MOF (Metal Organic Framework) forming body as well as preparation method and application thereof

Abstract

The invention provides an MOF (Metal Organic Framework) forming body as well as a preparation method and application thereof, and relates to the technical field of forming of metal organic framework materials. The forming body is in the shape of spherical or short rod-shaped particles, the diameter of the particles is 0.5-8 mm, the strength of the particles is 1-200 N, the proportion of micropores in a pore structure is 30%-70%, the proportion of mesopores in the pore structure is 10%-65%, the proportion of macropores in the pore structure is 5%-40%, and the tap density of the particles is 0.2-0.8 g / cm. The invention also provides a preparation method of the MOF forming body. According to the MOF forming body, accurate design of the pore structure of the MOF forming body is achieved by regulating and controlling the moisture content, the adhesive type and dosage, the forming mode and the drying technology of material-equipment volume matching and gradient temperature interval, the forming body is high in adsorption efficiency on formaldehyde, VOC and odor molecules, proper in mechanical strength, not prone to powder falling and large in unit volume adsorption capacity, and the forming body is suitable for being used in a large-scale production process. The method is suitable for industrial adsorption devices and air purification equipment.

Description

Technical Field

[0001] This invention relates to the field of metal-organic framework (MOF) material molding technology, specifically to a MOF molded body, its preparation method, and its application. Background Technology

[0002] MOF (Metal-Oxide-Factory) materials have broad application prospects in gas adsorption due to their high specific surface area and tunable pore structure. However, MOFs are usually in powder form, which can easily generate dust, high pressure drop, and large mass transfer resistance in practical applications, requiring molding processes to prepare them into granular products. Existing molding technologies often use binders and solvents (such as water) to blend with MOF powder and granulate them through methods such as extrusion, rounding, or pelletizing. However, improper parameter control during the molding process can lead to problems such as unreasonable pore structure, insufficient or excessive strength, and low mass transfer efficiency in the MOF molded body, thus affecting adsorption performance. For example, excessively high or low moisture content may cause particle cracking or compaction; improper binder dosage can lead to decreased strength or pore blockage; if the drying process only controls the temperature and ignores the "match between material feed rate and equipment volume", it can cause surface defects, pore collapse, or incomplete drying. Especially when using different types of drying equipment, improper temperature control can easily lead to performance fluctuations (such as incomplete drying leading to a decrease in the formaldehyde adsorption capacity of the material). Furthermore, if the diameter, strength, pore distribution, and packing density of the molded body are not optimized, the adsorption capacity and mass transfer rate per unit volume will be significantly reduced. Therefore, there is an urgent need for a complete preparation method that can precisely control the pore structure and physical properties of MOF molded bodies and cover different types of drying equipment, in order to improve their adsorption efficiency for formaldehyde, VOCs, and odors. Summary of the Invention

[0003] The purpose of this invention is to address the problems in existing technologies, such as poor pore structure control, difficulty in balancing strength and mass transfer, and the lack of coverage of different equipment types and ease of circumvention in drying processes. This invention provides a MOF molded body, its preparation method, and applications. By controlling the molding process parameters and the synergistic relationship of "material-equipment volume matching + gradient temperature" during drying, this invention regulates the pore structure, strength, and packing density of the MOF molded body, thereby optimizing its adsorption performance for formaldehyde, volatile organic compounds (VOCs), and odors. The molded body of this invention is suitable for air purification, environmental remediation, and other fields, exhibiting highly efficient adsorption capacity for formaldehyde, VOCs, and odor molecules.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: The present invention first provides a MOF molded body, which is spherical or short rod-shaped particles with a diameter of 0.5-8 mm, a strength of 1N-200N, a pore structure in which micropores account for 30%-70%, mesopores account for 10%-65%, macropores account for 5%-40%, and the particle tap density is 0.2-0.8 g / cm³.

[0005] The present invention also provides a method for preparing MOF molded articles, comprising: Step 1: Blending: Blend MOF powder, water, and binder to obtain a blend; wherein the water content accounts for 60%-400% of the mass of MOF powder, and the binder accounts for 1%-20% of the mass of MOF powder; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated to obtain MOF particles; the diameter of the MOF particles is 0.5-8 mm; Step 3: Drying: The MOF particles from Step 2 are dried in a drying equipment to obtain MOF molded bodies; The total volume of MOF particles in the drying equipment shall not exceed 50% of the effective volume of the drying equipment, and the MOF particles shall be placed in a single layer or in layers, with each layer of particles having a stacking height of ≤10cm. The drying process involves a first drying at 40-70℃, followed by a second drying at 80-180℃.

