Preparation method and application of MOFs (Metal-Organic Frameworks) derived cross-channel bimetallic carbon-nitrogen material

Abstract

The invention discloses a preparation method and application of an MOFs (Metal-Organic Frameworks) derived cross-channel bimetallic carbon-nitrogen material. The method specifically comprises the following steps: adding a cobalt salt solution into an organic ligand solution, and carrying out stirring, hydrothermal treatment, centrifugation and drying to obtain ZIF-67; injecting the ethanol solution of the ZIF-67 into the ethanol solution of the second metal salt, standing, centrifuging and drying to obtain M-ZIF-67 (M is Fe, Zr, Cu or Ni); and calcining the M-ZIF-67 to obtain the cross-channel bimetallic carbon-nitrogen material. The material shows excellent performance in a reaction of oxidizing o-xylene to generate o-toluic acid, and the catalyst is simple to separate and good in cycling stability, can be reused after being washed and dried, and still keeps relatively high catalytic activity after being used for multiple times, so that the problems of difficulty in separation, low reutilization rate, environmental pollution and the like of the existing catalyst are solved; good industrial application prospects are realized.

Description

Technical Field

[0001] The present invention relates to the field of preparation and synthesis of metal-organic framework materials (MOFs), and particularly to a method for preparing and applying an MOF-derived cross-channel bimetallic carbonitride material. Background Art

[0002] MOFs are porous materials with a periodic network structure composed of metal centers and organic ligands through self-assembly. Their derived materials have advantages such as high specific surface area, high porosity, stable structure, and high designability, and have broad applications in heterogeneous catalysis. Hollow MOFs are a type of material with voids inside and adjustable outer shells, having many advantages such as large enclosed cavities, low density, and large specific surface area. Compared with solid MOFs, they have faster mass transfer, multiple active components, more exposed active sites, and better compatibility.

[0003] Single-metal catalysts have problems such as unsatisfactory activity and selectivity, poor stability, and difficulty in achieving multifunctional catalysis. Bimetallic catalysts have more diverse catalytic active sites and adsorption sites, making them exhibit excellent performance in selective catalysis and multifunctional catalysis.

[0004] Chinese Patent CN 109574829A reports a production method of o-toluic acid. This method requires cobalt naphthenate as a catalyst and one or more benzoheterocyclic nitrogen-containing compounds as co-catalysts, and the oxidation reaction needs to be carried out at high temperature (170 °C) and high pressure (1.3 MPa). The catalysts in the reported production method of o-toluic acid are difficult to recover, the reaction conditions are harsh, and the environmental pollution is serious. Considering economic benefits, operability, and environmental protection, etc., it is not the best choice for large-scale application.

[0005] Therefore, it is of great significance to develop an MOF-derived hollow bimetallic material and apply it to the oxidation of o-xylene to o-toluic acid. Summary of the Invention

[0006] The object of the present invention is to provide a method for preparing MOFs-derived cross-channel bimetallic carbonitride materials and their application in the oxidation of o-xylene. The present invention uses ZIF-67 as a precursor to prepare cross-channel bimetallic carbonitride materials by a metal salt etching method, introducing active metals, and at the same time increasing the specific surface area and porosity of the materials, which is beneficial to the progress of catalytic reactions. The present invention can catalyze the oxidation of o-xylene to produce the target product o-toluic acid. Under mild conditions, the conversion rate of o-xylene reaches 58.7%, and the yield of o-toluic acid reaches 48.2%, solving the problems of harsh reaction conditions and difficult separation of the catalyst from the product in the prior art. The reaction process involved in the present invention has the advantages of high yield of the target product, easy separation of the catalyst from the product, good catalyst activity and selectivity, and high reuse rate, etc.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] A method for preparing MOFs-derived cross-channel bimetallic carbonitride materials, which consists of the following steps:

[0009] (1) In a beaker, cetyltrimethylammonium bromide (CTAB) and cobalt acetate tetrahydrate are added to deionized water and stirred to dissolve to obtain a metal salt solution; 2-methylimidazole is added to deionized water and stirred to dissolve to obtain an organic ligand solution;

[0010] (2) The two are mixed and stirred evenly, transferred to a hydrothermal autoclave, cooled to room temperature after hydrothermal treatment, centrifuged to obtain a precipitate, and dried to obtain a precursor of the cross-channel bimetallic carbonitride material, namely ZIF-67;

[0011] (3) The prepared ZIF-67 is dissolved in an ethanol solution of a second metal salt, allowed to stand for several minutes, centrifuged to obtain a precipitate, and dried to obtain an etched material M-ZIF-67, where M is Fe, Zr, Cu or Ni;

[0012] (4) The prepared etched material is calcined by heating under an inert atmosphere to obtain MOFs-derived bimetallic carbonitride materials.

[0013] Preferably, in step (1), the organic ligand is selected from 2-methylimidazole; the surfactant is selected from cetyltrimethylammonium bromide (CTAB); the cobalt salt is selected from cobalt acetate tetrahydrate.

