Phthalocyanine-based two-dimensional covalent organic framework material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of electro-catalysis, and discloses a phthalocyanine-based two-dimensional covalent organic framework material as well as a preparation method and application thereof. The phthalocyanine-based two-dimensional covalent organic framework material provided by the invention is obtained by polymerizing a perfluorometal phthalocyanine monomer and 2, 3, 5, 6-tetra (amino) p-benzoquinone, and the monomer has excellent conductivity and is beneficial to electron migration and ethylene adsorption; the material is high in crystallinity and has a face-to-face and layer-by-layer stacked two-dimensional layered structure, efficient pi-pi interaction and charge migration are achieved, and a core structure foundation with excellent electro-catalytic performance is formed; the material has a developed porous structure, so that rapid diffusion of reactants / products is facilitated, and efficient migration of electrons, protons and molecules is synchronously realized; the preparation method of the material is simple in step, mild in condition, low in raw material cost and suitable for industrial application; the catalyst can be applied to chloride or bromide mediated electrocatalytic ethylene oxidation, the product is 2-chloroethanol or 2-bromoethanol, and the electrocatalytic efficiency and selectivity are high.

Description

Technical Field

[0001] The present invention relates to the field of electrocatalysis technology, and in particular to a phthalocyanine-based two-dimensional covalent organic framework material and a preparation method and application thereof. Background Art

[0002] The oxidation reaction of ethylene (C2H4) is an important process in chemical production. Its products are widely used in the synthesis of chemicals such as ethylene oxide, acetaldehyde, acetic acid, and vinyl alcohol. The main methods of ethylene oxidation reaction include traditional chemical oxidation, biocatalytic oxidation, photocatalytic oxidation, and electrocatalytic oxidation. Among them, electrocatalytic chloride / bromide mediated ethylene oxidation reaction is an electrochemical method in the presence of chloride ions (Cl - ) or bromide ion (Br - ) in an electrolyte containing ethylene, ethylene is selectively oxidized to 2-chloroethanol or 2-bromoethanol through the action of a catalyst. This process is sustainable and has mild reaction conditions, and has potential for industrial application.

[0003] However, in the electrocatalytic chloride / bromide-mediated ethylene oxidation reaction, the ethylene oxidation catalyst relies on precious metals. For example, the use of precious metal Ir1 / Co3O4 materials to catalyze the oxidation of ethylene to 2-chloroethanol has a Faradaic efficiency of 94.8% at 2V; the use of precious metal Pt-RuO2 materials to catalyze the oxidation of ethylene to 2-bromoethanol has a Faradaic efficiency of 94.8% at 40mA / cm 2 The Faradaic efficiency at this current density reaches 90%, but precious metals are expensive and scarce. Compared to precious metals, transition metals are abundant and less expensive. Therefore, developing efficient ethylene oxidation electrocatalysts composed of transition metals will effectively address the limitations of precious metal catalysts that limit the application of electrocatalytic ethylene oxidation reactions.

[0004] Covalent organic frameworks (COFs) are a class of crystalline materials composed of lightweight elements (such as C, O, N, and B) linked by strong covalent bonds, exhibiting long-range ordered pore structures and high stability. COFs possess the following characteristics: ① The molecules are completely connected by covalent bonds, resulting in high stability; ② The structural design is controllable, allowing for the easy introduction of suitable functional groups; and ③ Functional design is amenable to widespread application in gas storage and separation, photoelectrocatalysis, and batteries. Therefore, COFs are highly promising heterogeneous electrocatalysts. However, few reports have been published on COF-based electrocatalysts for ethylene oxidation. Therefore, developing COFs with catalytically active sites to replace traditional precious metal electrocatalysts is of great significance for promoting the industrial application of electrocatalytic ethylene oxidation. Summary of the Invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems in the prior art. To this end, one of the objectives of the present invention is to provide a phthalocyanine-based two-dimensional covalent organic framework material.

[0006] The second object of the present invention is to provide a method for preparing the phthalocyanine-based two-dimensional covalent organic framework material.

[0007] The third object of the present invention is to provide applications of this phthalocyanine-based two-dimensional covalent organic framework material.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] The first aspect of the present invention provides a phthalocyanine-based two-dimensional covalent organic framework material, the structural formula of which is shown in formula (I):

[0010]

[0011] Wherein, M is selected from at least one of Co, Ni, Cu, Fe, Mn, Zn, Cr, and V.

