CN111589311A - Method for preparing metal organic framework molecular sieve membrane by supercritical fluid technology - Google Patents
Method for preparing metal organic framework molecular sieve membrane by supercritical fluid technology Download PDFInfo
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Abstract
The invention discloses a method for preparing a Metal-Organic Framework (MOF) molecular sieve membrane by a supercritical fluid technology. Firstly, a porous carrier (supporting matrix) modified by a compact metal precursor layer and solid organic ligand powder are placed in a reactor cavity in a supercritical kettle and are subjected to supercritical fluid (CO)2) Under the action, the solid organic ligand in the cavity is gradually dissolved to form a homogeneous reaction system, and the homogeneous reaction system and the metal precursor layer are subjected to coordination reaction in an interface region to form a continuous MOF molecular sieve film layer which has excellent gas separation performance. In addition, the process for preparing the molecular sieve membrane by the supercritical fluid process realizes zero emission and green cyclic utilization of all chemical reagents. In a word, the MOF molecular sieve membrane is prepared by utilizing the supercritical fluid technology, and the green and environment-friendly membrane preparation process can be considered at the same timeExcellent separation performance with molecular sieve membrane, thus having good industrial application prospect.
Description
Technical Field
The invention belongs to the technical field of membrane separation, and particularly relates to a method for preparing an MOF molecular sieve membrane by a supercritical fluid technology and gas separation application thereof.
Background
The chemical separation process is one of the important energy consumption steps in the chemical industry. The traditional separation technologies such as rectification separation and the like are complex to operate and have huge energy consumption, so that a novel separation technology is urgently needed to be developed. The membrane separation technology is widely concerned due to the advantages of simple operation, high separation efficiency, environmental protection and the like. In recent years, polymer membranes have been widely used in various gas-liquid separation systems, but the separation performance of the polymer membranes is greatly affected by the Trade-off effect, and the further large-scale application of the polymer membranes is limited by the problems that the membrane materials are easy to plasticize and pollute under severe conditions such as high temperature and high pressure. The polycrystalline molecular sieve membrane is a continuous, compact and uniform molecular sieve membrane layer growing on a porous carrier, and the excellent sieving performance of the polycrystalline molecular sieve membrane provides a new idea for the development of membrane separation. The MOF material is widely used for preparing a polycrystalline molecular sieve membrane due to the advantages of uniform and adjustable pore diameter, rich functional groups, stable framework structure and the like. The MOF membrane has great application potential in the fields of gas separation, pervaporation, desalination, nanofiltration, ultrafiltration, reverse osmosis, microfiltration, chromatographic separation, ion screening, membrane catalysis, photoelectric sensing and the like. The current preparation process of the MOF molecular sieve membrane is developed at a high speed, but the sustainability of the preparation process and the excellence of the membrane performance are still difficult to be simultaneously considered. For example, the introduction of a liquid phase solvent during the preparation process of a classical liquid phase synthesis method (including a hydrothermal/solvothermal method, a layer-by-layer self-assembly method, an interface microfluid method, a back diffusion method and the like) inevitably causes a large amount of consumption and waste of expensive precursor solution, and seriously pollutes the environment; the solid phase synthesis method is difficult to prepare a molecular sieve film with excellent separation performance; the problems of harsh operating conditions, expensive equipment and the like of the gas phase conversion method also limit the large-scale application of the gas phase conversion method. Therefore, the development of a novel efficient green and environment-friendly MOF molecular sieve membrane preparation process is still necessary.
Supercritical fluid is a homogeneous fluid with a temperature and pressure higher than its critical point. As a green solvent, the supercritical fluid has various excellent characteristics due to its unique supercritical phase (different from the traditional liquid phase and gas phase), such as high solubility of the liquid-like substance and high diffusibility of the gas-like substance, low viscosity, zero surface tension, etc., and is widely used for chemical reaction and separation and purification in the fields of medicine, chemical engineering, food and environmental protection. In particular, compared to conventional liquid phase solvents, solvents in the supercritical state have the following unique advantages: 1) zero surface tension, low viscosity, high diffusion rate and high dissolving capacity, and is very favorable for making up for nanometer intercrystalline defects in the molecular sieve membrane, thereby being favorable for remarkably improving the separation performance of the MOF membrane; 2) the supercritical fluid is easy to switch between different phases and easy to control the solubility. In the membrane preparation process, the mild transformation of the solvent between the supercritical state and the gaseous state can be regulated and controlled only by changing the temperature and the pressure, so that the supercritical fluid and a reaction reagent (an expensive and environmentally harmful organic ligand) dissolved in the supercritical fluid can be automatically separated, the supercritical fluid is convenient to efficiently recover and reuse, and the zero emission and the sustainability of the preparation process are realized. Therefore, the MOF molecular sieve membrane prepared by the supercritical fluid technology can simultaneously realize the sustainability of the membrane preparation process and the excellence of the membrane separation performance, and has wide large-scale application prospect.
