Molecular sieve boron SSZ-121, its synthesis and use

Abstract

A novel synthetic crystalline molecular sieve material called boron SSZ-121 is provided. Boron SSZ-121 can be synthesized using 1,3-bis(1-adamantyl)imidazolium cation as a structure directing agent. Boron SSZ-121 can be used in organic compound conversion reactions and / or sorption processes.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 365,542, filed May 31, 2022, the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to a novel synthetic crystalline germanosilicate molecular sieve, designated as Boron SSZ-121, and its synthesis.

Background Art

[0003] Molecular sieves are a commercially important class of materials having a unique crystal structure with a distinct pore structure as indicated by a unique X-ray diffraction (XRD) pattern. Molecular sieves also have a specific chemical composition. The crystal structure defines cavities and pores that are characteristic of a particular type of molecular sieve. Providing new molecular sieves that differ in crystal structure as well as composition can lead to unique catalysts or adsorption / separation materials. Altering the crystal structure is always difficult, but if successful, can provide benefits for new catalysts for organic compound conversion reactions. U.S. Patent No. 11,161,750 discloses the preparation of SSZ-121. However, it does not disclose Boron SSZ-121.

Summary of the Invention

Means for Solving the Problems

[0004] According to the present disclosure, a new crystalline germanosilicate molecular sieve, designated as Boron SSZ-121, is synthesized using 1,3-bis(1-adamantyl)imidazolium cation as a structure directing agent (SDA). It has been found that the synthesis was successful in providing a boron-containing molecular sieve having the SSZ-121 crystal structure.

[0005] In one aspect, there is provided a boron SSZ-121 molecular sieve having a powder X-ray diffraction pattern with at least the following 2-theta scattering angles: 6.3 ± 0.2, 7.0 ± 0.2, 9.5 ± 0.2, 13.0 ± 0.2, 16.0 ± 0.2, 18.5 ± 0.2, 19.8 ± 0.2, 21.2 ± 0.2, 24.0 ± 0.2, 25.0 ± 0.2, 26.5 ± 0.2, 28.5 ± 0.2, and 30.0 ± 0.2 degrees 2-theta in its as-synthesized form.

[0006] In its as-synthesized and anhydrous form, the boron SSZ-121 molecular sieve may have the following molar relationship: [Table 1] (wherein Q may have a chemical composition including a 1,3-bis(1-adamantyl)imidazolium cation).

[0007] In a second aspect, there is provided a boron-containing SSZ-121 molecular sieve having a powder XRD pattern with at least the following 2-theta scattering angles: 6.5 ± 0.2, 9.5 ± 0.2, 13.0 ± 0.2, 18.5 ± 0.2, 19.8 ± 0.2, 21.2 ± 0.2, 24.0 ± 0.2, 25.0 ± 0.2, 26.5 ± 0.2, 28.5 ± 0.2, and 30.0 ± 0.2 degrees 2-theta in its calcined form.

[0008] In its calcined form, the boron-containing boron SSZ-121 molecular sieve may have the following molar relationship: B2O3:(n)(SiO2 + GeO2) (wherein n is ≥ 10).

[0009] In a further aspect, there is provided a method for synthesizing a molecular sieve described herein, the method comprising: (1) preparing a reaction mixture comprising: (a) an FAU framework type zeolite; (b) a source of germanium; (c) a source of boron; (d) a structure directing agent (Q) comprising a 1,3-bis(1-adamantyl)imidazolium cation; (e) a source of fluoride ions; and (f) water; and (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of a boron molecular sieve. The boron-containing SSZ-121 molecular sieve is then treated to remove the SDA, which can be achieved by calcination or ozone treatment.

[0010] In yet another aspect, there is provided a process for converting a raw material comprising an organic compound into a conversion product, the process comprising contacting the raw material with a catalyst comprising a boron SSZ-121 molecular sieve described herein under organic compound conversion conditions.

