A catalyst based on black phosphorus for enhancing hydrophobic performance and preparation and application thereof

Abstract

The application discloses a catalyst based on black phosphorus for enhancing hydrophobic performance and a preparation and application thereof, comprising a composite carrier and a platinum active component loaded on the composite carrier; the composite carrier comprises a porous silica substrate and a black phosphorus / hydrophobic agent composite grafted on the surface of the porous silica substrate; in the application, the silica carrier is modified after the black phosphorus is combined with a hydrophobic modifier, and finally, a platinum active center is loaded, so that a high-efficiency hydrophobic composite catalyst material used in LPCE is constructed; by using the intrinsic hydrophobicity of the black phosphorus and the strong interaction between the black phosphorus and the metal platinum, the catalyst with high activity, high hydrophobicity, high stability and long service life is obtained.

Description

Technical Field

[0001] This invention relates to the fields of nuclear energy environmental protection and catalytic materials technology, and in particular to a catalyst based on black phosphorus to enhance hydrophobic properties, its preparation and application. Background Technology

[0002] Among numerous clean energy sources, nuclear energy stands out due to its abundant reserves and safe, environmentally friendly characteristics. However, with the development and utilization of nuclear energy, various types of reactors and nuclear fuel reprocessing plants generate large amounts of tritium-containing wastewater, posing significant harm to the environment and society. Liquid-phase catalytic exchange (LPCE) technology is a key process for separating and recovering tritium from wastewater. Its core lies in using a hydrophobic catalyst to promote the isotope exchange reaction between tritium water and hydrogen. An ideal LPCE catalyst needs to possess high activity, strong hydrophobicity, and long-term stability. Currently, industrial hydrophobic catalysts mainly employ two approaches: one is to use high molecular weight polymers such as polystyrene-divinylbenzene (SDB) and polytetrafluoroethylene (PTFE) as hydrophobic supports to support platinum; the other is to treat hydrophilic supports (such as Al2O3, SiO2, activated carbon, etc.) with a hydrophobic coating. However, both methods have significant drawbacks. First, polymer supports such as SDB and PTFE are prone to swelling, degradation, or structural damage under long-term irradiation, humid heat, and chemical environments, leading to a decrease in the mechanical strength of the catalyst and the loss of active components. Second, the hydrophobic coating itself may cover some active sites or encapsulate platinum particles during the preparation process, reducing the utilization rate of platinum. In addition, the coating may be uneven and unstable, and it is easy to fall off under harsh conditions, resulting in the exposure of the hydrophilicity of the support and the deactivation of the catalyst due to water flooding.

[0003] To address the aforementioned issues, the commonly used methods are to modify or replace the support. Although existing technologies can effectively enhance the mechanical strength and hydrophobic properties of the support, they still have limitations. First, its hydrophobicity is highly dependent on the monolayer formed by the low surface energy material (such as silane) coated on the surface of the support or reinforcing phase. This coating is prone to aging and peeling under harsh conditions such as long-term damp heat, irradiation, and fluid shearing, leading to irreversible degradation of hydrophobic properties. Second, the relationship between the active metal and the hydrophobic interface is mostly a physical loading relationship, lacking strong chemical interactions, which can easily lead to the deactivation or loss of active sites in complex environments.

[0004] Therefore, finding a novel material that combines intrinsic hydrophobicity, excellent stability, and strong synergy with the active center to reconstruct the catalyst interface has become the key to breaking through the current technological bottleneck. Summary of the Invention

[0005] In view of this, this application provides a catalyst based on black phosphorus to enhance hydrophobic properties, and its preparation and application, to solve the problem that the performance of LPCE catalysts in existing heavy water detritium removal technology is drastically reduced due to the aging and peeling of hydrophobic coatings under harsh conditions and the easy agglomeration and deactivation of platinum metal.