Disclosure of Invention
The invention researches the potential application of the supercritical technology in the synthesis of MOF molecular sieve membranes and invents a method for preparing the MOF molecular sieve membranes by the supercritical fluid technology. By using supercritical CO2The fluid is used as a green reaction medium, the MOF molecular sieve membrane with good separation performance is prepared on a commercial porous carrier modified by a metal precursor layer, and the problem that the preparation process is green and environment-friendly and the separation performance is excellent in the current membrane preparation process is effectively solved, so that long-term toggle is difficult to combine. In a word, the preparation of the MOF molecular sieve membrane by using the supercritical fluid has the advantages of environmental protection of an industrial route, high-efficiency recycling of chemical reagents, zero discharge of chemical reagents, excellent membrane separation performance and the like, thereby having wide application prospect.
In the invention, the dense and continuous MOF molecular sieve membrane is prepared by the following steps:
1) a porous carrier modified by a compact metal precursor layer is used as a supporting substrate and is placed in the micro-reactor cavity;
2) placing solid organic ligand powder in a micro-reactor cavity, and placing the micro-reactor cavity in a supercritical kettle;
3) gaseous CO2High pressure enters the supercritical kettle after the action of a matched compressor, and the pressure and the temperature in the kettle are adjusted to realizeGaseous CO2To supercritical CO2Conversion of the fluid followed by supercritical CO2The fluid diffuses into the microreactor chamber;
4) in supercritical CO2Under the action of fluid, the solid organic ligand powder in the cavity is gradually dissolved and diffused to form uniform supercritical CO which can fully dissolve the organic ligand2A homogeneous reaction system;
5) in the cavity, CO in supercritical state2Organic ligand molecules fully dissolved in a homogeneous reaction system and a metal precursor layer on the surface of the carrier generate coordination in an interface region, and are gradually converted to form a continuous and compact MOF molecular sieve membrane layer;
6) after the reaction is finished, the pressure is released and the temperature is reduced, so that the organic ligand/supercritical CO remained in the reactor cavity in the kettle2The homogeneous solution automatically generates phase separation, the solid organic ligand powder stays in the micro-reactor cavity for recovery, and the gaseous CO2Releasing and recovering through a supercritical kettle exhaust port, and taking out the MOF molecular sieve membrane. Finally, all chemical reagents and reaction media participating in the reaction can be efficiently recovered and reused, so that the process for preparing the MOF molecular sieve membrane by using the supercritical fluid has sustainability.
Preferably, the structure of the porous carrier in the step 1) is a flat plate type, a tubular type or a hollow fiber type; the porous carrier is a porous metal oxide, porous metal or porous non-metal oxide carrier. Further, the porous metal oxide is porous alumina, porous titania, porous zirconia, or porous YSZ; the porous metal is porous stainless steel or porous nickel; the porous non-metal oxide is porous silicon oxide, porous glass or porous silicon carbide. Furthermore, the porous carrier is a flat plate type porous alumina carrier.
Preferably, the metal precursor layer in step 1) is a metal oxide, a metal hydroxide or a metal salt; the metal element in the metal precursor layer is zinc, magnesium, zirconium, iron, cobalt, nickel or copper. The metal oxide is zinc oxide (ZnO), magnesium oxide (MgO) or zirconium dioxide (ZrO)2) Iron-series oxide, cobalt-series oxide, nickelOxides of the series iron or copper, wherein the oxides of the series iron are FeO, Fe2O3Or Fe3O4The cobalt series oxide is Co2O3Or Co3O4The nickel series oxide is NiO, Ni3O4Or Ni2O3The copper series oxide is CuO or Cu2O; the metal hydroxide and the metal salt are the corresponding metal hydroxide and metal salt of the aforementioned various metals (metals involved in the metal oxide), and the metal salt is carbonate, nitrate, chloride, sulfate or acetate. Further, the metal precursor layer is a metal oxide, and further, the metal precursor layer is a zinc oxide (ZnO) layer.
Preferably, in the step 1), the carrier is modified by a physical deposition method (such as spin/dip coating or magnetron sputtering), a chemical deposition method (such as sol-gel, chemical reaction or electrochemical deposition), a Chemical Vapor Deposition (CVD) or an Atomic Layer Deposition (ALD); the deposition thickness of the metal precursor layer is 10 nm-20 μm, and the particle size is 10 nm-5 μm. Further, the metal precursor layer modification process is a chemical deposition method (sol-gel).
