High-silicon EMT molecular sieve as well as synthesis method and application thereof

Abstract

The invention discloses a high-silicon EMT molecular sieve as well as a synthesis method and application thereof, and belongs to the technical field of molecular sieves. The synthesis method of the EMT molecular sieve comprises the following steps: a) mixing an aluminum source A1, a silicon source Si1, an alkali metal source M1, an organic template agent R1 and water to obtain a raw material I, and aging the raw material I to obtain a guiding agent; b) mixing an aluminum source A2, a silicon source Si2, an alkali metal source M2, an organic template agent R2 and water to obtain a raw material II, namely initial gel; and c) adding the guiding agent into the initial gel, uniformly stirring, and crystallizing in a sealed reaction kettle to obtain the high-silicon EMT molecular sieve with the EMT topological structure. The EMT molecular sieve provided by the invention has a silicon-aluminum oxide ratio of 7-30, high crystallinity and purity, and good hydrothermal / thermal stability, can be used for catalytic reactions such as production of high-octane gasoline by alkylation of isobutane / 2-butene, and has important significance in actual chemical production.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular sieve synthesis, and in particular to a high-silicon EMT molecular sieve and a synthesis method and application thereof. Background Art

[0002] Although Moor et al. predicted as early as 1964 that in addition to cubic stacking (FAU), faujasite can also produce another structure through hexagonal stacking, which was later named EMT, and in the following decades, some materials with code names CSZ-1, CSZ-3, ECR-30, ECR-35, ZSM-2, ZSM-3, and ZSM-20 were reported one after another. They are all mixed growth materials of FAU and EMT, but due to factors such as the lack of pure hexagonal products and limited characterization methods, they have not attracted enough attention. It was not until Delproto et al. used crown ether as a directing agent to synthesize pure hexagonal faujasite (EMT), because it has straight through pores in the two-dimensional direction and has a higher initial synthetic silicon-aluminum ratio than FAU, that it has aroused widespread research interest. There have been many reports on the application of this large-pore zeolite with good industrial application prospects in catalysis and adsorption. In particular, in the catalytic reaction of isobutane / 2-butene alkylation to produce high-octane gasoline, EMT zeolite showed catalytic performance superior to FAU.

[0003] However, the application of EMT is limited by the necessity of using excessive amounts of highly toxic and expensive template agents during synthesis, as well as the huge energy consumption caused by the long crystallization time. Therefore, it is of great practical significance to use non-toxic and inexpensive template agents to replace 18-crown-6 ether to directly synthesize EMT zeolites. Summary of the invention

[0004] In view of this, the present invention provides a high-silicon EMT molecular sieve and a synthesis method and application thereof, the main purpose of which is to solve the technical problems of low silicon-to-aluminum ratio, low purity and crystallinity, and poor environmental protection of the EMT molecular sieve.

[0005] In one aspect, the present invention provides a high-silicon EMT molecular sieve, whose anhydrous chemical structure is Formula I:

[0006] kM·mR 1 ·nR 2 ·(Si x Al EMT )O2 Formula I;

[0007] Wherein, M is selected from at least one of alkali metal elements;

[0008] R 1 , R 2 is an organic template; R 1 , R2 Each is independently selected from one of the quaternary phosphorus compounds;

[0009] k is per mole (Si x Al EMT ) The number of moles of the alkali metal element M corresponding to O2, k = 0 to 0.20;

[0010] m and n are respectively per mole (Si x Al EMT ) O2 corresponding template R 1 , R 2 The number of moles, m = 0.01 ~ 0.20, n = 0.01 ~ 0.20;

[0011] x and EMT are the molar fractions of Si and Al respectively, 2x / EMT=7-40, and x+EMT=1.

[0012] The high-silicon EMT molecular sieve with an EMT topological structure provided by the present invention has a silicon-aluminum oxide ratio of 7 to 30, and the molecular sieve has high crystallinity and purity and good hydrothermal / thermal stability.

[0013] Optionally, the structural formula of the quaternary phosphorus compound is Formula II:

[0014]

[0015] In formula II, R 21 , R 22 , R 23 and R 24 Each independently selected from C1 to C 12 Alkyl, C1~C 12 Alkoxy, C1~C 12 Hydroxyalkyl, C7~C 12 Phenyl alkyl, C7~C 12 Alkylphenyl or adamantyl;

[0016] X n- Selected from OH - , Cl - Br - ,I - 、NO3 - 、HSO4 - 、H2PO3 - 、SO4 2- 、HPO3 2- or PO3 3- ;

[0017] Optionally, M in Formula I is selected from at least one of Na, K, and Cs; 2x / EMT=8-30.

[0018] Optionally, 2x / EMT is selected from any value of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 and 30, or a range between any two of them.

[0019] Optionally, the high-silicon EMT molecular sieve has an EMT topological structure, and a silicon-aluminum oxide ratio of the molecular sieve is 7-30.

[0020] Optionally, the silicon aluminum oxide ratio of the molecular sieve is selected from any value of 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 and 30, or any range between two values.

