Preparation method of hydrophobic catalyst, hydrophobic catalyst and application of hydrophobic catalyst in hydrogen-water isotope exchange reaction

Abstract

The invention provides a preparation method of a hydrophobic catalyst for hydrogen-water isotope exchange reaction, the hydrophobic catalyst and application of the hydrophobic catalyst. The preparation method of the hydrophobic catalyst comprises the following steps: carrying out roughening treatment on a silicon-containing hydrophobic molecular sieve carrier by adopting an etching agent which is a solution containing hydrofluoric acid, and carrying out hydrophobization treatment on the roughened silicon-containing hydrophobic molecular sieve carrier by adopting a hydrophobizing agent to obtain a hydrophobic modified molecular sieve carrier, and loading an active component on the hydrophobic modified molecular sieve carrier. The hydrophobic catalyst prepared by the method disclosed by the invention has good hydrophobicity and catalytic activity.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a preparation method of a hydrophobic catalyst for a hydrogen-water isotope exchange reaction, a hydrophobic catalyst and applications thereof. Background Art

[0002] The hydrogen-water isotope exchange method is a new technology for separating hydrogen isotopes from water. It can be used in the production of heavy water, the extraction of tritium from tritiated water (heavy water), and the reduction of tritium in tritium-containing wastewater. The emergence of hydrophobic catalysts allows the hydrogen-water isotope catalytic exchange reaction to be carried out at room temperature, greatly reducing the energy consumption of the process and overcoming the problem of the active sites of the hydrophilic catalyst being covered by liquid water and deactivated. With the deepening of research, the hydrogen-water isotope exchange method has gradually developed from gas-phase catalytic exchange to liquid-phase catalytic exchange, combined electrolytic catalytic exchange, and dual-temperature water hydrogen catalytic exchange. It can be used in the production of heavy water, the extraction of tritium from tritiated water (heavy water), and the reduction of tritium in tritium-containing wastewater. Among them, the dual-temperature water hydrogen catalytic exchange process is the latest technology for heavy water production and the most advanced heavy water production process at present. However, this process needs to be carried out under high temperature and high pressure conditions. The activity of ordinary hydrophobic catalysts will drop sharply under the high temperature and high pressure environment of the hot tower. Therefore, it is necessary to develop a hydrophobic catalyst that is resistant to high temperature and high pressure.

[0003] At present, the commonly used hydrophobic catalysts for hydrogen-water isotope exchange are mainly Pt / SDB and Pt / C / PTFE. Both types of catalysts use polymer materials directly as carriers or as hydrophobic materials to build a hydrophobic environment for the catalyst. However, under high temperature conditions, the performance stability of polymer materials is poor, which makes the hydrophobic catalysts inactivated in a short time when exposed to water. Therefore, the development of hydrophobic catalysts that can withstand high temperature and high pressure is the key to realizing the dual-temperature catalytic exchange process.

[0004] Molecular sieves are a type of crystalline nanoporous material with large specific surface area, ordered and easily adjustable microporous channels, and controllable pH. They have high thermal and hydrothermal stability, excellent catalytic activity and product selectivity. In recent years, molecular sieves have also been proven to be ideal carriers for fixing metal species. Compared with other supported metal catalysts, molecular sieve-supported catalysts have many advantages, such as easy formation of ultra-small and stable metal species, excellent thermal / hydrothermal stability during catalytic reactions, especially under harsh conditions, and shape selectivity in catalytic reactions, meeting the requirements of dual-temperature catalytic exchange catalyst carriers, but usually have poor hydrophobicity and generally require hydrophobic modification.

[0005] In the prior art, common methods for hydrophobic modification of molecular sieves include dealumination modification and silanization agent modification, but such modification methods are complicated and time-consuming, and the hydrophobic effect cannot meet the requirements for the hydrophobicity of the catalyst in the hydrogen-water isotope exchange process.

[0006] Therefore, in order to prepare a hydrophobic catalyst with good hydrophobic effect and excellent catalytic activity, it is necessary to develop a method for preparing a hydrophobic catalyst with a simple process and good hydrophobic effect. Summary of the invention

[0007] In view of this, the main object of the present invention is to provide a hydrophobic catalyst suitable for a dual-temperature catalytic exchange process of a hydrogen-water isotope exchange reaction, wherein the hydrophobic catalyst has good hydrophobic properties and improved catalytic activity.