[0006] Preferably, the MOF powder mentioned in step one is selected from one or more of the ZIF series, MIL series, UIO series, CAU series, Fum series, UTSA series, CALF series, HKUST series, amino acid series or MUF series.

[0007] Preferably, the adhesive described in step one is selected from one or more of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), methylcellulose (MC), carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), hydroxyethylcellulose (HEC), starch, sodium alginate, gelatin, polyacrylic acid, polyacrylate, polyurethane, silica sol, aluminum sol, rubber latex, or PVAc latex.

[0008] Preferably, the molding and granulation in step two is performed by forming spherical or short rod-shaped MOF particles using an extruder, a rounding machine, or a pelletizing machine.

[0009] Preferably, the molding and granulation process in step two uses the following process conditions for an extruder: the extruder speed is controlled at 80~120 rpm, the feed rate is controlled at 0.8~1.2 kg / min, and the extrusion temperature is ≤40℃.

[0010] Preferably, the molding and granulation process in step two, using a rounding machine, has the following process conditions: rounding speed controlled at 200-1500 rpm, and rounding time at 3-15 min.

[0011] Preferably, the granulation process in step two, using a pelletizing machine, has the following process conditions: the extrusion speed of the pelletizing machine is controlled at 50~80 rpm, the feeding speed is controlled at 0.2~0.5 kg / min, and the pelletizing roller speed is controlled at 15~20 rpm.

[0012] Preferably, when placing the items in a layered, flat manner as described in step three, the number of layers is 2-40.

[0013] The present invention also provides the application of the above-mentioned MOF molded articles in the adsorption of formaldehyde and VOC odor molecules.

[0014] Beneficial effects of the present invention This invention provides a MOF molded body, its preparation method, and its applications. The molded body is in the shape of spherical or short rod-shaped particles with a diameter of 0.5-8 mm and a strength of 1 N-200 N. The pore structure comprises 30%-70% micropores, 10%-65% mesopores, and 5%-40% macropores, with a particle tap density of 0.2-0.8 g / cm³. This invention achieves precise design of the pore structure of the MOF molded body by controlling the moisture content, binder type and dosage, molding method, and a drying process of "material-equipment volume matching + gradient temperature range (pore control + shaping)". The molded body exhibits high adsorption efficiency for formaldehyde, VOCs, and odor molecules, suitable mechanical strength, minimal powder shedding, and a large adsorption capacity per unit volume, making it suitable for industrial adsorption devices and air purification equipment. Specifically… 1. Diameter Control: The particle diameter of this invention is 0.5-8 mm. If the diameter is too small (e.g., <0.5 mm), the particles will be too densely packed, increasing the mass transfer resistance (gas resistance); if the diameter is too large (e.g., >8 mm), the external surface area will be insufficient, reducing the adsorption capacity. This invention selects a diameter of 0.5-8 mm to balance mass transfer and external surface area.

[0015] 2. Strength Control: The strength of the molded body of this invention is 1N-200N. When the strength is below 1N, the particles are prone to powdering, affecting the service life; when the strength is above 200N, the particles are too dense, the pores are reduced, and mass transfer is poor. The strength range of this invention ensures the mechanical integrity of the particles without affecting the pore structure.

[0016] 3. Pore Structure Design: In this invention, micropores (<2nm) primarily provide high specific surface area and adsorption sites, but an excessively high proportion (e.g., >70%) will restrict molecular diffusion. Mesopores (2-50nm) and macropores (>50nm) facilitate mass transfer, but an excessively high proportion (e.g., >70%) will reduce the specific surface area. This invention optimizes adsorption capacity and mass transfer rate by controlling the proportion of micropores to 30%-70%, mesopores to 10%-65%, and macropores to 5%-40%, making it particularly suitable for the rapid adsorption of formaldehyde, VOCs, and odor molecules (typically small to medium molecular weight).