[0021] Optionally, R in Formula I 1 , R 2 Each is independently selected from at least one of tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

[0022] Optionally, R in Formula I 1 At least one selected from tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, and tetrapropyl phosphonium hydroxide;

[0023] R in Formula I 2 At least one selected from tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

[0024] In a second aspect, the present invention provides a method for synthesizing a high-silicon EMT molecular sieve, comprising the following steps:

[0025] a) adding an aluminum source A 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water to obtain a mixture I, and the mixture I is aged to obtain a directing agent;

[0026] The aluminum source A in the mixture I 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water have the following molar ratios:

[0027] SiO2 / Al2O3=5-30;

[0028] M 1 2O / Al2O3=0~7,where M 1 At least one selected from alkali metal elements;

[0029] R 1 / Al2O3=1-40;

[0030] H2O / Al2O3=100-600;

[0031] b) adding an aluminum source A 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 and water raw materials to obtain an initial gel;

[0032] The aluminum source A in the initial gel 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 and water have the following molar ratios:

[0033] SiO2 / Al2O3=10-200;

[0034] M 2 2O / Al2O3=0~30,where M 2 At least one selected from alkali metal elements;

[0035] R 2 / Al2O3=1~45;

[0036] H2O / Al2O3=100-8000;

[0037] c) adding the directing agent in step a) to the initial gel in step b) to form a synthetic gel, and crystallizing the synthetic gel under closed conditions to obtain a high-silicon EMT molecular sieve with an EMT topological structure;

[0038] Among them, the silicon source Si 1 、Silicon source Si 2 The number of moles is based on SiO2;

[0039] Aluminum source A 1 、Aluminum source A 2 The number of moles is calculated as Al2O3;

[0040] Template R 1 、Template R 2 The number of moles is R 1 , R 2 The number of moles itself;

[0041] Alkali metal source M 1 The number of moles of the corresponding alkali metal M 1 Metal oxide M 1 2O moles;

[0042] Alkali metal source M 2 The number of moles of the corresponding alkali metal M 2 Metal oxide M 2 2O in moles.

[0043] The invention provides a method for synthesizing a high-silicon EMT molecular sieve with an EMT topological structure, which promotes the synthesis of a high-silicon (silicon-aluminum oxide ratio of 7 to 30) EMT molecular sieve by adding a directing agent solution into a synthetic gel system and introducing an organic template into the synthetic gel system.

[0044] Optionally, the silicon source Si in step a) 1 and the silicon source Si in step b) 2 Each independently selected from at least one of methyl orthosilicate, ethyl orthosilicate, silica sol, solid silica gel, white carbon black and sodium silicate;

[0045] The aluminum source A in step a) 1 and the aluminum source A in step b) 2 Each independently selected from at least one of sodium aluminate, aluminum oxide, aluminum hydroxide, aluminum isopropoxide, aluminum 2-butoxide, aluminum chloride, aluminum sulfate, aluminum nitrate and pseudo-boehmite;

[0046] The alkali metal source M in step a) 1 and the alkali metal source M in step b) 2 Each is independently selected from at least one of sodium hydroxide, potassium hydroxide and cesium hydroxide.

[0047] Optionally, the organic template R in step a) 1 and the organic template R in step b) 2 Each is independently selected from one of the quaternary phosphorus compounds;

[0048] The structural formula of the quaternary phosphorus compound is shown in Formula II;

[0049]

[0050] Among them, R in Formula II 21 , R 22 , R 23 and R 24 Each independently selected from C1 to C 12 Alkyl, C1~C 12 Alkoxy, C1~C 12 A hydroxyalkyl group, an aryl group or an adamantyl group;

[0051] X n- Selected from OH - , Cl - Br - ,I - 、NO3 - 、HSO4 - 、H2PO3 - 、SO4 2- 、HPO3 2- or PO3 3- .

[0052] Optionally, the “C1~C 12 "C7~C 12 Phenylalkyl".

[0053] Optionally, the "aryl" includes "C7~C 12 "

[0054] Optionally, the "C7~C 12 "Aryl" includes "C7~C 12 "Alkyl aryl".

[0055] Optionally, the organic template R in step a) 1 and the organic template R in step b) 2Each is independently selected from at least one of tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

[0056] Optionally, the organic template R in step a) 1 At least one selected from tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, and tetrapropyl phosphonium hydroxide;

[0057] The organic template R in step b) 2 At least one selected from tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

[0058] Optionally, in step a), the aging temperature is 25 to 140° C., and the aging time is 0.5 to 30 days.

[0059] Optionally, in step a), the aging is carried out in two stages, the first stage aging temperature is 30-40°C, and the first stage aging time is 0.5-5 days; the second stage aging temperature is 50-100°C, and the second stage aging time is 2-8 days.

[0060] Optionally, step a) comprises: adding an aluminum source A 1 , alkali metal source M 1 , organic template R 1 Mix well with water and add silicon source S 1 The mixture is stirred and then aged at a temperature of 25 to 140° C. for 1 to 30 days to obtain a directing agent.

[0061] When preparing the directing agent, the present invention can induce crystallization through an aging step to promote the synthesis of high-silicon EMT molecular sieve.

[0062] Optionally, in step a), the aging temperature is selected from any value among 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 110°C, 120°C, 130°C and 140°C, or any range between two values.

[0063] Optionally, in step a), the aging time is selected from any value of 0.5 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 18 days, 20 days, 25 days and 30 days, or any range value therebetween.

[0064] Optionally, the aging method in step a) is static placement and / or rotation.

[0065] Optionally, in step a), the aluminum source A 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water have the following molar ratios:

[0066] SiO2 / Al2O3=5-30;

[0067] M 1 2O / Al2O3=0~5,where M 1 At least one selected from alkali metal elements;

[0068] R 1 / Al2O3=5~40;

[0069] H2O / Al2O3=100~600.

