Kilogram-level preparation method of metal organic thin-layer material

Abstract

The invention relates to the technical field of preparation of metal organic thin-layer materials, in particular to a kilogram-level preparation method of a metal organic thin-layer material. The preparation method comprises the following steps: S1, adding zirconium tetrachloride and H2BPYDC into a polytetrafluoroethylene reaction kettle, dissolving, and adding a compound; s2, sequentially adding a DMF solution of palladium fluoroacetate, a catalyst and concentrated hydrochloric acid into the reaction kettle; s3, transferring the reaction kettle into a drying oven, standing for 18-20 hours, centrifuging to obtain a cyan suspended matter, dispersing the cyan suspended matter in a DMF (Dimethyl Formamide) solution in batches at 60 DEG C, standing for 5-6 hours, and removing an unreacted substrate to obtain a solid; s4, the solid obtained in the S3 is washed with DMF and tetrahydrofuran respectively, vacuum drying is conducted for 12 h, and the metal organic thin-layer material is obtained. According to the kilogram-level preparation method of the metal organic thin-layer material, the problems that in the prior art, the preparation yield of the metal organic thin-layer material is low, the speed is low, and kilogram-level preparation is difficult to achieve are solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of metal-organic thin layer material preparation, in particular to a kilogram-level preparation method of metal-organic thin layer material. BACKGROUND

[0002] Metal-organic thin layer material (MOL) is a kind of metal-organic functional material with two-dimensional layered structure, which is a "thin layer" derivative of metal-organic framework (MOFs), and the core feature is that metal ions / metal clusters (nodes) are connected with organic ligands through coordination bonds to form a sheet structure of a single atomic layer or a few atomic layers, the thickness is usually 1-10 nm, and the lateral size can extend from several hundred nanometers to microns, which has unique structure and performance, and has wide application prospects in the fields of building material thermal insulation and sound insulation.

[0003] Traditional building organic thermal insulation materials (such as polystyrene board EPS and extruded board XPS) have low thermal conductivity, but poor temperature resistance; inorganic thermal insulation materials (such as rock wool and glass wool) have high temperature resistance but high thermal conductivity and performance degradation after absorbing moisture; MOL can have both low thermal conductivity and high temperature resistance.

[0004] The preparation method of metal-organic thin layer material usually includes traditional solvothermal method, mechanical grinding and ultrasonic peeling method, and chemical vapor deposition method, wherein the traditional solvothermal method depends on high temperature and high pressure, the reaction kinetics is slow, the reaction time is as long as several hours to several days, and the single yield is usually milligram level; the mechanical grinding and ultrasonic peeling method has a low yield, usually about 15%, and the structure is easily damaged, which is difficult to realize large-scale kilogram-level production; the chemical vapor deposition method has high requirements for equipment and process, which is also not conducive to large-scale production, and cannot become the core component of a new generation of building thermal insulation materials, so it cannot be widely used in civil buildings, industrial buildings and other fields. SUMMARY

[0005] The application provides a kilogram-level preparation method of metal-organic thin layer material to solve the problems of low yield, slow rate and difficulty in kilogram-level preparation of metal-organic thin layer material in the related art.

[0006] To achieve the above object, the application provides a kilogram-level preparation method of metal-organic thin layer material, which comprises the following steps: S1, adding zirconium tetrachloride and H2BPYDC into a polytetrafluoroethylene reactor, dissolving, and then adding a composite; S2, adding a DMF solution of palladium fluoroacetate, a catalyst, and concentrated hydrochloric acid into the reactor in sequence; S3, transfer the reactor to the 75~80℃ oven, centrifuge to obtain the blue suspension after 18~20h, disperse the blue suspension in DMF solution at 60℃, remove the unreacted substrate after 5~6h, and obtain the solid; S4, use DMF and tetrahydrofuran to clean the solid obtained in S3, and vacuum dry at 110~120℃ for 12h to obtain the metal organic thin layer material.

[0007] Preferably, in S1, the complex is a DMF solution of hydroxyethyl cellulose and sodium methylene bis-methyl naphthalene sulfonate with a mass ratio of 1:(1~1.2), and the sum of the mass of the hydroxyethyl cellulose and sodium methylene bis-methyl naphthalene sulfonate is 0.1~0.5% of the mass of zirconium tetrachloride.

[0008] Preferably, in S1, the complex is dispersed before being added, and the dispersion power is 200~300W and the dispersion time is 5~10min.