[0017] 4. Bulk density optimization: When the density is below 0.2 g / cm³, the adsorption capacity per unit volume is limited; when the density is above 0.8 g / cm³, the mass transfer kinetics decrease. The density range of this invention ensures high volumetric adsorption efficiency and excellent kinetics.

[0018] 5. Drying Process: The core of the drying process in this invention lies in the coordinated control of "material-equipment volume matching + gradient temperature range," neither of which can be omitted. If only the material feed rate is controlled without defining the gradient temperature range, it is easy to experience uncontrolled mesopore / macropore quantity (too high temperature) or inability to solidify the pore structure (too low temperature); if only the temperature range is defined while ignoring the material bulk density, uneven local pore distribution will occur; if neither is controlled, it will lead to pore structure collapse, strength fluctuations, or decreased adsorption performance. This invention, by clearly defining the gradient temperature requirements and functions of the 40-70℃ low-temperature range (pore control) and the 80-180℃ high-temperature range (shaping), and combining the matching rules of material and equipment volume, ensures that stable MOF molded bodies can be prepared regardless of the type of drying equipment used or the adjustment of the operating time, effectively avoiding the technical circumvention behavior of only adjusting the time or equipment type without following the core parameters. Attached Figure Description

[0019] Figure 1 This is a pore size distribution diagram of the MOF molded body prepared in Example 1 of the present invention; Figure 2 This is a pore size distribution diagram of the MOF molded body prepared in Comparative Example 6 of the present invention; Figure 3 This is a pore size distribution diagram of the MOF molded body prepared in Comparative Example 10 of the present invention; Figure 4 This is a SEM image of the MOF molded body prepared in Example 2 of the present invention; Figure 5 This is a SEM image of the MOF molded body prepared in Comparative Example 9 of this invention; Figure 6 This is a photograph of the MOF molded body prepared in Example 1 of the present invention; Figure 7 This is a photograph of the MOF molded body prepared in Example 2 of the present invention; Figure 8 This is a photograph of the MOF molded body prepared in Comparative Example 4 of this invention. Figure 9 This is a photograph of the MOF molded body prepared in Comparative Example 1 of the present invention. Detailed Implementation

[0020] The present invention first provides a MOF molded body, which is spherical or short rod-shaped particles with a diameter of 0.5-8 mm, preferably 2-4 mm, a strength of 1N-200N, preferably 20-100N, more preferably 30-80N, and a pore structure in which micropores account for 30%-70%, preferably 35%-65%, more preferably 38%-62%, mesopores account for 10%-65%, preferably 20%-60%, more preferably 25%-50%, macropores account for 5%-40%, preferably 8%-20%, more preferably 10%-15%, and the particle tap density is 0.2-0.8 g / cm³, preferably 0.4-0.6 g / cm³.

[0021] The present invention also provides a method for preparing MOF molded articles, comprising: Step 1: Blending: MOF powder, water, and binder are blended to obtain a blend; wherein the water content accounts for 60%-400% of the mass of MOF powder, preferably 80%-220%, more preferably 120%-200%, and the binder accounts for 1%-20% of the mass of MOF powder, preferably 2%-15%, more preferably 3%-8%. Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated to obtain MOF particles; the diameter of the MOF particles is 0.5-8 mm; Step 3: Drying: The MOF particles from Step 2 are dried in a drying equipment to obtain MOF molded bodies; The total volume of MOF particles in the drying equipment shall not exceed 50% of the effective volume of the drying equipment, and the MOF particles shall be placed in a single layer or in layers, with each layer of particles having a stacking height of ≤10cm; when placed in layers, the number of layers shall be 2-40, preferably 4-25, and more preferably 6-20.

[0022] The drying process involves a first drying at 40-70°C, preferably 50-70°C, followed by a second drying at 80-180°C, preferably 100-150°C. According to the present invention, the drying equipment is not particularly limited, and is preferably a conventional drying equipment used in the art, such as a vacuum oven, tunnel oven, or forced-air oven. When a vacuum oven or forced-air oven is used, the first drying time is preferably 4-60 hours, more preferably 23-36 hours; the second drying time is preferably 1-80 hours, more preferably 18-50 hours. When a tunnel oven is used, the first drying time is preferably 1-60 minutes, more preferably 5-45 minutes, and most preferably 40-45 minutes; the second drying time is preferably 1-30 minutes, more preferably 3-25 minutes, and most preferably 20-21 minutes.