[0014] Preferably, in step (1), the molar ratio of cetyltrimethylammonium bromide (CTAB) to cobalt acetate tetrahydrate is 1:1 to 10; the concentration of CTAB is 1 to 8 g / L, and the concentration of cobalt acetate tetrahydrate is 0.01 to 0.1 mol / L.

[0015] Preferably, in step (1), the molar ratio of cobalt acetate tetrahydrate to 2-methylimidazole is 1:10 to 50; the concentration of 2-methylimidazole is 0.5 to 10 mol / L.

[0016] Preferably, in step (2), the volume ratio of the metal salt mixed solution to the organic ligand solution is 1 to 5:1; the stirring time is 0.5 to 4 h; the hydrothermal time is 5 to 15 h; the hydrothermal temperature is 100 to 150 °C; the drying temperature is 50 to 80 °C.

[0017] Preferably, in step (3), the mass ratio of ZIF-67 to the second metal salt is 0.1 to 10:1; the standing time is 0 to 10 min; the drying temperature is 50 to 80 °C. The second metal salt is selected from ferric chloride hexahydrate, zirconium chloride, copper chloride dihydrate or nickel chloride hexahydrate.

[0018] Preferably, in step (4), the inert atmosphere is an argon atmosphere; the calcination temperature is 300 to 800 °C, the calcination time is 1 to 3 h, and the heating rate is 1 to 5 °C / min.

[0019] A MOFs-derived cross-channel bimetallic carbonitride material is prepared by the above preparation method.

[0020] The present invention also provides an application of the MOFs-derived cross-channel bimetallic carbonitride material in the oxidation of o-xylene to o-methylbenzoic acid, and the catalyst is the MOFs-derived cross-channel bimetallic carbonitride material prepared by the above preparation method.

[0021] The specific application method is as follows: o-xylene and the cross-channel bimetallic carbonitride material catalyst are sequentially added into a reaction kettle, oxygen is introduced, stirred and heated to 80 to 200 °C, and after constant temperature reaction for 2 to 18 h, it is cooled to room temperature, and the cross-channel bimetallic carbonitride material is separated from the reaction system by centrifugation operation to obtain o-methylbenzoic acid. The dosage ratio of o-xylene to the cross-channel bimetallic carbonitride material catalyst is 1 g:(0.1 g to 0.01 g).

[0022] Compared with the prior art, the technical effects of the present invention are as follows:

[0023] (1) A MOFs-derived cross-channel bimetallic carbonitride material is prepared by Lewis acid etching. Compared with traditional metal-organic frameworks, the hollow structure increases the specific surface area of the material, provides more accessible active sites, is beneficial to the mass transfer of reaction molecules, and thus effectively accelerates the reaction process.

[0024] (2) By introducing a second metal species through metal species coordination, the synergistic effect of the bimetal can further promote the oxidation reaction. The synergistic regulation of both structure and composition can significantly improve the reaction activity and selectivity.

[0025] (3) The cross-channel bimetallic carbonitride material involved has high catalytic activity and good selectivity. Under mild conditions, the conversion rate of o-xylene reaches 58.7%, and the yield of o-methylbenzoic acid reaches 48.2%. Secondly, the cross-channel bimetallic carbonitride material catalyst provided by the present invention has good stability and can be separated from the reaction system by centrifugation. After washing with water and drying, it can be used again. After multiple uses, it still maintains good reaction activity, effectively solving the problems of low reaction activity, difficult separation, low reuse rate, and environmental pollution of existing catalysts. Description of the Drawings

[0026] Figure 1 (a) is the scanning electron microscope image (SEM) of ZIF-67 prepared in Example 1; Figure 1 (b) is the scanning electron microscope image (SEM) of ZIF-67 prepared in Example 2; Figure 1 (c) is the scanning electron microscope image (SEM) of ZIF-67 prepared in Example 3; Figure 1 (d) is the scanning electron microscope image (SEM) of Fe-ZIF-67 prepared in Example 4; Figure 1 (e) is the scanning electron microscope image (SEM) of Fe-ZIF-67 prepared in Example 5; Figure 1 (f) is the scanning electron microscope image (SEM) of Fe-ZIF-67 prepared in Example 6; Figure 1 (g) is the scanning electron microscope image (SEM) of 7#FeCo / CN prepared in Example 7; Figure 1 (h) is the scanning electron microscope image (SEM) of 8#FeCo / CN prepared in Example 8; Figure 1 (i) is the scanning electron microscope image (SEM) of 9#FeCo / CN prepared in Example 9;

[0027] Figure 2 (a) is the scanning electron microscope image (SEM) of Fe-ZIF-67 prepared in Example 1; Figure 2 (b) is the transmission electron microscope image (TEM) of Fe-ZIF-67 prepared in Example 1; Figure 2 (c) is the scanning electron microscope image (SEM) of 1#FeCo / CN prepared in Example 1; Figure 2 (d) is the transmission electron microscope image (TEM) of 1#FeCo / CN prepared in Example 1;