[0008] To this end, the present invention provides a method for preparing a hydrophobic catalyst for hydrogen-water isotope exchange reaction, comprising the following steps:

[0009] The silicon-containing hydrophobic molecular sieve carrier is roughened by using an etchant, wherein the etchant is a solution including hydrofluoric acid.

[0010] The roughened silicon-containing hydrophobic molecular sieve carrier is subjected to hydrophobic treatment by using a hydrophobic agent to obtain a hydrophobically modified molecular sieve carrier.

[0011] The active component is loaded on the hydrophobically modified molecular sieve carrier.

[0012] In some embodiments, the volume ratio of hydrofluoric acid:water in the etchant is 1:5-1:1, preferably 1:3.

[0013] In some embodiments, the roughening treatment is performed for 30-150 seconds.

[0014] In some embodiments, the hydrophobic agent includes a hydrophobic component and a solvent, the hydrophobic component is selected from one or more of silane and siloxane, and the solvent is ethanol.

[0015] In some embodiments, in the hydrophobic agent, the concentration of the hydrophobic component is 0.2 wt%-0.5 wt%, preferably, the concentration of the hydrophobic component is 0.2 wt%.

[0016] In some embodiments, the hydrophobic treatment time is 12-15 hours.

[0017] In some embodiments, the loading of active components comprises impregnating the hydrophobically modified molecular sieve with an active component precursor solution, and performing gas phase reduction in a hydrogen-containing gas after drying.

[0018] In some embodiments, the concentration of the active component precursor solution is 10-20 mol / L, and the active component is one or more selected from platinum and palladium.

[0019] In some embodiments, the mass content of the active component relative to the hydrophobically modified molecular sieve carrier is 0.5 wt%-2 wt%.

[0020] In some embodiments, the hydrogen-containing gas is a mixed gas of hydrogen and nitrogen, wherein the volume ratio of hydrogen to nitrogen is 1:1.

[0021] The present invention also provides a hydrophobic catalyst prepared according to the preparation method of the first aspect of the present invention.

[0022] The present invention also provides use of the hydrophobic catalyst of the present invention in a hydrogen-water isotope exchange reaction.

[0023] The method of the present invention uses all-silicon molecular sieve as a carrier, and the carrier is roughened by an etching method, combined with a hydrophobic treatment, so that the molecular sieve carrier has enhanced surface hydrophobicity on the one hand, and on the other hand, the specific surface area of ​​the carrier can be increased, thereby improving the catalytic activity of the hydrophobic catalyst. In addition, the method of the present invention first performs a hydrophobic treatment, and then loads the active component to avoid the active site in the hydrophobic catalyst from being covered, which is conducive to improving the utilization rate of the active component, reducing the amount of precious metals, and saving costs. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0026] It should be noted that, in the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method or device including a series of elements includes not only the elements explicitly stated, but also other elements not explicitly listed, or also includes elements inherent to the implementation of the method or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other related elements in the method or device including the element.

[0027] It should be noted that the terms "first\second\third" involved in the embodiments of the present invention are only used to distinguish similar objects, and do not represent a specific order for the objects. It is understandable that "first\second\third" can be interchanged with a specific order or sequence where permitted. It should be understood that the objects distinguished by "first\second\third" can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those described herein.

[0028] Molecular sieve supported catalysts have excellent thermal / hydrothermal stability and shape selectivity in catalytic reactions, especially under harsh conditions, and meet the requirements of dual-temperature catalytic exchange catalyst carriers, but usually have poor hydrophobicity.

[0029] In view of this, the present invention provides a method for preparing a hydrophobic catalyst, comprising the following steps:

[0030] The silicon-containing hydrophobic molecular sieve carrier is roughened by using an etchant, wherein the etchant is a solution including hydrofluoric acid.

[0031] The roughened silicon-containing hydrophobic molecular sieve carrier is subjected to hydrophobic treatment by using a hydrophobic agent to obtain a hydrophobically modified molecular sieve carrier.

[0032] The active component is loaded on the hydrophobically modified molecular sieve carrier.

