Modified copper-based metal organic framework material, preparation method and application thereof and method for removing sulfides

Abstract

The present application relates to the technical field of metal organic framework materials, in particular to a modified copper-based metal organic framework material, a preparation method and application thereof, and a sulfide removal method. The modified copper-based metal organic framework material comprises a metal organic framework formed by copper and an organic ligand, and silver doped on the metal organic framework; and the crystal surface of the modified copper-based metal organic framework material has long and narrow honeycomb-shaped pores. + and Ag + The modified copper-based metal organic framework material has suitable pore structures and rich adsorption sites for removing various organic sulfides, and the modified copper-based metal organic framework material has Cu + and Ag + which can adsorb sulfides through π bond action, and has a large adsorption capacity and high adsorption selectivity for sulfides (such as mercaptans, sulfides, thiophenes, etc.) as a desulfurization adsorbent.

Description

Technical Field

[0001] This invention relates to the field of metal-organic framework materials technology, specifically to a modified copper-based metal-organic framework material, its preparation method and application, and a method for removing sulfides. Background Technology

[0002] Aromatic sulfides (ASCs) account for more than 60% of total sulfides and are a major obstacle to achieving deep desulfurization. Traditional hydrodesulfurization technology is ineffective in removing ASCs and is gradually failing to meet the increasingly stringent sulfur emission regulations. Most existing adsorption materials are effective at removing small-molecule sulfides such as hydrogen sulfide and thiols, but they cannot simultaneously achieve effective adsorption of large-molecule sulfides, such as aromatic sulfides.

[0003] MOFs (Metal-Organic Frameworks) exhibit high adsorption and desulfurization activity, especially copper-containing MOFs. However, the stable valence state of copper-containing MOFs is divalent copper. According to the hard-soft acid-base theory, soft bases such as (RS)₂ and RSH more readily combine with soft acids such as Cu(I) and Ag(I). Furthermore, Cu(I) can form a strong π-complex with ASCs (Metal-Organic Frameworks). Therefore, breaking some Cu-O bonds in the MOF structure to form a framework containing both Cu(I) and Cu(II) is of great significance for desulfurization. Existing technologies for reducing Cu-based metal-organic frameworks mostly require other reducing agents, which introduce heteroatoms and are relatively expensive. For example, CN109575306A uses sodium thiosulfate or phenol as reducing agents, introducing thiosulfate ions into the solvent, posing environmental challenges. In addition, existing technologies use MOFs materials as sacrificial templates and reduce them by high-temperature carbonization to obtain Cu(I)-containing oxides. For example, CN109908941A carbonizes copper-based MOFs materials at 500-700℃ for 2-8 hours. This reduction method will have an adverse effect on adsorption because it destroys the original structure of MOFs.

[0004] In summary, the synthesis of multivalent metal-organic framework materials currently under research all require the addition of reducing agents or involve relatively harsh reduction conditions, which increases costs and causes environmental pollution. Therefore, it is imperative to develop inexpensive, environmentally friendly multivalent metal-organic framework materials that are effective in removing macromolecular sulfides. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem that the synthesis of multivalent metal-organic framework materials in the prior art requires the addition of reducing agents or harsh reduction conditions. This invention provides a modified copper-based metal-organic framework material, its preparation method and application, and a method for removing sulfides. The modified copper-based metal-organic framework material has narrow honeycomb-like pores on its crystal surface, which allows it to adsorb sulfides (such as thiols, thioethers, thiophenes, etc.) with a large adsorption capacity and high adsorption selectivity as a desulfurization adsorbent.

[0006] To achieve the above objectives, a first aspect of the present invention provides a modified copper-based metal-organic framework material, comprising a metal-organic framework formed by copper and an organic ligand and silver doped on the metal-organic framework; the crystal surface of the modified copper-based metal-organic framework material has elongated honeycomb-like pores.

[0007] A second aspect of the present invention provides a method for preparing the modified copper-based metal-organic framework material, the method comprising:

[0008] S1: Dissolve the silver salt and organic ligand in an alcohol solvent and optionally solvent a to obtain solution A; dissolve the divalent copper salt in solvent b to obtain solution B;

[0009] S2: Add solution B to solution A and mix to obtain a mixture;

[0010] S3: After the mixture in S2 is liquidized, it is separated and dried to obtain the modified copper-based metal-organic framework material.

[0011] A third aspect of the present invention provides an application of the modified copper-based metal-organic framework material described herein as a desulfurization adsorbent.

[0012] A fourth aspect of the present invention provides a method for removing sulfides, the method comprising: contacting a sulfide-containing material with the modified copper-based metal-organic framework material of the present invention.

[0013] Through the above technical solution, the modified copper-based metal-organic framework material provided by the present invention has narrow honeycomb-shaped pores on its crystal surface; according to a preferred embodiment of the present invention, the modified copper-based metal-organic framework material has two valence states, Cu(II) and Cu(I).