[0028] Figure 3Powder X-ray diffraction patterns (PXRD) of the 1# FeCo / CN material prepared in Example 1, the 10# ZrCo / CN material prepared in Example 10, the 14# CuCo / CN material prepared in Example 14, and the 18# NiCo / CN material prepared in Example 18;

[0029] Figure 4 Nitrogen adsorption-desorption isotherms of the 1# FeCo / CN material prepared in Example 1, the 10# ZrCo / CN material prepared in Example 10, the 14# CuCo / CN material prepared in Example 14, and the 18# NiCo / CN material prepared in Example 18;

[0030] Figure 5 (a) Scanning electron microscopy (SEM) image of Zr-ZIF-67 prepared in Example 10; Figure 5 (b) Transmission electron microscopy (TEM) image of Zr-ZIF-67 prepared in Example 10; Figure 5 (c) Scanning electron microscopy (SEM) image of the 10# ZrCo / CN prepared in Example 10; Figure 5 (d) Transmission electron microscopy (TEM) image of the 10# ZrCo / CN prepared in Example 10;

[0031] Figure 6 (a) Scanning electron microscopy (SEM) image of Zr-ZIF-67 prepared in Example 11; Figure 6 (b) Scanning electron microscopy (SEM) image of Zr-ZIF-67 prepared in Example 12; Figure 6 (c) Scanning electron microscopy (SEM) image of Zr-ZIF-67 prepared in Example 13; Figure 6 (d) Scanning electron microscopy (SEM) image of Cu-ZIF-67 prepared in Example 15; Figure 6 (e) Scanning electron microscopy (SEM) image of Cu-ZIF-67 prepared in Example 16; Figure 6 (f) Scanning electron microscopy (SEM) image of Cu-ZIF-67 prepared in Example 17; Figure 6 (g) Scanning electron microscopy (SEM) image of Ni-ZIF-67 prepared in Example 19; Figure 6 (h) Scanning electron microscopy (SEM) image of Ni-ZIF-67 prepared in Example 20; Figure 6 (i) Scanning electron microscopy (SEM) image of Ni-ZIF-67 prepared in Example 21;

[0032] Figure 7 (a) Scanning electron microscopy (SEM) image of Cu-ZIF-67 prepared in Example 14;Figure 7 (b) is the transmission electron microscope image (TEM) of Cu-ZIF-67 prepared in Example 14; Figure 7 (c) is the scanning electron microscope image (SEM) of 14#CuCo / CN prepared in Example 14; Figure 7 (d) is the transmission electron microscope image (TEM) of 14#CuCo / CN prepared in Example 14;

[0033] Figure 8 (a) is the scanning electron microscope image (SEM) of Ni-ZIF-67 prepared in Example 18; Figure 8 (b) is the transmission electron microscope image (TEM) of Ni-ZIF-67 prepared in Example 18; Figure 8 (c) is the scanning electron microscope image (SEM) of 18#NiCo / CN prepared in Example 18; Figure 8 (d) is the transmission electron microscope image (TEM) of 18#NiCo / CN prepared in Example 18;

[0034] Figure 9 Performance diagrams of the 1#FeCo / CN material prepared in Example 1, the 10#ZrCo / CN material prepared in Example 10, the 14#CuCo / CN material prepared in Example 14, and the 18#NiCo / CN material prepared in Example 18 for the catalytic oxidation of o-xylene to o-methylbenzoic acid;

[0035] Figure 10 It is the performance diagram of the 1#FeCo / CN material prepared in Example 1 for the catalytic oxidation of o-xylene to o-methylbenzoic acid. Detailed implementation manners

[0036] The present invention will be further described below through examples, but the patent rights are not limited to these examples.

[0037] Example 1

[0038] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0039] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal autoclave, maintained at 120 °C for 10 h, cooled to room temperature, and the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain a precursor of the cross-channel FeCo / CN material, namely ZIF-67; 36 mg of ferric chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of ferric chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of ferric chloride. After standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain an etched material, namely Fe-ZIF-67; the prepared Fe-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel FeCo / CN material (labeled as 1# FeCo / CN material).

[0040] Figure 1 (a) is the SEM image of ZIF-67 obtained in this example. It can be seen from Figure 1 (a) that the material has a square flake morphology with a size of about 500 - 900 nm and a smooth surface.

[0041] Figure 2 (a) is the SEM image of Fe-ZIF-67 obtained in this example. It can be seen from Figure 2 (a) that the material has a square flake morphology and faintly shows a cross-channel structure.

[0042] Figure 2 (b) is the TEM image of Fe-ZIF-67 obtained in this example. It can be seen from Figure 2 (b) that the material has a square flake morphology with a size of about 500 - 900 nm and an internal cross-channel structure.

[0043] Figure 2 (c) is the SEM image of 1# FeCo / CN obtained in this example. It can be seen from Figure 2 (c) that the material has a square flake morphology with a size of about 500 - 900 nm, and the surface is rough with faintly visible cross-channels.

[0044] Figure 2 (d) is the TEM image of 1# FeCo / CN obtained in this example. It can be seen from Figure 2 (d) that the material has a square flake morphology and an internal cross-channel structure.