[0070] Optionally, in step a), the molar ratio of SiO2 / Al2O3 is selected from any value among 5.0, 6.0, 7.0, 8.0, 9.0, 10, 11, 12, 13, 14, 15, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 and 30, or any range between two values.

[0071] Optionally, in step a), the molar ratio of M2O / Al2O3 is selected from any value among 0.1, 0.5, 1.8, 2.0, 3.0, 4.0, 4.5, 4.8 and 5.0 or any range between two values.

[0072] Optionally, in step a), R 1The molar ratio of / Al2O3 is selected from any value among 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 22, 25, 28, 29, 30, 32, 35, 34, 38 and 40, or any range therebetween.

[0073] Optionally, the molar ratio of H2O / Al2O3 in step a) is selected from any value among 100, 150, 180, 200, 250, 300, 350, 400, 450, 500, 550 and 600 or any range therebetween.

[0074] Optionally, step b) comprises: adding an aluminum source A 1 , alkali metal source M 1 , organic template R 2 Mix well with water and add silicon source Si 2 , add directing agent, mix and prepare initial gel.

[0075] Optionally, the aluminum source A in step b) 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 and water have the following molar ratios:

[0076] SiO2 / Al2O3=10-200;

[0077] M 2 2O / Al2O3=0~30,where M 2 At least one selected from alkali metal elements;

[0078] R 2 / Al2O3=1~45;

[0079] H2O / Al2O3=100~6000.

[0080] Optionally, in step b), the molar ratio of SiO2 / Al2O3 is selected from any value among 10, 15, 20, 30, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 and 200, or any range between two values.

[0081] Optionally, in step b), the molar ratio of M2O / Al2O3 is selected from any value among 0.1, 1.8, 2.0, 3.0, 4.0, 4.5, 4.8, 5.0, 6.0, 7.0, 8.0, 9.0, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 22, 25, 28 and 30, or any range between two values.

[0082] Optionally, the molar ratio of R / Al2O3 is selected from any value among 1, 2, 3, 3.6, 4, 4.5, 4.8, 5, 5.2, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 22, 25, 28, 29, 30, 32, 35, 38, 40, 42 and 45, or any range therebetween.

[0083] Optionally, the molar ratio of H2O / Al2O3 is selected from any value among 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3200, 3500, 3800, 4000, 5000 and 6000, or any range therebetween.

[0084] Optionally, in step c), the mass ratio of silicon dioxide in the directing agent to silicon dioxide in the initial gel is 0.05-0.3:1.

[0085] Optionally, in step c), the mass ratio of silica in the directing agent to silica in the initial gel is any ratio among 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1, 0.16:1, 0.15:1, 0.20:1, 0.25:1, 0.30:1, and the range value between any two of the ratios.

[0086] Optionally, in step c), the crystallization temperature is 90 to 180° C., and the crystallization time is 1 to 15 days.

[0087] Optionally, the crystallization temperature in step c) is 90-180° C., and the crystallization time is 2-15 days.

[0088] Optionally, the crystallization temperature in step c) is selected from any value among 90°C, 100°C, 110°C, 140°C, 150°C, 160°C and 180°C, or any range between two of them.

[0089] Optionally, the crystallization time in step c) is selected from any value among 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days and 15 days, or any range between two of them.

[0090] Optionally, in step c), the crystallization method is dynamic crystallization and / or static crystallization.

[0091] Optionally, the crystallization method in step c) is rotational crystallization.

[0092] Optionally, in step c), the synthetic gel is crystallized in a sealed reactor at a crystallization temperature of 90 to 140° C. for 3 to 15 days; after the crystallization is completed, the obtained solid is separated, washed, and dried to obtain the high-silicon EMT molecular sieve having an EMT topological structure.

[0093] As a specific implementation, the method comprises the following steps:

[0094] a) adding an aluminum source A 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water to obtain a mixture I, and the mixture I is aged to obtain a directing agent;

[0095] Aluminum source A in the mixture I 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water have the following molar ratios:

[0096] SiO2 / Al2O3=5-30;

[0097] M 1 2O / Al2O3=0~5,where M 1 At least one selected from alkali metal elements;

[0098] R 1 / Al2O3=5~40;

[0099] H2O / Al2O3=100-600;

[0100] b) adding an aluminum source A 2 、Silicon source Si 2 , alkali metal source M2 , organic template R 2 Mixing the raw materials with water to obtain an initial gel;

[0101] The aluminum source A in the initial gel 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 , water has the following molar ratio:

[0102] SiO2 / Al2O3=10-200;

[0103] M 2 2O / Al2O3=0~30,where M 2 At least one selected from alkali metal elements;

[0104] R 2 / Al2O3=1~45;

[0105] H2O / Al2O3=100-6000;

[0106] c) adding the directing agent in step a) to the initial gel in step b), mixing evenly and placing in a sealed reactor for crystallization, the crystallization temperature is 90-180° C., and the crystallization time is 2-15 days; after the crystallization is completed, the obtained solid is separated, washed, and dried to obtain the high-silicon EMT molecular sieve with an EMT topological structure;

[0107] Among them, the silicon source Si 1 、Si 2 The molar number of SiO2 is calculated; the aluminum source A 1 , A 2 The molar number of Al2O3; template R 1 , R 2 The number of moles is R 1 , R 2 The molar number of itself; alkali metal source M 1 、M 2 The number of moles of the corresponding alkali metal M 1 、M 2 The corresponding metal oxide M 1 2O, M 2 2O mole count.