[0006] To achieve the above technical objectives, this application adopts the following technical solution: In a first aspect, this application provides a catalyst based on black phosphorus to enhance hydrophobic properties, comprising a composite support and a platinum active component supported on the composite support; the composite support comprises a porous silica matrix and a black phosphorus / hydrophobic agent composite grafted onto the surface of the porous silica matrix.

[0007] Secondly, this application provides a method for preparing a catalyst based on black phosphorus-enhanced hydrophobic properties, comprising the following steps: S1. Under inert atmosphere and light-protected conditions, black phosphorus and hydrophobic modifier were used as raw materials to carry out a heating reaction to obtain a black phosphorus / hydrophobic agent complex; S2. The black phosphorus / hydrophobic agent composite is heated and refluxed with a silica support to obtain a composite support; S3. Platinum precursor is loaded onto the composite support, and after drying, calcination, and reduction, the catalyst based on black phosphorus-enhanced hydrophobic properties is obtained.

[0008] Preferably, the black phosphorus is black phosphorus nanosheets or black phosphorus quantum dots; the hydrophobic modifier is one or more of alkyltrialkoxysilane, fluoroalkyltrialkoxysilane, and aryltrialkoxysilane.

[0009] Preferably, in step S1, the heating reaction temperature is 40-100℃ and the reaction time is 4-8h.

[0010] Preferably, the mass ratio of black phosphorus to hydrophobic agent is 1:10-30.

[0011] Preferably, before step S1, the process further includes treating the silica powder at 300℃-500℃ for 2-4 hours.

[0012] Preferably, in step S2, the reaction solvent for the reflux reaction is one or more of toluene, ethylbenzene, xylene, or cyclohexane and n-hexane; the temperature of the reflux reaction is 80-140℃, and the reaction time is 10-16h.

[0013] Preferably, the mass ratio of the black phosphorus / hydrophobic agent composite to the silica carrier is 1:10-100.

[0014] Preferably, step S3 specifically involves: loading the platinum precursor onto the composite support by impregnation or rotary evaporation with an equal volume, drying it, calcining it under a protective atmosphere, and then performing liquid / gas phase reduction.

[0015] Thirdly, this application provides the application of a catalyst based on black phosphorus-enhanced hydrophobic properties in the liquid-phase catalytic conversion reaction of heavy water detritium removal.

[0016] The beneficial effects of this application are as follows: This invention employs an in-situ hydrolysis co-assembly process to introduce black phosphorus nanosheets into a silane-modified system via chemical bonding, constructing a robust composite hydrophobic interface. Compared to traditional silane modification methods that rely on monolayer coverage, the rigid sheets of black phosphorus in this invention provide skeletal support and synergistically form a rigid-flexible composite structure with the silane chains, effectively resisting damp heat aging and radiation damage under extreme conditions. Furthermore, this material forms a dual protection mechanism for hydrophobic function: even if the surface silane layer is partially damaged, the inner black phosphorus layer can still maintain an effective hydrophobic barrier, thereby significantly delaying the overall performance degradation. This application anchors platinum metal ions with lone pair electrons on the surface of black phosphorus. On the one hand, it can effectively regulate the electron distribution of platinum atoms, thereby improving the activity. On the other hand, it induces platinum nucleation and restricts its growth and migration during the subsequent reduction process of the catalyst. This strong interaction effectively prevents the sintering and agglomeration of platinum nanoparticles during use, greatly improves the dispersion and stability of active sites, and thus improves the initial activity and service life of the catalyst. This application allows for precise control of the catalyst's hydrophobicity, platinum particle size, and dispersion by adjusting parameters such as the ratio of black phosphorus to silane coupling agent and platinum, as well as reduction conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0018] Figure 1 A simplified diagram of the LPCE testing process; Figure 2 TEM images of different hydrophobic catalysts. Detailed Implementation

[0019] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0023] Unless otherwise explicitly defined and specified herein, all technical and scientific terms used in this application shall have the generally accepted meanings understood by one of ordinary skill in the field of chemical and chemical materials technology (including but not limited to polymer chemistry, inorganic chemistry, organic synthesis, catalysis chemistry, materials processing, and chemical unit operations) based on their professional knowledge and conventional practice. The use of any terminology herein is intended to describe the specific embodiments of this application in the clearest and most accurate manner, so as to fully disclose the technical solution. Such use shall not in any way be construed as a limitation on the scope of the claims, nor does it imply the exclusion of equivalent technical solutions that could be reasonably known by one of skill in the art based on the concept of this application.