[0011] Among other factors, a boron SSZ-121 molecular sieve, which is a boron germanosilicate, can be obtained by this process. This new molecular sieve prepared by this process can impart unique capabilities as a catalyst in organic compound conversion reactions. The molecular sieve also finds important value as an adsorption / separation material. **DETAILED DESCRIPTION OF THE INVENTION**

[0012] Definitions The term "framework type" has the meaning described in "Atlas of Zeolite Framework Types" by Ch. Baerlocher, L. B. McCusker and D. H. Olsen (Elsevier, Sixth Revised Edition, 2007).

[0013] The term "borongermanosilicate" refers to a crystalline microporous solid containing boron, germanium, and silicon oxide within its framework structure. Borongermanosilicates can be "pure borongermanosilicates" (i.e., without other detectable metal oxides in their framework structure) or optionally substituted. When described as "optionally substituted", each framework may contain one or more other atoms (e.g., Al, Ga, In, Fe, Ti, Zr) that replace one or more atoms that are not yet present in the parent framework.

[0014] As used herein, the term "as-synthesized" refers to the molecular sieve in its form after crystallization and before removal of the structure-directing agent.

[0015] As used herein, the term "anhydrous" refers to a molecular sieve substantially free of both physically adsorbed and chemisorbed water.

[0016] As used herein, the group numbering scheme of the periodic table is as disclosed in Chem. Eng. News 1985, 63(5), 26 - 27.

[0017] Synthesis of Molecular Sieves The present molecular sieve boron SSZ - 121 can be synthesized by a method comprising (1) preparing a reaction mixture containing (a) an FAU framework type zeolite; (b) a source of germanium; (c) a source of boron; (d) a structure-directing agent (Q) containing a 1,3-bis(1-adamantyl)imidazolium cation; (e) a source of fluoride ions; and (f) water; and then (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the boron SSZ - 121 molecular sieve. When aluminum is present, it is present in only a small amount. Thus, the framework contains a predominant amount of boron. The SiO2 / Al2O3 ratio can be 300 or more.

[0018] The reaction mixture has a composition with a molar ratio within the range described in Table 2.

Table 2

[0019] Suitable sources of silicon oxide may include any suitable known sources such as colloidal silica, fumed silica, precipitated silica, or alkali metal silicate. FAU framework type zeolites, such as zeolite Y, can also be a source of silicon oxide. In such a case, the FAU framework type zeolite can be an ammonium type zeolite or a hydrogen type zeolite and is a source of silica for the reaction. FAU zeolites will generally have a SiO2 / Al2O3 molar ratio of at least 300 or more. Examples of FAU framework type zeolites include zeolite Y (e.g., HSZ-HUA390). Zeolite Y can have a SiO2 / Al2O3 molar ratio of 300 to 500. The FAU framework type zeolite can include two or more zeolites. The two or more zeolites can be Y zeolites having different silica-to-alumina molar ratios. The FAU framework type zeolite can be a single or the most important source of silicon. In some embodiments, silicon from separate sources can be added. Separate sources of silicon include colloidal silica, fumed silica, precipitated silica, alkali metal silicate, and tetraalkyl orthosilicate.

[0020] Suitable sources of germanium include germanium oxide and germanium alkoxides (e.g., germanium ethoxide, germanium isopropoxide).

[0021] Silicon and germanium can be present in the reaction mixture at a SiO2 / GeO2 molar ratio of 4 to 12 (e.g., 6 to 10).

[0022] Suitable sources of boron may include boric acid, which is preferred.

[0023] Suitable sources of fluoride ions include hydrogen fluoride, ammonium fluoride, and ammonium hydrogen fluoride.

[0024] The structure-directing agent is the following structure (1):

Chemical formula

[0025] Suitable sources of Q are hydroxides, chlorides, bromides, and / or other salts of quaternary ammonium compounds.