[0014] The modified copper-based metal-organic framework material possesses a suitable pore structure capable of removing various organosulfur compounds and abundant adsorption sites, and the modified copper-based metal-organic framework material has Cu + and Ag + It can adsorb aromatic sulfides through π-bond interactions, and as a desulfurization adsorbent, it exhibits high adsorption capacity and selectivity for various sulfides (such as thiols, thioethers, and thiophenes). This provides a technical solution for achieving higher-precision desulfurization requirements (1 μg / g S) in low-sulfur crude oil, which is difficult to achieve with single catalytic hydrodesulfurization.

[0015] The preparation method provided by this invention uses a solution containing silver ions and an alcohol solvent to synthesize modified copper-based metal-organic frameworks (MOFs) in one step. This method maximizes the preservation of the original structure of MOFs, resulting in modified MOFs with elongated honeycomb-like pores on the crystal surface. It is speculated that in the preparation method provided by this invention, Cu(II) bonds with O in the ligand. Under the catalysis of Ag, some Cu(II)-O bonds break, forming Cu(I)-O. Furthermore, in addition to its catalytic effect, the transition metal Ag can also provide effective sulfide adsorption sites, further improving the desulfurization performance of the MOF. Attached Figure Description

[0016] Figure 1 This is an appearance diagram of the metal-organic framework material described in Example 1;

[0017] Figure 2 This is an appearance diagram of the metal-organic framework material described in Comparative Example 3;

[0018] Figure 3 The XRD patterns of the metal-organic framework materials in Examples 1-5 and Comparative Examples 1-3 are shown.

[0019] Figure 4 SEM images of the metal-organic framework material in Example 1 at different magnifications;

[0020] Figure 5 Here is a SEM image of the metal-organic framework material in Comparative Example 1;

[0021] Figure 6 Here is a SEM image of the metal-organic framework material in Comparative Example 2;

[0022] Figure 7 Here is a SEM image of the metal-organic framework material in Comparative Example 3;

[0023] Figure 8 It is the Cu 2p of the metal-organic framework material in Example 1. 3 / 2 X-ray photoelectron spectroscopy;

[0024] Figure 9 It is the Cu 2p of the metal-organic framework material in Example 5. 3 / 2 X-ray photoelectron spectroscopy;

[0025] Figure 10 Comparative Example 1: Cu 2p metal-organic framework material 3 / 2 X-ray photoelectron spectroscopy;

[0026] Figure 11 Comparative Example 2: Cu 2p metal-organic framework material 3 / 2 X-ray photoelectron spectroscopy;

[0027] Figure 12 Comparative Example 3: Cu 2p metal-organic framework material 3 / 2 X-ray photoelectron spectroscopy. Detailed Implementation

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] In this invention, Cu(II) refers to divalent copper; Cu(I) refers to monovalent copper; and Ag(I) refers to monovalent silver.

[0030] The first aspect of the present invention provides a modified copper-based metal-organic framework material, the modified copper-based metal-organic framework material comprising a metal-organic framework formed by copper and an organic ligand and silver doped on the metal-organic framework; the crystal surface of the modified copper-based metal-organic framework material has elongated honeycomb-like pores.

[0031] According to a preferred embodiment of the present invention, the modified copper-based metal-organic framework material crystal has a cuboid structure.

[0032] According to a preferred embodiment of the present invention, the modified copper-based metal-organic framework material has an average crystal size of 1-5 μm.

[0033] According to a preferred embodiment of the present invention, the specific surface area of ​​the modified copper-based metal-organic framework material is 450-1000 m². 2 ·g -1 The total pore volume is 0.2-1.2 cm³. 3 ·g -1 The micropore volume is 0.05-0.55 cm³. 3 ·g -1 The mesopore size is 2-25 nm.

[0034] According to a preferred embodiment of the present invention, in the modified copper-based metal-organic framework material, copper has two valence states, Cu(I) and Cu(II), preferably, the molar ratio of Cu(I) to Cu(II) is 0.05-5; more preferably, it is 1.15-1.8.

[0035] According to a preferred embodiment of the present invention, the molar ratio of copper to silver is 0.5-20:1, preferably 4-8.5:1, based on elemental composition.

[0036] According to a preferred embodiment of the present invention, the organic ligand is an aromatic carboxylic acid.

[0037] In this invention, the range of selectable aromatic carboxylic acids is relatively wide. According to a preferred embodiment of this invention, the aromatic carboxylic acid is selected from at least one of pyromellitic acid, terephthalic acid, phthalic acid, 2-amino-terephthalic acid, biphenyl-3,4,5-tricarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,3,5-tris(4-carboxyphenyl)benzene, and 3,3,5,5-biphenyltetracarboxylic acid, preferably terephthalic acid and / or 2-amino-terephthalic acid.

[0038] According to a preferred embodiment of the present invention, the modified copper-based metal-organic framework material is a dark green powder with a shimmering metallic luster.

[0039] According to a preferred embodiment of the present invention, the modified copper-based metal-organic framework material has a characteristic diffraction peak at 38.2° in its XRD pattern, which is a characteristic diffraction peak of Ag2O at 38.2°.