[0023] According to the present invention, the MOF powder mentioned in step one is preferably selected from one or more of the ZIF series, MIL series, UIO series, CAU series, Fum series, UTSA series, CALF series, HKUST series, amino acid series or MUF series, and more preferably ZIF-8, ZIF-67, MIL-101, MIL-53, UIO-66 or MUF-16.

[0024] According to the present invention, the adhesive described in step one is preferably selected from one or more of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), methylcellulose (MC), carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), hydroxyethylcellulose (HEC), starch, sodium alginate, gelatin, polyacrylic acid, polyacrylate, polyurethane, silica sol, aluminum sol, rubber latex, or PVAc latex.

[0025] According to the present invention, there are no special restrictions on the molding and granulation in step two, and existing conventional equipment can be used. Preferably, it is formed into spherical or short rod-shaped MOF particles by extrusion machine, rounding machine or pelletizing machine.

[0026] The preferred process conditions for using an extruder are: controlling the extruder speed at 80~120rpm, the feeding speed at 0.8~1.2kg / min, and the extrusion temperature at ≤40℃.

[0027] The preferred process conditions for using a round polishing machine are: controlling the round polishing speed at 200~1500 rpm and the round polishing time at 3~15 min.

[0028] The preferred process conditions for using a pellet mill are: controlling the pellet mill extrusion speed at 50~80 rpm, the feeding speed at 0.2~0.5 kg / min, and the pellet rolling speed at 15~20 rpm.

[0029] According to this invention, the drying process in step three must meet the dual requirements of "material accumulation and equipment volume matching + gradient temperature range", as follows: 1. Material and Equipment Volume Matching: In a drying equipment with an effective volume of 1m³, the total volume of MOF granules dried in a single batch should be ≤0.5m³ (not exceeding 50% of the effective volume of the equipment); and the granules should be placed in a single layer or layered flat arrangement, with each layer not exceeding 10cm in height, to ensure uniform heating and rapid moisture release, avoiding uneven drying due to excessive local density. If the effective volume of the drying equipment is adjusted, the total volume of granules dried in a single batch should be scaled up by 50% of the effective volume of the equipment, while maintaining a layer height of ≤10cm.

[0030] 2. Gradient Temperature Range and Its Function: The drying equipment used in this invention must follow a gradient temperature method of "drying at a low temperature first, then drying at a high temperature." The specific temperature ranges and their functions are as follows: 1) Low temperature stage: The temperature is controlled at 40-70℃. The core function of this stage is to control the number and size of mesopores and macropores. By slowly removing surface and shallow moisture from the particles, the rapid evaporation of moisture is prevented from damaging the pore structure, ensuring that the proportion of mesopores is maintained at 10%-65% and the proportion of macropores is maintained at 5%-40%.

[0031] 2) High temperature stage: The temperature is controlled at 80-180℃. The core function of this stage is to quickly solidify the shape under the controlled pore distribution state. By thoroughly removing residual moisture inside the particles, the mesoporous and macroporous structures are locked to prevent the channels from collapsing or deforming during subsequent use.

[0032] The present invention also provides the application of the above-mentioned MOF molded articles in the adsorption of formaldehyde and VOC odor molecules.

[0033] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given below are for further illustration of the present invention, but should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention. Unless otherwise stated, the raw materials and reagents used in this application are all commercially available products, or can be prepared by known methods.

[0034] Example 1: ZIF-8 spherical molded body, Step 1: Blending: ZIF-8 powder, water, and PVA binder are blended to obtain a blend; wherein the water content accounts for 150% of the MOF powder mass, and the PVA binder accounts for 5% of the MOF powder mass; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated on a rounding machine at a speed of 420 rpm for 5 minutes to obtain MOF particles; the diameter of the MOF particles is 3-4 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a vacuum oven with a particle stack volume of 0.4 m³, and layered flat (20 layers, 6 cm per layer); the low-temperature section is first dried at 50°C for 36 hours to control pores, and the high-temperature section is further dried at 100°C for 48 hours to solidify, thus obtaining the MOF molded body.