[0108] As a specific implementation method, the synthesis process of the high-silicon EMT molecular sieve is as follows:

[0109] a) Preparation of directing agent: aluminum source, silicon source, organic template R 1 and deionized water according to 1Al2O3:(5~30)SiO2:(0~7)M 12O:(1~40)R 1 :(100-600)H2O in a molar ratio, stirring for 2 hours to obtain a uniform mixture, and then continuing to stir / stand at 25-140°C for 1-30 days to obtain a directing agent;

[0110] b) Preparation of synthetic gel: aluminum source, silicon source, sodium hydroxide, organic template R 2 and deionized water in the following proportions:

[0111] SiO2 / Al2O3=10-200;

[0112] M 2 2O / Al2O3=0~30,where M 2 At least one selected from alkali metal elements;

[0113] R 2 / Al2O3=1~45;

[0114] H2O / Al2O3=100-8000;

[0115] Mix and stir evenly at room temperature to obtain an initial gel, then add a certain amount of the directing agent in step a) and stir for 1 to 4 hours to obtain a synthetic gel;

[0116] c) Synthesis of high-silicon EMT molecular sieve: The above synthetic gel is crystallized at 90-180° C. under autogenous pressure for 2-15 days. After the crystallization is completed, the solid product is separated by filtration, washed with deionized water until neutral, and dried to obtain a high-silicon EMT molecular sieve.

[0117] In a third aspect, the present invention provides a catalyst, which includes the above-mentioned high-silicon EMT molecular sieve or the high-silicon EMT molecular sieve with an EMT topological structure prepared by the above-mentioned method.

[0118] In a fourth aspect, the present invention provides the use of the above-mentioned high-silicon EMT molecular sieve or the high-silicon EMT molecular sieve with EMT topological structure prepared by the above-mentioned method or the above-mentioned catalyst in the alkylation of isobutane / 2-butene to produce high-octane gasoline.

[0119] In this application, C1~C 12 、C7~C 12 etc. all refer to the number of carbon atoms contained. 12 The term "alkyl" refers to an alkyl group having 1 to 4 carbon atoms.

[0120] In the present application, "alkyl" refers to a group formed by losing any hydrogen atom from an alkane compound molecule. The alkane compound includes straight-chain alkanes, branched-chain alkanes, cycloalkanes, and branched cycloalkanes.

[0121] In the present application, "alkoxy" refers to a group formed by losing a hydrogen atom from an OH group on an alkyl alcohol compound molecule, such as a methoxy group -OCH3 formed by losing a hydrogen atom from an OH group on a CH3OH molecule.

[0122] In the present application, "hydroxyalkyl" refers to a group formed by losing any hydrogen atom on a non-OH group on an alkyl alcohol compound molecule, such as hydroxymethyl HOCH2- formed by losing a hydrogen atom on a methyl group on a CH3OH molecule.

[0123] In the present application, "aryl" is a group formed by losing a hydrogen atom on an aromatic ring in an aromatic compound molecule; for example, toluene loses a hydrogen atom at the para position of the methyl group on the benzene ring to form p-tolyl.

[0124] In the present application, "alkylphenyl" is a group formed when a benzene ring containing a substituent loses a hydrogen atom; for example, toluene loses a hydrogen atom at the para position of the methyl group on the benzene ring to form p-tolyl.

[0125] In the present application, "phenylalkyl" is a group formed by the loss of any hydrogen atom from an alkyl substituent on a benzene ring; for example, a benzyl group (benzyl) is formed by the loss of a hydrogen atom from a methyl group on toluene.

[0126] Compared with the prior art, the present invention has the following beneficial effects:

[0127] 1) The present invention synthesizes a high-silicon EMT molecular sieve with a silicon-aluminum oxide ratio of 7 to 30 by introducing an organic template agent into a synthetic gel and adding a directing agent.

[0128] 2) The high silicon-aluminum ratio EMT molecular sieve synthesized by the present invention has high crystallinity and purity, good hydrothermal / thermal stability, and can be used for catalytic reactions such as isobutane / 2-butene alkylation to produce high-octane gasoline, which is of great significance in the field of actual chemical production. BRIEF DESCRIPTION OF THE DRAWINGS

[0129] Figure 1 is the X-ray diffraction (XRD) spectrum of sample EMT1 of Example 1 of the present invention;

[0130] Figure 2 is a scanning electron microscope (SEM) image of sample EMT1 of Example 1 of the present invention;

[0131] Figure 3 is the silicon nuclear magnetic resonance ( 29 Si-NMR) spectrum;

[0132] Figure 4 is the X-ray diffraction (XRD) spectrum of sample S1 of comparative example 1 of the present invention;

[0133] Figure 5It is the X-ray diffraction (XRD) spectrum of sample T1 of comparative example 2 of the present invention. DETAILED DESCRIPTION

[0134] The present application is further described below in conjunction with specific embodiments. The following are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application discloses the following preferred embodiments, they are not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the above disclosed technical content to make some changes or modifications are equivalent to equivalent implementation cases and are within the scope of the technical solution.