[0026] The reaction mixture may have a Q / F molar ratio in the range of 0.80 to 1.20 (for example, 0.85 to 1.15, 0.90 to 1.10, 0.95 to 1.05, or 1 to 1).

[0027] The reaction mixture may contain seeds of molecular sieve materials such as boron SSZ-121 obtained from previous syntheses in an amount of 0.01 to 10,000 ppm by weight of the reaction mixture (for example, 100 to 5000 ppm by weight). The addition of seeds may be convenient when reducing the time required for complete crystallization. Furthermore, the addition of seeds may result in an increase in the purity of the obtained product by promoting the nucleation and / or formation of boron SSZ-121 over undesirable phases.

[0028] It is noted that the reaction mixture components may be supplied by two or more sources. Also, two or more reaction components may be provided by one source. The reaction mixture can be prepared either batchwise or continuously.

[0029] Crystallization and Post-Synthesis Processing In line with the boron route, the crystallization of boron SSZ-121 molecular sieve from the above reaction mixture can be carried out at a temperature of 100 °C to 200 °C (e.g., 150 °C to 175 °C) for a time sufficient for crystallization to occur at the temperature used (e.g., 1 day to 14 days, or 2 days to 10 days) under static, rotating, or stirring conditions in a suitable reactor vessel (e.g., a polypropylene jar or a Teflon - processed or stainless - steel autoclave). The hydrothermal crystallization process is typically carried out under pressure, such as in an autoclave, preferably under autogenous pressure.

[0030] Once the molecular sieve crystals are formed, the solid product can be recovered from the reaction mixture by standard mechanical separation techniques such as centrifugation or filtration. The recovered crystals are washed with water and then dried to obtain the as - synthesized molecular sieve crystals. The drying step can be carried out at a high temperature (e.g., 75 °C to 150 °C) for several hours (e.g., about 4 to 24 hours). The drying step can be carried out either under vacuum or at atmospheric pressure.

[0031] 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 pore structure.

[0032] As-synthesized molecular sieves are also subjected to a process of removing some or all of the structure-directing agent used in their synthesis. This is conveniently effected by a heat treatment (i.e., calcination) in which the as-synthesized material is heated at a temperature of at least about 370 °C for at least 1 minute and generally less than 20 hours. Sub-atmospheric pressures can be utilized for the heat treatment, but atmospheric pressure is desirable for simplicity. The heat treatment can be carried out at temperatures up to about 925 °C. The heat treatment can be carried out in an atmosphere selected from air, nitrogen, or mixtures thereof. For example, the heat treatment can be carried out in air for a period of 3 to 8 hours at a temperature of 400 °C to 600 °C. Alternatively, the structure-directing agent Q can be removed by treatment with ozone. Ozone treatment can include heating the as-synthesized molecular sieve in the presence of ozone, such heating can be at a temperature of 50 °C to 350 °C (e.g., 100 °C to 300 °C, or 125 °C to 250 °C). It has also been found that the SDA can be removed by treatment with dimethylformamide, e.g., by treatment at about 150 °C.

[0033] Characterization of Molecular Sieves In its as-synthesized and anhydrous form, the boron-containing molecular sieve SSZ-121 can have the following molar relationships set forth in Table 1: [Table 1] (wherein Q can include the 1,3-bis(1-adamantyl)imidazolium cation). In some embodiments, the molecular sieve can have a SiO2 / GeO2 molar ratio in the range of 4 to 12 (e.g., 6 to 10). In one embodiment, the (SiO2 + GeO2) / B2O3 molar ratio ranges from 15 to 20.

[0034] In its calcined form, the boron-containing molecular sieve SSZ-121 has the following molar relationship: B2O3:(n)(SiO2 + GeO2) It may have a chemical composition including (wherein n is ≥ 10 (for example, from 10 to 30, from 15 to 30, and from 15 to 20)).