[0045] Figure 3 is the powder X-ray diffraction pattern of 1# FeCo / CN obtained in this example. From Figure 3 it can be seen that the material exhibits three characteristic diffraction peaks at 44.2°, 51.5°, and 75.9°, corresponding to the characteristic peaks of elemental Co; while the Fe metal peak does not appear, possibly due to the low content.

[0046] Figure 4 is the nitrogen adsorption-desorption isotherm of 1# FeCo / CN obtained in this example, and its specific surface area is 40.4 m 2 / g.

[0047] Example 2

[0048] This example provides a preparation method of MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0049] In a 100 mL beaker, add cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) to 42 mL of deionized water, stir to dissolve to obtain a metal salt solution; add 2-methylimidazole (3.6 g) to 15 mL of deionized water, stir to dissolve to obtain an organic ligand solution; mix the two evenly, stir for 50 min, transfer to a hydrothermal autoclave, maintain at 120 °C for 10 h, cool to room temperature and then centrifuge to obtain the precipitate, dry at 60 °C for 12 h to obtain the precursor of the cross-channel FeCo / CN material, namely ZIF-67; dissolve 36 mg of ferric chloride hexahydrate in 180 mL of ethanol to obtain an ethanol solution of ferric chloride, inject 108 mg of the prepared ZIF-67 ethanol solution into the ethanol solution of ferric chloride, let it stand for 4 min, then centrifuge to obtain the precipitate, dry at 60 °C for 12 h to obtain the etched material, namely Fe-ZIF-67; calcine the prepared Fe-ZIF-67 in an argon atmosphere at a heating rate of 2 °C / min to 500 °C for 2 h to obtain the cross-channel FeCo / CN material (labeled as 2# FeCo / CN material).

[0050] Example 3

[0051] This example provides a preparation method of MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0052] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 12 h, cooled to room temperature, and the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel FeCo / CN material, namely ZIF-67; 36 mg of ferric chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of ferric chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of ferric chloride. After standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Fe-ZIF-67; the prepared Fe-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel FeCo / CN material (labeled as 3# FeCo / CN material).

[0053] Example 4

[0054] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0055] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, and the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel FeCo / CN material, namely ZIF-67; 18 mg of ferric chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of ferric chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of ferric chloride. After standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Fe-ZIF-67; the prepared Fe-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel FeCo / CN material (labeled as 4# FeCo / CN material).

[0056] Example 5

[0057] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0058] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, centrifuged to obtain a precipitate, and dried at 60 °C for 12 h to obtain a precursor of the cross-channel FeCo / CN material, namely ZIF-67; 36 mg of ferric chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of ferric chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of ferric chloride. After standing for 5 min, the precipitate was centrifuged and dried at 60 °C for 12 h to obtain an etched material, namely Fe-ZIF-67; the prepared Fe-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain a cross-channel FeCo / CN material (labeled as 5# FeCo / CN material).

[0059] Example 6

[0060] This example provides a method for preparing a MOFs-derived cross-channel bimetallic carbonitride material, which includes the following steps:

[0061] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, centrifuged to obtain a precipitate, and dried at 60 °C for 12 h to obtain a precursor of the cross-channel FeCo / CN material, namely ZIF-67; 36 mg of ferric chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of ferric chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of ferric chloride. After standing for 6 min, the precipitate was centrifuged and dried at 60 °C for 12 h to obtain an etched material, namely Fe-ZIF-67; the prepared Fe-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain a cross-channel FeCo / CN material (labeled as 6# FeCo / CN material).

[0062] Example 7

[0063] This example provides a method for preparing a MOFs-derived cross-channel bimetallic carbonitride material, which includes the following steps:

[0064] In a 100 mL beaker, add cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) to 42 mL of deionized water, stir to dissolve to obtain a metal salt solution; add 2-methylimidazole (3.6 g) to 15 mL of deionized water, stir to dissolve to obtain an organic ligand solution; mix the two evenly, stir for 60 min, transfer to a hydrothermal autoclave, maintain at 120 °C for 10 h, after cooling to room temperature, centrifuge to collect the precipitate, dry at 60 °C for 12 h to obtain the precursor of the cross-channel FeCo / CN material, namely ZIF-67; dissolve 36 mg of ferric chloride hexahydrate in 180 mL of ethanol to obtain an ethanol solution of ferric chloride, inject 108 mg of the prepared ZIF-67 ethanol solution into the ethanol solution of ferric chloride, after standing for 4 min, centrifuge to collect the precipitate, dry at 60 °C for 12 h to obtain the etched material, namely Fe-ZIF-67; calcine the prepared Fe-ZIF-67 in an argon atmosphere at a heating rate of 5 °C / min to 500 °C for 2 h to obtain the cross-channel FeCo / CN material (labeled as 7#FeCo / CN material).