Preferably, the microreactor in the step 1) is of a semi-permeable type or a full-permeable type, the semi-permeable type is provided with holes at the lower part, the full-permeable type is provided with holes all over, and the hole diameter is 50-6000 meshes. Furthermore, the micro-reactor is a semi-permeable reactor with a pore size of 200-1000 meshes.
Preferably, the organic ligand in the step 2) is at least one of imidazole, carboxylic acid and pyridine ligands. Further, the organic ligand is at least one of imidazole and carboxylic acid organic ligand. Further, the organic ligand is a 2-methylimidazole organic ligand.
Preference is given to CO in the supercritical state as described in step 3)2The temperature range of the pressure sensor is 31.1-150.0 ℃, and the pressure range of the pressure sensor is 7.4-100.0 MPa. Further, CO in a supercritical state2More preferably, the temperature is 35.0 to 100.0 ℃ and the pressure is 10.0 to 50.0 MPa.
Preference is given to CO in the supercritical state as described in step 4)2Homogeneous phase reactorThe concentration of the organic ligand (the number of moles of the organic ligand/volume of the container) is preferably 0.0001 to 10 mol/l. Further, the supercritical CO2The concentration of organic ligand in the homogeneous reaction system (mol number of organic ligand/volume of container) is 0.03-0.3 mol/l.
Preferably, the growth cycle of the supercritical single flow in the step 5) is 0.1-96 h. Furthermore, the growth period of the single process in the supercritical state is 6-36 h.
The MOF molecular sieve membrane prepared in the step 5) is preferably molecular sieve membranes of HKUST-1 series, ZIF series, MOF-74 series, MIL series, UiO series or IRMOF series; the thickness of the MOF molecular sieve membrane is 10 nm-20 μm, and the grain size is 10 nm-5 μm. Further, the MOF molecular sieve membrane is a ZIF-8 molecular sieve membrane.
Supercritical CO described in step 6)2The preferred decompression rate is 0.01-5 MPa/min, and the preferred cooling rate is 0.1-10 ℃/min.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. the method provided by the invention is to convert a dense metal precursor layer of a support matrix into a continuous MOF molecular sieve membrane layer in a supercritical fluid reaction medium. In the reaction process, the greenhouse gas CO is utilized2As a separate reaction solvent to produce a high value-added molecular sieve membrane, CO2Provides a new idea for sustainable utilization. Meanwhile, due to the characteristics of the supercritical fluid, the phase state of the system can be easily regulated and controlled through temperature and pressure, so that CO is converted into CO2The solvent and the organic ligand spontaneously separate after the reaction is finished, so that the solvent and the organic ligand can be efficiently recovered and recycled, and a sustainable membrane preparation process is realized.
2. The method provided by the invention is growth in a supercritical fluid medium. By utilizing the unique properties of the supercritical fluid, such as zero surface tension, low viscosity, high diffusion coefficient, high dissolving capacity and the like, and CO in a supercritical state2Organic ligand molecules fully dissolved in a homogeneous reaction system can freely enter intergranular defects formed by the MOF molecular sieve membrane layer at the initial growth stage, so that the continuous growth and repair of the defects are promoted, and the MOF molecular sieve membrane layer with good connectivity is finally formed, and gas is generatedSeparation tests show that the MOF molecular sieve membrane prepared by the supercritical fluid technology has excellent gas separation performance and further has wide application prospect.