[0035] It should be noted that as-synthesized boron SSZ-121 molecular sieve may have a molar ratio different from the molar ratio of the reactants of the reaction mixture used to prepare it in the as-synthesized form. This result may occur because 100% of the reactants of the reaction mixture are not completely incorporated into the crystals formed (from the reaction mixture).

[0036] In its as-synthesized form, boron molecular sieve SSZ-121 shows a powder XRD pattern having at least the following 2-theta scattering angles: 6.3 ± 0.2, 7.0 ± 0.2, 9.5 ± 0.2, 13.0 ± 0.2, 16.0 ± 0.2, 18.5 ± 0.2, 19.8 ± 0.2, 21.2 ± 0.2, 24.0 ± 0.2, 25.0 ± 0.2, 26.5 ± 0.2, 28.5 ± 0.2 and 30.0 ± 0.2 degrees 2-theta. In its calcined form, molecular sieve SSZ-121 having boron shows a powder XRD pattern having at least the following 2-theta scattering angles: 6.5 ± 0.2, 9.5 ± 0.2, 13.0 ± 0.2, 18.5 ± 0.2, 19.8 ± 0.2, 21.2 ± 0.2, 24.0 ± 0.2, 25.0 ± 0.2, 26.5 ± 0.2, 28.5 ± 0.2 and 30.0 ± 0.2 degrees 2-theta.

[0037] The powder X-ray diffraction patterns presented herein were collected by standard techniques. The radiation was CuKα radiation. The peak height and position as a function of 2θ where θ is the Bragg angle were read from the relative intensity of the peaks (adjusted with respect to the background), and the lattice plane spacing d corresponding to the recorded lines could be calculated.

[0038] Small variations in the diffraction pattern can result from variations in the molar ratio of the framework species of the sample due to changes in the lattice constant. Furthermore, irregular substances and / or sufficiently small crystals will affect the shape and intensity of the peaks, resulting in significant peak broadening. Small variations in the diffraction pattern can also result from variations in the organic compounds used in the preparation. Calcination can also cause a small shift in the XRD pattern. Despite these small perturbations, the basic crystal lattice structure remains unchanged.

Industrial Applicability

[0039] Molecular sieve boron SSZ-121 (with some or all of the structure-directing agent removed) can be used as an adsorbent or as a catalyst to catalyze a wide variety of organic compound conversion processes. A particular area of potential use is in the modification process of boron SSZ-121.

[0040] Catalytic reforming is one of the basic petroleum refining processes for reforming light hydrocarbon feedstocks, often referred to as naphtha feedstocks. The products obtained from catalytic reforming can include high-octane gasoline, aromatics (e.g., benzene, toluene, xylene, and ethylbenzene), and / or hydrogen, which are useful as automotive fuels. Reactions typically involved in catalytic reforming include dehydrocylization, isomerization, and dehydrogenation of naphtha-range hydrocarbons, and dehydrogenation cyclization and dehydrogenation of straight-chain and slightly branched alkanes as well as dehydrogenation of cyclic paraffins result in the production of aromatics. Dealkylation and hydrocracking are generally not desirable due to the low value of the resulting light hydrocarbon products.

[0041] The boron SSZ-121 catalyst used in the reforming reaction will often contain a Group VIII metal such as platinum or palladium, or a second catalytic metal that acts as a promoter in addition to the Group VIII metal. Examples of metals useful as promoters include rhenium, tin, tungsten, germanium, cobalt, nickel, rhodium, ruthenium, iridium, or combinations thereof. The catalytic metal or metals may be dispersed on a support such as alumina, silica, or silica-alumina.