[0040] In this invention, any material possessing the characteristics of the modified copper-based metal-organic framework material described herein can achieve the purpose of this invention. There are no particular requirements for the preparation method of the modified copper-based metal-organic framework material. Regarding this invention, a second aspect provides a method for preparing the modified copper-based metal-organic framework material, the method comprising:

[0041] S1: Dissolve the silver salt and organic ligand in an alcohol solvent and optionally solvent a to obtain solution A; dissolve the divalent copper salt in solvent b to obtain solution B;

[0042] S2: Add solution B to solution A and mix to obtain a mixture;

[0043] S3: After the mixture in S2 is liquidized, separated, and dried, the modified copper-based metal-organic framework material is obtained.

[0044] The preparation method provided by this invention can preserve the original structure of MOF materials to the greatest extent, resulting in modified copper-based metal-organic framework materials with elongated honeycomb-like pores on the crystal surface. In the preparation method provided by this invention, Cu(II) bonds with O in the ligand; under the catalysis of Ag, some Cu(II)-O bonds break, forming Cu(I)-O. Furthermore, in addition to its catalytic effect, the transition metal Ag can also provide effective sulfide adsorption sites, further improving the desulfurization performance of the metal-organic framework material.

[0045] In this invention, the volume ratio of solvent a to solvent b can be selected within a wide range. According to a preferred embodiment of this invention, the volume ratio of solvent a to solvent b is 0-100:1, preferably 0.1-10:1.

[0046] In this invention, the ratio of alcohol solvent to silver salt can be selected over a wide range. According to a preferred embodiment of this invention, the ratio of alcohol solvent to silver salt is 10-200 mL alcohol solvent / g silver salt, preferably 40-100 mL alcohol solvent / g silver salt.

[0047] In this invention, the ratio of solvent a to silver salt can be selected over a wide range. According to a preferred embodiment of this invention, the ratio of solvent a to silver salt is 10-200 mL solvent a / g silver salt, preferably 20-100 mL solvent a / g silver salt.

[0048] In this invention, the ratio of solvent b to divalent copper salt can be selected over a wide range. According to a preferred embodiment of this invention, the ratio of solvent b to divalent copper salt is 10-200 mL solvent b / g divalent copper salt, preferably 20-100 mL solvent b / g divalent copper salt.

[0049] In this invention, there is no particular limitation on the molar ratio of the divalent copper salt to the organic ligand. The molar ratio of the divalent copper salt to the organic ligand can be reasonably adjusted according to the type of organic ligand to form a metal-organic framework material. According to a preferred embodiment of this invention, the molar ratio of the divalent copper salt to the organic ligand is 1:0.1-5, preferably 1:0.2-2.

[0050] In this invention, the molar ratio of divalent copper salt to silver salt can be selected over a wide range. According to a preferred embodiment of this invention, the molar ratio of divalent copper salt to silver salt, based on metal ions, is 1-200:1, preferably 1.5-10:1.

[0051] In this invention, there is no particular limitation on the mixing conditions in step S2, which can be conventional mixing conditions in the art. According to a preferred embodiment of the present invention, the mixing conditions include: a temperature of 20-50°C and a time of 0.5-24h, preferably 0.5-10h.

[0052] In this invention, there is no particular limitation on the mixing method in step S2, and it can be a conventional mixing method in the art. According to a preferred embodiment of the present invention, the mixing method is to add solution B dropwise to solution A for mixing. More preferably, the dropping speed is controlled to be 0.1-20 ml / min, preferably 1-5 ml / min.

[0053] According to a preferred embodiment of the present invention, in step S2, the alcohol solvent accounts for 15-80 wt% of the total solvent content in the mixture, preferably 20-70 wt%. The alcohol solvent content being in the range of 20-70 wt% is beneficial to improving the dynamic sulfur adsorption capacity of the modified copper-based metal-organic framework material.

[0054] In this invention, there is no particular limitation on the crystallization conditions in step S3, which can be conventional crystallization conditions in the art. According to a preferred embodiment of the present invention, the crystallization conditions in step S3 include: a temperature of 30-150°C, preferably 60-110°C; a time of 3-48h, preferably 10-24h; and a rotation speed of 0-700r / min, preferably 10-300r / min.

[0055] In this invention, the drying conditions in step S3 are not particularly limited and can be conventional drying conditions in the art. According to a preferred embodiment of the invention, the drying conditions in step S3 include: a drying temperature of 40-250°C and a drying time of 2-48 hours; preferably, the drying is carried out in two stages, the temperature of the first stage is 50-100°C, preferably 50-80°C, and the drying time is 1-24 hours, preferably 2-10 hours; the drying temperature of the second stage is 100-250°C, preferably 100-200°C, and the drying time is 1-24 hours, preferably 2-10 hours.

[0056] In this invention, the range of selectable alcohol solvents is relatively wide. According to a preferred embodiment of this invention, the alcohol solvent is selected from C1-C4 monohydric alcohols or dihydric alcohols, preferably at least one of methanol, ethanol, propanol, butanol and ethylene glycol.

[0057] In this invention, there is no particular limitation on the type of silver salt, as long as the silver salt can be dissolved in an alcohol solvent or solvent a. According to a preferred embodiment of this invention, the silver salt is silver nitrate.