Drawings/table description:
FIG. 1 is an X-ray diffraction (XRD) pattern of a porous support modified with a ZnO layer prepared in example 1;
FIG. 2 is a Scanning Electron Microscope (SEM) image of a ZnO layer-modified porous support prepared in example 1;
FIG. 3 is an XRD pattern of a ZIF-8 film prepared in example 2;
FIG. 4 is an SEM image of a ZIF-8 thin film prepared in example 2;
FIG. 5 is an XRD pattern of the recovered ligand powder of example 2;
FIG. 6 is an XRD pattern of a ZIF-8 film prepared in example 3;
FIG. 7 is an SEM image of a ZIF-8 thin film prepared in example 3;
FIG. 8 is an XRD pattern of a ZIF-8 film prepared in example 4;
FIG. 9 is an SEM image of a ZIF-8 thin film prepared in example 4;
FIG. 10 is an XRD pattern of a ZIF-8 film prepared in example 5;
FIG. 11 is an SEM image of a ZIF-8 thin film prepared in example 5;
FIG. 12 is an XRD pattern of a ZIF-8 film prepared in example 6;
FIG. 13 is an SEM image of a ZIF-8 thin film prepared in example 6;
FIG. 14 is an XRD pattern of a ZIF-8 film prepared in example 7;
FIG. 15 is an SEM image of a ZIF-8 thin film prepared in example 7;
FIG. 16 is an XRD pattern of a ZIF-67 film prepared in example 9;
FIG. 17 is an SEM image of a ZIF-67 thin film prepared in example 9;
FIG. 18 is an XRD pattern of the HKUST-1 thin film prepared in example 10;
FIG. 19 is an SEM image of a HKUST-1 thin film prepared in example 10;
FIG. 20 is an XRD pattern of the Mg-MOF-74 thin film prepared in example 11;
FIG. 21 is an SEM image of a Mg-MOF-74 thin film prepared in example 11;
FIG. 22 is the XRD pattern of the UiO-66 film prepared in example 12;
FIG. 23 is an SEM image of a UiO-66 thin film prepared in example 12;
FIG. 24 is an XRD pattern of a ZIF-8 film prepared in comparative example 1;
FIG. 25 is an SEM image of a ZIF-8 film prepared in comparative example 1;
Detailed Description
The present invention will be described in further detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
Example 1
Metal oxide layer modified porous support: deposition by sol-gel method
(1) And dispersing and dissolving the metal salt in an organic solvent, stirring to form a homogeneous solution, and adding an alcohol amine aging metal salt solution to obtain the stable metal-based sol.
(2) Coating the metal-based sol on a clean porous alumina carrier (the flat plate type/tubular type carrier is coated by a spin-coating method/dip-coating method respectively, and the coating is repeated for 2-3 times), and then carrying out calcination heat treatment to remove the solvent, thus obtaining the dense porous carrier modified by the metal oxide layer.
(3) The modification steps of the sol-gel method for depositing the metal oxide layer in this example 1 are well-established preparation processes, and do not fall within the scope of the present invention.
The method is used for preparing the uniform and compact zinc oxide modification layer on the flat plate type porous alumina carrier, and XRD (figure 1) and SEM (figure 2) show that the uniform and compact zinc oxide modification layer is successfully prepared on the porous alumina carrier, and the detailed synthesis process references (J.Mater.chem.A., 2013,1, 10635.).
The method is used for preparing uniform and compact cobaltosic oxide on the flat plate type porous alumina carrier(Co3O4) Modification layer, detailed synthetic procedure reference (j.memb.sci.,2019,573,200.).
The method is used for preparing uniform and compact zirconium dioxide (ZrO) on a flat plate type porous alumina carrier2) Modification layer, detailed synthetic procedure reference (j.memb.sci.,2018,556, 54.).
Example 2
Preparation of ZIF-8 membrane by supercritical fluid technology
1. The flat plate type porous alumina carrier support layer modified by the zinc oxide (ZnO) layer prepared in the example 1 is placed above a semi-permeable micro-reactor cavity in a supercritical kettle, and 200mg of solid 2-methylimidazole (2-mIm) ligand powder after grinding is placed below the micro-reactor cavity. Subsequent gaseous CO2High pressure enters into the supercritical kettle through a preposed compressor, and CO is generated2Is gradually increased to 10MPa and the temperature is increased to 95 ℃ while the gaseous CO is present2Conversion to supercritical CO2And diffused from below the microreactor into the cavity thereof.
2. In the cavity, CO in supercritical state2The solvent gradually dissolves 2-mIm solid powder below the cavity to form uniform supercritical CO fully dissolving the organic ligand2Homogeneous reaction system, and supercritical CO diffusion filled into the whole micro reactor cavity2The concentration of 2-mIm in the homogeneous reaction system was about 0.03 mol/l. In the area near the interface of the carrier supporting layer modified by the ZnO layer, the dissolved 2-mIm molecules and ZnO modified on the surface of the carrier generate coordination reaction, and the compact ZnO layer is converted into a continuous defect-free ZIF-8 molecular sieve film layer after 24h of supercritical state growth (single flow growth period).
3. After the reaction is finished, the temperature controller is closed, and the temperature reduction rate of the supercritical kettle is about 4 ℃/min. And simultaneously opening an exhaust port of the supercritical kettle to reduce the pressure, wherein the pressure reduction rate is about 0.02 MPa/min. Supercritical CO fully dissolving organic ligand in temperature and pressure reduction process2The homogeneous reaction system automatically generates phase separation and supercritical CO2CO of solvent changed into gas2Removing and recovering from the lower part of the cavity, and taking out the rest unreacted powderMOF molecular sieve membranes, hence CO2The solvent and the organic ligand can be efficiently recovered and reused, and the zero-emission sustainable molecular sieve membrane preparation process is realized.