[0042] The boron SSZ-121 reforming catalyst can be utilized in the form of pellets, spheres, granules, fragments, or various special shapes, arranged as a fixed bed within the reaction zone, and the feedstock can pass through in the liquid phase, gas phase, or mixed phase, either ascending, descending, or in radial flow. Alternatively, the reforming catalyst can be used in a moving bed or fluidized solid process where the feedstock ascends through a turbulent bed of finely divided catalyst. However, a fixed bed system or a dense phase moving bed system is preferred due to less catalyst consumption and other operating advantages. In a fixed bed system, the feed material is preheated (by any suitable heating means) to the desired reaction temperature and then passed through a reaction zone containing a fixed bed of catalyst. This reaction zone can be one or more separate reactors having suitable means to maintain the desired temperature at the reactor inlet. Since the reforming reaction is typically endothermic in nature, the temperature must be maintained.

[0043] The actual reforming conditions often depend, at least in part, on the feedstock used, whether it is highly aromatic, paraffinic, or naphthenic, and on the desired octane number of the product and the desired amount of hydrogen production.

Examples

[0044] The following examples are intended to be non-limiting.

[0045] (Example 1) Synthesis of SSZ-121 Boron To a bagged and weighed cup, 42.5 grams of an SDA solution is added as OH, which is at a molarity of 0.28. Next, to the solution, (a) 1.20 grams of Tosoh Corporation's HUA 390 FAU zeolite with SAR = 500, (b) 0.225 grams of germanium dioxide, and (c) 0.06 grams of boric acid are added. Next, the open bagged and weighed cup is placed in a hood and evaporated until the H2O / TO2 ratio drops to 7. Next, HF is given to the reactants in an amount equal to the amount of SDA in millimoles. Next, the contents of the cup are transferred to a 23 ml Teflon cup for a Parr stainless steel reactor, which is closed and placed on a rotating spit (43 RPM) in a convection heating oven. Crystallization is carried out at 160 °C for about 15 days (typically, it may be advantageous to add seed crystals for zeolite synthesis using about 3 wt% of the Tosoh reagent used). The product is collected and washed 4 times with 50 ml H2O for each aliquot.

[0046] Next, the recovered product can be treated to remove the SDA.

[0047] (Example 2) Calcination of boron in SSZ-121 The as-synthesized molecular sieve of Example 1 is calcined in a muffle furnace in a stream of air heated to 550 °C at a rate of 1 °C / min, held at 550 °C for 5 hours, cooled, and then can be analyzed by powder XRD. From the XRD pattern, it was confirmed that the product is boron SSZ-121.

[0048] (Example 3) Boron SSZ-121 can be calcined, but first, it is preferred to treat the zeolite with ozone at 150 °C to remove the SDA guest molecules. Furthermore, it has also been found that much of the SDA can be first removed by treatment with dimethylformide at 150 °C in a sealed reactor; 1 gram of the as-produced zeolite and 7 ml of dimethylformamide are left standing and heated for 3 - 5 days.

[0049] Place the as-made boron SSZ-121 in a cell and then pass ozone through it while heating to 150 °C. The treatment is carried out for 16 - 20 hours. The mass loss (when not treated with dimethylformamide) can be approximately 40%.

[0050] The XRD pattern can be essentially the same as the previously described calcined XRD pattern.

[0051] (Example 4) Characterization by argon uptake The boron SSZ-121 prepared in Example 1 was subjected to ozonolysis to remove the SDA. The ozonolysis treatment was as described in Example 3.

[0052] After ozonolysis, the adsorption of argon gas at 87 K was measured, and the results related to zeolite characterization were as follows: [Table A]

[0053] Characterization of boron SSZ-121 shows good catalytic activity.

[0054] As used in this disclosure, the words "comprises" or "comprising" are intended to be non-limiting transitional terms that mean the inclusion of the stated elements but do not necessarily exclude other unstated elements. The phrase "consists essentially of" or "consisting essentially of" is intended to mean the exclusion of other elements that are of essential importance to the composition. The phrase "consisting of" or "consists of" is intended to be a transitional term that means the exclusion of all except the recited elements, except for trace impurities.