[0012] In some embodiments of the present invention, the M is selected from Co, Ni or Cu.

[0013] In some embodiments of the present invention, the phthalocyanine-based two-dimensional covalent organic framework material has a face-to-face, layer-by-layer stacking structure with an interlayer spacing of 0.2-0.5 nm.

[0014] In some preferred embodiments of the present invention, the phthalocyanine-based two-dimensional covalent organic framework material has a face-to-face, layer-by-layer stacking structure with an interlayer spacing of 0.3-0.45 nm.

[0015] In some embodiments of the present invention, the stacking manner of the phthalocyanine-based two-dimensional covalent organic framework material is an overlapping arrangement (AA stacking) or a staggered arrangement (AB stacking).

[0016] In some embodiments of the present invention, the AA stacking refers to that the phthalocyanine molecules in adjacent layers are completely aligned, and the molecular centers (MN4) are overlapped in the vertical direction.

[0017] In some embodiments of the present invention, the AB stacking refers to a staggered arrangement of phthalocyanine molecules in adjacent layers, with the center (MN4) of the upper layer molecule located above the pore of the lower layer molecule.

[0018] In some embodiments of the present invention, the phthalocyanine-based two-dimensional covalent organic framework material has a pore structure with a pore diameter of 1-3 nm.

[0019] In some preferred embodiments of the present invention, the phthalocyanine-based two-dimensional covalent organic framework material has a pore structure with a pore diameter of 1-2 nm.

[0020] In some embodiments of the present invention, the phthalocyanine-based two-dimensional covalent organic framework material is a black solid powder.

[0021] In some embodiments of the present invention, the phthalocyanine-based two-dimensional covalent organic framework material is prepared from the following raw materials: perfluorometallic phthalocyanine monomer, 2,3,5,6-tetrakis(amino)-benzoquinone, a catalyst and a solvent;

[0022] The structural formula of the perfluorometallic phthalocyanine monomer is shown in formula (a): Wherein, the definition of M is as described in the first aspect of the present invention.

[0023] In some embodiments of the present invention, the molar ratio of the perfluorometal phthalocyanine monomer to 2,3,5,6-tetrakis(amino)-p-benzoquinone is 1:(1-3).

[0024] In some preferred embodiments of the present invention, the molar ratio of the perfluorometal phthalocyanine monomer to 2,3,5,6-tetrakis(amino)-p-benzoquinone is 1:(1-2).

[0025] In some embodiments of the present invention, the solid-to-liquid ratio of the perfluorometallic phthalocyanine monomer to the solvent is (15-30) mg:1 mL.

[0026] In some preferred embodiments of the present invention, the solid-to-liquid ratio of the perfluorometallic phthalocyanine monomer to the solvent is (15-26) mg:1 mL.

[0027] In some embodiments of the present invention, the solvent is selected from at least one of 1,4-dioxane, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0028] In some preferred embodiments of the present invention, the solvent is 1,4-dioxane and acetonitrile in a volume ratio of 1:(0.8-1.2).

[0029] In some embodiments of the present invention, the catalyst is selected from at least one of triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,8-diazobispiro[5.4.0]undec-7-ene, and 4-dimethylaminopyridine.

[0030] In some preferred embodiments of the present invention, the catalyst is selected from triethylamine or 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0031] In some embodiments of the present invention, the volume ratio of the catalyst to the solvent is 1:(40-100).

[0032] The basic principles of the present invention are described as follows:

[0033] The phthalocyanine-based two-dimensional covalent organic framework material provided by the present invention is a two-dimensional crystalline covalent organic framework material formed by covalent bonds using a perfluorometallic phthalocyanine compound and 2,3,5,6-tetra(amino)-p-benzoquinone as monomers in a specific molar ratio:

[0034] ① The phthalocyanine molecule is composed of four isoindole units, forming an 18π electron conjugated system with a wide range of electron delocalization, similar to conductive polymers such as graphene or polyaniline. After perfluorinated substitution, the strong electron-withdrawing effect of the fluorine atom can reduce the lowest unoccupied orbital energy level and enhance the electron-accepting capacity. At the same time, the p orbital of the fluorine atom forms a p-π conjugation with the π system of the phthalocyanine ring, promoting electron delocalization. That is, perfluorinated substitution further regulates the electronic structure of the phthalocyanine molecule. The perfluorinated metal phthalocyanine monomer has excellent conductivity and electron transfer ability.