[0065] Example 8

[0066] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0067] In a 100 mL beaker, add cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) to 42 mL of deionized water, stir to dissolve to obtain a metal salt solution; add 2-methylimidazole (3.6 g) to 15 mL of deionized water, stir to dissolve to obtain an organic ligand solution; mix the two evenly, stir for 60 min, transfer to a hydrothermal autoclave, maintain at 120 °C for 10 h, after cooling to room temperature, centrifuge to collect the precipitate, dry at 60 °C for 12 h to obtain the precursor of the cross-channel FeCo / CN material, namely ZIF-67; dissolve 36 mg of ferric chloride hexahydrate in 180 mL of ethanol to obtain an ethanol solution of ferric chloride, inject 108 mg of the prepared ZIF-67 ethanol solution into the ethanol solution of ferric chloride, after standing for 4 min, centrifuge to collect the precipitate, dry at 60 °C for 12 h to obtain the etched material, namely Fe-ZIF-67; calcine the prepared Fe-ZIF-67 in an argon atmosphere at a heating rate of 2 °C / min to 600 °C for 2 h to obtain the cross-channel FeCo / CN material (labeled as 8#FeCo / CN material).

[0068] Example 9

[0069] This implementation provides a method for preparing MOFs-derived cross-channel bimetallic carbonitride materials, which includes the following steps:

[0070] In a 100 mL beaker, add cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) to 42 mL of deionized water, stir to dissolve to obtain a metal salt solution; add 2-methylimidazole (3.6 g) to 15 mL of deionized water, stir to dissolve to obtain an organic ligand solution; mix the two evenly, stir for 60 min, transfer to a hydrothermal autoclave, maintain at 120 °C for 10 h, cool to room temperature, centrifuge to obtain the precipitate, and dry at 60 °C for 12 h to obtain the precursor of the cross-channel FeCo / CN material, namely ZIF-67; dissolve 36 mg of ferric chloride hexahydrate in 180 mL of ethanol to obtain an ethanol solution of ferric chloride, inject 108 mg of the prepared ZIF-67 ethanol solution into the ethanol solution of ferric chloride, let stand for 4 min, centrifuge to obtain the precipitate, and dry at 60 °C for 12 h to obtain the etched material, namely Fe-ZIF-67; calcine the prepared Fe-ZIF-67 at a heating rate of 2 °C / min to 700 °C in an argon atmosphere for 2 h to obtain the cross-channel FeCo / CN material (labeled as 9# FeCo / CN material).

[0071] Example 10

[0072] This implementation provides a method for preparing MOFs-derived cross-channel bimetallic carbonitride materials, which includes the following steps:

[0073] In a 100 mL beaker, add cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) to 42 mL of deionized water, stir to dissolve to obtain a metal salt solution; add 2-methylimidazole (3.6 g) to 15 mL of deionized water, stir to dissolve to obtain an organic ligand solution; mix the two evenly, stir for 60 min, transfer to a hydrothermal autoclave, maintain at 120 °C for 10 h, cool to room temperature, centrifuge to obtain the precipitate, and dry at 60 °C for 12 h to obtain the precursor of the cross-channel ZrCo / CN material, namely ZIF-67; dissolve 18 mg of zirconium chloride in 180 mL of ethanol to obtain an ethanol solution of zirconium chloride, inject 108 mg of the prepared ZIF-67 ethanol solution into the ethanol solution of zirconium chloride, let stand for 6 min, centrifuge to obtain the precipitate, and dry at 60 °C for 12 h to obtain the etched material, namely Zr-ZIF-67; calcine the prepared Zr-ZIF-67 at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel ZrCo / CN material (labeled as 10# ZrCo / CN material).

[0074] Figure 5(a) is the SEM image of Zr-ZIF-67 obtained in this example. From Figure 5 it can be seen from (a) that the material has a square flake morphology and faintly shows a cross-channel structure.

[0075] Figure 5 (b) is the TEM image of Zr-ZIF-67 obtained in this example. From Figure 5 it can be seen from (b) that the material has a square flake morphology with a size of about 500 - 900 nm and a cross-channel structure inside.

[0076] Figure 5 (c) is the SEM image of 10#ZrCo / CN obtained in this example. From Figure 5 it can be seen from (c) that the material has a square flake morphology with a size of about 500 - 900 nm and its surface is rough with faintly cross channels.

[0077] Figure 5 (d) is the TEM image of 10#ZrCo / CN obtained in this example. From Figure 5 it can be seen from (d) that the material has a square flake morphology and a cross-channel structure inside.

[0078] Figure 3 is the powder X-ray diffraction pattern of 10#ZrCo / CN obtained in this example. From Figure 3 it can be seen that the material shows three characteristic diffraction peaks at 44.2°, 51.5°, and 75.9°, corresponding to the characteristic peaks of elemental Co; while no Zr metal peak appears, probably because its content is low.

[0079] Figure 4 is the nitrogen adsorption - desorption isotherm of 10#ZrCo / CN obtained in this example, and its specific surface area is 49.0 m 2 / g.