[0024] The terms "comprising," "including," "having," "containing," and any grammatical variations or similar expressions used in the specification and claims of this application are all open-ended and non-exhaustive descriptive terms. Their purpose is to explicitly describe the existence of the stated technical features, components, steps, or parts, while explicitly allowing and covering the possibility that other features, components, steps, parts, or any combinations thereof not explicitly listed may exist or be added to the technical solution, as long as such additions do not destroy the integrity and inventiveness of the original technical solution.

[0025] When the terms "embodiments," "some embodiments," or "specific embodiments" are mentioned in the specification, they refer to examples that, in conjunction with the specific parameters, materials, steps, and results described in that section, constitute one or a group of examples for implementing the technical solutions of this application. These embodiments are used for full disclosure and illustrative purposes, not for exhaustive enumeration. Those skilled in the art should understand that, without departing from the overall inventive concept of this application, the various technical features disclosed in different embodiments can be combined, substituted, modified, or deleted to form other implementation methods that are not listed one by one in the specification but also fall within the protection scope of this application.

[0026] Unless otherwise expressly specified and limited, all terms related to chemical process operations, material preparation, processing, and analytical testing involved in this application shall be interpreted in the broadest sense based on the conventional understanding of those skilled in the art.

[0027] Regarding performance testing and structural characterization, all testing and characterization methods involved in this application, unless otherwise specified, refer to conventional methods known in the art. Specific testing conditions may be selected and adjusted according to the sample properties and relevant national standards, international standards, or industry-standard methods. Test items may include mechanical properties (such as tensile, bending, and impact strength), thermal properties (such as DSC and TGA analysis), and chemical stability (such as solvent resistance and acid / alkali corrosion resistance). Structural characterization methods may include FT-IR, NMR, XRD, SEM, TEM, and BET. All test results should be understood to be within the allowable range of conventional experimental errors.

[0028] Regarding numerical values ​​and ranges, all parameter ranges expressed in this application in the form of "from a certain value to a certain value" should be understood as explicitly disclosing the endpoints of the range, each specific numerical point between the endpoints, and all sub-ranges formed by any two numerical points within the range. For example, "30℃ to 80℃" discloses 30, 31, ..., 80℃, as well as sub-ranges such as 30-50℃, 45-70℃, etc. When a numerical value is preceded by "about," "approximately," or similar words, it indicates that the numerical value is allowed to have reasonable errors recognized in the art under the measurement or control conditions, which can generally be understood as the deviation allowed by relevant standards or a normal fluctuation range of ±5% or ±10%.

[0029] Black phosphorus (BP), as an emerging two-dimensional material, possesses excellent and stable intrinsic hydrophobicity due to its unique wrinkled lattice structure and electron distribution. Furthermore, its abundant lone pairs of electrons provide ideal sites for anchoring active metals. However, the challenge lies in transforming the hydrophobic properties of black phosphorus from a simple material property into a durable and dominant water-resistant component in catalysts, and in constructing a robust chemically integrated system with the support and active metal, rather than merely using it as a physical additive or dispersant.

[0030] Based on this, this application was created.

[0031] This application provides a catalyst based on black phosphorus to enhance hydrophobic properties, comprising a composite support and a platinum active component supported on the composite support; the composite support comprises a porous silica matrix and a black phosphorus / hydrophobic agent composite grafted onto the surface of the porous silica matrix.