[0033] The method of the present invention is to roughen the surface of the silicon-containing hydrophobic molecular sieve carrier by using an etchant to process it, and since the silicon-containing hydrophobic molecular sieve itself is a hydrophobic material, the surface roughness of the silicon-containing hydrophobic molecular sieve is increased, which is conducive to further improving the hydrophobicity of the silicon-containing hydrophobic molecular sieve carrier, which is conducive to improving the hydrophobicity of the prepared hydrophobic catalyst. Further, the surface roughness of the silicon-containing hydrophobic molecular sieve increases, and the specific surface area of ​​the silicon-containing hydrophobic molecular sieve carrier can be improved, and then the specific surface area of ​​the prepared hydrophobic catalyst is improved, which is conducive to improving the content of the active component of the subsequent load, providing more catalytic active sites, and improving the catalytic activity of the prepared hydrophobic catalyst. The silicon-containing hydrophobic molecular sieve carrier subjected to roughening treatment is hydrophobized by a hydrophobic agent, and the hydrophobic performance of the hydrophobic catalyst can be further improved. The method of the present invention can reduce the coverage of the hydrophobic component to the active component by first carrying out hydrophobic treatment on the silicon-containing hydrophobic molecular sieve carrier, and then loading the step of active component, save the amount of active component, and improve the utilization efficiency of active component.

[0034] In the present invention, the silicon-containing hydrophobic molecular sieve carrier is not specifically limited, and the silicon-containing molecular sieve that can be used to prepare the hydrophobic catalyst in the art is suitable for the method of the present invention. Exemplarily, the silicon-containing hydrophobic molecular sieve carrier is selected from all-silicon molecular sieve, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10Z molecular sieve, 13Z molecular sieve, Y-type molecular sieve, ZSM-5 molecular sieve, etc.

[0035] In some embodiments, the volume ratio of hydrofluoric acid: water in the etchant is 1:5-1:1. By making the etchant concentration within the above range, it is beneficial to improve the efficiency of the roughened all-silicon molecular sieve. Exemplarily, the volume ratio of hydrofluoric acid: water in the etchant can be 1:5, 1:4, 1:3, 1:2, 1:1 or a value between the ranges consisting of any two of them. In a preferred embodiment, the volume ratio of hydrofluoric acid: water in the etchant is 1:3.

[0036] In the present invention, there is no specific limitation on the amount of the etchant, as long as it can immerse the silicon-containing hydrophobic molecular sieve carrier.

[0037] In some embodiments, the roughening treatment time is 30-150s. By controlling the roughening treatment time within the above range, it is beneficial to controllably adjust the roughening degree of the all-silicon molecular sieve carrier. Exemplarily, the roughening treatment time can be 30s, 45s, 60s, 90s, 120s, 150s or a value between the ranges consisting of any two of them.

[0038] In some embodiments, after the roughening treatment, the roughened all-silicon molecular sieve is cleaned with deionized water. In this way, the incompletely reacted etchant is removed for subsequent treatment. It is understood that the cleaned carrier can be dried. In some embodiments, it is dried at 90-95° C. for 6-8 hours. Drying can be carried out in a manner known in the art, such as drying in an oven.

[0039] In some embodiments, the hydrophobic agent includes a hydrophobic component and a solvent, the hydrophobic component is selected from one or more of silane and siloxane, and the solvent is ethanol. The above-mentioned hydrophobic component can undergo a polycondensation reaction with the silanol group on the surface of the all-silicon molecular sieve, thereby tightly binding to the surface of the carrier. The organosilicon hanging energy group of the hydrophobic component is conducive to enhancing the hydrophobicity of the surface of the prepared hydrophobic catalyst, and the above-mentioned hydrophobic component has a stable structure and is resistant to high temperature, and can be applied to a high temperature and high pressure catalytic environment. Exemplarily, the hydrophobic component can be selected from tridecafluorooctyl triethoxysilane (C 14 H 19 F 13 In some preferred embodiments, the hydrophobic component is tridecafluorooctyl trimethylsiloxane. In some preferred embodiments, the hydrophobic agent is an ethanol solution of tridecafluorooctyl triethoxysilane. Thus, it is further beneficial for the hydrophobic catalyst to obtain super hydrophobic properties.

[0040] In some embodiments, the concentration of the hydrophobic component in the hydrophobic agent is 0.2wt%-0.5wt%. This is conducive to the hydrophobic component covering the all-silicon molecular sieve carrier after the roughening treatment, further improving the hydrophobicity of the carrier. In some preferred embodiments, the concentration of the hydrophobic component is 0.2wt%. This is conducive to the hydrophobic catalyst having super hydrophobic properties.

[0041] In some embodiments, the hydrophobic treatment time is 12-15h. Thus, it is beneficial for the hydrophobic component to fully react with the all-silicon molecular sieve. Exemplarily, the hydrophobic treatment time can be 12h, 13h, 14h, 15h or a value between the ranges consisting of any two of them.