[0055] All patents and publications cited in this specification are incorporated herein by reference to the extent not inconsistent with this specification. It will be understood that some of the structures, functions, and operations of the above-described embodiments are not necessary for carrying out the present invention and are included herein merely for the sake of completeness of exemplary embodiments or embodiments. Further, it will be understood that the specific structures, functions, and operations described in the above-cited patents and publications can be implemented in conjunction with the present invention, but they are not essential for its implementation. Accordingly, it is to be understood that the present invention can be practiced otherwise than as specifically described without actually departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A molecular sieve having a powder X-ray diffraction pattern with at least the following 2-theta scattering angles: 6.5 ± 0.2, 9.5 ± 0.2, 13.0 ± 0.2, 18.5 ± 0.2, 19.8 ± 0.2, 21.2 ± 0.2, 24.0 ± 0.2, 25.0 ± 0.2, 26.5 ± 0.2, 28.5 ± 0.2, and 30.0 ± 0.2 degrees 2-theta, and containing boron within the framework.

2. Having a composition comprising the following molar relationship: B ２ O ３ :(n)(SiO ２ + GeO ２ ) (where n is ≥ 10), the molecular sieve according to claim 1.

3. Having a composition comprising the following molar relationship: B ２ O ３ :(n)(SiO ２ + GeO ２ ) (where n is ≥ 15), the molecular sieve according to claim 1.

4. In its as-synthesized form, having a powder X-ray diffraction pattern with at least the following 2-theta scattering angles: 6.3 ± 0.2, 7.0 ± 0.2, 9.5 ± 0.2, 13.0 ± 0.2, 16.0 ± 0.2, 18.5 ± 0.2, 19.8 ± 0.2, 21.2 ± 0.2, 24 ± 0.2, 25.0 ± 0.2, 26.5 ± 0.2, 28.5 ± 0.2, and 30.0 ± 0.2 degrees 2-theta, and containing boron within the framework.

5. Having a chemical composition comprising the following molar relationship: 【Table 1A】 (where Q contains the 1,3-bis(1-adamantyl)imidazolium cation), the molecular sieve according to claim 4.

6. Having a chemical composition comprising the following molar relationship: 【Table 1B】 (where Q contains the 1,3-bis(1-adamantyl)imidazolium cation), the molecular sieve according to claim 4.

7. The molecular sieve according to claim 2, which is sulfided and contains a Group VIII metal.

8. The molecular sieve according to claim 7, wherein the Group VIII metal is platinum or palladium.

9. A method for synthesizing the molecular sieve according to claim 4, comprising: (1) preparing a reaction mixture comprising: (a) FAU framework type zeolite having an SiO ２ / Al ２ O ３ molar ratio of 300 or more; (b) a source of germanium; (c) a source of boron; (d) a structure-directing agent (Q) containing the 1,3-bis(1-adamantyl)imidazolium cation; (e) a source of fluoride ions; and (f) water; and (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve. A method.

10. The method according to claim 9, wherein the reaction mixture has a composition with respect to the following molar ratios: 【Table 2A】

11. The reaction mixture has a composition with respect to the molar ratios as follows: 【Table 2B】 The method according to claim 9, having Claim 12 The FAU framework type zeolite is zeolite Y having a molar ratio of SiO ２ / Al ２ O ３ of 300 or more. The method according to claim 9 Claim 13 The method according to claim 9, wherein the crystallization conditions include a temperature of 100°C to 200°C. Claim 14 The method according to claim 9, wherein the reaction mixture has a molar ratio of Q / F in the range of 0.8 to 1.

2. Claim 15 A method for converting a raw material containing an organic compound into a conversion product, the method comprising contacting the raw material with a catalyst comprising the molecular sieve according to claim 7 under organic compound conversion conditions. Claim 16 The method according to claim 15, wherein the reaction is a reforming reaction and the catalyst contains platinum. Claim 17 A molecular sieve prepared by the method according to claim 9.

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