[0058] In this invention, there is no particular limitation on the type of divalent copper salt, as long as the divalent copper salt can dissolve in solvent b. According to a preferred embodiment of this invention, the divalent copper salt is selected from at least one of copper nitrate, copper chloride, copper acetate, copper carbonate, and copper sulfate.

[0059] In this invention, there is no particular limitation on the type of solvent a, as long as it can form a solution with alcohol solvents and silver salts. According to a preferred embodiment of the present invention, solvent a is selected from one or more of amine solvents, ketone solvents, dimethyl sulfoxide, tetrahydrofuran and deionized water. Preferably, solvent a is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, triethylamine, tetrahydrofuran, dimethyl sulfoxide, acetone and deionized water.

[0060] In this invention, there is no particular limitation on the type of solvent b, as long as it can form a solution with divalent copper salt. According to a preferred embodiment of the present invention, solvent b is selected from one or more of amine solvents, ketone solvents, dimethyl sulfoxide, tetrahydrofuran and deionized water. Preferably, solvent b is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, triethylamine, tetrahydrofuran, dimethyl sulfoxide, acetone and deionized water.

[0061] A third aspect of this invention provides an application of the modified copper-based metal-organic framework material as a desulfurization adsorbent. The modified copper-based metal-organic framework material possesses a suitable pore structure capable of removing various organic sulfides and abundant adsorption sites, and the modified copper-based metal-organic framework material has Cu... + and Ag + It can adsorb aromatic sulfides through π-bond interactions, and as a desulfurization adsorbent, it has a large adsorption capacity and high adsorption selectivity for various sulfides (such as thiols, thioethers, thiophenes, etc.).

[0062] A fourth aspect of the present invention provides a method for removing sulfides, the method comprising: contacting a sulfide-containing material with the modified copper-based metal-organic framework material of the present invention.

[0063] In this invention, there is no particular limitation on the type of sulfide. The modified copper-based metal-organic framework material of this invention can adsorb conventional sulfides in the art as a desulfurization adsorbent. According to a preferred embodiment of this invention, the sulfide is selected from at least one of thiols, thiophenes, thioethers, benzothiophenes, and dibenzothiophenes.

[0064] According to a preferred embodiment of the present invention, the material space velocity containing sulfides is 0.01-5 h⁻¹. -1 .

[0065] According to a preferred embodiment of the present invention, the sulfide concentration in the sulfide-containing material is 10-3000 wppm.

[0066] According to a preferred embodiment of the present invention, when the sulfide is a thiol, the concentration of the thiol in the sulfide-containing material is 100-3000 ppm.

[0067] According to a preferred embodiment of the present invention, when the sulfide is thiophene, the concentration of thiophene in the sulfide-containing material is 10-500 ppm.

[0068] The technical solution of the present invention will be further illustrated below through embodiments, but the scope of protection of the present invention is not limited to the embodiments. In the present invention, wt% is a mass fraction.

[0069] In this invention, the XRD pattern testing conditions for the samples were as follows: MOF crystal phase analysis was performed using a Rigaku-Ultima X-ray diffractometer (Japan). CuKα radiation was used, with a wavelength λ = 0.15432 nm. The X-ray diffraction pattern scanning range was 2θ = 5-80°, the scanning speed was 5° / min, and the step size was 0.02°.

[0070] In this invention, scanning electron microscope (SEM) images of the samples were taken using a Hitachi S-4800II scanning electron microscope. The instrument's accelerating voltage was 15 kV, and all samples underwent chrome plating before analysis.

[0071] X-ray photoelectron spectroscopy (XPS) was performed using the ESCALAB 250 system from Thermo Fisher Scientific, USA. The instrument test conditions were: Al target, 14 kV, and 250 W power.

[0072] The instruments and methods for measuring the average pore size, specific surface area, and pore volume of the samples were as follows: Physical adsorption was performed using a 3H-2000PM2 physical adsorption instrument at -196℃ using nitrogen gas to analyze the pore structure characteristics of each adsorbent material sample. The initial degassing conditions were: degassing at 150℃ for 6 hours. After measuring the adsorption isotherm of nitrogen on the samples, the specific surface area was calculated using the BET (Brunauer-Emmett-Teller) method, and the pore volume and pore size distribution were calculated using the BJH (Barrett-Joyner-Halenda) method.

[0073] The elemental content (ICP) of the samples was determined using a Varian 725-ES full-spectrum direct-reading inductively coupled plasma atomic emission spectrometer from Agilent Technologies, Inc.

[0074] Example 1

[0075] S1. Weigh 0.8g of terephthalic acid and add it to a mixture of 20mL ethanol and 20mL N,N-dimethylformamide. Stir thoroughly for 30min. Then add 0.5g of silver nitrate to the above solution and stir thoroughly for 20min to obtain homogeneous solution A. Weigh 1.5g of copper nitrate trihydrate and add it to 50mL N,N-dimethylformamide. Stir thoroughly for 30min to obtain homogeneous solution B.

[0076] S2. At 30℃, add solution B dropwise to solution A at a rate of 5 ml / min, stir thoroughly, and then sonicate for 20 min.

