Metal composite catalyst constructed based on metal phenolic complex-crystalline porous material as well as preparation method and application of metal composite catalyst

Abstract

The invention belongs to the technical field of composite catalysts, and particularly discloses a metal composite catalyst constructed based on a metal phenolic complex-crystalline porous material as well as a preparation method and application of the metal composite catalyst. The preparation method comprises the following steps: mixing a polyphenol solution and an organic salt solution, and carrying out coordination complexation reaction to obtain a metal phenolic complex; sequentially carrying out first reaction and second reaction on the metal phenolic complex solution and the crystalline porous material precursor solution to obtain a metal phenolic complex-crystalline porous material core-shell structure compound; and then blending with an inorganic metal salt solution, and sequentially carrying out reduction reaction and centrifugal separation to obtain the metal composite catalyst. The hierarchical porous structure and the metal-organic concerted catalysis interface are constructed through interface coordination engineering, and the method has wide application in the fields of electro-catalysis, electro-biological coupling catalysis systems, photo-thermal sterilization and the like. The catalyst is mild in preparation process condition, controllable in structure and suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of composite catalyst technology, and in particular to a metal composite catalyst based on a metal phenolic complex-crystalline porous material, its preparation method, and its application. Background Technology

[0002] Precise design and controllable preparation of catalytic materials are core challenges in the field of energy catalysis. Traditional heterogeneous catalysts (such as noble metal and transition metal-based materials) generally rely on high-temperature reduction / calcination processes (>500℃), resulting in the following technical defects: (1) significant high energy consumption; (2) thermodynamic driving force induces Ostwald ripening effect, causing the average particle size of active particles to exceed 10nm; (3) high-temperature induced lattice distortion causes disorder of the coordination structure of active sites. Although porous confinement strategies can control particle size to the sub-5nm range through steric hindrance, the existing technology system still has multiple technical barriers. For example, carbon layer confinement strategies require multiple high-temperature treatments, resulting in significant energy consumption. Recent studies have pointed out that crystalline porous materials can precisely control the dispersion and electronic structure of active sites through confinement effects. Their periodic channels can both inhibit particle migration and aggregation and optimize the mass transfer pathway of reactants. For example, core-shell structure confined catalysts achieve active center protection through kinetic control coating method, but the synthesis temperature is highly sensitive, and there is a contradiction between low-temperature confinement and high-temperature loading.

[0003] In summary, developing a universal and mild crystalline porous catalyst synthesis platform that simultaneously achieves particle size control, dispersion enhancement, and stability strengthening through confinement effects has become a key direction for overcoming existing technological bottlenecks. Summary of the Invention

[0004] In view of this, the present invention provides a metal composite catalyst based on metal phenolic complex-crystalline porous material, its preparation method and application, which solves the various problems existing in the existing catalyst preparation methods.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material includes the following steps:

[0007] 1) Mix polyphenol solution and organic salt solution to carry out coordination complexation reaction to obtain metal phenolic complex;

[0008] 2) The metal phenolic complex solution and the crystalline porous material precursor solution are subjected to the first and second reactions in sequence to obtain the metal phenolic complex-crystalline porous material core-shell structured composite.

[0009] 3) The solution of metal phenolic complex-crystalline porous material core-shell structure composite was mixed with an inorganic metal salt solution, and then subjected to reduction reaction and centrifugation in sequence to obtain the metal composite catalyst.

[0010] Preferably, the temperature of the coordination complexation reaction in step 1) is 0-40°C, the time of the coordination complexation reaction is 2-48h, and the stirring rate of the coordination complexation reaction is 100-1200rpm.

[0011] The volume ratio of the polyphenol solution to the organic salt solution is 1 to 10:1;

[0012] The mass concentration of the polyphenol solution is 0.1–10 mg / mL;

[0013] The organic salt solution has a mass concentration of 0.1–10 mg / mL.

[0014] Preferably, the polyphenols in the polyphenol solution in step 1) include one or more of tannic acid, gallic acid, anthocyanins, catechins, quercetin, ellagic acid and arbutin;

[0015] The organic salt in the organic salt solution includes one or more of acetylacetone salt, citrate, stearate, zinc myristate, and isooctanoate.

[0016] Preferably, the volume ratio of the metal phenolic complex solution and the crystalline porous material precursor solution in step 2) is 1:1 to 10;

[0017] The mass concentration of the metal phenolic complex solution is 0.01–5 mg / mL;

[0018] The mass concentration of the crystalline porous material precursor solution is 0.01–10 mg / mL;

[0019] The temperature of the first reaction is 0–40°C, and the reaction time is 2–48 h;

[0020] The temperature of the second reaction is 0–70°C, and the reaction time is 2–120 h.