[0032] This application first combines black phosphorus with a hydrophobic modifier, then modifies the silica support, and finally loads platinum active centers to construct a highly efficient hydrophobic composite catalytic material for LPCE. By utilizing the intrinsic hydrophobicity of black phosphorus and its strong interaction with metallic platinum, a catalyst with high activity, high hydrophobicity, high stability, and long lifespan is obtained.

[0033] This application provides a method for preparing a catalyst with enhanced hydrophobic properties based on black phosphorus, comprising the following steps: S1. Under inert atmosphere and light-protected conditions, black phosphorus and hydrophobic modifier were used as raw materials and heated in a solvent. After the reaction was completed, the mixture was filtered, washed and dried to obtain a black phosphorus / hydrophobic agent complex. S2. The black phosphorus / hydrophobic agent composite is heated and refluxed with a silica carrier. After the reaction is completed, the composite carrier is obtained by filtration, washing, drying and molding. S3. Platinum precursor is loaded onto the composite support, and after drying, calcination and reduction, the catalyst (Pt / BP-SiO2) based on black phosphorus-enhanced hydrophobic properties is obtained.

[0034] This application first uses black phosphorus as a hydrophobic component, and constructs a composite hydrophobic unit by reacting black phosphorus with a silane coupling agent. Then, the silica support is hydrophobically modified to achieve efficient and stable hydrophobicity. Finally, platinum metal is loaded, and the electronic structure of the active metal is adjusted by coordinating the lone pair electrons of black phosphorus with platinum particles, which promotes the improvement of reaction activity and the dispersion of active components, effectively overcomes the aggregation of active components of the catalyst, and improves the long-term stability of the catalyst. Finally, it is applied to the heavy water detritium removal LPCE process to achieve efficient proton exchange while improving the hydrophobicity and long-term stability of the catalyst.

[0035] In some embodiments, the black phosphorus is black phosphorus nanosheets or black phosphorus quantum dots; the hydrophobic modifier is one or more of alkyltrialkoxysilane, fluoroalkyltrialkoxysilane, and aryltrialkoxysilane.

[0036] In some embodiments, in step S1, the heating reaction temperature is 40-100°C, and the reaction time is 4-8 hours; the inert gas atmosphere includes one or a mixture of nitrogen and argon; the solvent is one or more of water, methanol, ethanol, isopropanol, N-methylpyrrolidone, and dimethyl sulfoxide; the drying conditions are vacuum drying or drying under a nitrogen or argon atmosphere, and the drying process is drying at 60-90°C for 6-12 hours.

[0037] In some embodiments, the mass ratio of black phosphorus to hydrophobic agent is 1:10-30.

[0038] In some embodiments, before step S1, the method further includes: pretreating the silica powder in a muffle furnace or tube furnace at 300°C-500°C for 2-4 hours to remove impurities such as free water from the pores.

[0039] In some embodiments, in step S2, the reaction solvent for the reflux reaction is one or more of toluene, ethylbenzene, xylene, or cyclohexane and n-hexane; the temperature of the reflux reaction is 80-140℃, and the reaction time is 10-16h; the molding process involves shaping the modified silica carrier powder into a regular shape of 1-5mm; the drying process is vacuum drying or drying under a nitrogen or argon atmosphere, and the drying process is drying at 60-90℃ for 6-12h.

[0040] In some embodiments, the mass ratio of the black phosphorus / hydrophobic agent composite to the silica carrier is 1:10-100.

[0041] In some embodiments, step S3 specifically involves: loading the platinum precursor onto the composite carrier by impregnation or rotary evaporation with equal volume, drying it at 60-130°C for 4-8 hours by vacuum drying or drying under a nitrogen or argon atmosphere, calcining it at 300-600°C for 2-6 hours under a protective nitrogen or argon atmosphere, and then performing liquid-phase reduction or gas-phase reduction.

