Preparation method and application of eight-membered ring aluminum-rich mordenite nanosheet
By preparing eight-membered ring aluminum-rich mordenite nanosheets, the problem of insufficient catalytic activity and stability of mordenite molecular sieves in carbonylation reactions was solved, achieving higher catalytic performance and reaction selectivity, which is suitable for the separation of gas and liquid mixtures and catalyst support in the petrochemical field.
Patent Information
- Application Number
- CN202511001327.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-21
- Publication Date
- 2025-10-24
AI Technical Summary
Existing mordenite molecular sieves exhibit insufficient catalytic activity and stability in methanol or dimethyl ether carbonylation reactions. The twelve-membered ring channels are prone to olefin side reactions, leading to coking and affecting reaction selectivity and conversion. Conventional post-treatment methods also affect crystallinity and pore structure.
Eight-membered ring aluminum-rich mordenite nanosheets were prepared by mixing silicon source, inorganic base, aluminum source, template agent and metal additive in an ice-water bath, followed by hydrothermal crystallization, centrifugation, calcination and ammonium ion exchange. This process controlled crystal growth and aluminate site distribution, resulting in shorter longitudinal channels in the molecular sieve.
It improves catalytic activity and stability, enhances carbonylation efficiency, reduces side reactions, improves reaction selectivity and stability, and increases specific surface area and product diffusion capacity.
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Figure CN120829167A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of synthesis of molecular sieve catalytic materials, and particularly relates to a preparation method of an eight-membered ring aluminum-rich mordenite nanosheet and application thereof. BACKGROUND
[0002] Zeolite molecular sieve is a kind of inorganic crystal material with regular pore structure, strong acidity and high hydrothermal stability, which has been widely used in the fields of catalysis, adsorption and ion exchange, and is an extremely potential industrial catalyst and carrier. The chemical performance of the zeolite molecular sieve is influenced by physical parameters such as crystallinity, silicon-aluminum ratio, pore structure, morphology, grain size and distribution of alumina sites, which will directly affect the catalytic activity, adsorption capacity and carrier stability. Therefore, it is necessary to synthesize molecular sieve materials with specific properties to meet different industrial application requirements.
[0003] Taking mordenite as an example, it has been proved that the mordenite can catalyze the carbonylation of methanol or dimethyl ether to generate acetic acid or methyl acetate with high selectivity. However, the acid sites in the twelve-membered ring pores are prone to olefin side reactions, and the generated macromolecular olefins gradually block the pores and cause carbon deposition, thereby reducing the activity of the catalyst and affecting the selectivity and conversion rate of the reaction.
[0004] In order to ensure the stability of the mordenite molecular sieve in the reaction of methanol to acetic acid or dimethyl ether to methyl acetate, post-processing methods such as acid-base treatment, recrystallization, pyridine adsorption and selective dealumination are often used to reduce the acid sites in the twelve-membered ring of the mordenite molecular sieve. However, these post-processing methods are not only time-consuming and laborious, but also may affect the crystallinity and pore structure of the mordenite molecular sieve itself, thereby affecting its catalytic performance.
[0005] Therefore, the present application provides a preparation method of an eight-membered ring aluminum-rich mordenite nanosheet and application thereof. SUMMARY
[0006] The present application aims to provide a preparation method of an eight-membered ring aluminum-rich mordenite nanosheet, which can improve the catalytic activity and stability of the mordenite molecular sieve in the carbonylation reaction and can play an excellent performance in the reaction of methanol or dimethyl ether carbonylation to prepare acetic acid or methyl acetate.