[0021] Preferably, the crystalline porous material precursor in the crystalline porous material precursor solution includes one or more of metal-organic framework material precursors, covalent organic framework material precursors, and hydrogen-bonded organic framework material precursors.

[0022] Preferably, the metal-organic framework material precursor comprises one or more of the following: 1,3,5-benzenetricarboxylic acid and copper nitrate, terephthalic acid and zinc nitrate, 2,5-dihydroxyterephthalic acid and magnesium acetate, 2-methylimidazolium and zinc nitrate, and 2-aminoterephthalic acid and cerium nitrate.

[0023] The covalent organic framework material precursor includes one or more of the following: 1,3,5-tricarboxyphenyl and p-phenylenediamine, 1,3,5-tricarboxyphenyl and benzylenediamine, 2,5-dimethoxy-p-phenylenedialdehyde and p-phenylenediamine, and pyromellitic tricarboxyaldehyde and p-phenylenediamine.

[0024] The precursors of the hydrogen-bonded organic framework material are 1,3,6,8-tetra(parabenzoic acid)pyrene and / or 1,8-naphthamide.

[0025] Preferably, when the crystalline porous material precursor solution contains a covalent organic framework material precursor, a catalyst needs to be added for the second reaction;

[0026] The catalyst comprises acetic acid and / or tris(pentafluorophenyl)borane.

[0027] Preferably, in step 3), the volume ratio of the metal phenolic complex-crystalline porous material core-shell structure composite solution to the inorganic metal salt solution is 0.1 to 10:1;

[0028] The mass concentration of the metal phenolic complex-crystalline porous material core-shell structure composite solution is 0.5–5 mg / mL;

[0029] The inorganic metal salt solution has a mass concentration of 0.5–20 mg / mL;

[0030] The inorganic metal salt in the solution includes one or more of copper nitrate, silver nitrate, and cobalt sulfate.

[0031] The reduction reaction in step 3) is carried out at a temperature of 0–60°C for a time of 0.5–24 h.

[0032] The reducing agent used in the reduction reaction includes one or more of sodium borohydride, hydrazine monohydrate, ascorbic acid, and oxalic acid.

[0033] Another object of the present invention is to provide a metal composite catalyst prepared by the above preparation method.

[0034] Another objective of this invention is to provide an application of the above-mentioned metal composite catalyst in electrocatalysis, electro-biological coupled catalytic systems, and photothermal sterilization.

[0035] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. Achieve synthesis under mild conditions, overcoming the limitations of high-temperature preparation:

[0037] The entire preparation process of this invention (including coordination complexation, core-shell structure construction, and reduction) can be completed under low-temperature conditions (0°C to 70°C), effectively avoiding the high-temperature reduction or calcination steps (temperatures typically above 500°C) commonly found in traditional processes. This characteristic significantly reduces energy consumption, improves operational safety, and aligns with the core concepts of green chemistry and sustainable development.

[0038] 2. Achieve precise control over the particle size of metal nanoparticles, significantly suppressing aggregation:

[0039] Crystalline porous materials provide a clear confinement space and steric hindrance effect, which effectively constrains the migration behavior of metal nanoparticles during the reduction process and suppresses Ostwald ripening, thereby achieving precise control of particle size and significantly improving particle dispersion stability.

[0040] 3. Stabilize catalytic active sites and maintain ordered coordination structure:

[0041] Crystalline porous materials not only play a crucial role in size confinement, but their unique pore environment and tunable coordination sites also stabilize the structure of metal nanoparticles, preventing surface reconstruction or aggregation. This structure helps maintain the ordered coordination state of metal active sites, thereby improving the consistency and long-term stability of catalytic performance. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0043] Figure 1 The image shows a SEM image of the metal-phenolic complex nanoparticles prepared in Example 1. Figure 1 The 'a' in the text corresponds to MPNs(Fe Ⅲ SEM image of ) Figure 1 b in the text corresponds to MPNs(Cu) Ⅱ SEM image of ) Figure 1 c in the text corresponds to MPNs (Al) Ⅲ SEM image of ) Figure 1 In this context, d corresponds to MPNs(Co) Ⅲ SEM image of ) Figure 1 In the diagram, 'e' represents the particle size distribution.

[0044] Figure 2 This is a TEM image of the metal-phenolic complex-crystalline organic framework core-shell structured composite prepared in Example 1. Figure 2In this context, 'a' corresponds to a copper phenolic complex-metal-organic framework core-shell structured composite. Figure 2 In this context, 'b' corresponds to a copper phenolic complex-covalent organic framework material core-shell structured composite. Figure 2 The 'c' in the text corresponds to a copper phenolic complex-hydrogen bonded organic framework material core-shell structure complex.