[0080] Example 11

[0081] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0082] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal reactor and maintained at 120 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel ZrCo / CN material, namely ZIF-67; 24 mg of zirconium chloride was dissolved in 180 mL of ethanol to obtain an ethanol solution of zirconium chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of zirconium chloride. After standing for 6 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Zr-ZIF-67; the prepared Zr-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel ZrCo / CN material (labeled as 11# ZrCo / CN material).

[0083] Example 12

[0084] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, which includes the following steps:

[0085] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal reactor and maintained at 120 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel ZrCo / CN material, namely ZIF-67; 18 mg of zirconium chloride was dissolved in 180 mL of ethanol to obtain an ethanol solution of zirconium chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of zirconium chloride. After standing for 5 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Zr-ZIF-67; the prepared Zr-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel ZrCo / CN material (labeled as 12# ZrCo / CN material).

[0086] Example 13

[0087] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, which includes the following steps:

[0088] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal autoclave and maintained at 120 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel ZrCo / CN material, namely ZIF-67; 18 mg of zirconium chloride was dissolved in 180 mL of ethanol to obtain an ethanol solution of zirconium chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of zirconium chloride. After standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Zr-ZIF-67; the prepared Zr-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel ZrCo / CN material (labeled as 13#ZrCo / CN material).

[0089] Example 14

[0090] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0091] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal autoclave and maintained at 120 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel CuCo / CN material, namely ZIF-67; 90 mg of copper chloride dihydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of copper chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of copper chloride. After standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Cu-ZIF-67; the prepared Cu-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel CuCo / CN material (labeled as 14#CuCo / CN material).

[0092] Figure 7 (a) is the SEM image of the Cu-ZIF-67 obtained in this example. From Figure 7 (a), it can be seen that the material has a square flake morphology and faintly shows a cross-channel structure.

[0093] Figure 7 (b) is a TEM image of Cu-ZIF-67 obtained in this example. Figure 7 (b) shows that the material has a square flake morphology with a size of about 500 to 900 nm and a cross-channel structure inside.

[0094] Figure 7 (c) is the SEM image of 14#CuCo / CN obtained in this example. Figure 7 (c) shows that the material has a square flake morphology with a size of about 500 to 900 nm and a rough surface with faint cross channels.

[0095] Figure 7 (d) is the TEM image of 14#CuCo / CN obtained in this example. Figure 7 (d) It can be seen that the material has a square flake morphology with a cross-channel structure inside.

[0096] Figure 3 This is the powder X-ray diffraction pattern of 14#CuCo / CN obtained in this example. Figure 7 It can be seen that the material exhibits three characteristic diffraction peaks at 44.2°, 51.5°, and 75.9°, which correspond to the characteristic peaks of elemental Co; while there is no Cu metal peak, which may be due to its low content.

[0097] Figure 4 This is the nitrogen adsorption-desorption isotherm of 14#CuCo / CN obtained in this example, and its specific surface area is 58.2m 2 / g.

[0098] Embodiment 15

[0099] This embodiment provides a method for preparing a MOFs-derived cross-channel bimetallic carbon-nitrogen material, comprising the following steps:

[0100] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, and the precipitate was collected by centrifugation, dried at 60 °C for 12 h to obtain the precursor of the cross-channel CuCo / CN material, namely ZIF-67; 72 mg of copper chloride dihydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of copper chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of copper chloride. After standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Cu-ZIF-67; the prepared Cu-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel CuCo / CN material (labeled as 15#CuCo / CN material).

[0101] Example 16

[0102] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, which includes the following steps:

[0103] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, and the precipitate was collected by centrifugation, dried at 60 °C for 12 h to obtain the precursor of the cross-channel CuCo / CN material, namely ZIF-67; 90 mg of copper chloride dihydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of copper chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of copper chloride. After standing for 5 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Cu-ZIF-67; the prepared Cu-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel CuCo / CN material (labeled as 16#CuCo / CN material).

[0104] Example 17

[0105] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, which includes the following steps:

[0106] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, centrifuged to obtain a precipitate, and dried at 60 °C for 12 h to obtain a precursor of the cross-channel CuCo / CN material, namely ZIF-67; 90 mg of copper chloride dihydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of copper chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of copper chloride. After standing for 6 min, the precipitate was centrifuged and dried at 60 °C for 12 h to obtain the etched material, namely Cu-ZIF-67; the prepared Cu-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel CuCo / CN material (labeled as 17#CuCo / CN material).

[0107] Example 18

[0108] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0109] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly, stirred for 60 min, transferred to a hydrothermal reactor, maintained at 120 °C for 10 h, cooled to room temperature, centrifuged to obtain a precipitate, and dried at 60 °C for 12 h to obtain a precursor of the cross-channel NiCo / CN material, namely ZIF-67; 360 mg of nickel chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of nickel chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of nickel chloride. After standing for 6 min, the precipitate was centrifuged and dried at 60 °C for 12 h to obtain the etched material, namely Ni-ZIF-67; the prepared Ni-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel NiCo / CN material (labeled as 18#NiCo / CN material).

