Molecular sieve SSZ-113 having high acidity, its synthesis and use

Abstract

There is provided a novel synthetic crystalline molecular sieve material designated SSZ-113 that exhibits increased acidity. SSZ-113 can be synthesized using 1,3-bis(2,3-dimethyl-1H-imidazolium)propane dication as a structure directing agent. The synthesis utilizes a boron route to obtain increased acid sites. The SSZ-113 with increased acidity can be used in organic compound conversion and / or sorption processes.

Description

Technical Field

[0001] This application claims the priority of U.S. Provisional Patent Application No. 63 / 365,515, filed on May 31, 2022, the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] This application relates to a novel synthetic crystalline molecular sieve having increased acidity, designated SSZ-113, and its synthesis.

Background Art

[0003] Zeolite materials are known to be useful as adsorbents and to have catalytic performance for various types of organic compound conversion reactions. Certain zeolite materials are ordered porous crystalline materials that have a defined crystal structure as measured by X-ray diffraction, with a large number of smaller cavities therein that can be interconnected by some smaller channels or pores. These cavities and pores are of uniform size within a particular zeolite material. Since the dimensions of these pores are such that they accept sorbate molecules of a particular size and not those of larger size, these materials have come to be known as "molecular sieves" and are used in various ways that utilize these properties.

Summary of the Invention

Problems to be Solved by the Invention

[0004] There are currently over 250 known zeolite framework structures recognized by the International Zeolite Association. There is a need for new structures with properties different from those of known materials to improve the performance of many organic compound conversion and sorption processes. Each structure has unique pore, channel, and cage dimensions, giving it its specific properties as described above. Each structure has a specific composition. Improvements in preparing purer single-phase materials are always important. Providing a molecular sieve with increased acid sites can be beneficial with respect to catalysis in organic compound conversion reactions.

Means for Solving the Problems

[0005] According to the present disclosure, a novel molecular sieve structure designated SSZ-113 with increased acid sites was synthesized using 1,3-bis(2,3-dimethyl-1H-imidazolium)propanedication as a structure-directing agent. The synthesis was carried out via a boron route. The final molecular sieve contains some boron within its framework. In one embodiment, the amount of boron can range from 50 to 250 ppm.

[0006] This aluminogermanosilicate SSZ-113 molecular sieve with increased acid sites and thus increased acidity has the following molar relationships:

Table A

[0007] The boron route involves preparing a boron SSZ-113 molecular sieve. This boron germanosilicate molecular sieve is then treated to replace boron in the framework with aluminum, resulting in an SSZ-113 molecular sieve having increased acid sites thereby.

[0008] In another embodiment, a method of synthesizing a molecular sieve having an increased acidity as described herein, comprising: (a) preparing a reaction mixture comprising: (1) a source of germanium oxide; (2) a source of silicon oxide; (3) a source of boron; (4) a source of 1,3-bis(2,3-dimethyl-1H-imidazolium) propane dication; (5) a source of fluoride ions; and (6) water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of a boron molecular sieve. The boron-containing SSZ-113 molecular sieve is then treated to remove the SDA and subsequently treated to replace some or all of the boron with aluminum. The result is SSZ-113 having increased acid sites.

[0009] In yet a further aspect, a method of converting a raw material containing an organic compound into a conversion product is provided, comprising contacting the raw material under organic compound conversion conditions with a catalyst comprising an active form of an SSZ-113 molecular sieve having increased acid sites as described herein.

[0010] Among other factors, the present method allows for the production of SSZ-113 molecular sieves with increased acid sites, i.e., SSZ-113 that is rich in acid or has an increased acidity. The increased acid sites mean that by using the present process along with its boron route, SSZ-113 molecular sieves can be obtained with more acid sites than would be possible by preparing the molecular sieves in the conventional manner in a simple way that has aluminum sites and no boron sites. When the conventional route is utilized, it has been found that some amorphous phase occurs and a decrease in Al acid sites is experienced. Extremely surprisingly, it has been found that by first inserting boron into the framework and then replacing boron with aluminum, SSZ-113 molecular sieves with a relatively increased number of acid sites can be obtained. The increased acid sites can lead to improved catalytic properties of the present SSZ-113 molecular sieves. The present SSZ-113 molecular sieves also contain some boron.

Mode for Carrying Out the Invention

[0011] Introduction The term "aluminogermanosilicate" refers to a crystalline microporous solid that contains aluminum, germanium, and silicon oxide within its framework. In some cases, one or more of these oxides can be replaced by other oxides.