[0135] The analysis method in the examples of this application is as follows:

[0136] The X-ray powder diffraction phase analysis (XRD) of the product was carried out using an X'Pert PRO X-ray diffractometer from PANalytical of the Netherlands, with a Cu target, a Kα radiation source (λ=0.15418 nm), a voltage of 40 KV, and a current of 40 mA.

[0137] The instrument used for scanning electron microscopy (SEM) testing is Hitachi SU8020 field emission scanning electron microscope with an accelerating voltage of 2 kV.

[0138] The elemental composition was determined using a Philips Magix 2424 X-ray fluorescence analyzer (XRF).

[0139] Silicon NMR ( 29 Si MAS NMR experiments were performed on a Bruker Avance III 600 (14.1 Tesla) spectrometer using a 7 mm double resonance probe at 8 kHz. A high power proton decoupling program was used, with 1024 samples, a π / 4 pulse width of 2.5 μs, a sampling delay of 10 s, and 4,4-dimethyl-4-propanesulfonic acid sodium (DSS) as the chemical shift reference, calibrated to 0 ppm.

[0140] Carbon NMR ( 13 C MAS NMR experiments were performed on a Bruker Avance III 600 (14.1 Tesla) spectrometer using a 4 mm triple resonance probe at a rotation speed of 12 kHz and adamantane as the chemical shift reference, calibrated to 0 ppm.

[0141] Example 1 (Preparation of sample EMT1)

[0142] Preparation of directing agent: 1.3g sodium hydroxide (analytical grade, Tianjin Komiou Chemical Reagent Co., Ltd.) and 1.7g aluminum oxide (chemically pure, China Pharmaceutical (Group) Shanghai Chemical Reagent Co., Ltd.) were dissolved in 84.1g tetraethyl phosphonium hydroxide (35wt% aqueous solution, Aladdin Reagent (Shanghai) Co., Ltd.) and stirred until clear, then 34.7g ethyl orthosilicate (chemically pure, China Pharmaceutical (Group) Shanghai Chemical Reagent Co., Ltd.) was added dropwise and stirred for 2h. The above solution was aged at 50°C for 12h and then transferred to 100°C and allowed to stand for 48h.

[0143] Preparation of synthetic gel: 0.7g sodium aluminate (Al2O3: 48.3wt%, Na2O: 36.3wt%, China Pharmaceutical (Group) Shanghai Chemical Reagent Company), 0.20g sodium hydroxide, 9.8g tetrapropyl phosphine hydroxide (25wt%) were dissolved in 4.8g deionized water and stirred until clear, and 14.7g silica sol (SiO2: 30wt%, Shenyang Chemical Co., Ltd.) was added dropwise and stirred for 2h, and then 4.9g of the above-mentioned directing agent was added and stirred for 3h.

[0144] Synthesis of high-silica EMT molecular sieve: The synthetic gel was transferred into a stainless steel reactor and crystallized at 130°C for 5 days. After the crystallization, the solid and liquid were separated and washed to neutrality, and dried at 100°C for 12 hours. This was recorded as sample EMT1.

[0145] The X-ray powder diffraction pattern (XRD) of sample 1 is as follows: Figure 1 As shown, it is shown that sample 1 is a molecular sieve with an EMT framework structure. Figure 2 As shown, sample 1 is a thin film structure with a thickness of 50nm to 100nm. 29 Si MAS NMR spectrum Figure 3 As shown in the figure, the framework silicon-aluminum ratio obtained by fitting calculation is consistent with that calculated by XRF. 13 The elemental composition of sample 1 obtained by normalization of C MAS NMR analysis is: 0.07Na·0.02R1 2 0.05R2 1 (Si 0.86 Al 0.14 )O2, where R1 2 is tetraethylphosphonium hydroxide, R2 1 It is tetrapropylphosphonium hydroxide.

[0146] Example 2 (Preparation of samples EMT2 to EMT30)

[0147] The preparation process of samples EMT2-EMT30 is the same as that of Example 1. The types of raw materials, molar ratios, crystallization conditions, product crystal structures and silicon-aluminum ratios (the silicon-aluminum ratios of the products are the results of X-ray fluorescence analyzer (XRF) measurement) are shown in Table 1. The aging temperature, time, aging method, amount of guiding agent added and sample composition of samples EMT2-EMT30 are shown in Table 2.

[0148] Table 1. Raw material types, molar ratios, crystallization conditions, crystal structures and Si / Al ratios of EMT1-EMT30 samples

[0149]

[0150]

[0151]

[0152] Note: Al2O3 1 :Alumina; SiO2 1 :Silica sol; R1 1 : Tetramethylphosphonium hydroxide; R2 1 :Tetrapropylphosphonium hydroxide

[0153] Al2O3 2 :Aluminum isopropoxide; SiO2 2 : Ethyl orthosilicate; R1 2 : Tetraethyl phosphine hydroxide; R2 2 :Triethylhexyl phosphonium hydroxide

[0154] Al2O3 3 :Sodium aluminate; SiO2 3 :White carbon black; R1 3 : Tetrapropylphosphonium hydroxide; R2 3 :Triethylbenzylphosphonium hydroxide

[0155] Al2O3 4 :Aluminum nitrate; SiO2 4 :Silica gel; R1 4 : Choline; R2 4 :N,N,N-Tripropylaminobutyric acid phosphonium hydroxide

