass spectrometry (ICP-MS).

[0093] To exchange palladium for 0.5 wt.% Pd, 1.6 g of NH4 was used. + The Pd-form material was combined with 15.3 g of deionized water and 7.0 g of 0.156 N NH4OH solution, followed by 1.6 g of palladium solution prepared by combining 0.36 g of Pd(NH3)4(NO3)2 with 3 g of 0.148 N NH4OH solution in 21 g of deionized water. The pH was then checked and adjusted to 10 dropwise with concentrated ammonium hydroxide if necessary, until pH 10 was achieved. After standing at room temperature for 3 days, the pH was checked again and readjusted to 10 if necessary, followed by standing for 1 day. The material was recovered by filtration, washed with deionized water, and air-dried overnight at 85 °C. The Pd-form material was calcined in dry air by incline heating to 120 °C at 1 °C / min and holding at 120 °C for 180 min, followed by heating to 482 °C at 1 °C / min and holding at 482 °C for 180 min. Finally, the material was granulated at 5 kpsi, crushed, and sieved to 20-40 mesh.

[0094] Example 6

[0095] In a 125 mL polytetrafluoroethylene autoclave, 5.37 g of an aqueous solution of 1,3,4-trimethylimidazolium hydroxide (0.88 mmol OH) was added. – The mixture was prepared by mixing 27.18 g of 1M KOH and 20.1 g of DI water. Then, 29.0 g of alumina-coated silica (SAR = 80; 26.9% solids, Nalco) was added, followed by zeolite TON seed crystals, and the mixture was thoroughly mixed. The mixture was then heated in a sealed autoclave at 175°C and 43 rpm for 2 days. The material was recovered by filtration and washed with copious amounts of water, and finally dried in air at 85°C.

[0096] The material was calcined and converted into ammonium form according to the method described in Example 5.

[0097] Powder XRD patterns of calcined materials Figure 11 The image shows that the material is a TON framework zeolite. Figures 12(A) and 12(B) show exemplary SEM images of the product at various magnifications. As shown, the crystals have a certain degree of layered morphology and the crystal size is very small.

[0098] The acid site density was characterized using n-propylamine TPD and determined to be 340 μmol H. + / g.

[0099] The nitrogen micropore volume was found to be 0.10 cm³. 3 / g(t-plot analysis) and the BET surface area is 240.1m. 2 / g.

[0100] According to ICP-MS, the SAR of this material is 70.1.

[0101] The exchange of up to 0.5 wt.% Pd was performed according to the method described in Example 5.

[0102] Example 7

[0103] Hydrogenation conversion of n-hexadecane

[0104] A 0.5 g palladium exchange sample was loaded at the center of a 23-inch long × 0.25-inch outer diameter stainless steel reactor tube, with aluminum powder loaded upstream of the catalyst for preheating the feed (total pressure 1200 psig; downward flow hydrogen rate 160 mL / min at 1 atm and 25°C; downward flow liquid feed rate 1 mL / h). All materials were first reduced in flowing hydrogen at approximately 315°C for 1 hour. The products were analyzed every 30 minutes by online capillary gas chromatography (GC). Raw data from the GC were collected using an automated data acquisition / processing system, and hydrocarbon conversion was calculated based on the raw data.

[0105] Conversion was defined as the amount of n-hexadecane that reacted to produce other products, including the iso-C16 isomer. Yield was expressed as the weight percentage of products other than n-C16, including the iso-C16 as a yield product. Results at 96% conversion are reported in Table 3.

[0106] Table 3 Summary of hexadecane hydrogenation conversion at 96% conversion rate

[0107]

[0108] Example 8

[0109] Hydrogenation conversion of n-decane

[0110] For catalytic testing, 0.5 g of Pd catalyst (weight of the dehydrated sample, as determined by thermogravimetric analysis at 600 °C) was loaded at the center of a 23-inch long × 0.25-inch outer diameter stainless steel reactor tube, with aluminum powder loaded upstream of the catalyst for preheating the feed (total pressure 1200 psig; downward flow hydrogen rate of 12.5 mL / min at 1 atm and 25 °C; and downward flow liquid feed rate of 1 mL / h). The catalyst was first reduced in flowing hydrogen at 315 °C for 1 h. The reaction was carried out at temperatures from 230 °C to 310 °C. The products were analyzed approximately every 60 minutes by online capillary GC. Raw data from the GC were collected using an automated data collection / processing system, and hydrocarbon conversion was calculated from the raw data. Conversion was defined as the amount of n-decane reacted to produce other products (including iso-C10) in mol%. The yield of iso-C10 was expressed as the molar percentage of products other than n-decane. The yield of cracking products (less than C10) is expressed as the molar percentage of n-decane converted to cracking products. Results in... Figures 13 to 18 The results are shown in Table 4, and the key catalytic performance indicators are also shown in Table 4.

[0111] The modified constraint index (CI*) is calculated as the ratio of 2-methylnonane to 5-methylnonane when the total isomer yield is approximately 5%, and is shown in Table 4.

[0112] Table 4 Summary of n-decane hydrogenation conversion at maximum total isomer yield

[0113]

Claims

1. A method for synthesizing TON framework-type molecular sieves, the method comprising: (1) Forming a reaction mixture comprising: (a) A combined source of silicon and aluminum, wherein the combined source of silicon and aluminum is alumina-coated silica, FAU-framework type aluminosilicate zeolite, or a mixture thereof; (b) A structure-directing agent Q containing a 1,3,4-trimethylimidazolium cation; (c) Hydroxide ion source; (d) Water; and (e) Seed crystals comprising a TON framework-type molecular sieve; and (2) Subject the reaction mixture to crystallization conditions sufficient to cause crystals of the molecular sieve to form. The reaction mixture has the following composition in molar ratio: SiO2 / Al2O3 30 to 170 Q / SiO2 0.03 to 0.50 OH / SiO2 0.05 to 1.00 H2O / SiO2 5 to 100.

2. The method of claim 1, wherein the reaction mixture has the following composition in molar ratio: SiO2 / Al2O3 35 to 130 Q / SiO2 0.04 to 0.30 OH / SiO2 0.10 to 0.50 H2O / SiO2 10 to 50.

3. The method of claim 1, wherein the FAU framework type aluminosilicate zeolite is zeolite Y.

4. The method of claim 1, wherein the hydroxide ion source comprises an alkali metal hydroxide.

5. The method of claim 4, wherein the alkali metal is lithium, sodium, potassium, or a mixture thereof.

6. The method of claim 5, wherein the molar ratio of alkali metal cation to SiO2 is in the range of 0.1 to 1.

0.

7. The method of claim 1, wherein the reaction mixture comprises 0.01 ppm to 10,000 ppm of seed crystals by weight.

8. The method of claim 1, wherein the reaction mixture further comprises a separate silicon source.

9. The method of claim 8, wherein the separate silicon source comprises colloidal silica, precipitated silica, pyrolytic silica, alkali metal silicates, tetraalkyl orthosilicates, or mixtures thereof.

10. The method of claim 1, wherein the crystallization conditions include a temperature of 125°C to 200°C and a time of 1 to 10 days.

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