[0045] Figure 3 This is a TEM image of the copper-based catalyst prepared in Example 1.

[0046] Figure 4 This is a TEM image of the copper / silver composite catalyst prepared in Example 2.

[0047] Figure 5 This is a TEM image of the silver-based catalyst prepared in Example 3.

[0048] Figure 6 This is a TEM image of the gold-based catalyst prepared in Example 4.

[0049] Figure 7 The Faraday efficiency of the catalyst in Experiment Example 1 under different currents is shown.

[0050] Figure 8 The catalyst of Experimental Example 1 was tested at 500 mA / cm². -2 Long-term stability.

[0051] Figure 9 The catalyst for Experimental Example 2 was at 25 cm 2 On the MEA electrode, the Faraday efficiency of CO2 conversion to liquid products under different total currents.

[0052] Figure 10 The catalyst used in Experiment 2 was at 25 cm 2 The changes in ethanol Faraday efficiency, relative purity, and cell voltage during constant current operation in an MEA electrolyzer.

[0053] Figure 11 This represents one heating and cooling cycle of the gold composite catalyst in Experiment Example 3.

[0054] Figure 12 This is the photothermal sterilization effect of the gold composite catalyst in Experiment Example 3. Among them, Figure 12 In the diagram, 'a' represents no light and 'b' represents light. Detailed Implementation

[0055] This invention provides a method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material, comprising the following steps:

[0056] 1) Mix polyphenol solution and organic salt solution to carry out coordination complexation reaction to obtain metal phenolic complex;

[0057] 2) The metal phenolic complex solution and the crystalline porous material precursor solution are subjected to the first and second reactions in sequence to obtain the metal phenolic complex-crystalline porous material core-shell structured composite.

[0058] 3) The solution of metal phenolic complex-crystalline porous material core-shell structure composite was mixed with an inorganic metal salt solution, and then subjected to reduction reaction and centrifugation in sequence to obtain the metal composite catalyst.

[0059] In this invention, the temperature of the coordination complexation reaction in step 1) is 0–40°C, specifically 2°C, 5°C, 8°C, 10°C, 12°C, 15°C, 20°C, 25°C, 30°C, or 35°C; the time of the coordination complexation reaction is 2–48 h, specifically 6 h, 10 h, 12 h, 15 h, 18 h, 20 h, 24 h, 30 h, 35 h, 36 h, 40 h, or 42 h; and the stirring rate of the coordination complexation reaction is 100–1200 rpm, specifically 200 rpm, 400 rpm, 500 rpm, 600 rpm, 800 rpm, or 1000 rpm.

[0060] In this invention, the volume ratio of the polyphenol solution to the organic salt solution is 1 to 10:1, preferably 2 to 8:1, and more preferably 5:1.

[0061] In this invention, the mass concentration of the polyphenol solution is 0.1 to 10 mg / mL, specifically 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, or 8 mg / mL.

[0062] In this invention, the mass concentration of the organic salt solution is 0.1 to 10 mg / mL, specifically 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, or 8 mg / mL.

[0063] In this invention, the solvent for the organic salt solution is preferably methanol and / or acetone.

[0064] In this invention, the polyphenols in the polyphenol solution in step 1) include one or more of tannic acid, gallic acid, anthocyanins, catechins, quercetin, ellagic acid and arbutin.

[0065] In this invention, the organic salt in the organic salt solution includes one or more of acetylacetone salt, citrate, stearate, zinc myristate, and isooctanoate.

[0066] In this invention, the volume ratio of the metal phenolic complex solution and the crystalline porous material precursor solution in step 2) is 1:1 to 10, preferably 1:2 to 8, more preferably 1:4 to 6, and even more preferably 1:5.

[0067] In this invention, the mass concentration of the metal phenolic complex solution is 0.01 to 5 mg / mL, specifically 0.2 mg / mL, 0.5 mg / mL, 0.8 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, or 4 mg / mL.

[0068] In this invention, the mass concentration of the crystalline porous material precursor solution is 0.01 to 10 mg / mL, specifically 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, or 8 mg / mL.

[0069] In this invention, the temperature of the first reaction is 0 to 40°C, specifically 2°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, and 35°C; the reaction time is 2 to 48 hours, specifically 6 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 24 hours, 30 hours, 35 hours, 36 hours, 40 hours, and 42 hours.

[0070] In this invention, the temperature of the second reaction is 0 to 70°C, specifically 2°C, 15°C, 20°C, 35°C, 50°C, 65°C, or 70°C; the reaction time is 2 to 120 hours, specifically 12 hours, 24 hours, 48 ​​hours, 72 hours, 96 hours, or 120 hours.