[0007] In order to achieve the above technical effects, the present application is implemented by the following technical scheme:
[0008] A preparation method of an eight-membered ring aluminum-rich mordenite nanosheet, characterized in that the method comprises the following steps:
[0009] S1, a silicon source, an inorganic base, an aluminum source, a template agent Te, water and a metal additive Me are weighed according to a molar ratio of 1:0.1-0.3:0.02-0.08:0.1-0.3:10-40:0.01-0.1, respectively;
[0010] S2, the above-mentioned weighed silicon source, inorganic base, aluminum source, template Te, water and metal additive Me are stirred and mixed in an ice water bath at 2-10℃ for 2-4h to obtain an initial gel;
[0011] S3, the initial gel is placed in a hydrothermal reactor, and hydrothermal crystallization is carried out in a drying oven at 160-190℃ for 2-4 days, then it is placed in a centrifuge and centrifuged at a speed of 5000-8000r / min, after centrifugation, the product is filtered, then the filtered product is placed in a drying oven at 90-120℃ and dried for 8-12h to obtain a sodium-type mordenite molecular sieve;
[0012] S4, the sodium-type mordenite molecular sieve is calcined at 500-550℃ for 4-6h to remove the organic template;
[0013] S5, the calcined sodium-type mordenite molecular sieve and a 0.5-1.5mol / L ammonium chloride solution are simultaneously placed in a water bath at 60-80℃ and stirred for 2-6h to perform ammonium ion exchange to obtain an ammonium-type mordenite molecular sieve;
[0014] S6, the ammonium-type mordenite molecular sieve is calcined at a temperature of 510-550℃ for 4-6h in an air atmosphere to obtain a hydrogen-type eight-membered ring aluminum-rich mordenite nanosheet.
[0015] Further, the silicon source in S1 is one or more of fumed silica, silica gel, silica sol, nano-silica powder and ethyl silicate.
[0016] Further, the inorganic base in S1 is one or more of sodium hydroxide, potassium hydroxide and lithium hydroxide.
[0017] Further, the aluminum source in S1 is one or more of sodium metaaluminate, aluminum powder, aluminum hydroxide, aluminum oxide, aluminum sulfate, aluminum nitrate, aluminum sol and isopropyl alcohol aluminum.
[0018] Further, the template Te in S1 is one or more of cetyltrimethylammonium bromide, sodium cetylbenzenesulfonate, sodium carboxymethylcellulose, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium bromide, triethylamine, triethanolamine, polyvinyl alcohol, ethanol and morpholine.
[0019] Further, the metal additive Me in S1 is one or more of copper nitrate trihydrate, magnesium nitrate hexahydrate, zinc nitrate hexahydrate, manganese nitrate tetrahydrate and ferric nitrate nonahydrate.
[0020] Further, the ammonium ion exchange in S5 needs to be repeated three times, and each time needs to be filtered, and after drying in a 90-120 DEG C drying box for 8-12h, the next ion exchange is carried out.
[0021] Another object of the present application is to provide the application of the eight-membered ring aluminum-rich mordenite nanosheet, characterized in that the eight-membered ring aluminum-rich mordenite nanosheet is used as an adsorbent for separating a gas and a liquid mixture or as a catalyst carrier in the petrochemical field.
[0022] Further, the application of the eight-membered ring aluminum-rich mordenite nanosheet in the reaction of methanol carbonylation to prepare acetic acid or dimethyl ether carbonylation to prepare methyl acetate.
[0023] The present application has the following advantages:
[0024] 1. The synthesized mordenite has a more special distribution of aluminate sites under the joint action of metal additives and template agents, and the ratio of the number of aluminum sites in the eight-membered ring to that in the twelve-membered ring is larger than that of the traditional synthesized mordenite molecular sieve, which can enhance the carbonylation efficiency and catalytic performance, reduce side reactions, and improve the selectivity and stability of the reaction.
[0025] 2. The synthesized mordenite molecular sieve has a crystal size of nanometer scale, which can better control the growth of the crystal, and the molecular sieve has a larger specific surface area, which can help the adsorption of gas and the diffusion of product in the catalytic reaction, and improve the performance and stability of the reaction.