[0156] Al2O3 5 :2-Butanol Aluminum; R2 5 :Dipropyldibutylphosphonium hydroxide

[0157] Al2O3 6 :Aluminum sulfate; R2 6 : Benzyltripropylphosphonium hydroxide

[0158] Al2O3 7 :Aluminum powder; R27 : Benzyltrimethylphosphonium hydroxide

[0159] R2 8 :Tetrabutylphosphonium hydroxide R2 9 :Tetrahexylphosphonium hydroxide

[0160] R2 10 :Tributyl-hydroxyethyl phosphonium hydroxide R2 11 :Tripropyl-hydroxyethyl phosphonium hydroxide

[0161] Table 2. Aging temperature, time, addition amount and sample composition of EMT1-EMT30 directing agents

[0162]

[0163]

[0164] Note: R1 1 : Tetramethylphosphonium hydroxide; R2 1 :Tetrapropylphosphonium hydroxide

[0165] R1 2 : Tetraethyl phosphine hydroxide; R2 2 :Triethyl-hexylphosphonium hydroxide

[0166] R1 3 : Tetrapropylphosphonium hydroxide; R2 3 :Triethylbenzylphosphonium hydroxide

[0167] R1 4 : Choline; R2 4 :N,N,N-Tripropylaminobutyric acid phosphonium hydroxide

[0168] R2 5 :Dipropyl-dibutylphosphonium hydroxide

[0169] R2 6 :Tripropyl-benzylphosphonium hydroxide

[0170] R2 7 : Benzyltrimethylphosphonium hydroxide

[0171] R2 8 :Tetrabutylphosphonium hydroxide

[0172] R2 9 :Tetrahexylphosphonium hydroxide

[0173] R2 10 :Tributyl-hydroxyethyl phosphonium hydroxide

[0174] R2 11 :Tripropyl-hydroxyethyl phosphonium hydroxide

[0175] Comparative Example 1 (Preparation of Comparative Samples S1 to S30)

[0176] The difference between Comparative Example 1 and Example 1 is that there is no directing agent preparation step in Comparative Example 1, and no directing agent is added in the subsequent gel synthesis step; the specific types of raw materials, molar ratios, batching process and crystallization conditions for synthesizing the gel are the same as those for the preparation of sample 1# in Example 1; the types of raw materials, molar ratios, crystallization conditions and product crystal structures of the products synthesized in the comparative example are detailed in Table 3, and the obtained samples are recorded as comparative samples S1 to S30.

[0177] Table 3. Raw material types, molar ratios, crystallization conditions, and crystal structures of samples S1-S30

[0178]

[0179]

[0180] Note: Al2O3 1 :Alumina; SiO2 1 : Silica sol; R2 1 :Tetrapropylphosphonium hydroxide

[0181] Al2O3 2 :Aluminum isopropoxide; SiO2 2 : Ethyl orthosilicate; R2 2 :Triethyl-hexylphosphonium hydroxide

[0182] Al2O3 3 :Sodium aluminate; SiO2 3 :White carbon black; R2 3 :Triethyl-benzylphosphonium hydroxide

[0183] Al2O3 4 :Aluminum nitrate; SiO2 4 :Silica gel; R2 4 :N,N,N-tripropylammonium hydroxide Al2O3 5 :2-Butanol Aluminum; R2 5 :Dipropyldibutylphosphonium hydroxide

[0184] Al2O3 6 :Aluminum sulfate; R2 6 : Benzyltripropylphosphonium hydroxide

[0185] Al2O3 7 :Aluminum powder; R2 7 : Benzyltrimethylphosphonium hydroxide

[0186] R2 8 :Tetrabutylphosphonium hydroxide R2 9 :Tetrahexylphosphonium hydroxide

[0187] R2 10 :Tributyl-hydroxyethyl phosphonium hydroxide R2 11 :Tripropyl-hydroxyethyl phosphonium hydroxide

[0188] Comparative Example 2 (Preparation of Comparative Samples T1 to T30)

[0189] The difference between Comparative Example 2 and Example 1 is that after the preparation of the directing agent in Comparative Example 2 is completed, it is only stirred at room temperature for 2 hours without aging; the specific raw material types, molar ratios, ingredient process and crystallization conditions are the same as the preparation of sample EMT1 in Example 1; the raw material types, molar ratios, crystallization conditions, the amount of directing agent added, and the product crystal structure of each product synthesized in Comparative Example 2 are detailed in Table 4. The obtained samples are recorded as comparative samples T1 to T30.

[0190] Table 4. Types of raw materials, amount of directing agent added, molar ratio, crystallization conditions and crystal structures of samples T1 to T30

[0191]

[0192]

[0193]

[0194] Note: Al2O3 1 :Alumina; SiO2 1 :Silica sol; R1 1 : Tetramethylphosphonium hydroxide; R2 1 :Tetrapropylphosphonium hydroxide

[0195] Al2O3 2 :Aluminum isopropoxide; SiO2 2 : Ethyl orthosilicate; R1 2 : Tetraethyl phosphine hydroxide; R2 2 :Triethylhexyl phosphonium hydroxide

[0196] Al2O3 3 :Sodium aluminate; SiO2 3 :White carbon black; R1 3 : Tetrapropylphosphonium hydroxide; R2 3 :Triethylbenzylphosphonium hydroxide