[0077] S3. Place the mixture from step S2 into a homogeneous reactor, set the rotation speed to 20 r / min, and crystallize at 100℃ for 20 h. After crystallization, cool to room temperature, centrifuge to remove the mother liquor, and wash several times with ethanol. Drying is carried out in two stages: the first stage is at 75℃ for 6 h, and the second stage is at 180℃ for 10 h. After drying, Ag-Cu-BDC metal-organic framework material is obtained, and the molar ratio of Cu to Ag is 8:1 as determined by ICP testing.

[0078] Ag-Cu-BDC, for example Figure 1 As shown, the modified copper-based metal-organic framework material is a dark green powder with a shimmering metallic luster.

[0079] The XRD pattern of the modified copper-based metal-organic framework material is shown below. Figure 3 In addition to the characteristic diffraction peaks of Cu-BDC at 10.2°, 12.5°, 14.2°, 17.5°, and 24.3°, a characteristic diffraction peak of Ag2O appeared at 38.2°.

[0080] SEM images of the modified copper-based metal-organic framework material are shown below. Figure 4 It can be seen that a narrow, honeycomb-like structure appears on the side of the crystal. The crystal material has a cuboid structure, and the average crystal size is 2 μm.

[0081] XPS plot of the modified copper-based metal-organic framework material is shown below. Figure 8 This indicates that the modified copper-based metal-organic framework material contains both Cu(I) and Cu(II), with a Cu(I) to Cu(II) molar ratio of 3:2.

[0082] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0083] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the feed space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 199.9 mg / g.

[0084] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 155.7 mg / g.

[0085] Example 2

[0086] The method of Example 1 was followed, except that in step S1, the amount of terephthalic acid used was 0.4 g, and the other conditions were the same as in Example 1. An Ag-Cu-BDC metal-organic framework material was obtained, and the molar ratio of Cu to Ag was found to be 9:1 according to ICP testing.

[0087] The SEM image of this modified copper-based metal-organic framework material is similar to that of the modified copper-based metal-organic framework material in Example 1, showing a narrow, elongated honeycomb-like structure on the crystal side. The crystalline material has a cuboid structure with a crystal size of 1.8 μm.

[0088] In this modified copper-based metal-organic framework material, the molar ratio of Cu(I) to Cu(II) is 1.1:1;

[0089] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0090] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 165.3 mg / g.

[0091] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 110.1 mg / g.

[0092] Example 3

[0093] The method of Example 1 was followed, except that in step S1, the amount of silver nitrate used was 1.0 g, and the other conditions were the same as in Example 1. An Ag-Cu-BDC metal-organic framework material was obtained, and ICP testing showed that the molar ratio of Cu to Ag was 4:1.

[0094] The SEM image of this modified copper-based metal-organic framework material is similar to that of the modified copper-based metal-organic framework material in Example 1, showing a narrow, elongated honeycomb-like structure on the crystal side. The crystalline material has a cuboid structure with a crystal size of 2.5 μm.

[0095] In this modified copper-based metal-organic framework material, the molar ratio of Cu(I) to Cu(II) is 1.3:1;

[0096] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0097] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1The dynamic adsorption capacity of the adsorbent material was measured to be 190.1 mg / g.

[0098] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 143.6 mg / g.

[0099] Example 4

[0100] S1. Weigh 0.8g of terephthalic acid and add it to a mixture of 35mL ethanol and 25mL N,N-dimethylformamide. Stir thoroughly for 30min. Then add 0.5g of silver nitrate to the above solution and stir thoroughly for 20min to obtain homogeneous solution A. Weigh 1.5g of copper nitrate trihydrate and add it to 30mL N,N-dimethylformamide. Stir thoroughly for 30min to obtain homogeneous solution B.

[0101] Steps S2 and S3 are the same as in Example 1, and Ag-Cu-BDC metal-organic framework material is obtained. The molar ratio of Cu to Ag is 7:1 as determined by ICP testing.

[0102] The SEM image of this modified copper-based metal-organic framework material is similar to that of the modified copper-based metal-organic framework material in Example 1, showing a narrow, elongated honeycomb-like structure on the crystal side. The crystal material has a cuboid structure and a crystal size of 3 μm.

[0103] In this modified copper-based metal-organic framework material, the molar ratio of Cu(I) to Cu(II) is 1.8:1.

[0104] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0105] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 195.4 mg / g.

[0106] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 136.5 mg / g.

[0107] Example 5

[0108] S1. Weigh 0.8g of terephthalic acid and add it to a mixture of 70mL ethanol and 20mL N,N-dimethylformamide. Stir thoroughly for 30min. Then add 0.5g of silver nitrate to the above solution and stir thoroughly for 20min to obtain homogeneous solution A. Weigh 1.5g of copper nitrate trihydrate and add it to 10mL N,N-dimethylformamide. Stir thoroughly for 30min to obtain homogeneous solution B.

[0109] Steps S2 and S3 are the same as in Example 1, and Ag-Cu-BDC metal-organic framework material is obtained. The molar ratio of Cu to Ag is 6.5:1 as determined by ICP testing.