[0071] In this invention, the crystalline porous material precursor in the crystalline porous material precursor solution includes one or more of metal-organic framework material precursors, covalent organic framework material precursors, and hydrogen-bonded organic framework material precursors.

[0072] In this invention, the metal-organic framework material precursor includes one or more of the following: 1,3,5-benzenetricarboxylic acid and copper nitrate, terephthalic acid and zinc nitrate, 2,5-dihydroxyterephthalic acid and magnesium acetate, 2-methylimidazolium and zinc nitrate, and 2-aminoterephthalic acid and cerium nitrate; the covalent organic framework material precursor includes one or more of the following: 1,3,5-tricarboxyphenyl and p-phenylenediamine, 1,3,5-tricarboxyphenyl and benzyldiamine, 2,5-dimethoxyterephthalaldehyde and p-phenylenediamine, and pyromellitic tricarboxaldehyde and p-phenylenediamine; the hydrogen-bonded organic framework material precursor is 1,3,6,8-tetra(terebenzoic acid)pyrene and / or 1,8-naphthamide.

[0073] In this invention, when the crystalline porous material precursor solution contains a covalent organic framework material precursor, a catalyst is required for the second reaction; the catalyst includes acetic acid and / or tris(pentafluorophenyl)borane.

[0074] In this invention, in step 3), the volume ratio of the metal phenolic complex-crystalline porous material core-shell structure composite solution to the inorganic metal salt solution is 0.1 to 10:1, preferably 0.5 to 5:1, more preferably 0.8 to 1.2:1, and even more preferably 1:1.

[0075] In this invention, the blending time is 2 to 72 hours, specifically 6 hours, 12 hours, 24 hours, 30 hours, 48 ​​hours, or 60 hours.

[0076] In this invention, the mass concentration of the metal phenolic complex-crystalline porous material core-shell structure composite solution is 0.5-5 mg / mL, specifically 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.4 mg / mL, 4 mg / mL, and 4.5 mg / mL.

[0077] In this invention, the mass concentration of the inorganic metal salt solution is 0.5 to 20 mg / mL, specifically 1 mg / mL, 2 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 8 mg / mL, 10 mg / mL, 12 mg / mL, 14 mg / mL, 15 mg / mL, 16 mg / mL, and 18 mg / mL.

[0078] In this invention, the inorganic salt in the inorganic metal salt solution includes one or more of copper nitrate, silver nitrate, and cobalt sulfate.

[0079] In this invention, the temperature of the reduction reaction in step 3) is 0 to 60°C, specifically 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, and 55°C; the time is 0.5 to 24 hours, specifically 1 hour, 5 hours, 6 hours, 10 hours, 12 hours, 15 hours, 18 hours, and 20 hours.

[0080] In this invention, the reducing agent used in the reduction reaction includes one or more of sodium borohydride, hydrazine monohydrate, ascorbic acid, and oxalic acid.

[0081] The present invention also provides a metal composite catalyst prepared by the above preparation method.

[0082] The present invention also provides an application of the above-mentioned metal composite catalyst in electrocatalysis, electro-biological coupled catalytic systems, and photothermal sterilization.

[0083] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0084] Example 1:

[0085] 1) Synthesis of metal-phenolic complex nanoparticles

[0086] Tannic acid aqueous solution (concentration: 0.8 mg / mL) and acetylacetone iron solution (concentration: 1.66 mg / mL, dissolved in methanol) were mixed at a volume ratio of 1:1 and stirred at 25°C (500 rpm) for 24 h to carry out a coordination complexation reaction, yielding iron-phenolic complex nanoparticles (denoted as MPN(Fe)). Ⅲ Its scanning electron microscope (SEM) image is as follows: Figure 1 As shown in 'a', the particle size distribution results are as follows: Figure 1 As shown in e.

[0087] By replacing the acetylacetone iron solution with an acetylacetone copper solution, and following the same synthesis formulation and method as above, copper phenolic complex nanoparticles (denoted as MPN(Cu)) were obtained. Ⅱ Its scanning electron microscope (SEM) image is as follows: Figure 1 As shown in b, the particle size distribution results are as follows: Figure 1 As shown in e.

[0088] By replacing the acetylacetone iron solution with the acetylacetone aluminum solution, and following the same synthesis formula and method as above, aluminum phenolic complex nanoparticles (denoted as MPN(Al)) were obtained. Ⅲ Its scanning electron microscope (SEM) image is as follows: Figure 1 As shown in c, the particle size distribution results are as follows: Figure 1 As shown in e.

[0089] By replacing the iron acetylacetone solution with a cobalt acetylacetone solution, and using the same synthesis formula and method as above, cobalt phenolic complex nanoparticles (denoted as MPN(Co)) were obtained. Ⅲ Its scanning electron microscope (SEM) image is as follows: Figure 1 As shown in d, the particle size distribution results are as follows: Figure 1 As shown in e.