[0197] Al2O3 4 :Aluminum nitrate; SiO2 4 :Silica gel; R1 4 : Choline; R2 4 :N,N,N-Tripropylaminobutyric acid phosphonium hydroxide

[0198] Al2O3 5 :2-Butanol Aluminum; R25 :Dipropyldibutylphosphonium hydroxide

[0199] Al2O3 6 :Aluminum sulfate; R2 6 : Benzyltripropylphosphonium hydroxide

[0200] Al2O3 7 :Aluminum powder; R2 7 :choline

[0201] R2 8 :Tetrabutylphosphonium hydroxide

[0202] R2 9 :Tetrahexylphosphonium hydroxide

[0203] R2 10 :Tributyl-hydroxyethyl phosphonium hydroxide

[0204] R2 11 :Tripropyl-hydroxyethyl phosphonium hydroxide

[0205] Example 3 (Characterization and Analysis of Samples EMT1 to EMT30 and Comparative Samples S1 and T1)

[0206] The X-ray diffraction method was used to analyze the phases of samples EMT1~EMT30 and comparative samples S1~S30 and T1~T30.

[0207] The results show that the samples EMT1 to EMT30 prepared in Example 1 and Example 2 are all high-purity and high-crystallinity EMT-type molecular sieves, and typical representatives are as follows Figure 1 XRD spectrum of sample EMT1, Figure 2 is the SEM image of EMT1. Figure 3 is the silicon NMR of EMT1 sample. The XRD spectrum results of samples EMT2-EMT30 are similar to Figure 1 Close, that is, the diffraction peak position and shape are basically the same, and the relative peak intensity fluctuates within the range of ±5% depending on the changes in the synthesis conditions, indicating that samples EMT1-EMT30 have the structural characteristics of EMT-type molecular sieves and are free of impurity crystals.

[0208] The comparative samples S1-S30 and comparative samples T1-T30 in Table 3 and Table 4 are all amorphous, wherein the XRD spectra of comparative sample S1 and comparative sample T1 are as follows: Figure 4 and Figure 5 shown.

[0209] From the above comparison, it can be seen that in the synthesis of high-silicon EMT molecular sieves, the addition of a directing agent is necessary, and the directing agent must be aged at high temperature during its preparation to play a role in inducing crystallization, which is the key to the synthesis of high-silicon EMT molecular sieves.

[0210] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A high-silicon EMT molecular sieve, characterized in that: The anhydrous chemical structure of the high-silicon EMT molecular sieve is Formula I: kM·mR 1 ·nR 2 ·(Si x Al EMT )O2 Formula I; Wherein, M is selected from at least one of alkali metal elements; R 1 , R 2 R is an organic template; 1 , R 2 Each is independently selected from one of the quaternary phosphorus compounds; k is per mole (Si x Al EMT ) The number of moles of the alkali metal element M corresponding to O2, k = 0 to 0.20; m and n are respectively per mole (Si x Al EMT ) O2 corresponding template R 1 , R 2 The number of moles, m = 0.01 ~ 0.20, n = 0.01 ~ 0.20; x and EMT are the molar fractions of Si and Al respectively, 2x / EMT=7-40, and x+EMT=1.

2. A high-silicon EMT molecular sieve according to claim 1, characterized in that: The structural formula of the quaternary phosphorus compound is Formula II: In formula II, R 21 , R 22 , R 23 and R 24 Each independently selected from C1 to C 12 Alkyl, C1~C 12 Alkoxy, C1~C 12 Hydroxyalkyl, C7~C 12 Phenyl alkyl, C7~C 12 Alkylphenyl or adamantyl; X n- Selected from OH - , Cl - Br - ,I - 、NO3 - 、HSO4 - 、H2PO3 - 、SO4 2- 、HPO3 2- or PO3 3- ; Preferably, M in Formula I is selected from at least one of Na, K, and Cs; 2x / EMT=8-30; Preferably, the high-silicon EMT molecular sieve has an EMT topological structure, and the silicon-aluminum oxide ratio of the molecular sieve is 7 to 30; Preferably, R in Formula I 1 , R 2 each independently selected from at least one of tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride; Preferably, R in Formula I 1 At least one selected from tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, and tetrapropyl phosphonium hydroxide; R in Formula I 2 At least one selected from tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

3. A method for synthesizing a high-silicon EMT molecular sieve according to claim 1 or 2, characterized in that: The following steps are involved: a) adding an aluminum source A 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water to obtain a mixture I, and the mixture I is aged to obtain a directing agent; The aluminum source A in the mixture I 1 、Silicon source Si 1 , alkali metal source M 1 , organic template R 1 and water in the following molar ratio: SiO2 / Al2O3=5-30; M 1 2O / Al2O3=0~7,where M 1 At least one selected from alkali metal elements; <h2 style=";text-align:left;direction:ltr">R<h2 style=";text-align:left;direction:ltr"> 1 <h2 style=";text-align:left;direction:ltr"> / Al2O3=1~40; H2O / Al2O3=100-600; b) adding an aluminum source A 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 and water raw materials to obtain an initial gel; The aluminum source A in the initial gel 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 and water in the following molar ratio: SiO2 / Al2O3=10-200; M 2 2O / Al2O3=0~30,where M 2 At least one selected from alkali metal elements; <h2 style=";text-align:left;direction:ltr">R<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / Al2O3=1~45; H2O / Al2O3=100-8000; c) adding the directing agent in step a) to the initial gel in step b) to form a synthetic gel, and crystallizing the synthetic gel under closed conditions to obtain a high-silicon EMT molecular sieve with an EMT topological structure; Among them, the silicon source Si 1 、Silicon source Si 2 The number of moles is calculated as SiO2; Aluminum source A 1 、Aluminum source A 2 The number of moles is calculated as Al2O3; Template R 1 、Template R 2 The number of moles is R 1 , R 2 The number of moles itself; Alkali metal source M 1 The number of moles of the corresponding alkali metal M 1 Metal oxide M 1 2O moles; Alkali metal source M 2 The number of moles of the corresponding alkali metal M 2 Metal oxide M 2 2O in moles.