[0042] In some embodiments, the carrier after hydrophobization treatment is dried at 90-95° C. for 2 hours, thereby fully drying the hydrophobic catalyst and facilitating further silanization reaction of the hydrophobic component, so that the hydrophobic component is more firmly attached to the carrier.

[0043] In some embodiments, the loading of active components includes impregnating a hydrophobically modified molecular sieve with an active component precursor solution, and then performing gas phase reduction in a hydrogen-containing gas after drying. The present invention adopts an impregnation-gas phase reduction method, wherein the active component precursor is loaded onto a molecular sieve carrier by impregnation, and then a full silicon molecular sieve loaded with active components is obtained by gas phase reduction.

[0044] In some embodiments, the concentration of the active component precursor solution is 10-20 mol / L. By making the concentration of the precursor active solution within the above range, it is beneficial to make the active component in the prepared hydrophobic catalyst evenly dispersed, thereby improving the catalytic activity of the hydrophobic catalyst. Exemplarily, the concentration of the active component precursor solution can be 10 mol / L, 12 mol / L, 14 mol / L, 16 mol / L, 18 mol / L, 20 mol / L or a value between the ranges consisting of any two of them.

[0045] In some embodiments, the active component is selected from one or more of platinum and palladium. These active components have high catalytic activity for hydrogen-water isotope exchange reaction.

[0046] In some embodiments, the mass content of the active component relative to the hydrophobically modified molecular sieve carrier is 0.5wt%-2wt%. By making the content of the active component within the above range, it is beneficial to improve the catalytic efficiency of the hydrophobic catalyst. In some preferred embodiments, the mass content of the active component relative to the hydrophobically modified molecular sieve carrier is 0.8wt%-2wt%.

[0047] The present invention does not impose any specific limitation on the amount of the active component precursor solution, as long as it can immerse the hydrophobically modified molecular sieve carrier.

[0048] In some embodiments, the hydrogen-containing gas is a mixed gas of hydrogen and nitrogen, wherein the volume ratio of hydrogen to nitrogen is 1:1.

[0049] In some embodiments, the gas phase reduction includes heating the reduction furnace to 200-250°C at a heating rate of 10°C / min under a N2 atmosphere with a flow rate of 500-1000ml / min; then reducing for 8-10h in a mixed gas atmosphere of N2 and H2 with a volume ratio of 1:1 at a flow rate of 500-1000ml / min, maintaining the temperature at 200-250°C; and finally naturally cooling to room temperature in a N2 atmosphere with a flow rate of 500ml / min.

[0050] The present invention also provides a hydrophobic catalyst prepared by the above method. The hydrophobic catalyst prepared by the method of the present invention has improved hydrophobicity, improved catalytic activity and high temperature resistance. The hydrophobic catalyst prepared by the method of the present invention has an increased surface roughness Rq, and in some embodiments, the surface roughness Rq of the hydrophobic catalyst is 200nm-280nm. Thus, it is conducive to improving the hydrophobicity and catalytic activity of the hydrophobic catalyst.

[0051] The present invention also provides the use of the hydrophobic catalyst of the present invention in a hydrogen-water isotope exchange reaction. The hydrophobic catalyst of the present invention has good hydrophobicity, catalytic activity and high temperature resistance, can be applied to hydrogen-water isotope exchange reactions under high temperature and high pressure conditions, and has good catalytic activity and catalytic reaction efficiency.

[0052] The following describes the embodiments of the present invention in detail through specific examples. It should be understood that these examples are only exemplary and cannot be used as a limitation on the scope of the present invention.

[0053] Example

[0054] Unless otherwise specified, conventional reagents used in the following examples can be obtained from commercial sources. The all-silicon molecular sieve used in the following examples was provided by the College of Chemistry of Jilin University.

[0055] Example 1

[0056] The all-silicon molecular sieve carrier was immersed in an etchant, which was an HF solution with a volume ratio of HF:H2O=1:4. After immersion for 45 seconds, it was taken out and washed with deionized water and ultrasonicated for 5 minutes. The washed carrier was taken out and dried at 90°C for 6 hours.

[0057] The roughened molecular sieve carrier was immersed in 0.2 wt % tridecafluorooctyl trimethylsiloxane (C 11 H 13 F 13 The samples were immersed in an ethanol solution of O3Si for 12 h and then dried at 95 °C for 2 h.