[0090] pass Figure 1 It can be seen that the synthesized metal phenolic complex nanoparticles exhibit excellent monodispersity, with a narrow particle size distribution range and high uniformity, indicating that the material has regular morphological characteristics.

[0091] 2) Synthesis of metal-phenolic complex-crystalline organic framework core-shell structured composites

[0092] The obtained copper phenolic complex nanoparticles were dispersed in water (concentration: 0.4 mg / mL) to prepare 100 mL solution A; simultaneously, 2-methylimidazole and zinc nitrate were dissolved in methanol (concentration: 1 mg / mL) to prepare 100 mL solution B. Solutions A and B were mixed at a volume ratio of 1:1 and reacted at 25 °C for 24 h. The resulting product was separated by centrifugation (5000 rpm) and dried to obtain a copper phenolic complex-metal-organic framework core-shell structured composite. Its transmission electron microscopy (TEM) results are shown below. Figure 2 As shown in 'a'.

[0093] Replace the crystalline porous material precursor solution in step 2): Dissolve 1,3,5-tricarboxyphenyl (concentration: 0.34 mg / mL) and p-phenylenediamine (concentration: 0.40 mg / mL) in 500 mL of acetonitrile to prepare solution B. React with 100 mL of solution A as described above, then add 0.05 mg / mL glacial acetic acid, and continue the reaction at 50 °C for 72 h. The resulting product was separated by centrifugation (5000 rpm) and dried to obtain a copper phenolic complex-covalent organic framework core-shell structured composite. Its transmission electron microscopy (TEM) results are as follows: Figure 2 As shown in b in the figure.

[0094] Replace the crystalline porous material precursor solution in step 2): Dissolve 1,3,6,8-tetra(terebenzoic acid)pyrene in 100 mL of methanol (concentration: 1 mg / mL) to prepare solution B. A copper phenolic complex-hydrogen-bonded organic framework core-shell structured composite was obtained. Its transmission electron microscopy (TEM) results are as follows: Figure 2 As shown in c in the figure.

[0095] pass Figure 2 It can be seen that, based on metal phenolic complex nanoparticles, various types of metal phenolic complex-crystalline organic framework material core-shell structured composites can be constructed.

[0096] 3) Synthesis of copper-based catalysts constructed from copper phenolic complexes and covalent organic materials

[0097] The obtained 30 mg copper phenolic complex-covalent organic framework core-shell structure composite was dispersed in methanol (concentration: 1.5 mg / mL), followed by the addition of 10 mL of copper nitrate aqueous solution (concentration: 10 mg / mL), and stirred for 10 h. The resulting mixture was centrifuged (8000 rpm) to remove unadsorbed Cu ions, and then 0.6 mL of 2 M sodium hydroxide solution was added under magnetic stirring (1000 rpm), and the reaction was allowed to proceed for 10 min. Next, 50 μL of hydrazine hydrate (N2H4·H2O) was added, and stirring was continued for 40 min. The final product was collected by centrifugation, washed three times with methanol, and dried to obtain a metal composite catalyst (copper-phenolic complex-covalent organic material-based copper catalyst) constructed from a metal phenolic complex and a crystalline porous material. Scanning electron microscopy and transmission electron microscopy results were obtained. Figure 3 As shown. (Through) Figure 3 It can be seen that the synthesized cuprous oxide nanoparticle catalyst is highly uniformly dispersed in the core-shell structure constructed by metal phenolic complex-crystalline organic framework material.

[0098] Example 2

[0099] The only difference from Example 1 is that copper nitrate aqueous solution was added after stirring and mixing with silver nitrate aqueous solution (concentration: 0.5 mg / mL, volume ratio 1:1) for 10 min. The resulting copper / silver composite catalyst was obtained, and its scanning electron microscopy and transmission electron microscopy results are as follows: Figure 4 As shown, through Figure 4 It can be seen that the synthesized cuprous oxide / Ag composite catalyst is highly uniformly dispersed in the core-shell structure constructed by metal phenolic complex-crystalline organic framework material.

[0100] Example 3

[0101] The only difference from Example 1 is that the copper nitrate aqueous solution in step 3) is replaced with a silver nitrate aqueous solution. A silver-based catalyst was obtained, and its scanning electron microscopy and transmission electron microscopy results are as follows... Figure 5 As shown, through Figure 5 It can be seen that the synthesized Ag nanoparticle catalyst is highly uniformly dispersed in the core-shell structure constructed by metal phenolic complex-crystalline organic framework material.