[0035] The MOF molded body prepared in Example 1 is spherical with a diameter of 3-4 mm, a strength of 50 N, and a porosity of 50%, mesopores of 37%, and macropores of 13%. The pore size distribution is shown in the figure below. Figure 1 As shown, the tap density is 0.5 g / cm³. A photograph of the actual object is shown below. Figure 6 As shown.

[0036] Example 2: MIL-101 Short Rod Molded Body Step 1: Blending: MIL-101 powder, water, and binder CMC are blended to obtain a blend; wherein the water content accounts for 120% of the MOF powder mass, and the binder CMC accounts for 8% of the MOF powder mass; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated on an extruder at a speed of 100 rpm and a feed rate of 1.0 kg / min to obtain MOF granules; the diameter of the MOF granules is 2-3 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a forced-air drying oven with a particle stack volume of 0.5m³, and layered flat (18 layers, 8cm per layer); the low-temperature section is first dried at 65℃ for 24 hours to control the pores, and the high-temperature section is further dried at 110℃ for 50 hours to set the shape, thus obtaining the MOF molded body.

[0037] The MOF molded body prepared in Example 2 is a short rod shape, and the SEM image is shown below. Figure 4 As shown, where, Figure 4 A is the SEM image of the particle surface. Figure 4 B is a SEM image of the particle cross-section. The molded body has a diameter of 2-3 mm, a strength of 80 N, a micropore content of 38%, a mesopore content of 50%, a macropore content of 12%, and a tap density of 0.4 g / cm³. A photograph of the actual product is shown below. Figure 7 As shown.

[0038] Example 3: UIO-66 spherical molded body Step 1: Blending: Blend UIO-66 powder, water, and PVP binder to obtain a blend; wherein the water content accounts for 200% of the MOF powder mass, and the PVP binder accounts for 3% of the MOF powder mass; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated on a rounding machine at a speed of 450 rpm for 5 minutes to obtain MOF particles; the diameter of the MOF particles is 2-3 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a tunnel oven (single layer without stacking); in the low-temperature section, they are first dried at 60°C for 40 minutes to control the pores, and in the high-temperature section, they are dried at 120°C for 20 minutes to solidify the shape, thus obtaining the MOF molded body.

[0039] The MOF molded body prepared in Example 3 is spherical with a diameter of 2-3 mm, a strength of 30 N, a micropore content of 52%, a mesopore content of 35%, a macropore content of 13%, and a tap density of 0.6 g / cm³.

[0040] Example 4: MUF-16 Spherical Molded Body Step 1: Blending: MUF-16 powder, water, and sodium alginate binder are blended to obtain a blend; wherein the water content accounts for 180% of the mass of MOF powder, and the sodium alginate binder accounts for 6% of the mass of MOF powder; Step 2: Forming and granulation: The blend from Step 1 is formed and granulated on a pelletizing machine. The extrusion speed is set to 70 rpm, the feed rate is 0.35 kg / min, and the pelletizing roller speed is 18 rpm to obtain MOF particles; the diameter of the MOF particles is 3-4 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a vacuum oven with a particle stacking volume of 0.35m³, and layered flat (15 layers, 7cm per layer); the low-temperature section is first dried at 45℃ for 35h to control the pores, and the high-temperature section is further dried at 130℃ for 21h to solidify the shape, thus obtaining the MOF molded body.

[0041] The MOF molded body prepared in Example 4 is spherical with a diameter of 3-4 mm, a strength of 45 N, a micropore content of 48%, a mesopore content of 42%, a macropore content of 10%, and a tap density of 0.5 g / cm³.

[0042] Example 5: MIL-53 Short Rod Molded Body Step 1: Blending: MIL-53 powder, water, and binder HPMC are blended to obtain a blend; wherein the water content accounts for 220% of the MOF powder mass, and the binder HPMC accounts for 7% of the MOF powder mass; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated on an extruder with a rotation speed of 90 rpm and a feed rate of 0.9 kg / min to obtain MOF granules; the diameter of the MOF granules is 3-4 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a vacuum oven with a particle stacking volume of 0.45m³, and layered flat (15 layers, 9cm per layer); the low-temperature section is first dried at 70℃ for 23h to control the pores, and the high-temperature section is further dried at 150℃ for 18h to solidify the shape, thus obtaining the MOF molded body.