[0009] Preferably, in S1, the mass ratio of zirconium tetrachloride to H2BPYDC is (7~7.5):9.

[0010] Preferably, in S2, the catalyst is added in an amount of 1~1.2% of the mass of H2BPYDC, and the catalyst comprises dimethylamine sulfonyl chloride and a carrier, and the mass ratio of the dimethylamine sulfonyl chloride to the carrier is 1:(2~3), and the carrier is at least one of povidone and micronized silica gel.

[0011] Preferably, the catalyst comprises dimethylamine sulfonyl chloride, povidone and micronized silica gel with a mass ratio of 1:1.5:1.5.

[0012] Preferably, in S2, the concentration of the DMF solution of palladium fluoroacetate is 0.83~1mmol / L.

[0013] Preferably, in S2, the concentration of the concentrated hydrochloric acid is 35~36.2wt%.

[0014] The technical scheme provided in the application has the following beneficial effects: The application provides a kilogram-level preparation method of a metal organic thin layer material, which uses a complex and a catalyst to activate the carboxyl group of H2BPYDC, reduce the activation energy of the coordination reaction, shorten the reaction time, and improve the reaction efficiency; fluorine acetic acid palladium is selected as the Pd source, and the catalyst carrier adsorbs Pd 2+ by high specific surface area, which provides sufficient active sites, and avoids the aggregation of Pd 2+The process achieves agglomeration while ensuring uniform embedding of the Zr-MOL thin film surface. Both hydroxyethyl cellulose and sodium methylene dimethylnaphthalene sulfonate are readily soluble in N,N-dimethylformamide (DMF), eliminating the need for additional co-solvents. Furthermore, they can be completely removed by simple DMF-ethanol washing (without residue), simplifying the post-processing steps for kilogram-scale production and avoiding the introduction of impurities that could affect product purity. By increasing the final yield, the effective utilization rate of raw materials is improved, thereby enabling kilogram-scale preparation, which has broad application prospects in building thermal insulation materials. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 SEM, TEM and HRTEM images of the metal-organic thin-film material Pd / Zr-MOL prepared in Example 1 provided for this application; Figure 2 AFM image of the metal-organic thin-film material Pd / Zr-MOL prepared in Example 1 provided for this application; Figure 3 The high-angle annular dark-field scanning transmission electron microscope and the corresponding EDX elemental mapping test image provided for this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] See Figures 1-3 As shown, this application provides a method for preparing metal-organic thin-film materials at the kilogram scale.

[0019] Example 1 The method for preparing kilogram-scale metal-organic thin-film materials provided in this embodiment includes the following steps: S101. Add 630 mg of zirconium tetrachloride and 810 mg of H2BPYDC to a 200 mL polytetrafluoroethylene reactor and dissolve them, then add the complex. The complex consists of a mixture of 1.26 mg hydroxyethyl cellulose, 1.26 mg sodium methylene dimethylnaphthalene sulfonate, and 5 mL DMF (ultrasonically dispersed for 5 min).

[0020] S102. Add 120 mL of DMF solution containing 0.1 mmol of palladium fluoroacetate, 8.4 mg of catalyst, and 4.5 mL of concentrated hydrochloric acid (36 wt%) to the reaction vessel in sequence. The catalyst consists of 2.1 mg dimethylaminosulfonyl chloride, 3.15 mg povidone, and 3.15 mg micronized silica gel (industrial grade, specific surface area 250 m²). 2 A mixture of (g) and (g).

[0021] S103. Transfer the reaction vessel to an 80℃ oven and let it stand for 20 hours. Centrifuge to obtain a blue suspension. Disperse the blue suspension in batches in DMF solution at 60℃ and let it stand for 6 hours. Remove the unreacted substrate to obtain a solid. S104. The solid obtained in S103 was washed three times with DMF and tetrahydrofuran respectively, and then dried under vacuum at 120°C for 12 hours to obtain 960 mg of metal-organic thin-layer material Pd / Zr-MOL, with a yield of about 65.37%.

[0022] Example 2 The method for preparing kilogram-scale metal-organic thin-film materials provided in this embodiment includes the following steps: S201. Add 675 mg of zirconium tetrachloride and 810 mg of H2BPYDC to a 200 mL polytetrafluoroethylene reactor and dissolve them. Then add the complex. The complex consists of a mixture of 0.33 mg hydroxyethyl cellulose, 0.345 mg sodium methylene dimethylnaphthalene sulfonate, and 3 mL DMF (ultrasonically dispersed for 5 min).