[0110] Figure 8 (a) is the SEM image of Ni-ZIF-67 obtained in this example. From Figure 8It can be seen from (a) that the material has a square flake morphology and faintly presents a cross-channel structure.

[0111] Figure 8 (b) is the TEM image of Ni-ZIF-67 obtained in this example. From Figure 8 (b), it can be seen that the material has a square flake morphology with a size of about 500 - 900 nm and a cross-channel structure inside.

[0112] Figure 8 (c) is the SEM image of 18#NiCo / CN obtained in this example. From Figure 8 (c), it can be seen that the material has a square flake morphology with a size of about 500 - 900 nm, and the surface is rough with faintly visible cross-channels.

[0113] Figure 8 (d) is the TEM image of 18#NiCo / CN obtained in this example. From Figure 8 (d), it can be seen that the material has a square flake morphology and a cross-channel structure inside.

[0114] Figure 3 is the powder X-ray diffraction pattern of 18#NiCo / CN obtained in this example. From Figure 3 it can be seen that the material shows three characteristic diffraction peaks at 44.2°, 51.5°, and 75.9°, corresponding to the characteristic peaks of elemental Co; while no Ni metal peak appears, probably due to the low content.

[0115] Figure 4 is the nitrogen adsorption - desorption isotherm of 18#NiCo / CN obtained in this example, and its specific surface area is 70.0 m 2 / g.

[0116] Example 19

[0117] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0118] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal reactor and maintained at 120 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel NiCo / CN material, namely ZIF-67; 420 mg of nickel chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of nickel chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of nickel chloride. After standing for 6 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Ni-ZIF-67; the prepared Ni-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel NiCo / CN material (labeled as 19#NiCo / CN material).

[0119] Example 20

[0120] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0121] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal reactor and maintained at 120 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the precursor of the cross-channel NiCo / CN material, namely ZIF-67; 360 mg of nickel chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of nickel chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of nickel chloride. After standing for 5 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Ni-ZIF-67; the prepared Ni-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel NiCo / CN material (labeled as 20#NiCo / CN material).

[0122] Example 21

[0123] This example provides a preparation method of a MOFs-derived cross-channel bimetallic carbonitride material, including the following steps:

[0124] In a 100 mL beaker, cetyltrimethylammonium bromide (CTAB) (83.4 mg) and cobalt acetate tetrahydrate (372 mg) were added to 42 mL of deionized water and stirred until dissolved to obtain a metal salt solution; 2-methylimidazole (3.6 g) was added to 15 mL of deionized water and stirred until dissolved to obtain an organic ligand solution; the two were mixed evenly and stirred for 60 min, then transferred to a hydrothermal autoclave, maintained at 120 °C for 10 h, cooled to room temperature, and the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain a precursor of the cross-channel NiCo / CN material, namely ZIF-67; 360 mg of nickel chloride hexahydrate was dissolved in 180 mL of ethanol to obtain an ethanol solution of nickel chloride. 108 mg of the prepared ZIF-67 ethanol solution was injected into the ethanol solution of nickel chloride, and after standing for 4 min, the precipitate was collected by centrifugation and dried at 60 °C for 12 h to obtain the etched material, namely Ni-ZIF-67; the prepared Ni-ZIF-67 was calcined at a heating rate of 2 °C / min to 500 °C in an argon atmosphere for 2 h to obtain the cross-channel NiCo / CN material (labeled as 21#NiCo / CN material).

[0125] Example 22

[0126] Application of MOF-derived 1#FeCo / CN material, 10#ZrCo / CN material, 14#CuCo / CN material, and 18#NiCo / CN in the catalytic oxidation of o-xylene to o-toluic acid.

[0127] In the reaction kettle, 2 mL of o-xylene and 0.02 g of catalyst (1#FeCo / CN material prepared in Example 1 or 10#ZrCo / CN material prepared in Example 10 or 14#CuCo / CN material prepared in Example 14 or 18#NiCo / CN material prepared in Example 18) were added in sequence, 1 MPa of oxygen was charged, and the mixture was stirred and heated to the reaction temperature of 180 °C and kept at a constant temperature for 6 hours. After the reaction, the 1#FeCo / CN material was separated by centrifugation, and the reaction solution was analyzed by gas chromatography-mass spectrometry.

[0128] Figure 9 It is the performance diagram of the catalytic oxidation of o-xylene to o-toluic acid by 1#FeCo / CN material prepared in Example 1, 10#ZrCo / CN material prepared in Example 10, 14#CuCo / CN material prepared in Example 14, and 18#NiCo / CN material prepared in Example 18. Among them, the MOF-derived 1#FeCo / CN material shows the best reaction effect, the conversion rate of o-xylene is 73.4%, and the yield of o-toluic acid is 53.4%, indicating that the synergistic effect of Fe and Co can promote the progress of the oxidation reaction.

[0129] Example 23

[0130] Application of MOF-derived 1# FeCo / CN material in the reaction of catalytic oxidation of o-xylene to o-toluic acid.