[0042] In this embodiment, the platinum precursor is one or more of acetylacetonate platinum, dimethyl (cyclooctadiene) platinum, and tetra(triphenylphosphine) platinum; the mass ratio of black phosphorus in the composite carrier to platinum in the precursor is 1-1:5; in step S3, the solvent used for rotary evaporation impregnation is one or more of toluene, ethylbenzene, xylene, cyclohexane, and n-hexane; the temperature used for rotary impregnation is 30-60℃, and the pressure is 10kPa-50kPa; the liquid-phase reduction process is carried out by reduction using one or more of hydrazine hydrate, sodium borohydride, potassium borohydride, formaldehyde, and formic acid; the gas-phase reduction process is carried out in a mixed atmosphere of hydrogen and nitrogen or argon, wherein the hydrogen system fraction is 1%-10%, at 100-300℃ for 2-4 hours.

[0043] This application provides the application of a catalyst based on black phosphorus-enhanced hydrophobic properties in the liquid-phase catalytic conversion reaction (LPCE) for detritium removal from heavy water.

[0044] The following specific embodiments further illustrate this solution.

[0045] Example 1 A catalyst based on black phosphorus-enhanced hydrophobic properties includes a composite support and a platinum active component supported on the composite support; the composite support includes a porous silica matrix and a black phosphorus / hydrophobic agent composite grafted onto the surface of the porous silica matrix.

[0046] The preparation method of the catalyst based on black phosphorus-enhanced hydrophobic properties includes the following steps: S1. Measure 200 mL of 5 mg / mL black phosphorus ethanol dispersion and place it in a beaker. Add 10 g of methyltrimethoxysilane according to the mass ratio of black phosphorus to hydrophobic agent of 1:10. Stir at 40 °C for 8 h under nitrogen protection and in the dark. After the reaction is completed, filter and wash three times with ethanol. Then place it in a vacuum drying oven and dry at 60 °C for 12 h to obtain black phosphorus / hydrophobic agent complex. S2. The black phosphorus / hydrophobic agent composite was ultrasonically dispersed in toluene for 30 min. 10 g of silica carrier powder calcined in a muffle furnace at 300 °C for 4 h was added at a black phosphorus to silica carrier mass ratio of 1:10. The mixture was refluxed at 80 °C for 16 h under stirring. After the reaction was completed, the mixture was filtered, washed three times with toluene, and then vacuum dried at 60 °C for 12 h. The mixture was then formed into 1 mm spheres to obtain the composite carrier. S3. Weigh 2.016 g of platinum acetylacetonate according to the atomic mass ratio of black phosphorus to platinum 1:1 and dissolve it in 30 mL of toluene. Then add the hydrophobically modified support spheres into the solution. Place the mixture in a pear-shaped flask and rotary evaporate until the solution is dry. The water bath temperature is 30 °C and the pressure is 10 kPa. After rotary evaporation, wash the solution three times with toluene and dry it in a vacuum drying oven at 60 °C for 8 h. Then calcine it at 300 °C for 6 h under a nitrogen atmosphere. After cooling, reduce it at 100 °C for 4 h in a 1% hydrogen-nitrogen mixture to obtain the hydrophobic catalyst Pt / BP-SiO2-1.

[0047] Example 2 A catalyst based on black phosphorus-enhanced hydrophobic properties includes a composite support and a platinum active component supported on the composite support; the composite support includes a porous silica matrix and a black phosphorus / hydrophobic agent composite grafted onto the surface of the porous silica matrix.