[0058] The hydrophobic treated molecular sieve carrier was immersed in 10 mol / L chloroplatinic acid ethanol solution. The carrier and the impregnation solution were immersed in equal volumes at a ratio of 1:1. The theoretical loaded platinum content was 0.8 wt%. After the impregnation solution was completely evaporated at room temperature, the catalyst was dried at 60 °C for 12 h.

[0059] The impregnated carrier was placed in a tubular reduction furnace, and the reduction furnace was heated to 220°C at a heating rate of 10°C / min in a N2 atmosphere with a flow rate of 500 ml / min. Then, the temperature was maintained at 220°C for 8 hours in a H2 mixed gas atmosphere with a flow rate of 500 ml / min and 500 ml / min. Finally, it was naturally cooled to room temperature in a N2 atmosphere with a flow rate of 500 ml / min to obtain a hydrophobic catalyst.

[0060] The prepared hydrophobic catalyst was subjected to a performance test according to the following method. The test results are recorded in Table 1.

[0061] Static water contact angle measurement:

[0062] Use the static contact angle measuring instrument SDC-350 (Dongguan Shengding Precision Instrument Co., Ltd.) to measure. Place the hydrophobic catalyst on the stage of the measuring instrument, move the stage upward to make it contact with the water droplets dripping from the needle tube, and after the two are fully in contact, move the stage downward to make the water droplets leave the needle tube and place them on the hydrophobic catalyst. Use the software that comes with the measuring instrument to fit the contact angle. The larger the static contact angle, the better the hydrophobic performance of the catalyst.

[0063] Hydrogen-water isotope exchange reaction efficiency:

[0064] Using hydrogen water isotope exchange reaction device [1] The efficiency of hydrogen-water isotope exchange reaction was measured.

[0065] The hydrogen-water isotope liquid phase exchange reaction device is mainly composed of deuterated water, a packing column, an exchange reaction column and a hydrogen source. The inner diameter of the packing column is 40 cm and the length is 40 cm. The packing is a 3×2 mm θ ring packing. The inner diameter of the catalytic column is 20 mm and the height is 40 cm. The hydrophobic catalyst is placed at the bottom of the column for catalytic reaction. The catalytic column housing is filled with 60°C circulating heated water. The catalytic column is connected to the condensation column and the drying tube, and the temperature is maintained at 8°C by a circulating condenser. 2mL of catalyst was used in the experiment. Under the indication of the flowmeter, hydrogen enters the bottom of the water vapor saturator at a gas rate of 1.88L / min. In this way, water vapor containing saturated deuterium can enter the catalytic column for hydrogen isotope exchange reaction, and then water and gas samples are extracted. The abundance of deuterium in gas and liquid samples was determined by measuring the deuterium abundance in gas samples using a mass spectrometer (MS) (MAT253; Thermo Scientific, USA) and the deuterium abundance in water samples using a densitometer (DMA5000; Anton Paar, Austria). The catalyst activity was characterized by the conversion rate η:

[0066]

[0067] lnα H-D=0.1636+333.7T+33840(3)

[0068] y t is the deuterium content in the gas phase at the outlet of the reaction tower; y0 is the deuterium abundance in the gas phase before the reaction. y* represents the equilibrium deuterium abundance in the gas phase at the outlet of the reaction tower, calculated by formula (2); α is the hydrogen-deuterium separation coefficient, which is calculated by the empirical formula (3) Comparative Example 1

[0069] The all-silica molecular sieve support was impregnated with 0.2 wt% tridecafluorooctyl trimethylsiloxane (C 11 H 13 F 13 The samples were immersed in an ethanol solution of O3Si for 12 h and then dried at 95 °C for 2 h.

[0070] The hydrophobic treated molecular sieve carrier was immersed in 10 mol / L chloroplatinic acid ethanol solution. The carrier and the impregnation solution were immersed in equal volumes at a ratio of 1:1. The theoretical loaded platinum content was 0.8 wt%. After the impregnation solution was completely evaporated at room temperature, the catalyst was dried at 60 °C for 12 h.

[0071] The impregnated carrier was placed in a tubular reduction furnace, and the reduction furnace was heated to 220°C at a heating rate of 10°C / min in a N2 atmosphere with a flow rate of 500 ml / min. Then, the temperature was maintained at 220°C for 8 hours in a H2 mixed gas atmosphere with a flow rate of 500 ml / min and 500 ml / min. Finally, it was naturally cooled to room temperature in a N2 atmosphere with a flow rate of 500 ml / min to obtain a hydrophobic catalyst.

[0072] The performance of the hydrophobic catalyst was tested according to the test method described in Example 1, and the results are recorded in Table 1.