[0035] ② The transition metal (M) in the perfluorometal phthalocyanine monomer is coordinated with four nitrogen atoms (MN4 structure) to form a catalytic active site. Its functions are as follows: the transition metal's d orbital couples with the π system of the phthalocyanine ring to form a metal-ligand charge transfer channel, promoting the transfer of electrons in the catalytic reaction. The variable valence state of the metal ion can also act as a redox medium in electrocatalysis, directly participating in the activation of the reactants.

[0036] ③The MN4 site can adsorb reactants (such as ethylene) through the empty d orbital of the metal, reducing the reaction energy barrier. The carbonyl oxygen of 2,3,5,6-tetra(amino)benzoquinone can assist in the adsorption of ethylene and act synergistically with the MN4 site.

[0037] The second aspect of the present invention provides a method for preparing the phthalocyanine-based two-dimensional covalent organic framework material according to the first aspect of the present invention, comprising the following steps:

[0038] S1, dissolving a perfluorometal phthalocyanine monomer and 2,3,5,6-tetrakis(amino)-p-benzoquinone in a solvent, adding a catalyst to obtain a mixed solution;

[0039] S2. The mixed solution is subjected to a freeze-thaw-vacuum cycle in liquid nitrogen, and a closed reaction is performed to obtain the phthalocyanine-based two-dimensional covalent organic framework material.

[0040] In some embodiments of the present invention, the reaction temperature is 100-150° C. and the reaction time is 2-5 days.

[0041] In some preferred embodiments of the present invention, the reaction temperature is 110-130° C. and the reaction time is 2-4 days.

[0042] In some embodiments of the present invention, after the reaction is completed, the process further includes washing and drying the phthalocyanine-based two-dimensional covalent organic framework material.

[0043] In some embodiments of the present invention, the washing reagent comprises tetrahydrofuran.

[0044] In some embodiments of the present invention, the washing time is 12-24 hours.

[0045] In some embodiments of the present invention, the drying method is vacuum drying at 80-120° C. for 2-4 hours.

[0046] The principle of the method for preparing the phthalocyanine-based two-dimensional covalent organic framework material of the present invention is described as follows:

[0047] In the preparation of phthalocyanine-based two-dimensional covalent organic framework materials, crystallinity directly affects the porosity, electronic conductivity and exposure of active sites, while catalytic activity is closely related to the metal center, ligand structure and electron transfer efficiency:

[0048] ① The present invention preferably uses a high boiling point solvent (such as 1,4-dioxane) and a strong polar solvent (such as acetonitrile). The high boiling point solvent can provide a high temperature reaction environment, promote slow crystallization, and obtain high crystallinity. The strong polar solvent can enhance the solubility of the monomer and prevent premature precipitation, thereby regulating the solubility and crystallization kinetics.

[0049] ② The catalyst can promote polymerization and crystallization. The present invention uses a catalyst such as 1,8-diazabicyclo[5.4.0]undec-7-ene, which can catalyze the formation of -CNC- bonds, reduce the polymerization energy barrier, regulate the reaction rate, avoid excessive polymerization leading to amorphous products, and avoid the occurrence of side reactions such as phthalocyanine demetallation caused by excessive catalyst by controlling the amount of catalyst and solvent used;

[0050] ③ The solvent thermal reaction temperature is 100-150℃. Below 100℃ will lead to incomplete reaction and low crystallinity, while above 150℃ may cause hydrolysis of imine bonds or skeleton collapse. By controlling the reaction temperature, the reaction rate and crystal quality can be balanced;

[0051] ④ The solvent thermal reaction time is 2-5 days. If the time is too short, it will lead to incomplete polymerization and poor crystallinity. If the time is too long, side reactions such as skeleton oxidation may occur.

[0052] ⑤ Remove oxygen and moisture through freeze-thaw-vacuum cycles to avoid metal oxidation or imine bond hydrolysis.

[0053] The third aspect of the present invention provides the use of the phthalocyanine-based two-dimensional covalent organic framework material described in the first aspect of the present invention in electrocatalytic ethylene oxidation.