[0026] 3. The synthesized mordenite molecular sieve has a shorter longitudinal channel under the help of the template, which can make the target product diffuse out of the molecular sieve channel quickly, reduce the possibility of other reactions in the twelve-membered ring, and improve the selectivity and stability of the reaction. BRIEF DESCRIPTION OF DRAWINGS
[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed for the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0028] Figure 1 XRD spectra of the mordenite molecular sieves obtained in Example 1, Example 8, Example 9 and Example 10 of the present application;
[0029] Figure 2This is a crystallinity diagram of the mordenite molecular sieve obtained in Examples 1, 8, 9 and 10 of the present invention relative to that in Example 1;
[0030] Figure 3 These are SEM images of the mordenite molecular sieves obtained in Examples 1, 8, 9, and 10 of the present invention;
[0031] Figure 4 This is a performance evaluation diagram of the mordenite molecular sieve obtained in Examples 1, 8, 9 and 10 of the present invention;
[0032] Figure 5 This is a space-time yield diagram of the mordenite molecular sieve obtained in Example 1, Example 8, Example 9 and Example 10 of the present invention;
[0033] Figure 6 NH3-TPD diagrams of mordenite molecular sieve obtained by implementing Examples 1, 8, 9 and 10 of the present invention;
[0034] Figure 7 The total B acid content of the mordenite molecular sieve obtained by implementing Example 1, Example 8, Example 9 and Example 10 of the present invention;
[0035] Figure 8 The pyridine infrared images of the mordenite molecular sieve obtained by implementing Example 1, Example 8, Example 9 and Example 10 of the present invention are as follows;
[0036] Figure 9 The hydroxyl infrared images of the mordenite molecular sieve obtained by implementing Example 1, Example 8, Example 9 and Example 10 of the present invention;
[0037] Figure 10 The 8-MR internal B acid amount diagram of the mordenite molecular sieve was obtained by implementing Example 1, Example 8, Example 9 and Example 10 of the present invention. DETAILED DESCRIPTION
[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.
[0039] Example 1
[0040] The invention provides an eight-membered ring aluminum-rich mordenite nanosheet. The mordenite has a MOR structure and does not contain other impurity crystals.
[0041] Reference is made to Figure 3 In the (a) and Figure 4 In the (a) shown, the embodiment provides a preparation method of eight-membered ring aluminum-rich mordenite nanosheet, comprising the following steps:
[0042] (1) Take 0.1 g of NaOH and 0.8 g of sodium metaaluminate and place them in 30 ml of deionized water, stir until clear and transparent, and then transfer the solution to an ice water bath at 5°C. Slowly add 6 g of fumed silica to the solution, stir for 1 h, then add 0.5 g of anhydrous ethanol and 0.24 g of copper nitrate trihydrate, and stir for 2 h to prepare an initial gel.
[0043] (2) The initial gel obtained in (1) is loaded into a hydrothermal reactor, which is crystallized in an oven at 160°C for 2 days. The obtained material is centrifuged at 5000 rpm in a centrifuge and washed with deionized water until neutral. After drying at 100°C in a drying oven for 12 h, sodium mordenite molecular sieve is obtained.
[0044] (3) The sodium mordenite molecular sieve obtained in (2) is placed in a muffle furnace and calcined at 500°C in an air atmosphere to remove the organic template.
[0045] (4) Prepare 100 ml of 1 mol / L ammonium chloride solution and stir in a 70°C water bath. Then, suspend the calcined mordenite molecular sieve in the ammonium chloride solution and stir for 4 h. Then, wash with deionized water until neutral, dry by filtration, and then place in a 100°C drying oven for 12 h. This step needs to be repeated three times to obtain ammonium mordenite molecular sieve.
[0046] (5) The ammonium mordenite molecular sieve obtained in (4) is calcined in a muffle furnace and calcined at 530°C in an air atmosphere to obtain hydrogen-type eight-membered ring aluminum-rich mordenite nanosheet.
[0047] Example 2
[0048] The embodiment provides a preparation method of eight-membered ring aluminum-rich mordenite nanosheet, comprising the following steps:
[0049] (1) Take 0.1 g of NaOH and 0.8 g of sodium metaaluminate and place them in 10 ml of deionized water, stir until clear and transparent, and then transfer the solution to an ice water bath at 5°C. Slowly add 20 g of silica sol to the solution, stir for 1 h, then add 4 g of cetyltrimethylammonium bromide and 0.24 g of copper nitrate trihydrate, and stir for 2 h to prepare an initial gel.