[0012] As used herein, the term "as-synthesized" is utilized to refer to the molecular sieve in that form after crystallization and before removal of the organic structure-directing agent.

[0013] As used herein, the term "anhydrous" is utilized to refer to a molecular sieve that is substantially free of both physically adsorbed water and chemically adsorbed water.

[0014] As used herein, the group numbering scheme for the periodic table is as disclosed in Chem. Eng. News 1985, 63(5), 26 - 27.

[0015] "Increased" or "more" acid sites means that the SSZ-113 molecular sieve prepared by the present process contains more acid sites than would be possible by preparing the molecular sieve conventionally without using this boron route. It has been found that when a conventional simple method using aluminum is utilized, an amorphous phase occurs, causing a decrease in Al acid sites. Extremely surprisingly, by first inserting boron into the SSZ-113 framework and then replacing boron with aluminum, an SSZ-113 molecular sieve having a relatively larger number of aluminum acid sites than would be obtained if boron were not introduced in the initial preparation of the molecular sieve has been found. Therefore, SSZ-113 is rich in acid or has an increased acidity. This increased acidity affects the catalytic properties of the molecular sieve and can be improved. The molecular sieve would be extremely useful, for example, in converting raw materials containing organic compounds into products. Due to the boron route, some boron remains within the SSZ-113 molecular sieve.

[0016] The reaction mixture used in the synthesis of the molecular sieve The aluminogermanosilicate molecular sieve SSZ-113 can be synthesized via a boron route by (a) preparing a reaction mixture containing (1) a source of germanium oxide; (2) a source of silicon oxide; (3) a source of boron; (4) a source of 1,3-bis(2,3-dimethyl-1H-imidazolium) propane dication (Q); (5) a source of fluoride ions; and (6) water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve. The SDA can then be removed either by calcination or ozonation. The calcined crystals of the molecular sieve having boron within the framework are then treated to replace at least most of the boron sites with aluminum, thereby providing an SSZ-113 molecular sieve having increased acid sites. Some of the boron will remain within the molecular sieve. The amount generally ranges from 50 to 250 ppm.

[0017] The reaction mixture for forming the boron SSZ-113 molecular sieve can have a composition within the following ranges with respect to molar ratios: [Table 1]

[0018] Suitable sources of germanium oxide include germanium oxide, germanium alkoxide (e.g., germanium ethoxide), germanium hydroxide, and germanium carboxylate.

[0019] Suitable sources of silicon oxide include colloidal silica, fumed silica, precipitated silica, alkali metal silicate, and tetraalkyl orthosilicate. For example, FAU framework type zeolites such as zeolite Y can also provide silicon oxide. The FAU zeolite will exhibit an SiO2 / Al2O3 molar ratio of at least 250, and in one embodiment at least 300, or a molar ratio in the range of 300 to 500.

[0020] The Si:Ge molar ratio can be at least 1:1 (e.g., in the range from 2:1 to 500:1 or further in the range from 5:1 to 100:1). In one embodiment, the ratio can be in the range from 4 to 12, for example, from 6 to 10.

[0021] A suitable source of boron can include boric acid, which is preferred.

[0022] A combined source of silicon oxide and aluminum oxide can be used additionally or alternatively and can include aluminosilicate zeolites (e.g., zeolite Y) and clay or treated clay (e.g., metakaolin).

[0023] For simplicity, Q is the following structure (I): [Chemical formula] and includes the 1,3-bis(2,3-dimethyl-1H-imidazolium) propane dication represented by

[0024] The above-mentioned diquaternary ammonium compound can be easily synthesized by reacting 1,3-dihalopropane (e.g., 1,3-dibromopropane or 1,3-diiodopropane) with 1,2-dimethylimidazole by a method known in the art (for example, see S.I. Zones et al., J. Mater. Chem. 2005, 15, 4215-4223).

[0025] A preferred source of Q is the hydroxide and / or other salts of the diquaternary ammonium compound or a mixture thereof.

[0026] Suitable sources of fluoride ions include hydrogen fluoride, ammonium fluoride, and ammonium bifluoride.

[0027] The reaction mixture may contain seed crystals of a boron SSZ-113 molecular sieve material, such as boron SSZ-113 obtained from a previous synthesis, in an amount of 0.01 to 10,000 weight ppm (e.g., 100 to 5000 weight ppm) of the reaction mixture. The addition of seed crystals can be advantageous in reducing the time required for complete crystallization. Further, the addition of seed crystals can result in an increase in the purity of the resulting product by promoting the nucleation and / or formation of boron SSZ-113 over undesirable phases.