[0054] In some embodiments of the present invention, the electrocatalytic ethylene oxidation comprises chloride or bromide-mediated ethylene oxidation.

[0055] In some embodiments of the present invention, the application includes coating the phthalocyanine-based two-dimensional covalent organic framework material on an electrode substrate material to form a working electrode; the loading amount of the phthalocyanine-based two-dimensional covalent organic framework material is 0.8-2 mg / cm 2 .

[0056] In some preferred embodiments of the present invention, the loading amount of the phthalocyanine-based two-dimensional covalent organic framework material is 0.8-1.5 mg / cm 2 .

[0057] In some embodiments of the present invention, the electrode substrate material is selected from carbon paper, carbon cloth, nickel foam, graphene or metal mesh.

[0058] In some embodiments of the present invention, in the electrocatalytic ethylene oxidation, the flow rate of ethylene is 3-7 mL / min.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] 1) The phthalocyanine-based two-dimensional covalent organic framework material provided by the present invention is obtained by polymerizing a perfluorometallic phthalocyanine monomer and 2,3,5,6-tetra(amino)-benzoquinone. The monomer has excellent electrical conductivity, which is conducive to electron migration and ethylene adsorption. The material has high crystallinity and a face-to-face, layer-by-layer stacked two-dimensional layered structure, which realizes efficient π-π interaction and charge migration, forming the core structural foundation of excellent electrocatalytic performance. The material has a well-developed pore structure, which is conducive to the rapid diffusion of reactants / products and the simultaneous efficient migration of electrons, protons and molecules.

[0061] 2) The method for preparing the phthalocyanine-based two-dimensional covalent organic framework material provided by the present invention has simple steps, mild reaction conditions, does not use precious metals, has low raw material costs, and is suitable for industrial use;

[0062] 3) The phthalocyanine-based two-dimensional covalent organic framework material provided by the present invention can be used as an electrocatalyst in chloride- or bromide-mediated electrocatalytic ethylene oxidation, and the product is 2-chloroethanol or 2-bromoethanol. The electrocatalytic efficiency and selectivity are high. At 2.3V, the Faradaic efficiency for the oxidation of ethylene to 2-chloroethanol is 79.6%, and at 1.6V, the Faradaic efficiency for the oxidation of ethylene to 2-bromoethanol is 76.5%. The reaction does not rely on precious metal catalysts, effectively solving the problem that precious metal catalysts limit the application of electrocatalytic ethylene oxidation reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 Schematic diagram of the structure of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1;

[0064] Figure 2This is a front view of the crystal structure of a phthalocyanine-based two-dimensional covalent organic framework material simulated using Material Studio software;

[0065] Figure 3 This is a side view of a phthalocyanine-based two-dimensional covalent organic framework material simulated using Material Studio software;

[0066] Figure 4 The XRD pattern of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1;

[0067] Figure 5 The XRD pattern of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF in Example 2;

[0068] Figure 6 The XRD pattern of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF in Example 3;

[0069] Figure 7 This is the infrared spectrum of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1;

[0070] Figure 8 This is an infrared spectrum of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF in Example 2;

[0071] Figure 9 This is the infrared spectrum of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF in Example 3;

[0072] Figure 10 The XPS patterns of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF (a) and Co(II) (b) in Example 1 are shown;

[0073] Figure 11 XPS graphs of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF (a) and Ni(II) (b) in Example 2;

[0074] Figure 12 XPS graphs of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF (a) and Cu(II) (b) in Example 3;

[0075] Figure 13 This is the solid-state NMR image of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1;

[0076] Figure 14This is the solid-state NMR image of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF in Example 2;

[0077] Figure 15 This is the solid-state NMR image of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF in Example 3;

[0078] Figure 16 This is a linear voltammogram of the chloride-mediated electrocatalytic ethylene oxidation involving the phthalocyanine-based two-dimensional covalent organic framework material in Application Example 1;

[0079] Figure 17 This is the selectivity diagram of 2-chloroethanol in the potential range of 2.0-2.4 V for chloride-mediated electrocatalytic ethylene oxidation involving the phthalocyanine-based two-dimensional covalent organic framework material in Application Example 1;

[0080] Figure 18 This is a linear voltammetric curve of the bromide-mediated electrocatalytic ethylene oxidation involving the phthalocyanine-based two-dimensional covalent organic framework material in Application Example 2;

[0081] Figure 19 This is the selectivity diagram of 2-bromoethanol in the potential range of 1.45-1.65V in the bromide-mediated electrocatalytic ethylene oxidation involving the phthalocyanine-based two-dimensional covalent organic framework material in Application Example 2. DETAILED DESCRIPTION

[0082] The present invention is further described in detail below by way of specific examples. Unless otherwise specified, the raw materials, reagents, or devices used in the examples are all commercially available or can be obtained by conventional methods. Unless otherwise specified, all experiments or testing methods are conventional methods in the art.