[0050] (2), the initial gel obtained in (1) is loaded into a hydrothermal reactor, crystallized at 170°C in an oven for 2 days, the obtained product is centrifuged at 5000 revolutions per minute in a centrifuge, and washed with deionized water until neutral, dried at 100°C in a drying oven for 12h after filtration, to obtain sodium mordenite molecular sieve.
[0051] (3), the sodium mordenite molecular sieve obtained in (2) is placed in a muffle furnace, calcined at 520°C under air atmosphere to remove the organic template.
[0052] (4), 100ml of 1 mole per liter of ammonium chloride solution is prepared and stirred in a 70°C water bath, then the calcined mordenite molecular sieve in (3) is suspended in the ammonium chloride solution and stirred for 4h, then washed with deionized water until neutral, dried at 100°C in a drying oven for 12h after filtration, and this step is repeated three times, to obtain ammonium mordenite molecular sieve.
[0053] (5), the ammonium mordenite molecular sieve obtained in (4) is calcined by placing it in a muffle furnace and calcining at 520°C under air atmosphere, to obtain hydrogen-type eight-membered ring aluminum-rich mordenite nanosheets.
[0054] Example 3
[0055] The present embodiment provides a method for preparing eight-membered ring aluminum-rich mordenite nanosheets, comprising the following steps:
[0056] (1), 0.3g of NaOH, 0.4g of KOH, and 0.5g of Al2O3 are placed in 30ml of deionized water, stirred until clear and transparent, and then transferred into an ice water bath at 5°C for stirring, 6g of silica gel is slowly added to the solution, stirred for 1h, then 4g of cetyltrimethylammonium bromide and 0.45g of zinc nitrate hexahydrate are added, and stirred for 2h, to prepare an initial gel.
[0057] (2), the initial gel obtained in (1) is loaded into a hydrothermal reactor, crystallized at 170°C in an oven for 2 days, the obtained product is centrifuged at 5000 revolutions per minute in a centrifuge, and washed with deionized water until neutral, dried at 100°C in a drying oven for 12h after filtration, to obtain sodium mordenite molecular sieve.
[0058] (3), the sodium mordenite molecular sieve obtained in (2) is placed in a muffle furnace, calcined at 520°C under air atmosphere to remove the organic template.
[0059] (4), 100 ml of 1 mol / L ammonium chloride solution was configured and stirred in a 70°C water bath, then the calcined mordenite molecular sieve in (3) was suspended in the ammonium chloride solution and stirred for 4 h, then washed with deionized water until neutral, dried at 100°C in a drying oven for 10 h after filtration, and the step was repeated three times to obtain the ammonium type mordenite molecular sieve.
[0060] (5), the ammonium type mordenite molecular sieve obtained in (4) was calcined in a muffle furnace, calcined at 520°C under air atmosphere to obtain hydrogen type eight-membered ring aluminum-rich mordenite nanosheets.
[0061] Example 4
[0062] The embodiment provides a preparation method of eight-membered ring aluminum-rich mordenite nanosheets, comprising the following steps:
[0063] (1), 1.1 g of KOH and 0.5 g of aluminum hydroxide were placed in 30 ml of deionized water and stirred until clear and transparent, then the solution was transferred into an ice water bath at 8°C and stirred, 6 g of silica gel was slowly added to the solution, stirred for 1 h, then 3 g of tetraethylammonium hydroxide and 0.45 g of zinc nitrate hexahydrate were added, and stirred for 2 h to prepare an initial gel.
[0064] (2), the initial gel obtained in (1) was loaded into a hydrothermal reaction kettle, crystallized in an oven at 170°C for 3 days, then centrifuged at 6000 rpm in a centrifuge and washed with deionized water until neutral, dried at 100°C in a drying oven for 10 h after filtration, to obtain sodium type mordenite molecular sieve.
[0065] (3), the sodium type mordenite molecular sieve obtained in (2) was placed in a muffle furnace, calcined at 520°C under air atmosphere to remove the organic template.
[0066] (4), 100 ml of 1 mol / L ammonium chloride solution was configured and stirred in a 80°C water bath, then the calcined mordenite molecular sieve in (3) was suspended in the ammonium chloride solution and stirred for 6 h, then washed with deionized water until neutral, dried at 100°C in a drying oven for 10 h after filtration, and the step was repeated three times to obtain the ammonium type mordenite molecular sieve.