4. The method for synthesizing the high-silicon EMT molecular sieve according to claim 3, characterized in that: The silicon source Si in step a) 1 and the silicon source Si in step b) 2 Each independently selected from at least one of methyl orthosilicate, ethyl orthosilicate, silica sol, solid silica gel, white carbon black and sodium silicate; The aluminum source A in step a) 1 and the aluminum source A in step b) 2 Each independently selected from at least one of sodium aluminate, aluminum oxide, aluminum hydroxide, aluminum isopropoxide, aluminum 2-butoxide, aluminum chloride, aluminum sulfate, aluminum nitrate and pseudo-boehmite; The alkali metal source M in step a) 1 and the alkali metal source M in step b) 2 Each is independently selected from at least one of sodium hydroxide, potassium hydroxide and cesium hydroxide.

5. The method for synthesizing the high-silicon EMT molecular sieve according to claim 3, characterized in that: The organic template R in step a) 1 and the organic template R in step b) 2 Each is independently selected from one of the quaternary phosphorus compounds; The structural formula of the quaternary phosphorus compound is shown in Formula II; Among them, R in Formula II 21 , R 22 , R 23 and R 24 Each independently selected from C1 to C 12 Alkyl, C1~C 12 Alkoxy, C1~C 12 A hydroxyalkyl group, an aryl group or an adamantyl group; X n- Selected from OH - , Cl - Br - ,I - 、NO3 - 、HSO4 - 、H2PO3 - 、SO4 2- 、HPO3 2- or PO3 3- .

6. The method for synthesizing the high-silicon EMT molecular sieve according to claim 3, characterized in that: The organic template R in step a) 1 and the organic template R in step b) 2 Each is independently selected from at least one of tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

7. The method for synthesizing the high-silicon EMT molecular sieve according to claim 3, characterized in that: The organic template R in step a) 1 At least one selected from tetramethyl phosphonium hydroxide, tetraethyl phosphonium hydroxide, and tetrapropyl phosphonium hydroxide; The organic template R in step b) 2 At least one selected from tetraethyl phosphonium hydroxide, tetrapropyl phosphonium hydroxide, tetrabutyl phosphonium hydroxide, tetrapentyl phosphonium hydroxide, tetrahexyl phosphonium hydroxide, tetrapropyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrapentyl phosphonium bromide, tripropyl-isobutyl phosphonium bromide, tributyl-cyclohexyl phosphonium hydroxide, dibutyl-dihexyl phosphonium hydroxide, choline, triethyl-hydroxyethyl phosphonium hydroxide, tripropyl-hydroxyethyl phosphonium hydroxide, tributyl-hydroxyethyl phosphonium hydroxide, tributyl-benzyl phosphonium hydroxide, triethyl-benzyl phosphonium hydroxide, tripropyl-benzyl phosphonium hydroxide, N,N,N-triethyl-adamantyl phosphonium chloride and N,N,N-tripropyl-adamantyl phosphonium chloride.

8. The method for synthesizing the high-silicon EMT molecular sieve according to claim 3, characterized in that: In step a), the aging temperature is 25 to 140° C., and the aging time is 0.5 to 30 days; Preferably, in step a), the aging is performed in two stages, the temperature of the first stage is 30-40°C, and the time of the first stage is 0.5-5 days; the temperature of the second stage is 50-100°C, and the time of the second stage is 2-8 days; Preferably, step a) comprises: adding an aluminum source A 1 , alkali metal source M 1 , organic template R 1 Mix well with water and add silicon source S 1 Stirring and mixing, and then aging at a temperature of 25 to 140° C. for 1 to 30 days to obtain a directing agent; Preferably, in step b), the aluminum source A 2 、Silicon source Si 2 , alkali metal source M 2 , organic template R 2 and water in the following molar ratio: SiO2 / Al2O3=10-200; M 2 2O / Al2O3=0~30,where M 2 At least one selected from alkali metal elements; <h2 style=";text-align:left;direction:ltr">R<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / Al2O3=1~45; H2O / Al2O3=100~6000.

9. The method for synthesizing high-silicon EMT molecular sieve according to claim 1, characterized in that: In step c), the mass ratio of the silicon dioxide in the directing agent to the silicon dioxide in the initial gel is 0.05 to 0.3:1; Preferably, in step c), the crystallization temperature is 90 to 180° C., and the crystallization time is 1 to 15 days; Preferably, in step c), the crystallization method is dynamic crystallization and / or static crystallization.

10. Use of the high-silicon EMT molecular sieve according to any one of claims 1 to 2 or the high-silicon EMT molecular sieve synthesized by the synthesis method according to any one of claims 3 to 9 in the alkylation of isobutane / 2-butene to produce high-octane gasoline.

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