[0102] Example 4

[0103] The only difference from Example 1 is that the aqueous copper nitrate solution in step 3) is replaced with an aqueous chloroauric acid solution. The gold-based catalyst was obtained, and its scanning electron microscopy and transmission electron microscopy results are as follows... Figure 6 As shown, through Figure 6 It can be seen that after doping with gold nanoparticles, the composite system structure still maintains its integrity, without obvious damage or collapse.

[0104] Experimental Example 1

[0105] Electrochemical testing:

[0106] Before the electrocatalytic reaction begins, the gas diffusion layer (GDL) is pretreated by spraying 1 wt% polytetrafluoroethylene (PTFE) emulsion onto its surface.

[0107] The electrocatalytic performance evaluation for the CO2 reduction reaction (CO2RR) was conducted on a DH7000C electrochemical workstation (Jiangsu Donghua Analytical Instruments Co., Ltd., Nanjing, China). The CO2RR experiments were performed in a self-made flow cell apparatus, which included an anode chamber, a cathode chamber, and an anion exchange membrane (FAB-PK-130). The cathode was prepared as follows: 2.5 mg of catalyst (Example 2), 0.2 mg of carbon black, and 2.5 μL of Nafion solution (5.0 wt%) were dispersed in 400 μL of isopropanol / water mixture. The mixture was ultrasonically treated in a water bath to form a uniform catalyst ink, which was then drop-coated onto the surface of hydrophobic carbon paper (YSL-30T) to form a loading of 1.0 mg·cm⁻¹. -2 Catalyst membrane.

[0108] A 1M KOH aqueous solution was used as the electrolyte in the experiment. The anode and cathode chambers were separated by anion exchange membranes, and 50 mL of 1M KOH solution was circulated to each chamber via a peristaltic pump at a constant flow rate of 20 mL / min. The CO2RR reaction time was 20 minutes, and gaseous CO2 was introduced into the back of the gas diffusion electrode (GDE) at a flow rate of 25 SCCM using a mass flow meter.

[0109] The applied potential was referenced to an Ag / AgCl reference electrode (3.5M KCl) and converted to a reversible hydrogen electrode (RHE) potential using the following formula:

[0110]

[0111] Ohmic loss was obtained by measuring the uncompensated resistance (R) between the working electrode and the reference electrode using electrochemical impedance spectroscopy (EIS) during the initial stage of electrolysis, and the potential was manually corrected by applying 70% IR compensation.

[0112] like Figure 7 As shown, the catalyst achieved an ethanol Faradaic efficiency (FEEtOH) of approximately 44.5 ± 1.5% and a current of 400 mA cm⁻¹ at -0.97 ± 0.06 V (after iR compensation). -2 Partial current density. At 900 mA / cm² -2 At current density, C 2+The total Faraday efficiency of oxygen-containing products reached 80.9±4.4%, which is superior to many advanced CO2 reduction catalysts reported in the literature.

[0113] like Figure 8 As shown, the reaction system volume was increased from 50 mL to 2 L, and the reaction was carried out at 500 mA / cm². -2 The system can operate stably for 70 hours at current density, and the ethanol Faraday efficiency (FE) is [not specified]. EtOH It is approximately 35%.

[0114] Experimental Example 2:

[0115] Electrocatalytic reduction performance of CO2 in a membrane electrode assembly (MEA) reactor:

[0116] The performance evaluation of the carbon dioxide electroreduction (CO2RR) was conducted on a self-made 5×5cm plate. 2 The studies were conducted in a membrane electrode assembly (MEA) electrolyzer using the catalyst prepared in Example 2, and neutral and alkaline anolytes. The cathode for the CO2RR experiments in acidic media was prepared by sputtering copper (Cu) onto a polytetrafluoroethylene (PTFE) substrate (i.e., Cu / PTFE). Electrochemical tests were performed on a dedicated testing platform equipped with a potentiometer, a current amplifier (MetrohmAutolab, 10A), a commercial CO2RR MEA electrolyzer (Dioxide Materials), a mass flow controller (SmartTrak 100, Sierra), an anolyte reservoir, a humidifier, and a peristaltic pump with silicone tubing.

[0117] The MEA electrolytic cell uses titanium anode flow field plates and stainless steel cathode flow field plates, each with a geometric area of ​​25 cm². 2 The MEA (Mechanism for Electrolyte Exchange) consists of a cathode electrode, an anode electrode (IrOx / Ni), and an anion exchange membrane (Sustaining X37-50). The electrodes are assembled on their respective flow field plates, separated by the AEM (Anion Exchange Membrane), with bolts applying uniform clamping force during assembly. Before assembly, the AEM is rinsed with deionized water for 10 minutes. The anode flow field circulates the anolyte, while the cathode flow field delivers humidified CO2 to the reaction sites.