[0067] (5), the ammonium type mordenite molecular sieve obtained in (4) was calcined in a muffle furnace, calcined at 520°C under air atmosphere to obtain hydrogen type eight-membered ring aluminum-rich mordenite nanosheets.
[0068] Example 5
[0069] The embodiment provides a preparation method of eight-membered ring aluminum-rich mordenite nanosheets, comprising the following steps:
[0070] (1), take 1 g NaOH, 0.8 g sodium metaaluminate is placed in 10 ml deionized water, stirring to clear and transparent, the solution is transferred to the ice water bath of 5 ℃ stirring, take 20 g silica sol slowly drop into the solution, stirring 1 h, then add 3.2 g tetraethylammonium bromide and 1.2 g iron nitrate nonahydrate, stirring 2 h, the initial gel is prepared.
[0071] (2), the initial gel obtained in (1) is loaded into the hydrothermal reactor, crystallized in the oven at 180 ℃ for 2 days, the obtained product is centrifuged in the centrifuge at 8000 rpm per minute, and washed with deionized water until neutral, dried at 120 ℃ in the drying oven for 12 h after filtering dry, sodium type mordenite molecular sieve is obtained.
[0072] (3), the sodium type mordenite molecular sieve obtained in (2) is placed in the muffle furnace, calcined at 550 ℃ under air atmosphere to remove the organic template.
[0073] (4), 100 ml of 1 mol / L ammonium chloride solution is configured, stirred in the 90 ℃ water bath, then the calcined mordenite molecular sieve in (3) is suspended in the ammonium chloride solution and stirred for 3 h, then washed with deionized water until neutral, dried after filtering dry, placed in the 120 ℃ drying oven for 12 h, this step needs to be repeated three times, ammonium type mordenite molecular sieve is obtained.
[0074] (5), the ammonium type mordenite molecular sieve obtained in (4) is calcined, placed in the muffle furnace, calcined at 550 ℃ under air atmosphere, hydrogen type eight-membered ring aluminum-rich mordenite nanosheet is obtained.
[0075] Example 6
[0076] The embodiment provides a preparation method of eight-membered ring aluminum-rich mordenite nanosheet, comprising the following steps:
[0077] (1), take 0.8 g NaOH, 0.1 g aluminum powder is placed in 40 ml deionized water, stirring to clear and transparent, the solution is transferred to the ice water bath of 10 ℃ stirring, take 6 g fumed silica slowly drop into the solution, stirring 1 h, then add 3 g tetraethylammonium hydroxide and 1.2 g manganese nitrate tetrahydrate, stirring 2 h, the initial gel is prepared.
[0078] (2), the initial gel obtained in (1) is loaded into the hydrothermal reactor, crystallized in the oven at 190 ℃ for 2 days, the obtained product is centrifuged in the centrifuge at 6000 rpm per minute, and washed with deionized water until neutral, dried at 110 ℃ in the drying oven for 12 h after filtering dry, sodium type mordenite molecular sieve is obtained.
[0079] (3), the sodium type mordenite molecular sieve obtained in (2) is placed in the muffle furnace, calcined at 540 ℃ under air atmosphere to remove the organic template.
[0080] (4) Prepare 100 ml of 1 mol / L ammonium chloride solution and stir in a 70°C water bath. Then suspend the calcined mordenite molecular sieve in (3) in the ammonium chloride solution and stir for 6 hours. Then wash with deionized water until neutral, filter and dry in a drying oven at 110°C for 12 hours. This step needs to be repeated three times to obtain ammonium-type mordenite molecular sieve.
[0081] (5) The ammonium-type mordenite molecular sieve obtained in (4) is calcined and placed in a muffle furnace, and calcined at 540° C. in an air atmosphere to obtain hydrogen-type eight-membered ring aluminum-rich mordenite nanosheets.