[0028] In each embodiment described herein, the molecular sieve reaction mixture can be supplied by two or more sources. Also, two or more reaction components can be provided by one source.

[0029] The reaction mixture can be prepared batchwise or continuously. The crystal size, morphology, and crystallization time of the molecular sieves described herein can vary depending on the nature of the reaction mixture and the crystallization conditions.

[0030] Crystallization and Synthetic Post-Treatment In line with the boron pathway, the crystallization of the molecular sieve from the above reaction mixture can be carried out at a temperature of 125 °C to 200 °C in a suitable reactor vessel such as a polypropylene jar or Teflon - processed or stainless - steel autoclave under static, rotating, or stirring conditions for a time sufficient for crystallization to occur at the temperature used, for example, 2 to 20 days. The crystallization is usually carried out in a closed system under autogenous pressure.

[0031] When molecular sieve crystals containing boron are formed, the solid product is recovered from the reaction mixture by standard mechanical separation techniques such as centrifugation or filtration. The crystals are washed with water and then dried to obtain as - synthesized molecular sieve crystals. The drying process is typically carried out at a temperature below 200 °C.

[0032] As a result of the crystallization process, the recovered crystalline molecular sieve product contains at least a portion of the organic structure - directing agent used in the synthesis within its pore structure. The molecular sieves described herein can be subjected to subsequent treatments to remove some or all of the structure - directing agent (Q) used in their synthesis.

[0033] Removal of the structure - directing agent can conveniently be effected by a heat treatment in which the as - synthesized material can be heated at a temperature of at least 370 °C for at least 1 minute and less than 24 hours. The heat treatment can be carried out at a temperature up to 925 °C. Pressures lower than atmospheric pressure and / or higher than atmospheric pressure can be utilized for the heat treatment, although atmospheric pressure may typically be desirable for simplicity.

[0034] Furthermore, or alternatively, the organic structure - directing agent can be removed by treatment with ozone (see, for example, A.N. Parikh et al., Micropor. Mesopor. Mater. 2004, 76, 17 - 22). In one embodiment, treatment with ozone is preferred in that it can give a higher micropore volume.

[0035] Next, the boron SSZ-113 molecular sieve crystals can be treated to replace at least a part of the boron, preferably almost all (90%) but not all of the boron, with aluminum. In one embodiment, the amount of boron remaining after the exchange can be an amount in the range of 50 to 250 ppm. For example, conventional techniques such as ion exchange can be used. However, treating the molecular sieve with an aqueous aluminum nitrate solution is a preferred way to replace boron in the framework with aluminum. The treatment can be carried out by contacting the molecular sieve with a refluxing aluminum nitrate solution.

[0036] Particularly, the SSZ-113 molecular sieve with increased acid sites in its metal, hydrogen, and ammonium forms is particularly useful in the catalysis of certain organic (e.g., hydrocarbon) conversion reactions. In the present disclosure, the hydrogen form of the organic-free molecular sieve is referred to as the "active form" of the molecular sieve regardless of the presence of a metal function.

[0037] Characterization of the Molecular Sieve The final molecular sieve SSZ-113 with increased acid may have a chemical composition including the following molar relationships: [Table 2]

[0038] This molecular sieve SSZ-113 exhibits its characteristic XRD pattern and also has increased acid sites. Some residual boron also remains in the structure. In one aspect, this molecular sieve has the following molar relationship: Al2O3:(n)(SiO2+GeO2) (where n is ≥ 20). In one embodiment, n in the above relationship ranges from 20 to 600.

[0039] The highly acidic SSZ-113 molecular sieve obtained after the aluminum exchange treatment will have a powder XRD pattern that includes at least the peaks in Table 3, although the molecular sieve also contains some boron and an increased acidity.

Table 3

[0040] As will be understood by those skilled in the art, the measurement of the parameter 2-theta (2θ) is subject to both human error and mechanical error, which can combine to give an uncertainty of about ±0.30° to each reported value of 2-theta. The relative intensity (100xI / I o ) is recorded as the ratio of the peak intensity to the intensity of the strongest peak designated as a value of 100. The relative intensities of the c1-spacing are indicated by the notations VS, S, M, and W, representing very strong, strong, medium, and weak, respectively. For relative intensities, the above names are such that W (weak) is less than 20; M (medium) is greater than 20 and less than 40; S (strong) is from 40 to less than 60; VS (very strong) is 60. When the intensity is close to an endpoint of a range, the intensity can be characterized as being within either side of that range. For example, an intensity of 18 - 22 can be listed as W - M. However, due to fluctuations in the intensity of the lines, as is known in the art, one or more lines can have intensities in the adjacent ranges.