[0083] Example 1

[0084] This example prepares a phthalocyanine-based two-dimensional covalent organic framework material in the following steps:

[0085] S11. In a solvent storage bottle (10 mL, 8 mm high vacuum valve, 19 mm outer diameter, 65 mm length), 21.3 mg of 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexafluoro-29H,31H-phthalocyanine cobalt (II) (0.025 mmol) and 4.2 mg of 2,3,5,6-tetrakis(amino)-p-benzoquinone (0.025 mmol) were added, 1 mL of 1:1 volume ratio of 1,4-dioxane and acetonitrile was added, and ultrasonic treatment was performed for 20 min to uniformly disperse the mixture. 1,8-diazabicyclo[5.4.0]undec-7-ene was added at a volume ratio of 1:40 to the solvent, and ultrasonic treatment was performed for 10 min.

[0086] S21, the solvent storage bottle was subjected to three freeze-thaw-vacuum cycles in liquid nitrogen, then sealed, and reacted in a 120°C oven for 3 days;

[0087] S22. After the reaction is completed, the temperature is naturally lowered to room temperature. The solvent storage bottle is washed three times with tetrahydrofuran. The product is collected by filtration. The collected black powder is transferred to a vacuum oven at 120°C and dried for 3 hours to obtain a phthalocyanine-based two-dimensional covalent organic framework material, which is recorded as CoPc-TABQ COF.

[0088] Figure 1 The schematic diagram of the structure of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1 is composed of Figure 1 It can be seen that CoPc-TABQ COF has the carbonyl oxygen structure of 2,3,5,6-tetrakis(amino)-p-benzoquinone and the CoN4 structure in which the transition metal cobalt in perfluorometallic cobalt phthalocyanine is coordinated with four nitrogen atoms. The yield of CoPc-TABQ COF based on perfluorocobalt phthalocyanine (CoPc) is 80%.

[0089] Figure 2 This is a front view of the crystal structure of a phthalocyanine-based two-dimensional covalent organic framework material simulated using Material Studio software, where: Figure 2 (a) is AA stacking, showing that the adjacent layers of phthalocyanine molecules are completely aligned, the molecular centers (CoN4) overlap in the vertical direction, and the pore size is 1.5nm. Figure 2 (b) in the figure shows AB stacking, where the adjacent layers of phthalocyanine molecules are staggered, with the center of the upper molecule (CoN4) located above the pores of the lower molecule.

[0090] Figure 3 This is a side view of a phthalocyanine-based two-dimensional covalent organic framework material simulated using Material Studio software. Figure 3 It can be seen that CoPc-TABQ COF has a face-to-face, layer-by-layer stacking structure, and the interlayer spacing between adjacent layers is 0.342 nm.

[0091] Example 2

[0092] This example prepares a phthalocyanine-based two-dimensional covalent organic framework material in the following steps:

[0093] S11. In a solvent storage bottle (10 mL, 8 mm high vacuum valve, 19 mm outer diameter, 65 mm length), 17.2 mg of 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexafluoro-29H,31H-phthalocyanine nickel (II) (0.02 mmol) and 6.7 mg of 2,3,5,6-tetrakis(amino)-p-benzoquinone (0.04 mmol) were added, 1 mL of 1,4-dioxane and acetonitrile in a volume ratio of 1:1.2 was added, and ultrasonic treatment was performed for 20 min to uniformly disperse the mixture. 1,8-diazabicyclo[5.4.0]undec-7-ene in a volume ratio of 1:60 to the solvent was added, and ultrasonic treatment was performed for 10 min.