[0082] Example 7
[0083] This embodiment is the first comparative example, comprising the following steps:
[0084] 0.8g NaOH, 0.1g aluminum powder, and 3g tetraethylammonium hydroxide were placed in 60ml of deionized water and stirred until clear. 6g of fumed silica was slowly added to the solution and stirred for 2 hours to obtain an initial gel. The initial gel was placed in a hydrothermal reactor and crystallized in an oven at 160°C for 2 days. The resulting product was centrifuged at 6000 rpm, washed with deionized water until neutral, filtered, and dried in a 100°C drying oven for 12 hours. 100ml of 1 mol / L ammonium chloride solution was directly added and stirred in a 70°C water bath. The product was then suspended in the ammonium chloride solution and stirred for 6 hours. The product was then washed with deionized water until neutral, filtered, and dried in a 100°C drying oven for 12 hours. This step was repeated three times. The resulting product was calcined in a muffle furnace at 540°C under air. The resulting sample was crystalline Al2O3 and could not be used to synthesize mordenite molecular sieve.
[0085] Example 8
[0086] See also Figure 3 (b) and Figure 4 As shown in (b), this embodiment is the second comparative example, comprising the following steps:
[0087] Example 1
[0088] Example 2
[0089] Reference to Figure 3 Example 3 Figure 4 This example is a 3rdcomparative example and includes the following steps:
[0090] Example 4
[0091] Example 5
[0092] Reference to Figure 3 Example 6 Figure 4 This example is a 4thcomparative example and includes the following steps:
[0093] Example 7
[0094] Put 1 g NaOH, 0.8 g sodium metaaluminate into 30 ml deionized water, stir until clear and transparent, transfer the solution into an ice water bath at 5 ℃ and stir, slowly add 6 g fumed silica into the solution and stir for 1 h, then add 0.24 g copper nitrate trihydrate and stir for 2 h to obtain an initial gel. The initial gel is loaded into a hydrothermal reactor and crystallized in an oven at 160 ℃ for 2 days. The obtained product is centrifuged at 5000 rpm in a centrifuge and washed with deionized water until neutral, dried at 100 ℃ in a drying oven for 12 h after being dried by filtration. The obtained product is calcined in a muffle furnace at 500 ℃ under air atmosphere. Prepare 100 ml of 1 mol / L ammonium chloride solution and stir in a 70 ℃ water bath, then suspend the product in the ammonium chloride solution and stir for 4 h, then wash with deionized water until neutral, dry by filtration and dry in a 100 ℃ drying oven for 12 h, and repeat this step three times. The obtained product is calcined in a muffle furnace at 530 ℃ under air atmosphere. The obtained sample is a mordenite molecular sieve without the addition of Te.
[0095] Example 11
[0096] This example is a specific application of the eight-membered ring aluminiferous mordenite nanosheet prepared by the present application, and is specifically as follows:
[0097] Respectively weigh 1 gram of the eight-membered ring aluminiferous mordenite nanosheet synthesized in Example 1, Example 3, Example 8 and Example 10, and load it into a fixed bed reactor, pass 30 ml / min of argon, pretreat at normal pressure and 300 ℃ for 2 h, then pass 2% CH3OH / 44% CO / 54% Ar at 45 ml / min, increase the pressure to 4 MPa, and increase the temperature to 310 ℃ and keep the temperature for 10 h; the reaction results are shown in Figure 4 .
[0098] The present application obtains the eight-membered ring aluminiferous nanosheet with the best carbonylation performance under the best reaction conditions through the synergistic effect of the ice water bath, the addition of Me and Te, as shown in Figure 4 、 5 . Specifically, the ice water bath gel process before hydrothermal treatment inhibits the disordered nucleation of the molecular sieve crystal grains at low temperature, controls the size to be nanoscale, and forms ordered crystal nuclei at the nanoscale. On this basis, the Te template directs the molecular sieve to grow along the ordered crystal nuclei to form shorter longitudinal channels of the molecular sieve Figure 1 、 2 , 3. The addition of metal ions provides more B acid sites Figure 6 、 7 , 8, and drives aluminum to selectively enter the 8-membered ring to make it aluminiferous Figure 9 、 10), on the other hand, activates the gas molecules in the pore, prompting the gas molecules to carry out the carbonylation reaction on the acid sites. Due to the short length of the pore, the target product can quickly diffuse out of the molecular sieve pore, reducing the generation of by-products and improving the stability of the molecular sieve.