[0118] The IrOx / Ni anode electrode was prepared using a three-step method: (1) immersing a titanium felt in an ink solution containing 2-propanol, iridium tetrachloride hydrate (Premion, 99.99%), and hydrochloric acid; (2) drying at 100°C for 10 minutes; and (3) sintering at 500°C for 10 minutes. The final iridium loading of the electrode was 1 mg / cm³. -2During the experiment, a 0.1 M KHCO3 solution was supplied to the anode chamber as the anolyte, while fully humidified CO2 was continuously supplied to the cathode at a constant flow rate. Unless otherwise specified, the reaction flow rate was maintained at approximately 1 sccm / cm. 2 .

[0119] like Figure 9 As shown, the total current density is 1.25-4.75 A cm⁻¹. -2 Under these conditions, carbon dioxide electroreduction was performed at different current densities, with a total current of 4 A cm⁻¹. -2 Under these conditions, FEEtOH reached approximately 30%, fully validating the industrial feasibility of this catalyst system. At 130 mA / cm², -2 After continuous operation at a current density of 5.8 hours, the ethanol selectivity remained at approximately 25%. Figure 10 The obtained ethanol solution had a purity of up to 86.6%. These results fully demonstrate the great potential of this electrocatalyst and reactor design in the large-scale conversion of CO2 to ethanol, and successfully overcome the key obstacles in the industrial application of CO2RR.

[0120] Experimental Example 3

[0121] Electrocatalytic reduction of CO2 coupled with microbial cell catalysis for the synthesis of high-value-added compounds:

[0122] An electrochemical-microbial cell coupled catalytic system is used to efficiently convert CO2 into high-value-added compounds such as itaconic acid, isopropanol, and PHB. The system includes an electrocatalytic reduction step and a microbial fermentation step.

[0123] First, CO2 electrocatalytic reduction was carried out using the catalyst described in Example 2, and an electrolyte with an ethanol concentration of 10 g / L was obtained under optimized electrolysis conditions. This electrolyte was then sterilized by filtration through a 0.22 μm sterile membrane and added as the sole carbon source to autoclaved M9 fermentation medium. A recombinant *E. coli* strain possessing an enhanced ethanol metabolism pathway and biosynthetic pathways for itaconic acid, isopropanol, and PHB was inoculated, and fermentation was carried out for 72 hours at 30°C and an initial pH of 6.0. During fermentation, a Ca(OH)2 buffer system was used to maintain pH stability. Ultimately, itaconic acid yield reached 480 mg / L, isopropanol yield reached 109 mg / L, and PHB yield reached 295 mg / L, verifying the feasibility and application potential of the electro-biological coupling system constructed in this invention for high-value CO2 conversion.

[0124] Experiment Example 4

[0125] Sterilization based on the photothermal effect of gold-based catalysts:

[0126] Prepare 1 mg of a gold-based catalyst constructed based on a copper phenol-aldehyde complex-covalent organic material (Example 4), disperse it in 5 mL of deionized water, and take 1.5 mL into a liquid chromatography vial. Use a GCSLS-05-7W semiconductor laser at 2.0 W / cm². 2 Irradiation with NIR light (808nm) at high power density for 5 minutes, with temperature recorded every 2 seconds using a TES-1315K thermocouple thermometer. Figure 11 ).

[0127] A single colony was picked from the revived bacterial plate and inoculated into a test tube containing 4 mL of LB liquid medium. The tube was then placed in a constant temperature incubator at 37°C and 180 rpm for overnight incubation.

[0128] Control group: After the culture medium in the LB tubes became turbid, the OD was measured. 600 The test strains were prepared into 5×10⁶ liters of LB liquid medium. 5 CFU / mL bacterial suspension, 50 μL plate.

[0129] Materials were mixed with bacterial culture: After the culture medium in the LB tube became turbid, the OD was measured. 600 The test strains were prepared into 5×10⁶ liters of LB liquid medium. 5 Take 50 μL of a 0.2 mg / mL CFU / mL bacterial suspension (a gold-based catalyst constructed from copper phenolic complex and covalent organic material) and mix it with the bacterial solution. Spread the mixture onto a plate and then incubate it overnight at 37°C on a shaker.

[0130] Experimental group: After the culture medium in the LB test tube became turbid, the OD was measured. 600 The test strains were prepared into 5×10⁶ liters of LB liquid medium. 5 CFU / mL bacterial suspension. For the agar plate colony counting method, 50 μL of sample material (a gold-based catalyst constructed from a copper phenolic complex and covalent organic material) was mixed with 50 μL of the diluted bacterial suspension. After mixing, the mixture was photothermally heated in a 96-well plate for 10 min (808 nm laser, 2 W / cm²). 2 Spread evenly on an agar plate, then incubate overnight at 37°C on a shaker. Figure 12 ).