[0048] The preparation method of the catalyst based on black phosphorus-enhanced hydrophobic properties includes the following steps: S1. Measure 25 mL of 5 mg / mL black phosphorus ethanol dispersion into a beaker, add 175 mL of anhydrous ethanol, and add 2.5 g of methyltrimethoxysilane according to the mass ratio of black phosphorus to hydrophobic agent 1:20. Stir at 80 °C for 6 h under nitrogen protection and in the dark. After the reaction is completed, filter, wash three times with ethanol, and dry in a vacuum drying oven at 80 °C for 10 h to obtain black phosphorus / hydrophobic agent complex. S2. The black phosphorus / hydrophobic agent composite was ultrasonically dispersed in toluene for 30 min. 10 g of silica carrier powder calcined in a muffle furnace at 400 °C for 3 h was added at a black phosphorus to silica carrier mass ratio of 1:80. The mixture was refluxed at 120 °C for 12 h under stirring. After the reaction was completed, the mixture was filtered, washed three times with toluene, and then vacuum dried at 80 °C for 10 h. The mixture was then formed into 4 mm spheres to obtain the composite carrier. S3. According to the atomic mass ratio of black phosphorus to platinum of 1:4, 1.008 g of platinum acetylacetonate was dissolved in 30 mL of toluene. Then, the hydrophobically modified support spheres were added to the solution. The mixture was placed in a pear-shaped flask and rotary evaporated until the solution was dry. The water bath temperature was 40 °C and the pressure was 30 kPa. After rotary evaporation, the solution was washed three times with toluene and dried in a vacuum drying oven at 80 °C for 8 h. Then, it was calcined at 500 °C for 4 h under a nitrogen atmosphere. After cooling, it was reduced at 150 °C for 3 h in a 5% hydrogen-nitrogen mixture to obtain the hydrophobic catalyst Pt / BP-SiO2-2.

[0049] Example 3 A catalyst based on black phosphorus to enhance hydrophobic properties is described. The other contents are the same as in Example 2, except that 1.25 g of methyltrimethoxysilane is added at a black phosphorus to hydrophobic agent mass ratio of 1:10 to obtain the hydrophobic catalyst Pt / BP-SiO2-3.

[0050] Example 4 A catalyst based on black phosphorus to enhance hydrophobic properties is described. The other contents are the same as in Example 2, except that 3.75 g of methyltrimethoxysilane is added at a black phosphorus to hydrophobic agent mass ratio of 1:30 to obtain the hydrophobic catalyst Pt / BP-SiO2-4.

[0051] Example 5 A catalyst based on black phosphorus to enhance hydrophobic properties is described. The other contents are the same as in Example 2, except that 2.5 g of perfluorooctyltriethoxysilane is added at a black phosphorus to hydrophobic agent mass ratio of 1:20 to obtain the hydrophobic catalyst Pt / BP-SiO2-5.

[0052] Example 6 A catalyst based on black phosphorus-enhanced hydrophobic properties includes a composite support and a platinum active component supported on the composite support; the composite support includes a porous silica matrix and a black phosphorus / hydrophobic agent composite grafted onto the surface of the porous silica matrix.

[0053] The preparation method of the catalyst based on black phosphorus-enhanced hydrophobic properties includes the following steps: S1. Measure 20 mL of 5 mg / mL black phosphorus ethanol dispersion into a beaker, add 180 mL of anhydrous ethanol, add 3 g of methyltrimethoxysilane according to the mass ratio of black phosphorus to hydrophobic agent 1:30, stir at 100 °C for 4 h under nitrogen protection and in the dark, filter after the reaction is completed, wash three times with ethanol, and dry in a vacuum drying oven at 90 °C for 12 h to obtain black phosphorus / hydrophobic agent complex. S2. The black phosphorus / hydrophobic agent composite was ultrasonically dispersed in toluene for 30 min. 10 g of silica carrier powder that had been calcined in a muffle furnace at 500 °C for 2 h was added at a black phosphorus to silica carrier mass ratio of 1:100. The mixture was refluxed at 140 °C for 10 h under stirring. After the reaction was completed, the mixture was filtered, washed three times with toluene, and then vacuum dried at 90 °C for 6 h. The mixture was then formed into 5 mm spheres to obtain the composite carrier. S3. According to the atomic mass ratio of black phosphorus to platinum of 1:5, 1.008 g of platinum acetylacetonate was dissolved in 30 mL of toluene. Then, the hydrophobically modified support spheres were added to the solution. The mixture was placed in a pear-shaped flask and rotary evaporated until the solution was dry. The water bath temperature was 60 °C and the pressure was 50 kPa. After rotary evaporation, the solution was washed three times with toluene and dried in a vacuum drying oven at 130 °C for 4 h. Then, it was calcined at 600 °C for 2 h under a nitrogen atmosphere. After cooling, it was reduced at 300 °C for 2 h in a 10% hydrogen-nitrogen mixture to obtain the hydrophobic catalyst Pt / BP-SiO2-6.