[0043] The MOF molded body prepared in Example 5 is a short rod with a diameter of 3-4 mm, a strength of 60 N, a micropore content of 40%, a mesopore content of 45%, a macropore content of 15%, and a tap density of 0.5 g / cm³.

[0044] Example 6: MUF-16 Short Rod Molded Body Step 1: Blending: MUF-16 powder, water, and binder CMC are blended to obtain a blend; wherein the water content accounts for 160% of the mass of MOF powder, and the binder CMC accounts for 5% of the mass of MOF powder; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated on an extruder with a rotation speed of 80 rpm and a feed rate of 1.0 kg / min to obtain MOF granules; the diameter of the MOF granules is 2-3 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a tunnel oven; in the low-temperature section, they are first dried at 55°C for 45 minutes to control the pores, and in the high-temperature section, they are dried at 115°C for 21 minutes to solidify the shape, thus obtaining the MOF molded body.

[0045] The MOF molded body prepared in Example 6 is a short rod with a diameter of 3-4 mm, a strength of 55 N, a micropore content of 42%, a mesopore content of 43%, a macropore content of 15%, and a tap density of 0.5 g / cm³.

[0046] Example 7: ZIF-67 Spherical Molded Body Step 1: Blending: ZIF-67 powder, water, and PVA binder are blended to obtain a blend; wherein the water content accounts for 140% of the MOF powder mass, and the PVA binder accounts for 4% of the MOF powder mass; Step 2: Forming and granulation: The blend from Step 1 is formed and granulated on a pelletizing machine. The extrusion speed is set to 80 rpm, the feed rate is 0.45 kg / min, and the pelletizing roller speed is 20 rpm to obtain MOF particles; the diameter of the MOF particles is 2.5-3.5 mm. Step 3: Drying: The MOF particles from Step 2 are dried in a forced-air drying oven with a particle stack volume of 0.38m³, and layered flat (14 layers, 8cm per layer); the low-temperature section is first dried at 52℃ for 32h to control the pores, and the high-temperature section is further dried at 105℃ for 42h to fix the shape, thus obtaining the MOF molded body.

[0047] The MOF molded body prepared in Example 7 is spherical with a diameter of 2.5-3.5 mm, a strength of 38 N, a micropore content of 62%, a mesopore content of 25%, a macropore content of 13%, and a tap density of 0.5 g / cm³.

[0048] Comparative Example 1: ZIF-8 molded body with excessively low moisture content The preparation method and conditions are the same as in Example 1, except that the water content in step one accounts for 30% of the mass of the MOF powder.

[0049] The MOF molded body prepared in Comparative Example 1 was irregular in shape and cracked, as shown in the photograph. Figure 9 As shown, the molded body has a diameter of 2-5 mm, a strength of 20 N, a micropore content of 55%, a mesopore content of 30%, a macropore content of 15%, and a tap density of 0.7 g / cm³; the formaldehyde removal rate is 33% lower than that of Example 1.

[0050] Comparative Example 2: MIL-101 molded body with excessive moisture content The preparation method and conditions are the same as in Example 2, except that the water content in step one accounts for 450% of the mass of the MOF powder.

[0051] The MOF molded body prepared in Comparative Example 2 had a rough surface, a strength of 72 N, a micropore content of 30%, a mesopore content of 55%, a macropore content of 15%, and a tap density of 0.3 g / cm³; the toluene removal rate was 48% lower than that in Example 2.

[0052] Comparative Example 3: UIO-66 molded body with excessive adhesive content The preparation method and conditions are the same as in Example 3, except that the content of binder PVP in step one accounts for 25% of the mass of MOF powder.

[0053] The MOF molded body prepared in Comparative Example 3 was spherical in shape, with a strength of 220 N, micropores of 25%, mesopores of 60%, macropores of 15%, and tap density of 0.9 g / cm³; the toluene removal rate was one grade lower than that in Example 3.

[0054] Comparative Example 4: ZIF-8 molded body with insufficient adhesive content The preparation method and conditions are the same as in Example 1, except that the content of PVA binder in step one accounts for 0.5% of the mass of MOF powder.