Typical ZIF-8 characteristic diffraction peaks appear in XRD (figure 3), and the ZnO layer modified on the surface of the porous carrier is proved to be converted into a ZIF-8 film layer; SEM (figure 4) shows that the surface of the prepared ZIF-8 film is continuous and compact and has no obvious defects. Meanwhile, XRD (figure 5) also proves that the recovered organic ligand powder still maintains a good diffraction peak of a 2-mIm crystal structure without introducing any impurities.
Example 3
Preparation of ZIF-8 membrane by supercritical fluid technology
The difference from example 2 is that: in step 1, CO2The pressure was gradually increased to 10MPa and the temperature was increased to 35 ℃ and the rest of the procedure was the same as in example 2.
XRD (FIG. 6) and SEM (FIG. 7) demonstrated that the porous support surface modified ZnO layer converted to a dense ZIF-8 film.
Example 4
Preparation of ZIF-8 membrane by supercritical fluid technology
The difference from example 2 is that: in step 1, CO2The pressure was gradually increased to 50MPa and the temperature was increased to 95 ℃ and the rest of the procedure was the same as in example 2.
XRD (FIG. 8) and SEM (FIG. 9) demonstrated that the porous support surface modified ZnO layer converted to a dense ZIF-8 film.
Example 5
Preparing a ZIF-8 membrane by a supercritical fluid technology: recovery of 2-mIm ligand for reuse
The difference from example 2 is that: in the step 1, 500mg of solid 2-mIm ligand powder which is recycled and reused is ground for 5min again, and then the ground powder is placed below a micro-reactor cavity in a supercritical kettle, and supercritical CO is used for purifying2The concentration of 2-mIm in the homogeneous reaction system was about 0.075mol/l, and the rest of the procedure was the same as in example 2.
XRD (fig. 10) and SEM (fig. 11) demonstrated that the use of recovered 2-mIm solid powder was still reusable for the conversion of dense ZIF-8 thin films.
Example 6
Preparing a ZIF-8 membrane by a supercritical fluid technology: physical deposition
The difference from example 2 is that: in step 1, the sol-gel preparation method was replaced by physical deposition, and a ZnO layer-modified porous support layer (detailed synthetic process reference, published by luminography, 2008,03,455.) prepared by physical deposition was placed over the microreactor cavity in the supercritical reactor, and the rest of the steps were the same as in example 2. The metal oxide layer modification steps in the same example are well-established preparation processes, and do not fall within the scope of the present invention.
XRD (FIG. 12) and SEM (FIG. 13) demonstrated that the physically deposited modified ZnO layer on the surface of the porous support turned into a dense ZIF-8 film.
Example 7
Preparing a ZIF-8 membrane by a supercritical fluid technology: tubular porous alumina carrier
The difference from example 2 is that: in step 1, the flat plate type porous alumina prepared in example 1 is replaced with tubular porous alumina carrier to prepare a uniform and dense zinc oxide modification layer, a tubular porous alumina carrier support layer modified by a ZnO layer is suspended and placed above a cavity of a semi-permeable microreactor in a supercritical kettle, wherein the outer surface coated with the ZnO layer is exposed in the cavity, and the rest steps are the same as those in example 2.
XRD (FIG. 14) and SEM (FIG. 15) demonstrated that the surface-modified ZnO layer of the tubular porous support was converted to a dense ZIF-8 film.
Example 8
An MOF film: gas separation performance
H-treatment of the ZIF-8 film obtained in example 22/N2,H2/CH4And C3H6/C3H8And (5) mixed gas separation testing. At room temperature, the feed gas ratio was 1: 1, the permeation side is at normal pressure, and the sweep gas is helium.
Table 1 shows the gas separation performance of the ZIF-8 membrane, and the results show that the ZIF-8 membrane prepared by the supercritical fluid technology has excellent H2/N2，H2/CH4And C3H6/C3H8Separation performance.
TABLE 1ZIF-8 Membrane gas separation Performance
Example 9
Preparation of ZIF-67 membrane by supercritical fluid technology
1. Tricobalt tetraoxide (Co) prepared in example 13O4) The layer-modified flat plate type porous alumina carrier is placed above a semi-permeable micro-reactor cavity in a supercritical kettle, and 2000mg of ground solid 2-mIm ligand powder is placed below the micro-reactor cavity in the supercritical kettle. Supercritical CO2The concentration of 2-mIm in the homogeneous reaction system is about 0.3mol/l, and the reaction system is in supercritical CO2Surface modified Co under the action of fluid3O4The layer eventually transformed into a dense ZIF-67 membrane layer. CO as solvent CO2And the organic ligand can be efficiently recovered and recycled, and the zero-emission sustainable molecular sieve membrane preparation process is realized.