[0054] Comparative Example 1 A catalyst is prepared as follows: 1.008 g of platinum acetylacetonate is dissolved in 30 mL of toluene to prepare a solution. Then, 10 g of dried commercial SDB support is added to the solution. The mixture is placed in a pear-shaped flask and rotary evaporated until the solution is dry. The water bath temperature is 40 °C and the pressure is 30 kPa. After rotary evaporation, liquid-phase reduction is performed using a 0.1 mol / L potassium borohydride solution. After reduction, the solution is washed three times with ethanol and dried in a vacuum drying oven at 60 °C for 6 h to obtain the commercial hydrophobic catalyst Pt / SDB.

[0055] Comparative Example 2 A catalyst is prepared as follows: Silica is calcined in a muffle furnace at 400℃ for 3 hours. 10g of support is weighed and added to 100mL of toluene, then ultrasonically dispersed for 30 minutes. Subsequently, 4g of methyltrimethoxysilane is added. The reaction mixture is placed in a reaction flask and heated under reflux at 100℃ for 12 hours. After filtration and washing with toluene, the mixture is dried in a vacuum drying oven at 80℃ for 8 hours to obtain a hydrophobically modified support. The hydrophobic support is shaped into 3mm spheres. 1.008g of platinum acetylacetonate is dissolved in 30mL of toluene. Then, 10g of the hydrophobically modified support spheres are added to the solution. The mixture is placed in a pear-shaped flask and rotary evaporated until the solution is dry. The water bath temperature is 40℃ and the pressure is 30kPa. After rotary evaporation, the solution is washed three times with toluene and dried in a vacuum drying oven at 70℃ for 6 hours. Subsequently, it is calcined at 500℃ for 3 hours under a nitrogen atmosphere. After cooling, it is reduced at 150℃ for 3 hours in a 5% hydrogen-nitrogen mixture to obtain the hydrophobic catalyst Pt / SiO2.

[0056] Comparative Example 3 A catalyst is prepared by referring to the method described in CN109432422B to prepare black phosphorus quantum dot hybrid mesoporous silica (BMSF). 10 g of the BMSF material and 0.02 g of 3-aminopropyltrimethoxysilane (APTES) are refluxed in ethanol at 80 °C overnight for amination. The subsequent spheroidization and platinum loading steps are completed according to Comparative Example 2. The resulting catalyst is denoted as Pt / BP-SiO2-APTES.

[0057] Testing and Evaluation Activity tests were conducted on the hydrophobic catalysts obtained in different embodiments and comparative examples: The testing process is as follows Figure 1 As shown, 10 wt% deuterated water was prepared and preheated to 60°C. A metering pump was used to inject the deuterated water from the upper layer of the reaction column. Hydrogen gas was introduced from the bottom of the column, with the flow rate controlled by a mass flow meter. The water was heated to the reaction temperature and saturated with water vapor in the saturator. The saturated hydrogen gas underwent a catalytic exchange reaction with low-concentration heavy water in the reaction column. The water vapor carried by the hydrogen gas was cooled by a condenser, and then separated by a gas-liquid separator. The hydrogen gas was dried by a dryer and then analyzed by mass spectrometry. The low-concentration heavy water after the reaction was collected and flowed into a storage tank. The concentration of the low-concentration heavy water after the reaction was analyzed by a densitometer according to the experimental time. The volume ratio of the catalyst and hydrophilic packing material was controlled at 0.35, and the feed gas-liquid molar ratio was 2.