[0041] 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 intensities of the peaks (adjusted with respect to the background), and the lattice plane spacing d corresponding to the recorded lines could be calculated.

[0042] 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 small shifts in the XRD pattern. Despite these small perturbations, the basic crystal lattice structure remains unchanged.

[0043] The increased acidity of the molecular sieve can be measured, for example, by measuring its Bronsted acidity.

[0044] Adsorption and Catalysis Molecular sieve SSZ-113 having increased acid sites can be used as an adsorbent or as a catalyst to catalyze a variety of organic compound conversion methods, including many that are currently of commercial / industrial importance. Examples of chemical conversion methods effectively catalyzed by acid-rich SSZ-113, alone or in combination with one or more other substances that are active as catalysts, including other crystalline catalysts and functional metals, include those that require a catalyst or catalytic metal having acid activity. Examples of organic conversion methods that can be catalyzed by acid-rich SSZ-113 can include, for example, decomposition, hydrocracking, disproportionation, alkylation, oligomerization, and isomerization.

[0045] As with many catalysts, it may be desirable to combine SSZ-113 having increased acid sites with another material that is resistant to temperature and other conditions utilized in the organic conversion process. Such materials can include active and inactive materials as well as synthetic or naturally occurring zeolites and inorganic materials such as clays, silica and / or metal oxides such as alumina. The latter can be naturally occurring or in the form of a gelatinous precipitate or gel containing a mixture of silica and metal oxide. The use of a material combined with the acid-rich and active SSZ-113 (i.e., combined with the new material or present during its synthesis) can tend to change the conversion rate and / or selectivity of the catalyst in a particular organic conversion process. Inactive materials can preferably act as diluents that control the amount of conversion in a given process such that the product can be obtained in an economical and orderly manner without utilizing other means of controlling the rate of the reaction. These materials can be incorporated into naturally occurring clays (e.g., bentonite and kaolin) such that the crushing strength of the catalyst under commercial operating conditions can be improved. These materials (i.e., clays, oxides, etc.) can function as binders for the catalyst. In commercial use, it may be desirable to provide a catalyst having good crushing strength since it may be desirable to prevent the catalyst from crumbling into powdery material (fines). These clay and / or oxide binders have typically only been utilized for the purpose of improving the crushing strength of the catalyst.

[0046] Natural clays that can be combined with acid-rich SSZ-113 include montmorillonite and the kaolin family, which family includes sub-bentonite and kaolins or other materials where the major mineral components are halloysite, kaolinite, dickite, nacrite, or anauxite, commonly known as Dixie, McNamee, Georgia, and Florida clays. Such clays can be used as-mined or can first be subjected to calcination, acid treatment, or chemical modification. Binders useful for combining with acid-rich SSZ-113 can further or alternatively include inorganic oxides such as silica, zirconia, titania, magnesia, beryllia, alumina, and mixtures thereof.

[0047] In addition to or instead of the above materials, acid-rich SSZ-113 can be combined with porous matrix materials such as ternary compositions like silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania, and silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, and silica-magnesia-zirconia.

[0048] The relative ratios of SSZ-113 having increased acid sites to the inorganic oxide matrix can vary widely, and the SSZ-113 content can range from 1 to 90 weight percent (e.g., 2 to 80 weight percent) of the composite.

[0049] Example The following examples are intended to be non-limiting. (Example 1) Add 5 mmol of SDA 1,3-bis(2,3-dimethyl-1H-imidazolium) propane dihydroxide solution to a 23 ml reactor Teflon cup that has been measured by a windbag. Then, add 0.54 grams of Tosoh Corporation's HUA-390 FAU zeolite (SAR of about 500), 0.10 grams of GeO2, and 0.06 grams of H3BO3 (boric acid) to the cup. After evaporating in a hood for several days to reduce the H2O / TO2 ratio to 7, give 0.20 grams of 50% HF to the reactants, then seal and heat at 160 °C for 7 days while rotating at 43 RPM. After cooling and collecting the sample from filtration and washing, the XRD data shows that it is that of SSZ-113.

[0050] Next, the as-produced borongermanosilicate SSZ-113 can be calcined at 540 °C in air using a lamp program of holding from 1 °C to 120 °C / min for 2 hours, holding at 540 °C for 4 hours at 1 °C / min, and cooling in an oven.

[0051] The XRD pattern basically remains unchanged.