[0055] The MOF molded body prepared in Comparative Example 4 was spherical in shape, with a strength of 5 N, prone to powder shedding, and contained 50% micropores, 38% mesopores, and 12% macropores, with a tap density of 0.4 g / cm³. Its service life was one-third that of Example 1 (due to lower strength). Actual product photos are shown below. Figure 8 As shown, Comparative Example 5: MIL-101 molded body dried without gradient drying The preparation method and conditions are the same as in Example 2, except that the drying in step three is only carried out at 65°C for 30 hours.

[0056] The MOF molded body prepared in Comparative Example 5 is a short rod shape with a strength of 50 N, a micropore content of 53%, a mesopore content of 35%, a macropore content of 12%, and a tap density of 0.35 g / cm³; the formaldehyde removal rate is 41% lower than that in Example 2.

[0057] Comparative Example 6: MIL-101 molded body with a low-temperature range below the specified range The preparation method and conditions are the same as in Example 2. The difference is that in step three, the drying is first carried out at 35°C for 30 hours, and then at 110°C for 40 hours in the high-temperature section.

[0058] The MOF molded body prepared in Comparative Example 6 was a short rod-shaped specimen with shrinkage deformation, a diameter of 1.8-2.8 mm, a strength of 65 N, and a porosity of 83% micropores, 4% mesopores, and 13% macropores. The pore size distribution is shown in the figure below. Figure 2 As shown, the tap density is 0.32 g / cm³; the formaldehyde removal rate is 57% of that in Example 2.

[0059] Comparative Example 7: ZIF-8 molded body with diameter exceeding the range The preparation method and conditions are the same as in Example 1, except that the control condition in step two is a time of 18 min, resulting in MOF particles with a diameter of 8-9 mm.

[0060] The MOF molded body prepared in Comparative Example 7 was spherical in shape, with a strength of 60 N, a micropore content of 48%, a mesopore content of 37%, a macropore content of 15%, and a tap density of 0.55 g / cm³; the toluene removal rate was 50% lower than that in Example 1.

[0061] Comparative Example 8: ZIF-8 molded body with a diameter <1mm The preparation method and conditions are the same as in Example 1, except that the control condition in step two is a rotation speed of 2000 rpm, resulting in MOF particles with a diameter of 0.6-0.9 mm.

[0062] The MOF molded body prepared in Comparative Example 8 was spherical in shape, with a strength of 5N (too low), 48% micropores, 39% mesopores, 13% macropores, and a tap density of 0.75 g / cm³. The gas resistance was 3.2 times that of Example 1 (due to the small diameter), and the formaldehyde removal rate was 58% within the same time period.

[0063] Comparative Example 9: MIL-101 molded body with excess material during drying The preparation method and conditions are the same as in Example 2, except that the particle packing volume in step 3 is 0.6 m³ (exceeding 50% volume limit, resulting in uneven local pore control).

[0064] The MOF molded body prepared in Comparative Example 9 showed partial particle cracking, as shown in the SEM image. Figure 5 As shown, where, Figure 5 A is the SEM image of the particle surface. Figure 5 B is a SEM image of the particle cross-section, with a diameter of 2.8-3.8 mm, a strength of 60 N (lower than 80 N in Example 2), 52% micropores, 33% mesopores, and 15% macropores (pore distribution deviates from Example 2), and a tap density of 0.42 g / cm³; formaldehyde removal rate of 72% (lower than 9% in Example 1), and wear rate of 2.3 times that of Example 2.

[0065] Comparative Example 10: ZIF-8 molded body with low mesopore / macropore ratio due to insufficient temperature in the high-temperature section The preparation method and conditions are the same as in Example 1. The difference is that in step three, the drying is first carried out at 50°C for 36 hours, and then at 75°C for 60 hours in the high-temperature section.

[0066] The MOF molded particles prepared in Comparative Example 10 were soft, with a strength of 32 N (lower than 50 N in Example 1), and contained 77% micropores, 8% mesopores, and 15% macropores (the combined proportion of mesopores and macropores was 23%, lower than 50% in Example 1). The pore size distribution is shown in the figure. Figure 3 As shown, the tap density is 0.48 g / cm³; the formaldehyde removal rate is 53% lower than that of Example 1 (due to slow mass transfer), and the formaldehyde adsorption capacity is 13.1 mg / g (lower than 18.5 mg / g in Example 1, due to residual moisture).