[0094] S21, the solvent storage bottle was subjected to three freeze-thaw-vacuum cycles in liquid nitrogen, then sealed, and reacted in a 120°C oven for 3 days;

[0095] S22. After the reaction is completed, the temperature is naturally lowered to room temperature. The solvent storage bottle is washed three times with tetrahydrofuran. The product is collected by filtration. The collected black powder is transferred to a vacuum oven at 120°C and dried for 3 hours to obtain a phthalocyanine-based two-dimensional covalent organic framework material, which is recorded as NiPc-TABQ COF.

[0096] Example 3

[0097] This example prepares a phthalocyanine-based two-dimensional covalent organic framework material in the following steps:

[0098] S11. In a solvent storage bottle (10 mL, 8 mm high vacuum valve, 19 mm outer diameter, 65 mm length), 25.9 mg of 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexafluoro-29H,31H-phthalocyanine copper (II) (0.03 mmol) and 15.0 mg of 2,3,5,6-tetrakis(amino)-p-benzoquinone (0.09 mmol) were added, 1 mL of 1,4-dioxane and acetonitrile in a volume ratio of 1:1.2 was added, and ultrasonic treatment was performed for 20 min to uniformly disperse the mixture. 1,8-diazabicyclo[5.4.0]undec-7-ene in a volume ratio of 1:60 to the solvent was added, and ultrasonic treatment was performed for 10 min.

[0099] S21, the solvent storage bottle was subjected to three freeze-thaw-vacuum cycles in liquid nitrogen, then sealed, and reacted in a 120°C oven for 3 days;

[0100] S22. After the reaction is completed, the temperature is naturally lowered to room temperature. The solvent storage bottle is washed three times with tetrahydrofuran. The product is collected by filtration. The collected black powder is transferred to a vacuum oven at 120°C and dried for 3 hours to obtain a phthalocyanine-based two-dimensional covalent organic framework material, which is recorded as CuPc-TABQ COF.

[0101] The phthalocyanine-based two-dimensional covalent organic framework materials prepared in Examples 1-3 were characterized:

[0102] Figure 4 is the XRD pattern of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1, Figure 5 is the XRD pattern of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF in Example 2, Figure 6 is the XRD pattern of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF in Example 3, Figure 4-Figure 6 It can be seen that the XRD patterns of the phthalocyanine-based two-dimensional covalent organic framework materials prepared in Examples 1-3 are compared with the simulated stacking patterns, and the experimental peak positions all match the simulated peaks, indicating that CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF all have high crystallinity.

[0103] Figure 7 This is the infrared spectrum of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1. Figure 8 This is the infrared spectrum of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF in Example 2. Figure 9 The infrared spectrum of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF in Example 3 is shown in FIG. Figure 7-Figure 9 It can be seen that CoPc-TABQCOF, NiPc-TABQ COF and CuPc-TABQ COF are all at about 1600 cm -1 The CNC characteristic peak appears nearby, indicating that the perfluorometallic phthalocyanine monomer and 2,3,5,6-tetrakis(amino)-benzoquinone are successfully polymerized to form the target structure.

[0104] Figure 10 The XPS graphs of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF (a) and Co (II) (b) in Example 1 are shown. Figure 11 The XPS graphs of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF (a) and Ni (II) (b) in Example 2 are shown. Figure 12 The XPS graphs of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF (a) and Cu (II) (b) in Example 3 are shown in FIG. Figure 10-12It can be seen that the following characteristic peaks are present in the XPS spectrum: C 1s (~285 eV) comes from the phthalocyanine aromatic ring and the 2,3,5,6-tetra(amino)-benzoquinone skeleton, N 1s (~398 eV) comes from the imine bond (C=N) and metal coordinated nitrogen (M-N4), O1s (~531 eV) comes from the carbonyl group (C=O) in 2,3,5,6-tetra(amino)-benzoquinone, F 1s (~688 eV) comes from the perfluorinated substituent (-F), and transition metal peaks (such as Co 2p 3 / 2 ~780eV), indicating that the materials are composed of the expected elements without other impurities (such as Si, Al); and the transition metal elements therein are all +2 valence, which is directly related to the high catalytic activity of the material.

[0105] Figure 13 This is the solid-state NMR image of the phthalocyanine-based two-dimensional covalent organic framework material CoPc-TABQ COF in Example 1. Figure 14 is the solid-state NMR image of the phthalocyanine-based two-dimensional covalent organic framework material NiPc-TABQ COF in Example 2, Figure 15 is the solid-state NMR image of the phthalocyanine-based two-dimensional covalent organic framework material CuPc-TABQ COF in Example 3, Figure 13-15 It can be seen that the CN bonds in CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF were successfully coupled.