[0052] Next, perform a treatment to replace B with Al. Put 0.26 grams of calcined boron SSZ-113 into a glass vial with 10 ml of water, and then heat 0.30 grams of aluminum nitrate (nonahydrate). Seal the vial and heat statically at 95 °C for 2 days. After cooling, filter and then wash with HCL with a pH of 2 before distilled water. The following table shows the changes in elemental analysis before and after calcination and aluminum nitrate treatment:

Table B

[0053] (Example 2) Now, the SSZ-113 of Example 1, in which the treatment of replacing B with Al has been carried out, is measured with respect to acidity. The Bronsted acidity was determined by temperature-programmed desorption (TPD) of n-propylamine, modified from the published descriptions by T.J. Gricus Kofke et al. (J. Catal. 1988, 114, 34-45); T.J. Gricus Kofke et al. (J. Catal. 1989, 115, 265-272); and J.G. Tittensor et al. (J. Catal. 1992, 138, 714-720). The sample was pretreated in a dry H2 flow at 400 °C to 500 °C for 1 hour. Then, the dehydrated sample was cooled to 120 °C in a dry helium flow and maintained for adsorption in a helium flow saturated with n-propylamine at 120 °C for 30 minutes. Next, the n-propylamine-saturated sample was heated in a dry helium flow at a rate of 10 °C / min up to 500 °C. The Bronsted acidity was calculated based on the weight loss with respect to temperature by thermogravimetric analysis (TGA) and the effluent NH3 and propene by mass spectrometry. It is found that the material has strong acid sites. The desorption data of the peak around 400 °C corresponds to a measured value of 200 micromoles of amine per gram.

[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 recited elements but do not necessarily exclude other unrecited elements. The phrase "consists essentially of" or "consisting essentially of" is intended to mean the exclusion of other elements that have 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 elements other than those recited, 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 practicing the present invention and are included herein merely for the sake of example or for the completeness of one or more embodiments. Further, it will be understood that the specific structures, functions, and operations described in the above-cited patents and publications can be practiced in conjunction with the present invention, but they are not essential for its practice. Accordingly, it is 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. An X-ray diffraction pattern containing the peaks listed in the following table: 【Table A】 A molecular sieve having an X-ray diffraction pattern containing the peaks listed in the following table, containing boron, and having increased acid sites.

2. The following molar relationship: Al ２ O ３ :(n)(SiO ２ + GeO ２ ) (where n is at least 20) The molecular sieve according to claim 1, having a composition containing the following molar relationship:

3. The following molar relationship: Al ２ O ３ :(n)(SiO ２ +GeO ２ ) (where n ranges from 20 to 600) The molecular sieve according to claim 1, having a composition containing the following molar relationship:

4. The following molar relationship: 【Table B】 The molecular sieve according to claim 1, having a composition containing the following molar relationship:

5. The following molar relationship: 【Table C】 The molecular sieve according to claim 4, having a composition containing the following molar relationship:

6. A method for synthesizing the molecular sieve according to claim 1, comprising: (a) preparing a reaction mixture containing the following: (1) a source of germanium oxide; (2) a source of silicon oxide; (3) a source of boron; (4) a source of 1,3-bis(2,3-dimethyl-1H-imidazolium) propane dication (Q); (5) a source of fluoride ions; and (6) water; (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of a boron-containing molecular sieve; (c) removing at least a portion of Q; and (d) replacing a portion of the boron in the molecular sieve crystals obtained from (c) with aluminum The above method.

7. The method according to claim 6, wherein the reaction mixture has a composition as follows with respect to the molar ratio: 【Table D】

8. The method according to claim 6, wherein the reaction mixture has a composition as follows with respect to the molar ratio: 【Table E】

9. wherein said source of silicon oxide comprises zeolite Y having an SiO ２ / Al ２ O ３ ratio of at least 300, the method according to claim 6.

10. The method according to claim 6, wherein the crystallization conditions include a temperature of 125°C to 200°C.

11. The method according to claim 6, wherein Q is removed by calcination.

12. The method according to claim 6, wherein Q is removed by treatment with ozone.

13. The method according to claim 6, wherein replacing boron with aluminum includes refluxing the molecular sieve crystals with a solution of aluminum nitrate.

14. A method for converting a raw material containing an organic compound into a conversion product, comprising contacting the raw material with a catalyst containing the molecular sieve in the active form according to claim 1 under organic compound conversion conditions.

15. An SSZ-113 molecular sieve prepared by the method according to claim 6.

16. SSZ-113 molecular sieve prepared by the method according to claim 7.

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