[0073] Table 1

[0074]

[0075] As can be seen from the above test results, the hydrophobic catalyst prepared by roughening and then hydrophobizing in Example 1 can reach a static contact angle of about 170°, which is significantly improved compared with the hydrophobic catalyst (static contact angle of about 132°) modified with tridecafluorooctyl trimethylsiloxane reagent in Comparative Example 1. The hydrophobic catalyst prepared by 2ml of Example 1 is placed in the above-mentioned hydrogen-water exchange reaction device, and the gas flow rate is 1.88L / min. The optimal efficiency of hydrogen-water isotope exchange reaction can be stabilized at 45.1%, which is more than twice the activity of the catalyst prepared in Comparative Example 1 (19.4%), and the catalytic efficiency is significantly improved. The hydrophobic catalyst prepared by 6ml of Example 1 is placed in a laboratory-made gas-liquid co-current exchange device, and the gas flow rate is 1.88L / min. The optimal efficiency of hydrogen-water isotope exchange reaction can be stabilized at 91.4%, and the catalytic efficiency is excellent. The catalyst was calcined at 250°C for 3 hours, and the hydrophobicity and catalytic performance did not show a significant decrease. The catalyst has excellent high temperature resistance.

[0076] Example 2

[0077] The hydrophobic catalyst was prepared in a similar manner to Example 1, except that the immersion time in the HF solution was 90 seconds.

[0078] Example 3

[0079] A hydrophobic catalyst was prepared in a manner similar to that of Example 1, except that the etchant was an HF solution with a volume ratio of H2O:HF=3:1 (the volume concentration of HF was 25%), and the immersion time in the etchant was 60 seconds.

[0080] The hydrophobic catalysts prepared in Examples 2-3 were subjected to performance tests according to the test method described in Example 1. The results are shown in Table 2.

[0081] Table 2

[0082]

[0083] From the above results, it can be seen that the hydrophobic catalyst prepared by the method of the present invention in Example 2-3 has good hydrophobicity and improved catalytic efficiency.

[0084] The following references are incorporated herein by reference in their entirety.

[0085] References

[0086] 1.Qingqing Jia et al.Hydrophobically modified ceramic-supported Pt-particle catalyst for enhanced water-hydrogen exchange reactions,FusionEng.Des.2024,199,114154.; https: / / doi.org / 10.1016 / j.fusengdes.2024.114154

[0087] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a hydrophobic catalyst for hydrogen-water isotope exchange reaction, comprising the following steps: The silicon-containing hydrophobic molecular sieve carrier is roughened by using an etchant, wherein the etchant is a solution including hydrofluoric acid. The roughened silicon-containing hydrophobic molecular sieve carrier is subjected to hydrophobic treatment by using a hydrophobic agent to obtain a hydrophobically modified molecular sieve carrier. The active component is loaded on the hydrophobically modified molecular sieve carrier.

2. The preparation method according to claim 1, wherein The volume ratio of hydrofluoric acid to water in the etchant is 1:5-1:1, preferably 1:

3.

3. The preparation method according to claim 1 or 2, wherein The roughening treatment time is 30-150s.

4. The preparation method according to claim 1, wherein The hydrophobic agent comprises a hydrophobic component and a solvent, wherein the hydrophobic component is selected from one or more of silane and siloxane, and the solvent is ethanol; Preferably, in the hydrophobic agent, the concentration of the hydrophobic component is 0.2wt%-0.5wt%, more preferably, the concentration of the hydrophobic component is 0.2wt%.

5. The method according to claim 1, wherein: The time of the hydrophobic treatment is 12-15 hours.

6. The preparation method according to claim 1, wherein The active component loading method comprises impregnating the hydrophobically modified molecular sieve with an active component precursor solution, and performing gas phase reduction in a hydrogen-containing gas after drying.

7. The preparation method according to claim 6, wherein: The concentration of the active component precursor solution is 10-20 mol / L, and the active component is one or more selected from platinum and palladium; Preferably, the mass content of the active component relative to the hydrophobically modified molecular sieve carrier is 0.5 wt%-2 wt%.

8. The preparation method according to claim 6, wherein: The hydrogen-containing gas is a mixed gas of hydrogen and nitrogen, wherein the volume ratio of hydrogen to nitrogen is 1:

1.

9. A hydrophobic catalyst obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the hydrophobic catalyst according to claim 9 in a hydrogen-water isotope exchange reaction.

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