[0106] Application Example 1

[0107] The phthalocyanine-based two-dimensional covalent organic framework materials prepared in Examples 1-3 were used for chloride-mediated electrocatalytic ethylene oxidation, respectively, as follows:

[0108] Under room temperature conditions, a closed H-type electrolytic cell is used. The two polar chambers of the electrolytic cell are separated by a proton exchange membrane, which only allows protons to pass through. 2 1 mg of phthalocyanine-based two-dimensional covalent organic framework material was coated on carbon paper to form a working electrode. A platinum sheet was used as a counter electrode, Ag / AgCl was used as a reference electrode, and the electrolyte was 0.6 mol / L potassium chloride solution. A three-electrode system was used to evaluate the electrocatalytic performance of the material.

[0109] Ethylene gas was continuously blown onto the working electrode at a flow rate of 5 mL / min, and then the test was performed.

[0110] Among them, the phthalocyanine-based two-dimensional covalent organic framework materials are CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF prepared in Examples 1-3 respectively; all test potentials in the present invention are relative to the reversible hydrogen electrode (RHE) potential, and the results presented are converted to RHE potential according to the Nernst equation.

[0111] Figure 16 The linear voltammetric curve of the chloride-mediated electrocatalytic ethylene oxidation in the presence of the phthalocyanine-based two-dimensional covalent organic framework in Application Example 1 is shown in FIG. 1 . The scanning speed of the linear sweep polarization curve test is 5 mV / s. Figure 16 It can be seen that in the chloride-mediated electrocatalytic ethylene oxidation, CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF all have electrocatalytic performance, and within a certain voltage range, the current density corresponding to NiPc-TABQ COF is relatively large, indicating that it has relatively high electrocatalytic activity in the chloride-mediated ethylene oxidation reaction.

[0112] Figure 17 This is the selectivity diagram of 2-chloroethanol in the potential range of 2.0-2.4V for chloride-mediated electrocatalytic ethylene oxidation involving the phthalocyanine-based two-dimensional covalent organic framework material in Application Example 1. In the chloride-mediated ethylene oxidation electrocatalytic test, the oxidation product was analyzed by nuclear magnetic resonance hydrogen spectrum detection, confirming that the product was 2-chloroethanol, and almost no other liquid phase products were generated. The selectivity of 2-chloroethanol in the potential range of 2.0-2.4V was then tested, that is, the Faradaic efficiency (FE) of the test material. ClCH2CH2OH ), the calculation formula is Where n is the molar amount of the product, F is the Faraday coefficient, 96485C / mol; C (ClCH2CH2OH) is the concentration of 2-chloroethanol calculated by the internal standard method of nuclear magnetic resonance hydrogen spectrum, V is the volume of the electrolyte, and Q is the charge number in the catalytic process; Figure 17 It can be seen that in the potential range of 2.0-2.4V, CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF all have certain selectivity. At 2.3V, NiPc-TABQ COF shows the best selectivity, which can reach 79.6%.

[0113] Application Example 2

[0114] The phthalocyanine-based two-dimensional covalent organic framework materials prepared in Examples 1-3 were used for bromide-mediated electrocatalytic ethylene oxidation, respectively, as follows:

[0115] Under room temperature conditions, a closed H-type electrolytic cell is used. The two polar chambers of the electrolytic cell are separated by a proton exchange membrane, which only allows protons to pass through. 2 1 mg of phthalocyanine-based two-dimensional covalent organic framework material was coated on carbon paper to form a working electrode. A platinum sheet was used as a counter electrode, Ag / AgCl was used as a reference electrode, and the electrolyte was 0.5 mol / L potassium bromide solution. A three-electrode system was used to evaluate the electrocatalytic performance of the material.

[0116] Ethylene gas was continuously blown onto the working electrode at a flow rate of 5 mL / min, and then the test was performed.

[0117] Among them, the phthalocyanine-based two-dimensional covalent organic framework materials are CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF prepared in Examples 1-3 respectively; all test potentials in the present invention are relative to the reversible hydrogen electrode (RHE) potential, and the results presented are converted to RHE potential according to the Nernst equation.