[0110] The SEM image of this modified copper-based metal-organic framework material is similar to that of the modified copper-based metal-organic framework material in Example 1, showing a narrow, elongated honeycomb-like structure on the crystal side. The crystal material has a cuboid structure with a crystal size of 4.5 μm.

[0111] XPS plot of the modified copper-based metal-organic framework material is shown below. Figure 9 This indicates that the modified copper-based metal-organic framework material contains both Cu(I) and Cu(II), with a Cu(I) to Cu(II) molar ratio of 1.6:1.

[0112] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0113] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 162.3 mg / g.

[0114] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 119.7 mg / g.

[0115] Example 6

[0116] The preparation method is the same as in Example 1, except that step S1 is different, specifically:

[0117] S1. Weigh 1.04 g of 1,4-naphthalenedicarboxylic acid and add it to a mixture of 20 mL of methanol and 20 mL of N,N-dimethylformamide. Stir thoroughly for 30 min. Then add 0.5 g of silver nitrate to the above solution and stir thoroughly for 20 min to obtain homogeneous solution A. Weigh 1.5 g of copper nitrate trihydrate and add it to 50 mL of N,N-dimethylformamide. Stir thoroughly for 30 min to obtain homogeneous solution B.

[0118] Steps S2 and S3 are the same as in Example 1, and Ag-doped Cu-1,4-naphthalenedicarboxylic acid metal-organic framework material is obtained. The molar ratio of Cu to Ag is 6.8:1 according to the ICP test results.

[0119] The SEM image of this modified copper-based metal-organic framework material is similar to that of the modified copper-based metal-organic framework material in Example 1, showing a narrow, elongated honeycomb-like structure on the crystal side. The crystalline material has a cuboid structure with a crystal size of 3.8 μm.

[0120] In this modified copper-based metal-organic framework material, the molar ratio of Cu(I) to Cu(II) is 0.9:1;

[0121] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0122] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 160.7 mg / g.

[0123] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 109.4 mg / g.

[0124] Example 7

[0125] The preparation method of Example 1 was followed, except that 0.87 g of 2-aminoterephthalic acid was used instead of 0.8 g of p-xylene; steps S2 and S3 were the same as in Example 1, resulting in Cu-2-aminoterephthalic acid metal-organic framework material. ICP testing showed that the molar ratio of Cu to Ag was 8.5:1.

[0126] The SEM image of this modified copper-based metal-organic framework material is similar to that of the modified copper-based metal-organic framework material in Example 1, showing a honeycomb-like structure on the crystal side. The crystalline material has a cuboid structure with a crystal size of 2.2 μm.

[0127] In this modified copper-based metal-organic framework material, the molar ratio of Cu(I) to Cu(II) is 1.15:1.

[0128] The specific surface area and pore properties of the modified copper-based metal-organic framework material are shown in Table 1.

[0129] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1The dynamic adsorption capacity of the adsorbent material was measured to be 170.5 mg / g.

[0130] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 128.6 mg / g.

[0131] Table 1

[0132]

[0133]

[0134] Comparative Example 1

[0135] S1. Weigh 0.8g of terephthalic acid and add it to 40mL of N,N-dimethylformamide mixture. Stir thoroughly for 30min. Then add 0.5g of silver nitrate to the above solution and stir thoroughly for 20min to obtain homogeneous solution A. Weigh 1.5g of copper nitrate trihydrate and add it to 50mL of N,N-dimethylformamide mixture. Stir thoroughly for 30min to obtain homogeneous solution B.

[0136] S2. At room temperature, add solution B dropwise to solution A at a rate of 5 ml / min, stir thoroughly, and then sonicate for 20 min.

[0137] S3. Place the mixture from step S2 into a homogeneous reactor, set the rotation speed to 20 r / min, and crystallize at 100℃ for 20 h. After crystallization, cool to room temperature, centrifuge to remove the mother liquor, and wash several times with ethanol. Drying is carried out in two stages: the first stage is at 75℃ for 6 h, and the second stage is at 180℃ for 10 h. After drying, Ag-Cu-BDC is obtained.

[0138] The XRD pattern of the metal-organic framework material is shown below. Figure 3 In addition to the characteristic diffraction peaks of Cu-BDC at 10.2°, 12.5°, 14.2°, 17.5°, and 24.3°, a characteristic diffraction peak of AgO appeared at 38.2°.

[0139] SEM image of the metal-organic framework material is shown below. Figure 5 It can be seen that there is no obvious honeycomb-like structure on the side of the crystal, and there are many flocculent aggregates on the crystal surface. The crystal material has a truncated cubic structure and the crystal size is 4.8 μm.

[0140] The XPS plot of the metal-organic framework material is shown below. Figure 10 This metal-organic framework material contains only Cu(II).

[0141] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 125.8 mg / g.

[0142] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 82.0 mg / g.