2. Specific experimental procedure and supercritical CO2The parameters were the same as in example 2.
XRD (FIG. 16) and SEM (FIG. 17) demonstrate surface modified Co on porous support3O4The layer was converted to a dense ZIF-67 film.
Example 10
Preparation of HKUST-1 membrane by supercritical fluid technology
1. In this example 10, a porous alumina support was modified by depositing a metallic copper layer by a chemical reaction method, followed by calcination to obtain a copper oxide (CuO) layer. Firstly, dissolving copper sulfate pentahydrate, rochelle salt and sodium hydroxide in a formaldehyde water phase solution to prepare a chemical plating solution; then soaking the clean carrier in a chemical plating solution to obtain a metal copper deposition layer; finally, the alumina carrier is placed in a muffle furnace to be calcined to obtain the compact CuO layer modified flat-plate type alumina carrier, which is a detailed synthetic process reference (Compos. Sci. Technol.,2010,70, 2269.). The metal oxide layer modification steps in the same example are well-established preparation processes, and do not fall within the scope of the present invention.
2. Placing the alumina carrier modified by the copper oxide (CuO) layer prepared in the step 1 above a semi-permeable micro-reactor cavity in a supercritical kettle, and placing 800mg of ground solid 1.3.5-trimesic acid ligand powder below the micro-reactor cavity in the supercritical kettle. Supercritical CO2The concentration of 1.3.5-trimesic acid in the homogeneous reaction system is about 0.05mol/l, and the reaction system is under supercritical CO2Under the action of the fluid, the CuO layer with the modified surface is finally converted into a compact HKUST-1 film layer. CO as solvent CO2And the organic ligand can be efficiently recovered and recycled, and the zero-emission sustainable molecular sieve membrane preparation process is realized.
3. Specific experimental procedure and supercritical CO2With reference to example 2, the difference from example 2 is that: in step 1, CO2The pressure was gradually increased to 30MPa and the temperature was increased to 95 ℃ and the rest of the procedure was the same as in example 2.
XRD (FIG. 18) and SEM (FIG. 19) demonstrated that the porous support surface-modified CuO layer converted to a dense HKUST-1 thin film.
Example 11
Preparation of Mg-MOF-74 membrane by supercritical fluid technology
1. In this example 11, a magnesium carbonate layer was deposited by a chemical reaction method, and then a porous alumina support was modified by a magnesium oxide (MgO) layer obtained by calcination. Firstly, dissolving magnesium chloride and urea in a deionized water solution and uniformly stirring; then soaking the clean carrier in the solution, and obtaining the alumina carrier modified by the compact magnesium carbonate layer after hydrothermal reaction; and finally, placing the mixture in a muffle furnace for calcination to obtain a compact MgO layer modified flat-plate type alumina carrier, which is a reference in the detailed synthesis process (ceramics, int, 2009,35, 3355). The metal oxide layer modification steps in the same example are well-established preparation processes, and do not fall within the scope of the present invention.
2. Placing the alumina carrier modified by the magnesium oxide layer prepared in the step (1) above a semi-permeable micro-reactor cavity in a supercritical kettle, and placing 1000mg of ground solid 2, 5-dihydroxy terephthalic acid ligand powder in a supercritical kettleThe lower part of the micro reactor cavity in the boundary kettle. Supercritical CO2The concentration of 2, 5-dihydroxyterephthalic acid in the homogeneous reaction system is about 0.06mol/l in the supercritical CO2Under the action of the fluid, the surface modified MgO layer is finally converted into a compact Mg-MOF-74 film layer. While the solvent CO is2And the organic ligand can be efficiently recovered and recycled, and the zero-emission sustainable molecular sieve membrane preparation process is realized.
3. Specific experimental procedure and supercritical CO2With reference to example 2, the difference from example 2 is that: in step 1, CO2The pressure was gradually increased to 30MPa, the temperature was increased to 95 ℃ and the supercritical growth period in step 2 was 36 hours, and the rest of the procedure was the same as in example 2.
XRD (FIG. 20) and SEM (FIG. 21) demonstrate the conversion of the porous support surface modified MgO layer into a dense Mg-MOF-74 thin film.