[0118] Figure 18 The linear voltammetric curve of the bromide-mediated electrocatalytic ethylene oxidation in the presence of the phthalocyanine-based two-dimensional covalent organic framework in Application Example 2 is shown in FIG. 1 . The scanning speed of the linear sweep polarization curve test is 5 mV / s. Figure 18 It can be seen that in the bromide-mediated electrocatalytic ethylene oxidation, CoPc-TABQ COF has the most negative onset potential and the largest half-wave potential, showing the best catalytic reduction performance.

[0119] Figure 19 The selectivity of 2-bromoethanol in the electrocatalytic ethylene oxidation mediated by bromide in the potential range of 1.45-1.65V in the phthalocyanine-based two-dimensional covalent organic framework material in Application Example 2 is shown. In the electrocatalytic test of ethylene oxidation mediated by bromide, the oxidation product was analyzed by nuclear magnetic resonance hydrogen spectrum, confirming that the product was 2-bromoethanol, and almost no other liquid products were generated. In the H-type electrochemical electrolysis cell, Figure 19 It can be seen that in the potential range of 1.45-1.65V, CoPc-TABQ COF, NiPc-TABQ COF and CuPc-TABQ COF all have certain selectivity. At 1.6V, CoPc-TABQ COF shows the best selectivity, which can reach 76.5%.

Claims

1. A phthalocyanine-based two-dimensional covalent organic framework material, characterized in that: Its structural formula is shown in formula (I): Wherein, M is selected from at least one of Co, Ni, Cu, Fe, Mn, Zn, Cr, and V.

2. The phthalocyanine-based two-dimensional covalent organic framework material according to claim 1, characterized in that: The M is selected from at least one of Co, Ni, and Cu.

3. The phthalocyanine-based two-dimensional covalent organic framework material according to claim 1, characterized in that: The phthalocyanine-based two-dimensional covalent organic framework material has a face-to-face, layer-by-layer stacking structure with an interlayer spacing of 0.2-0.5 nm; And / or, the phthalocyanine-based two-dimensional covalent organic framework material has a pore structure with a pore diameter of 1-3 nm.

4. The phthalocyanine-based two-dimensional covalent organic framework material according to any one of claims 1 to 3, characterized in that: The phthalocyanine-based two-dimensional covalent organic framework material is prepared from the following raw materials: perfluorometallic phthalocyanine monomer, 2,3,5,6-tetrakis(amino)-p-benzoquinone, a catalyst and a solvent; The structural formula of the perfluorometallic phthalocyanine monomer is shown in formula (a): Wherein, the definition of M is as described in claim 1 or 2.

5. The phthalocyanine-based two-dimensional covalent organic framework material according to claim 4, characterized in that: The molar ratio of the perfluorometal phthalocyanine monomer to 2,3,5,6-tetrakis(amino)-p-benzoquinone is 1:(1-3); And / or, the solid-to-liquid ratio of the perfluorometallic phthalocyanine monomer to the solvent is (15-30) mg:1 mL.

6. The phthalocyanine-based two-dimensional covalent organic framework material according to claim 4, characterized in that: The solvent is selected from at least one of 1,4-dioxane, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone; And / or, the catalyst is selected from at least one of triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,8-diazobispiro[5.4.0]undec-7-ene, and 4-dimethylaminopyridine.

7. The method for preparing the phthalocyanine-based two-dimensional covalent organic framework material according to any one of claims 4 to 6, characterized in that: The following steps are involved: S1, dissolving a perfluorometal phthalocyanine monomer and 2,3,5,6-tetrakis(amino)-p-benzoquinone in a solvent, adding a catalyst to obtain a mixed solution; S2. The mixed solution is subjected to a freeze-thaw-vacuum cycle in liquid nitrogen, and a closed reaction is performed to obtain the phthalocyanine-based two-dimensional covalent organic framework material.

8. The preparation method according to claim 7, characterized in that The reaction temperature is 100-150° C. and the reaction time is 2-5 days.

9. Use of the phthalocyanine-based two-dimensional covalent organic framework material according to any one of claims 1 to 6 in electrocatalytic ethylene oxidation.

10. The use according to claim 9, characterized in that The electrocatalytic ethylene oxidation includes oxidation mediated by chloride or bromide.

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