[0143] Comparative Example 2

[0144] S1. Weigh 0.8g of terephthalic acid and add it to a mixture of 20mL ethanol and 30mL N,N-dimethylformamide. Stir thoroughly for 30min to obtain homogeneous solution A. Weigh 1.5g of copper nitrate trihydrate and add it to 40mL N,N-dimethylformamide. Stir thoroughly for 30min to obtain homogeneous solution B.

[0145] S2. At room temperature, add solution B dropwise to solution A at a rate of 5 ml / min, stir thoroughly, and then sonicate for 20 min.

[0146] S3. Place the mixture from step S2 into a homogeneous reactor, set the rotation speed to 20 r / min, and crystallize at 100℃ for 20 h. After crystallization, cool to room temperature, centrifuge to remove the mother liquor, and wash several times with ethanol. Drying is carried out in two stages: the first stage is at 75℃ for 6 h, and the second stage is at 180℃ for 10 h. After drying, Cu-BDC is obtained.

[0147] S4. Weigh 0.5g of silver nitrate and dissolve it in a mixture of 20mL ethanol and 70mL N,N-dimethylformamide, and stir thoroughly for 30min. Then add 1g of Cu-BDC prepared in step S3 to the above solution and stir thoroughly for 30min.

[0148] S5. Place the mixture from S4 into a homogeneous reactor, set the rotation speed to 20 r / min, and crystallize at 100℃ for 20 h. After crystallization, cool to room temperature, centrifuge to remove the mother liquor, and wash several times with ethanol. Drying is carried out in two stages: the first stage is at 75℃ for 6 h, and the second stage is at 180℃ for 10 h. After drying, Ag-Cu-BDC metal-organic framework material is obtained, with a Cu to Ag molar ratio of 30:1.

[0149] The XRD pattern of the metal-organic framework material is shown below. Figure 3In addition to the characteristic diffraction peaks of Cu-BDC at 10.2°, 12.5°, 14.2°, 17.5°, and 24.3°, characteristic diffraction peaks of AgNO3 appeared at 29.5° and 37°, indicating that the state of the loaded AgNO3 did not change during the two-step synthesis.

[0150] SEM image of the metal-organic framework material is shown below. Figure 6 It can be seen that there is no obvious honeycomb-like structure on the side of the crystal, but there are obvious defects. The crystal material has a cubic structure and the crystal size is 5.5 μm.

[0151] The XPS plot of the metal-organic framework material is shown below. Figure 11 The sample contains a small amount of Cu(I) and a large amount of Cu(II); the molar ratio of Cu(I) to Cu(II) is 1:8.

[0152] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 120.2 mg / g.

[0153] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 72.7 mg / g.

[0154] Comparative Example 3

[0155] S1. Weigh 0.8g of terephthalic acid and add it to 50mL of a mixture of N,N-dimethylformamide. Stir thoroughly for 50min to obtain homogeneous solution A. Weigh 1.5g of copper nitrate trihydrate and add it to 40mL of N,N-dimethylformamide. Stir thoroughly for 30min to obtain homogeneous solution B.

[0156] S2. At room temperature, add solution B dropwise to solution A at a rate of 5 ml / min, stir thoroughly, and then sonicate for 20 min.

[0157] S3. Place the mixture from step S2 into a homogeneous reactor, set the rotation speed to 20 r / min, and crystallize at 100℃ for 20 h. After crystallization, cool to room temperature, centrifuge to remove the mother liquor, and wash several times with ethanol. Drying is carried out in two stages: the first stage is at 75℃ for 6 h, and the second stage is at 180℃ for 10 h. After drying, Cu-BDC metal-organic framework material is obtained.

[0158] This metal-organic framework material, such as Figure 2 As shown, it is a blue powder with no metallic luster.

[0159] The XRD pattern of the metal-organic framework material is shown below. Figure 3 The characteristic diffraction peaks of Cu-BDC only appear at 10.2°, 12.5°, 14.2°, 17.5°, and 24.3°.

[0160] SEM image of the metal-organic framework material is shown below. Figure 7 It can be seen that the crystal surface is smooth on the side and has no porous structure or defects.

[0161] The XPS plot of the metal-organic framework material is shown below. Figure 12 All Cu in the sample were in the divalent state.

[0162] The desulfurization performance was evaluated using a fixed-bed propanethiol adsorption unit. The propanethiol concentration in the feed was 2000 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 106.3 mg / g.

[0163] The desulfurization performance was evaluated using a fixed-bed thiophene adsorption unit. The thiophene concentration of the feedstock was 200 ppm, and the space velocity was set to 0.2 h⁻¹. -1 The dynamic adsorption capacity of the adsorbent material was measured to be 64.9 mg / g.

[0164] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. The application of modified copper-based metal-organic framework materials as desulfurization adsorbents, characterized in that, The modified copper-based metal-organic framework material comprises a metal-organic framework formed by copper and organic ligands and silver doped on the metal-organic framework; the crystal surface of the modified copper-based metal-organic framework material has elongated honeycomb-like pores. In the modified copper-based metal-organic framework material, copper has two valence states, Cu(I) and Cu(II), and the molar ratio of Cu(I) to Cu(II) is 0.05-5. The organic ligand is selected from at least one of terephthalic acid, phthalic acid, 2-amino-terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,3,5-tris(4-carboxyphenyl)benzene and 3,3,5,5-biphenyltetracarboxylic acid.