[0058] Catalyst activity was evaluated using the column exchange efficiency (column efficiency) η.

[0059] ; In the formula, y is the deuterium abundance in the gas phase after the reaction, y0 is the deuterium abundance in the gas phase before the reaction, ye is the deuterium abundance in the gas phase at equilibrium, xe is the deuterium abundance in the liquid phase at equilibrium, and the separation factor α of H / D exchange at 60℃ is 3.134.

[0060] Meanwhile, the contact angle was tested using the plate method; the performance changes of the hydrophobic catalyst before and after 1000 hours of reaction are shown in Table 1. Figure 2 TEM images of the hydrophobic catalyst Pt / BP-SiO2-2 (left) and the hydrophobic catalyst Pt / SDB (right) of Comparative Example 1 after 1000 h of reaction.

[0061] Table 1 Test Results

[0062] The above results demonstrate that this application constructs a highly efficient hydrophobic composite catalyst for LPCE by combining black phosphorus with a hydrophobic modifier, modifying the silica support, and finally loading platinum active centers. By utilizing the intrinsic hydrophobicity of black phosphorus and its strong interaction with metallic platinum, a catalyst with high activity, high hydrophobicity, high stability, and long lifetime is obtained. When applied to the heavy water detritium removal LPCE process, it achieves efficient proton exchange.

[0063] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A catalyst based on black phosphorus to enhance hydrophobic properties, characterized in that, It includes a composite carrier and a platinum active component loaded on the composite carrier; the composite carrier includes a porous silica matrix and a black phosphorus / hydrophobic agent composite grafted onto the surface of the porous silica matrix.

2. A method for preparing a catalyst based on black phosphorus-enhanced hydrophobic properties as described in claim 1, characterized in that, Includes the following steps: S1. Under inert atmosphere and light-protected conditions, black phosphorus and hydrophobic modifier were used as raw materials to carry out a heating reaction to obtain a black phosphorus / hydrophobic agent complex; S2. The black phosphorus / hydrophobic agent composite is heated and refluxed with a silica support to obtain a composite support; S3. Platinum precursor is loaded onto the composite support, and after drying, calcination, and reduction, the catalyst based on black phosphorus-enhanced hydrophobic properties is obtained.

3. The preparation method according to claim 2, characterized in that, The black phosphorus is black phosphorus nanosheets or black phosphorus quantum dots; the hydrophobic modifier is one or more of alkyltrialkoxysilane, fluoroalkyltrialkoxysilane, and aryltrialkoxysilane.

4. The preparation method according to claim 2, characterized in that, In step S1, the heating reaction temperature is 40-100℃ and the reaction time is 4-8h.

5. The preparation method according to claim 2, characterized in that, The mass ratio of black phosphorus to hydrophobic agent is 1:10-30.

6. The preparation method according to claim 2, characterized in that, Between step S1, the process also includes: treating the silica powder at 300℃-500℃ for 2-4 hours.

7. The preparation method according to claim 2, characterized in that, In step S2, the reaction solvent for the reflux reaction is one or more of toluene, ethylbenzene, xylene, or cyclohexane and n-hexane; the temperature of the reflux reaction is 80-140℃, and the reaction time is 10-16h.

8. The preparation method according to claim 2, characterized in that, The mass ratio of the black phosphorus / hydrophobic agent composite to the silica carrier is 1:10-100.

9. The preparation method according to claim 2, characterized in that, The specific operation of step S3 is as follows: the platinum precursor is impregnated or rotary evaporated onto the composite support in equal volume, dried, calcined under a protective atmosphere, and then reduced in liquid / gas phase.

10. The application of a catalyst based on black phosphorus-enhanced hydrophobic properties as described in claim 1 in a liquid-phase catalytic conversion reaction for detritium removal from heavy water.

Images