[0131] pass Figure 12 It can be seen that the gold-based catalyst exhibits significant photothermal conversion capability under light conditions, thereby achieving efficient and controllable photothermal sterilization, providing a new approach for the development of antibacterial materials.

[0132] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0133] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material, characterized in that, Includes the following steps: 1) Mix polyphenol solution and organic salt solution to carry out coordination complexation reaction to obtain metal phenolic complex; 2) The metal phenolic complex solution and the crystalline porous material precursor solution are subjected to the first and second reactions in sequence to obtain the metal phenolic complex-crystalline porous material core-shell structured composite. 3) The solution of metal phenolic complex-crystalline porous material core-shell structure composite was mixed with an inorganic metal salt solution, and then subjected to reduction reaction and centrifugation in sequence to obtain the metal composite catalyst.

2. The method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to claim 1, characterized in that, The temperature of the coordination complexation reaction in step 1) is 0-40℃, the time of the coordination complexation reaction is 2-48h, and the stirring rate of the coordination complexation reaction is 100-1200rpm. The volume ratio of the polyphenol solution to the organic salt solution is 1 to 10:1; The mass concentration of the polyphenol solution is 0.1–10 mg / mL; The organic salt solution has a mass concentration of 0.1–10 mg / mL.

3. The method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to claim 2, characterized in that, The polyphenols in the polyphenol solution mentioned in step 1) include one or more of the following: tannic acid, gallic acid, anthocyanins, catechins, quercetin, ellagic acid, and arbutin. The organic salt in the organic salt solution includes one or more of acetylacetone salt, citrate, stearate, zinc myristate, and isooctanoate.

4. A method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to any one of claims 1 to 3, characterized in that, The volume ratio of the metal phenolic complex solution and the crystalline porous material precursor solution in step 2) is 1:1 to 10; The mass concentration of the metal phenolic complex solution is 0.01–5 mg / mL; The mass concentration of the crystalline porous material precursor solution is 0.01–10 mg / mL; The temperature of the first reaction is 0–40°C, and the reaction time is 2–48 h; The temperature of the second reaction is 0–70°C, and the reaction time is 2–120 h.

5. The method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to claim 4, characterized in that, The crystalline porous material precursor in the crystalline porous material precursor solution includes one or more of the following: metal-organic framework material precursor, covalent organic framework material precursor, and hydrogen-bonded organic framework material precursor.

6. The method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to claim 5, characterized in that, The metal-organic framework material precursors include one or more of the following: 1,3,5-benzenetricarboxylic acid and copper nitrate, terephthalic acid and zinc nitrate, 2,5-dihydroxyterephthalic acid and magnesium acetate, 2-methylimidazolium and zinc nitrate, and 2-aminoterephthalic acid and cerium nitrate. The covalent organic framework material precursor includes one or more of the following: 1,3,5-tricarboxyphenyl and p-phenylenediamine, 1,3,5-tricarboxyphenyl and benzylenediamine, 2,5-dimethoxy-p-phenylenedialdehyde and p-phenylenediamine, and pyromellitic tricarboxyaldehyde and p-phenylenediamine. The precursors of the hydrogen-bonded organic framework material are 1,3,6,8-tetra(parabenzoic acid)pyrene and / or 1,8-naphthamide.

7. A method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to claim 5 or 6, characterized in that, When the crystalline porous material precursor solution contains a covalent organic framework material precursor, a catalyst needs to be added for the second reaction; The catalyst comprises acetic acid and / or tris(pentafluorophenyl)borane.

8. The method for preparing a metal composite catalyst based on a metal-phenolic complex-crystalline porous material according to claim 7, characterized in that, In step 3), the volume ratio of the metal phenolic complex-crystalline porous material core-shell structure composite solution to the inorganic metal salt solution is 0.1–10:

1. The mass concentration of the metal phenolic complex-crystalline porous material core-shell structure composite solution is 0.5–5 mg / mL; The inorganic metal salt solution has a mass concentration of 0.5–20 mg / mL; The inorganic metal salt in the solution includes one or more of copper nitrate, silver nitrate, and cobalt sulfate. The reduction reaction in step 3) is carried out at a temperature of 0–60°C for a time of 0.5–24 h. The reducing agent used in the reduction reaction includes one or more of sodium borohydride, hydrazine monohydrate, ascorbic acid, and oxalic acid.

9. The metal composite catalyst prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the metal composite catalyst of claim 9 in electrocatalysis, electro-biological coupled catalytic systems, and photothermal sterilization.

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