[0023] S202. Add 120 mL of DMF solution containing 0.12 mmol of palladium fluoroacetate, 9.72 mg of catalyst, and 4.5 mL of concentrated hydrochloric acid (35 wt%) to the reactor in sequence. The catalyst is a mixture of 3.24 mg dimethylaminosulfonyl chloride and 6.48 mg povidone.

[0024] S203. Transfer the reaction vessel to an 80℃ oven and let it stand for 20 hours. Centrifuge to obtain a blue suspension. Disperse the blue suspension in batches in DMF solution at 60℃ and let it stand for 6 hours. Remove the unreacted substrate to obtain a solid. S204. The solid obtained in S203 was washed three times with DMF and tetrahydrofuran respectively, and then dried under vacuum at 120°C for 12 h to obtain 971 mg of metal-organic thin-layer material Pd / Zr-MOL, with a yield of 64%.

[0025] Example 3 The method for preparing kilogram-scale metal-organic thin-film materials provided in this embodiment includes the following steps: S301. Add 630 mg of zirconium tetrachloride and 810 mg of H2BPYDC to a 200 mL polytetrafluoroethylene reactor and dissolve them, then add the complex. The complex consisted of a mixture of 1.43 mg hydroxyethyl cellulose, 1.72 mg sodium methylene dimethylnaphthalene sulfonate, and 5 mL DMF (ultrasonically dispersed for 5 min).

[0026] S302. Add 120 mL of DMF solution containing 0.1 mmol of palladium fluoroacetate, 8.1 mg of catalyst, and 4.5 mL of concentrated hydrochloric acid (36.2 wt%) to the reactor in sequence. The catalyst consists of 2.1 mg dimethylaminosulfonyl chloride and 6 mg micronized silica gel (industrial grade, specific surface area 250 m²). 2 A mixture of (g) and (g).

[0027] S303. Transfer the reactor to a 75°C oven and let it stand for 18 hours. Centrifuge to obtain a blue suspension. Disperse the blue suspension in batches in DMF solution at 60°C and let it stand for 5 hours. Remove the unreacted substrate to obtain a solid. S304. The solid obtained in S303 was washed three times with DMF and tetrahydrofuran respectively, and then dried under vacuum at 110℃ for 12h to obtain 892mg of metal-organic thin-layer material Pd / Zr-MOL, with a yield of 60.72%.

[0028] Comparative Example 1 The difference from Example 1 is that in step S102, palladium fluoroacetate is replaced with an equal amount of palladium chloride, and no catalyst is added, resulting in 607 mg of organometallic thin-layer material Pd / Zr-MOL with a yield of 40.94%.

[0029] Comparative Example 2 The difference from Example 1 is that in step S102, palladium fluoroacetate is replaced with an equal amount of palladium chloride, and the catalyst is replaced with 2.1 mg of dimethylaminosulfonyl chloride, that is, no support is added, and 653 mg of metal-organic thin-layer material Pd / Zr-MOL is obtained with a yield of 44.05%.

[0030] Comparative Example 3 The difference from Example 1 is that no complex was added in step S101, and 659 mg of the metal-organic thin-film material Pd / Zr-MOL was obtained with a yield of 44.45%.

[0031] Comparative Example 1 and Comparative Example 2 used palladium chloride, which had poor dissociation. Although Comparative Example 2 retained some catalyst compared to Comparative Example 1, its catalytic effect was not obvious due to the lack of a support.

[0032] The metal-organic thin-film material prepared in Example 1 was characterized.

[0033] See Figure 1 As shown, these are SEM, TEM, and HRTEM images of the metal-organic thin-film material Pd / Zr-MOL prepared in Example 1, respectively. Figure 1 The SEM image in (a) shows that the metal-organic thin film material prepared in Example 1 is an ultrathin nanosheet with an irregular shape and a lateral size close to the micrometer scale; from Figure 1 (b) The TEM image shows multiple layers of ultrathin nanosheets stacked together, exhibiting clear characteristics of a two-dimensional material; see further details. Figure 1 As shown in (c), the HRTEM image indicates that no visible Pd nanoparticles were formed, suggesting that Pd ions were not reduced to nanoparticles during the low-temperature DMF solvothermal process.