[0099] Compared with the conventional preparation method, the present application does not need additional operation, and the yield of acetic acid and methyl acetate is improved by a relatively simple method. The method is based on the unique three-step synergistic effect, and provides a new idea for low-cost synthesis and modification of high-performance molecular sieves, and has extremely high industrialization potential.
Claims
1. A method for preparing an octagonal aluminous mordenite nanosheet, characterized in that, It comprises the following steps: S1, the silicon source, inorganic alkali, aluminum source, template Te, water and metal additive Me are weighed according to the molar ratio of 1:0.1-0.3:0.02-0.08:0.1-0.3:10-40:0.01-0.1 respectively; S2, the above-mentioned silicon source, inorganic alkali, aluminum source, template Te, water and metal additive Me are stirred and mixed in an ice water bath at 2-10℃ for 2-4h, and the initial gel is prepared; S3, the initial gel is placed in a hydrothermal reaction kettle, and hydrothermal crystallization is carried out in a drying oven at 160-190℃ for 2-4 days, then it is placed in a centrifuge at a speed of 5000-8000r / min, after centrifugation, the product is filtered, then the filtered product is placed in a drying oven at 90-120℃, and dried for 8-12h, and the sodium type mordenite molecular sieve is obtained; S4, the sodium type mordenite molecular sieve is calcined at 500-550℃ for 4-6h to remove the organic template; S5, the calcined sodium type mordenite molecular sieve and 0.5-1.5mol / L ammonium chloride solution are placed in a water bath at 60-80℃ at the same time, and stirred for 2-6h to exchange ammonium ions, and the ammonium type mordenite molecular sieve is obtained; S6, the ammonium type mordenite molecular sieve is calcined at 510-550℃ for 4-6h in air atmosphere, and the hydrogen type eight-membered ring aluminum-rich mordenite nanosheet is obtained.
2. The method according to claim 1, wherein the method is characterized by, The silicon source in S1 is one or more of fumed silica, silica gel, silica sol, nano silicon dioxide powder and ethyl silicate.
3. The method according to claim 1, wherein the method is characterized by, The inorganic alkali in S1 is one or more of sodium hydroxide, potassium hydroxide and lithium hydroxide.
4. The method according to claim 1, wherein the method is characterized by, The aluminum source in S1 is one or more of sodium metaaluminate, aluminum powder, aluminum hydroxide, aluminum oxide, aluminum sulfate, aluminum nitrate, aluminum sol and isopropyl alcohol aluminum.
5. The method for preparing eight-membered ring aluminum-rich mordenite nanosheets according to claim 1, characterized in that: The template Te in S1 is one or more of cetyltrimethylammonium bromide, sodium cetylphenyl sulfonate, sodium carboxymethyl cellulose, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium bromide, triethylamine, triethanolamine, polyvinyl alcohol, ethanol and morpholine.
6. The method for preparing eight-membered ring aluminum-rich mordenite nanosheets according to claim 1, characterized in that: The metal additive Me in S1 is one or more of copper nitrate trihydrate, magnesium nitrate hexahydrate, zinc nitrate hexahydrate, manganese nitrate tetrahydrate and iron nitrate nonahydrate.
7. The method according to claim 1, wherein the method is characterized by, The ammonium ion exchange in S5 needs to be repeated three times, and each time needs to be filtered, and after drying in a drying oven at 90-120℃ for 8-12h, the next ion exchange is carried out.
8. Use of the octagonal aluminous mordenite nanosheets obtained by the process according to any one of claims 1 to 7, characterized in that, The eight-membered ring aluminum-rich mordenite nanosheet is used as an adsorbent for separating gas and liquid mixture, or as a catalyst carrier in the field of petroleum chemical industry.
9. Use of the octagonal aluminous mordenite nanosheets according to claim 8, characterized in that, The eight-membered ring aluminum-rich mordenite nanosheet is used in the reaction of methanol carbonylation to acetic acid or dimethyl ether carbonylation to methyl acetate.
Citation Information
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