2. The application according to claim 1, wherein, The modified copper-based metal-organic framework material crystal has a cuboid structure; and / or The modified copper-based metal-organic framework material has an average crystal size of 1-5 μm; and / or The modified copper-based metal-organic framework material has a specific surface area of ​​450-1000 m². 2 ·g -1 The total pore volume is 0.2-1.2 cm³. 3 ·g -1 The micropore volume is 0.05-0.55 cm³. 3 ·g -1 The mesopore size is 2-25 nm.

3. The application according to claim 1, wherein, The molar ratio of Cu(I) to Cu(II) is 1.15–1.8; and / or The molar ratio of copper to silver is 0.5-20:

1.

4. The application according to claim 3, wherein, The molar ratio of copper to silver is 4-8.5:

1.

5. The application according to claim 1, wherein, The organic ligand is terephthalic acid and / or 2-amino-terephthalic acid.

6. The application according to any one of claims 1-5, wherein, The preparation method of the modified copper-based metal-organic framework material includes: S1. Dissolve the silver salt and organic ligand in an alcohol solvent and optionally solvent a to obtain solution A; dissolve the divalent copper salt in solvent b to obtain solution B; S2. Add solution B to solution A and mix to obtain a mixture; S3. Separate and dry the mixed liquid crystals from S2.

7. The application according to claim 6, wherein, The volume ratio of solvent a to solvent b is 0-100:1; and / or The ratio of alcohol solvent to silver salt is 10-200 mL alcohol solvent / g silver salt; and / or The ratio of solvent a to silver salt is 10-200 mL solvent a / g silver salt; and / or The ratio of solvent b to divalent copper salt is 10-200 mL solvent b / g divalent copper salt; and / or In step S2, the alcohol solvent accounts for 15-80 wt% of the total solvent volume; and / or The molar ratio of the divalent copper salt to the organic ligand is 1:(0.1-5); and / or Based on metal ions, the molar ratio of the divalent copper salt to the silver salt is (1-200):

1.

8. The application according to claim 7, wherein, The volume ratio of solvent a to solvent b is 0.1-10:1; and / or The ratio of alcohol solvent to silver salt is 40-100 mL alcohol solvent / g silver salt; and / or The ratio of solvent a to silver salt is 20-100 mL solvent a / g silver salt; and / or The ratio of solvent b to divalent copper salt is 20-100 mL solvent b / g divalent copper salt; and / or In step S2, the alcohol solvent accounts for 20-70 wt% of the total solvent volume; and / or The molar ratio of the divalent copper salt to the organic ligand is 1:(0.2-2); and / or Based on metal ions, the molar ratio of the divalent copper salt to the silver salt is (1.5-10):

1.

9. The application according to claim 6, wherein, In step S2, the mixing conditions include: a temperature of 20-50℃ and a time of 0.5-24h; and / or In step S3, the crystallization conditions include: a temperature of 30-150℃; a time of 3-48h; a rotation speed of 0-700r / min; and / or In step S3, the drying conditions include: a drying temperature of 40-250℃ and a drying time of 2-48h.

10. The application according to claim 9, wherein, In step S2, the mixing method is to add solution B dropwise to solution A for mixing, and control the dropping rate to 0.1-20 ml / min; and / or In step S3, the drying conditions include: the drying is carried out in two stages, the temperature of the first stage is 50-100℃, and the drying time is 1-24h; The second stage of drying involves a temperature of 100-250℃ and a time of 1-24 hours.

11. The application according to claim 6, wherein, The alcohol solvent is selected from C1-C4 monohydric alcohols or dihydric alcohols; and / or The silver salt is silver nitrate; and / or The divalent copper salt is selected from at least one of copper nitrate, copper chloride, copper acetate, copper carbonate, and copper sulfate; and / or Solvent a and solvent b are each selected from one or more of amine solvents, ketone solvents, dimethyl sulfoxide, tetrahydrofuran, and deionized water.

12. The application according to claim 11, wherein, The alcohol solvent is selected from at least one of methanol, ethanol, propanol, butanol, and ethylene glycol; and / or Solvent a and solvent b are each selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, triethylamine, tetrahydrofuran, dimethyl sulfoxide, acetone, and deionized water.

13. The application according to any one of claims 1-5, wherein, The method includes contacting a sulfide-containing material with the modified copper-based metal-organic framework material according to any one of claims 1-5.

14. The application according to claim 13, wherein, The sulfide is selected from at least one of thiols, thiophenes, thioethers, benzothiophenes, and dibenzothiophenes; and / or The space velocity of sulfide-containing materials is 0.01-5 h⁻¹. -1 ; and / or In materials containing sulfides, the concentration of sulfides is 10-3000 wppm.

15. The application according to claim 14, wherein, When the sulfide is a thiol, the concentration of the thiol in the sulfide-containing material is 100-3000 wppm; or When the sulfide is thiophene, the concentration of thiophene in the sulfide-containing material is 10-500 wppm.

Images