[0131] In a reaction kettle, 2 mL of o-xylene and 0.02 g of 1# FeCo / CN material were added in sequence, 1 MPa of oxygen was charged, and the mixture was stirred and heated to the reaction temperature (100 °C or 120 °C or 140 °C or 160 °C or 180 °C or 200 °C), and the reaction was carried out at a constant temperature for 6 hours. After the reaction, the 1# FeCo / CN material was separated by centrifugation, and the reaction solution was analyzed by gas chromatography-mass spectrometry.

[0132] Figure 10 Performance diagram of the catalytic oxidation of o-xylene to o-toluic acid by the 1# FeCo / CN material prepared in Example 1. It can be seen from the figure that when the reaction temperature is above 120 °C, the change range of the yield of o-toluic acid is small, indicating that the temperature has little effect on this reaction at this time.

[0133] It should be understood that the detailed description of the technical solution of the present invention by means of the optimized examples above is illustrative rather than restrictive. It cannot be determined that the specific implementation manner of the present invention is limited to this. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, modifying the technical solutions recorded in each example, or equivalently replacing some of the technical features, should all be regarded as belonging to the patent protection scope determined by the claims submitted by the present invention.

Claims

1. A method for preparing a MOFs-derived cross-channel bimetallic carbon-nitrogen material, characterized in that: The specific steps include: (1) adding a surfactant and a cobalt salt into deionized water, stirring and dissolving them, to obtain a metal salt solution; adding an organic ligand into deionized water, stirring and dissolving them, to obtain an organic ligand solution; (2) mixing the metal salt solution and the organic ligand solution described in step (1), stirring evenly, transferring to a hydrothermal reactor, cooling to room temperature after hydrothermal heating, centrifuging to obtain a precipitate, and drying to obtain a precursor of a cross-channel bimetallic carbon nitrogen material, namely ZIF-67; (3) injecting the ZIF-67 prepared in step (2) into an ethanol solution of a second metal, allowing to stand for several minutes, centrifuging to obtain a precipitate, and drying to obtain an etched material M-ZIF-67, where M is Fe, Zr, Cu or Ni; (4) The etched material prepared in step (3) is heated and calcined in an inert atmosphere to obtain a MOFs-derived cross-channel bimetallic carbon-nitrogen material.

2. The method for preparing the MOFs-derived cross-channel bimetallic carbonitride material according to claim 1, characterized in that: In step (1), the organic ligand is selected from 2-methylimidazole; the surfactant is selected from hexadecyltrimethylammonium bromide (CTAB); and the cobalt salt is selected from cobalt acetate tetrahydrate.

3. The method for preparing the MOFs-derived cross-channel bimetallic carbon-nitrogen material according to claim 1, characterized in that: In step (1), the molar ratio of the surfactant to the cobalt salt is 1:1-10; the concentration of the surfactant is 1-8 g / L, and the concentration of the cobalt salt is 0.01-0.1 mol / L.

4. The method for preparing the MOFs-derived cross-channel bimetallic carbon-nitrogen material according to claim 1, characterized in that: In step (1), the molar ratio of the cobalt salt to the organic ligand is 1:10-50; and the concentration of the organic ligand is 0.5-10 mol / L.

5. The method for preparing the MOFs-derived cross-channel bimetallic carbon nitride material according to claim 1, characterized in that: In step (2), the volume ratio of the metal salt mixed solution to the organic ligand solution is 1-5:1; the stirring time is 0.5-4 hours; the hydrothermal time is 5-15 hours; the hydrothermal temperature is 100-150°C; and the drying temperature is 50-80°C.

6. The method for preparing the MOFs-derived cross-channel bimetallic carbonitride material according to claim 1, characterized in that: In step (3), the mass ratio of ZIF-67 to the second metal salt is 0.1 to 10:1; the standing time is 0 to 10 min; the drying temperature is 50 to 80° C.; and the second metal salt is selected from ferric chloride hexahydrate, zirconium chloride, cupric chloride dihydrate or nickel chloride hexahydrate.

7. The method for preparing the MOFs-derived cross-channel bimetallic carbonitride material according to claim 1, characterized in that: In step (4), the inert atmosphere is an argon atmosphere; the calcination temperature is 300 to 800° C., the calcination time is 1 to 3 hours, and the heating rate is 1 to 5° C. / min.

8. Use of the MOFs-derived cross-channel bimetallic carbon-nitrogen material prepared by the preparation method according to any one of claims 1 to 7 in the oxidation of o-xylene.

9. The use according to claim 8, characterized in that: Add o-xylene and a cross-channel bimetallic carbon-nitrogen material catalyst into a reaction kettle in sequence, introduce oxygen, stir and heat to 80-200° C., react at a constant temperature for 2-18 hours, then cool to room temperature, separate the cross-channel bimetallic carbon-nitrogen material from the reaction system by centrifugation, and obtain o-toluic acid.

10. The use of the MOFs-derived cross-channel bimetallic carbon-nitrogen material in the oxidation of o-xylene according to claim 8, characterized in that: The dosage ratio of the o-xylene to the cross-channel bimetallic carbon-nitrogen material catalyst is 1g: (0.1g-0.01g).

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