[0034] See Figure 2 As shown, it is an AFM (atomic force microscopy) image of the metal-organic thin-film material Pd / Zr-MOL prepared in Example 1. The thickness of the ultrathin nanosheet was measured to be approximately 1.5 nm by AFM characterization, the lateral dimension of the nanosheet was approximately 1.5 μm, and it had no regular shape.

[0035] See Figure 3 As shown, in order to further confirm the ultrathin layer structure of Pd / Zr-MOL prepared in Example 1, we performed high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and corresponding EDX elemental mapping tests to study the elemental distribution characteristics of the ultrathin layer. Figure 3 EDX elemental mapping indicates that C( Figure 3 b), N ( Figure 3 c), O ( Figure 3 d), Zr ( Figure 3 e) and Pd( Figure 3 f) Elements; among which C, N, and O are present in higher amounts and are evenly distributed, corresponding to denser color highlights. Zr and Pd are present in relatively lower amounts and are distributed in multiple thin-layer stacking areas, relatively evenly distributed on the lamellar structure.

[0036] Furthermore, the metal-organic thin-film material Pd / Zr-MOL prepared in Example 1 of this application was applied to the CO2 hydrogenation performance test.

[0037] At a temperature of 300℃, a gas ratio of N2 / CO2 / H2 = 1:2:6, a pressure of 3.0 MPa, and a space velocity of 13500 mL·h, the following conditions were met: -1 ·g -1 Under the specified conditions, the catalytic performance of Pd / Zr-MOL prepared in Example 1 (1.5 nm), Pd / MOL (25 nm), and three-dimensional Pd / UiO-67-bpy were investigated. The catalytic results showed that the CO2 conversion rates of Pd / Zr-MOL prepared in Example 1 (1.5 nm), Pd / MOL (25 nm), and three-dimensional Pd / UiO-67-bpy were 19.66%, 12.1%, and 10.5%, respectively, with CO selectivities of 98%, 89%, and 73%, respectively. The 1.5 nm Pd / Zr-MOL exhibited the highest CO2 conversion rate and CO selectivity, mainly attributed to the fully exposed Pd active sites in the ultrathin layer structure, and the non-porous structure and smaller BET specific surface area which facilitated CO molecule desorption.

[0038] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a kilogram-scale metal-organic thin-film material, characterized in that, It includes the following steps: S1. Add zirconium tetrachloride and H2BPYDC to the polytetrafluoroethylene reactor and dissolve them, then add the composite. S2. Add the DMF solution of palladium fluoroacetate, the catalyst, and concentrated hydrochloric acid to the reaction vessel in sequence; S3. Transfer the reaction vessel to an oven at 75~80℃ and place it for 18~20h. Centrifuge to obtain a blue suspension. Disperse the blue suspension in batches in DMF solution at 60℃ and place it for 5~6h. Remove the unreacted substrate to obtain a solid. S4. The solid obtained in S3 is washed with DMF and tetrahydrofuran respectively, and then dried under vacuum at 110~120℃ for 12h to obtain a metal-organic thin film material.

2. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 1, characterized in that: In S1, the complex is a DMF solution of hydroxyethyl cellulose and sodium methylene dimethylnaphthalene sulfonate in a mass ratio of 1:(1~1.2), wherein the sum of the masses of the hydroxyethyl cellulose and sodium methylene dimethylnaphthalene sulfonate is 0.1~0.5% of the mass of zirconium tetrachloride.

3. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 1, characterized in that: In step S1, the complex is first dispersed before being added, with a dispersion power of 200-300W and a dispersion time of 5-10 minutes.

4. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 1, characterized in that: In S1, the mass ratio of zirconium tetrachloride to H2BPYDC is (7~7.5):

9.

5. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 1, characterized in that: In S2, the amount of catalyst added is 1 to 1.2% of the mass of H2BPYDC. The catalyst includes dimethylaminosulfonyl chloride and a support, and the mass ratio of dimethylaminosulfonyl chloride to the support is 1:(2 to 3). The support is at least one of polyvinyl ketone and micronized silica gel.

6. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 5, characterized in that: The catalyst comprises dimethylaminosulfonyl chloride, polyvinyl ketone, and micronized silica gel in a mass ratio of 1:1.5:1.

5.

7. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 1, characterized in that: In S2, the concentration of the DMF solution of palladium fluoroacetate is 0.83~1 mmol / L.

8. The method for preparing the metal-organic thin-film material at the kilogram scale as described in claim 1, characterized in that: In step S2, the concentration of the concentrated hydrochloric acid is 35-36.2 wt%.

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