[0067] Application Example 1: Formaldehyde Adsorption Experiment Experimental conditions: 1m³ sealed experimental chamber, initial formaldehyde concentration of 1500 mg / m³, 25℃, relative humidity of 40%.

[0068] The experimental results are shown in Table 1: Table 1

[0069] Application Example 2: VOC Adsorption Experiment (Taking Toluene as an Example) Experimental conditions: 1 m³ experimental chamber, initial toluene concentration 1058 mg / m³, 25℃, relative humidity 40%.

[0070] The experimental results are shown in Table 2: Table 2

[0071] The above experimental results show that the MOF molded body of the present invention has significantly better performance than the comparative examples in terms of formaldehyde and VOC adsorption (formaldehyde removal rate ≥97%, toluene removal rate ≥95%). In particular, Comparative Example 6 (insufficient low temperature) and Comparative Example 10 (insufficient high temperature) demonstrate that if the drying temperature exceeds the low temperature range of 40-70℃ or the high temperature range of 80-180℃, it will lead to uncontrolled mesopores / macropores and a decrease in adsorption rate, further demonstrating the necessity of the "gradient temperature range (pore control + shaping)" limitation of the present invention.

[0072] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A MOF molded article, characterized in that, The molded body is in the shape of spherical or short rod-shaped particles with a diameter of 0.5-8 mm, a strength of 1N-200N, and a pore structure in which micropores account for 30%-70%, mesopores account for 10%-65%, macropores account for 5%-40%, and the particle tap density is 0.2-0.8 g / cm³.

2. The method for preparing a MOF molded article according to claim 1, characterized in that, include: Step 1: Blending: Blend MOF powder, water, and binder to obtain a blend; wherein the water content accounts for 60%-400% of the mass of MOF powder, and the binder accounts for 1%-20% of the mass of MOF powder; Step 2: Molding and granulation: The blend from Step 1 is shaped and granulated to obtain MOF particles; the diameter of the MOF particles is 0.5-8 mm; Step 3: Drying: The MOF particles from step two are dried in a drying equipment to obtain MOF molded bodies; The total volume of MOF particles in the drying equipment shall not exceed 50% of the effective volume of the drying equipment, and the MOF particles shall be placed in a single layer or in layers, with each layer of particles having a stacking height of ≤10cm. The drying process involves a first drying at 40-70℃, followed by a second drying at 80-180℃.

3. The method for preparing a MOF molded article according to claim 2, characterized in that, The MOF powder mentioned in step one is selected from one or more of the ZIF series, MIL series, UIO series, CAU series, Fum series, UTSA series, CALF series, HKUST series, amino acid series or MUF series.

4. The method for preparing a MOF molded article according to claim 2, characterized in that, The adhesive mentioned in step one is selected from one or more of polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose, carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxyethylcellulose, starch, sodium alginate, gelatin, polyacrylic acid, polyacrylate, polyurethane, silica sol, aluminum sol, rubber latex, or PVAc latex.

5. The method for preparing a MOF molded article according to claim 2, characterized in that, The molding and granulation process described in step two involves forming spherical or short rod-shaped MOF particles using an extruder, a rounding machine, or a pelletizing machine.

6. The method for preparing a MOF molded article according to claim 5, characterized in that, The molding and granulation process described in step two uses the following process conditions for an extruder: the extruder speed is controlled at 80~120 rpm, the feed rate is controlled at 0.8~1.2 kg / min, and the extrusion temperature is ≤40℃.

7. The method for preparing a MOF molded article according to claim 5, characterized in that, The molding and granulation process described in step two uses a rounding machine with the following process conditions: rounding speed controlled at 200-1500 rpm, and rounding time at 3-15 min.

8. The method for preparing a MOF molded article according to claim 5, characterized in that, The granulation process described in step two uses a pelletizing machine with the following process conditions: the extrusion speed of the pelletizing machine is controlled at 50~80 rpm, the feeding speed is controlled at 0.2~0.5 kg / min, and the pelletizing roller speed is controlled at 15~20 rpm.

9. The method for preparing a MOF molded article according to claim 2, characterized in that, When placing the items in a layered, flat manner as described in step three, the number of layers is 2-40.

10. The MOF molded body according to claim 1 is used in the adsorption of formaldehyde and VOC odor molecules.

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