Example 12
Preparation of UiO-66 film by supercritical fluid technology
1. Zirconium dioxide (ZrO) prepared in example 12) The layer-modified porous alumina carrier is placed above a semi-permeable microreactor cavity in a supercritical kettle, and 2000mg of ground solid terephthalic acid ligand is placed below a microreactor cavity in the supercritical kettle. Supercritical CO2The concentration of terephthalic acid in the homogeneous reaction system is about 0.15mol/l, and the reaction system is under supercritical CO2Surface-modified ZrO by the action of a fluid2The layer eventually transforms into a dense UiO-66 film layer. CO as solvent CO2And the organic ligand can be efficiently recovered and recycled, and the zero-emission sustainable molecular sieve membrane preparation process is realized.
2. Specific experimental procedure and supercritical CO2With reference to example 2, the difference from example 2 is that: in step 1, CO2The pressure was gradually increased to 50MPa and the temperature was increased to 95 c, and the supercritical growth period in step 2 was 36 hours, and the rest of the procedure was the same as in example 2.
XRD (FIG. 22) and SEM (FIG. 23) demonstrate surface-modified ZrO on porous supports2The layer was converted to a dense UiO-66 film.
Comparative example 1
Liquid CO2Preparation of MOF molecular Sieve membranes (not according to the invention)
The difference from example 2 is that: in step 1, CO2Is gradually increased to 10MPa and the temperature is increased to 25 ℃, at which time the liquid CO is2Enters the cavity from the lower part of the microreactor. The remaining steps were the same as in example 2.
XRD (FIG. 24) and SEM (FIG. 25) demonstrate liquid CO2And only sporadic ZIF-8 crystals are sparsely distributed on the surface of the ZnO modified porous alumina carrier, and no compact ZIF-8 film is generated. Thus, the results of comparative example 1 demonstrate that: in the present invention, CO in a supercritical state2The solvent is a necessary link for preparing the continuous and compact MOF molecular sieve membrane.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A method for preparing a metal organic framework molecular sieve membrane by a supercritical fluid technology is characterized by comprising the following steps:
1) a porous carrier modified by a compact metal precursor layer is used as a supporting substrate and is placed in the micro-reactor cavity;
2) placing solid organic ligand powder in a micro-reactor cavity, and placing the micro-reactor cavity in a supercritical kettle;
3) gaseous CO2High pressure enters the supercritical kettle after the action of a matched compressor, and gaseous CO is realized by adjusting the pressure and the temperature in the kettle2To supercritical CO2Conversion of the fluid followed by supercritical CO2Diffusing the fluid into the microreactor chamber;
4) in supercritical CO2Under the action of fluid, the solid organic ligand powder in the cavity is gradually dissolved and diffused to form uniform supercritical CO which can fully dissolve the organic ligand2A homogeneous reaction system;
5) in the cavity, CO in supercritical state2Organic ligand molecules fully dissolved in a homogeneous reaction system and a metal precursor layer on the surface of the carrier generate coordination in an interface region, and are gradually converted to form a continuous and compact MOF molecular sieve membrane layer;
6) after the reaction is finished, the organic ligand/supercritical CO remained in the reactor cavity in the kettle is released by releasing the pressure and reducing the temperature2The homogeneous solution automatically generates phase separation, the solid organic ligand powder stays in the micro-reactor cavity for recovery, and the gaseous CO2Releasing and recovering through a supercritical kettle exhaust port, and taking out the MOF molecular sieve membrane.
2. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1, wherein the structure of the porous carrier in the step 1) is a flat plate type, a tubular type or a hollow fiber type; the porous carrier is a porous metal oxide, porous metal or porous non-metal oxide carrier.
3. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1, wherein the metal precursor layer in the step 1) is a metal oxide, a metal hydroxide or a metal salt, and the metal element in the metal precursor layer is zinc, magnesium, zirconium, iron, cobalt, nickel or copper; the organic ligand in the step 2) is at least one of imidazole, carboxylic acid and pyridine ligands.
4. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology as claimed in claim 1, wherein the carrier is modified by the metal precursor layer modification process in step 1) by physical deposition, chemical vapor deposition or atomic layer deposition, the deposition thickness of the metal precursor layer is 10 nm-20 μm, and the particle size is 10 nm-5 μm.
5. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1, wherein the microreactor in the step 1) is a semi-permeable or full-permeable reactor, and the pore diameter is 50-6000 meshes.
6. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1, wherein the supercritical CO in the step 3)2The temperature range of the pressure sensor is 31.1-150.0 ℃, and the pressure range of the pressure sensor is 7.4-100.0 MPa.
7. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1 or 3, wherein the supercritical CO in the step 4)2The concentration of the organic ligand in the homogeneous reaction system is 0.0001-10 mol/l.
8. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1, wherein the supercritical single-pass growth period in the step 5) is 0.1-96 h.
9. The method for preparing the metal organic framework molecular sieve membrane by the supercritical fluid technology according to claim 1, wherein the MOF molecular sieve membrane prepared in the step 5) is a HKUST-1 series, a ZIF series, an MOF-74 series, an MIL series, an UO series or an IRMOF series molecular sieve membrane; the thickness of the MOF molecular sieve membrane is 10 nm-20 μm, and the grain size is 10 nm-5 μm.
10. The preparation of metal organic framework molecular sieve membrane by supercritical fluid technology according to claim 1The method of (1), wherein the supercritical CO is used in the step 6)2The pressure reduction rate is 0.005-50 MPa/min, and the temperature reduction rate is 0.1-20 ℃/min.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112358623A (en) * | 2020-11-04 | 2021-02-12 | 天津理工大学 | In supercritical CO2Method for synthesizing zeolite imidazole ester framework metal organic material ZIF-67 |
| CN112952041A (en) * | 2021-02-25 | 2021-06-11 | 横店集团东磁股份有限公司 | Garnet type solid electrolyte composite positive electrode and preparation method and application thereof |
| CN113209842A (en) * | 2021-04-02 | 2021-08-06 | 浙江师范大学 | Composite separation membrane with electric field sensitivity during Congo red filtration |
| CN113413778A (en) * | 2021-05-19 | 2021-09-21 | 大连理工大学 | Method for preparing MOF (Metal organic framework) membrane by using seed crystal assisted supercritical technology and gas separation application of MOF membrane |
| CN114602332A (en) * | 2020-12-09 | 2022-06-10 | 中国科学院大连化学物理研究所 | New concept molecular sieve membrane and preparation method and application thereof |
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| WO2023285995A1 (en) * | 2021-07-13 | 2023-01-19 | King Abdullah University Of Science And Technology | Electrical synthesis of continuous metal-organic framework memranes |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101688298A (en) * | 2007-05-02 | 2010-03-31 | 法国原子能委员会 | The method and apparatus of preparation multilayered coating on substrate |
| WO2013192146A1 (en) * | 2012-06-18 | 2013-12-27 | Northwestern University | Metal-organic framework materials with ultrahigh surface areas |
| US20180043330A1 (en) * | 2015-02-23 | 2018-02-15 | The Royal Institution For The Advacement Of Learning/Mcgill University | Method for the preparation of metal-organic compounds |
| CN108704491A (en) * | 2018-06-22 | 2018-10-26 | 大连理工大学 | The method that steam gel method prepares laminated metal organic framework film |
| US20190168173A1 (en) * | 2017-10-27 | 2019-06-06 | Regents Of The University Of Minnesota | Nanocomposite membranes and methods of forming the same |
-
2020
- 2020-05-29 CN CN202010471162.9A patent/CN111589311B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101688298A (en) * | 2007-05-02 | 2010-03-31 | 法国原子能委员会 | The method and apparatus of preparation multilayered coating on substrate |
| WO2013192146A1 (en) * | 2012-06-18 | 2013-12-27 | Northwestern University | Metal-organic framework materials with ultrahigh surface areas |
| US20180043330A1 (en) * | 2015-02-23 | 2018-02-15 | The Royal Institution For The Advacement Of Learning/Mcgill University | Method for the preparation of metal-organic compounds |
| US20190168173A1 (en) * | 2017-10-27 | 2019-06-06 | Regents Of The University Of Minnesota | Nanocomposite membranes and methods of forming the same |
| CN108704491A (en) * | 2018-06-22 | 2018-10-26 | 大连理工大学 | The method that steam gel method prepares laminated metal organic framework film |
Non-Patent Citations (1)
| Title |
|---|
| LOPEZ-PERIAGO, A: "Exploring a novel preparation method of 1D metal organic frameworks based on supercritical CO2", 《ROYAL SOCIETY OR CHEMISTRY》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112358623A (en) * | 2020-11-04 | 2021-02-12 | 天津理工大学 | In supercritical CO2Method for synthesizing zeolite imidazole ester framework metal organic material ZIF-67 |
| CN114602332A (en) * | 2020-12-09 | 2022-06-10 | 中国科学院大连化学物理研究所 | New concept molecular sieve membrane and preparation method and application thereof |
| CN114602332B (en) * | 2020-12-09 | 2023-05-16 | 中国科学院大连化学物理研究所 | New concept molecular sieve membrane and preparation method and application thereof |
| CN112952041A (en) * | 2021-02-25 | 2021-06-11 | 横店集团东磁股份有限公司 | Garnet type solid electrolyte composite positive electrode and preparation method and application thereof |
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