阅读说明：本技术 双疏型含铂催化剂材料、其制备方法及应用 (Double-hydrophobic platinum-containing catalyst material, and preparation method and application thereof ) 是由 华道本 周磊 徐美芸 于 2021-10-15 设计创作，主要内容包括：本发明提供了一种双疏型含铂催化剂材料、其制备方法及应用,方法包括以下步骤：在表面构建多个硅羟基；在20-30℃条件下,利用含有硅酸酯类化合物、硅酸酯水解催化剂和水的混合溶液在表面生长纳米二氧化硅颗粒；在20-30℃条件下,利用氨基硅烷偶联剂溶液进行活化处理；在20-30℃条件下,利用含有芳香基硅烷化合物和氟烷基硅烷化合物的溶液进行功能化处理,得到双疏多孔基底材料；在双疏多孔基底材料表面生长纳米铂颗粒,得到双疏型含铂催化剂材料。本发明提供的制备方法所制备的双疏型含铂催化剂同时具有疏水和疏油性质,该型催化剂在室温下表现出优秀的氢同位素催化氧化性能,同时具有良好的重启性能及使用寿命。(The invention provides a double-hydrophobic platinum-containing catalyst material, a preparation method and application thereof, wherein the method comprises the following steps: constructing a plurality of silicon hydroxyl groups on the surface; under the condition of 20-30 ℃, growing nano silicon dioxide particles on the surface by using a mixed solution containing a silicate compound, a silicate hydrolysis catalyst and water; activating by using an aminosilane coupling agent solution at the temperature of 20-30 ℃; performing functionalization treatment by using a solution containing an aromatic silane compound and a fluoroalkyl silane compound at the temperature of 20-30 ℃ to obtain a hydrophobic and oleophobic porous substrate material; nanometer platinum particles grow on the surface of the amphiphobic porous substrate material to obtain the amphiphobic platinum-containing catalyst material. The double-hydrophobic platinum-containing catalyst prepared by the preparation method provided by the invention has hydrophobic and oleophobic properties, and the catalyst shows excellent hydrogen isotope catalytic oxidation performance at room temperature, and has good restarting performance and service life.)

1. A preparation method of a double-hydrophobic platinum-containing catalyst material is characterized by comprising the following steps:

constructing a plurality of silicon hydroxyl groups on the surface;

under the condition of 20-30 ℃, growing nano silicon dioxide particles on the surface of the porous substrate material after a plurality of silicon hydroxyl groups are constructed by using a mixed solution containing a silicate compound, a silicate hydrolysis catalyst and water, and obtaining the roughened porous substrate material after the reaction is finished;

activating the roughened porous substrate material by using an aminosilane coupling agent solution at the temperature of 20-30 ℃, and obtaining the activated porous substrate material after the reaction is finished; performing functionalization treatment on the activated porous substrate material by using a solution containing an aromatic silane compound and a fluoroalkylsilane compound at the temperature of 20-30 ℃, and obtaining a amphiphobic porous substrate material after the reaction is finished;

and (3) growing nano platinum particles on the surface of the amphiphobic porous substrate material to obtain the amphiphobic platinum-containing catalyst material.

2. The preparation method according to claim 1, wherein the nano platinum particles are grown on the surface of the amphiphobic porous substrate material by a method comprising the following steps:

adsorbing an acetone solution containing chloroplatinic acid in the amphiphobic porous substrate material, and drying the amphiphobic porous substrate material adsorbed with the acetone solution containing chloroplatinic acid to obtain the amphiphobic porous substrate material attached with chloroplatinic acid;

and (3) carrying out reduction treatment on the amphiphobic porous substrate material attached with chloroplatinic acid by using reducing gas at the temperature of 180-275 ℃, and obtaining the amphiphobic platinum-containing catalyst material after the reaction is finished.

3. The method of claim 2, wherein the nano platinum particles have a particle size of less than 6 nm.

4. The preparation method according to claim 1, wherein the silicate compound comprises one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate; the silicate ester hydrolysis catalyst comprises one or more of ammonia water, hydrofluoric acid, hydrochloric acid, ammonia water, sulfuric acid and acetic acid; wherein, when the mixed solution is prepared, the volume fraction of the silicate ester hydrolysis catalyst is 4.6-15.4%.

5. The method as claimed in claim 1, wherein the nano silica particles have a particle size ranging from 50 to 500 nm.

6. The preparation method of claim 1, wherein the aminosilane coupling agent comprises one or more of KH-550, KH-540 and (2-aminoisopropyl) triethoxysilane, and the solvent in the aminosilane coupling agent solution comprises one or more of alcohols, esters, ethers and aromatic solvents.

7. The production method according to claim 1, wherein the aromatic silane compound comprises a compound represented by formula (1), and the fluoroalkyl silane compound comprises a compound represented by formula (2):

wherein R is₁Is phenyl, phenylaminomethyl or phenethyl; r₂One selected from hydrogen, C1-C3 alkyl; r₃One selected from hydrogen, C1-C3 alkyl; and m is 0-11.

8. A double-hydrophobic platinum-containing catalyst material is characterized by comprising a porous substrate containing silicon elements, wherein nano metal platinum, hydrophobic groups and oleophobic groups are attached to the surface of the porous substrate, and the double-hydrophobic platinum-containing catalyst material is prepared by the method of claims 1-8.

9. Use of the bis-hydrophobic platinum-containing catalyst material of claim 8 in the oxidative dehydrogenation of isotopes of hydrogen from a gas.

10. The application according to claim 9, characterized in that the method adopted by the application comprises the following steps:

under the condition of 25-75 ℃, the gas to be treated with the hydrogen isotope gas content of 100-^-1Through the double hydrophobic platinum-containing catalyst material.

Technical Field

The invention relates to the technical field of material preparation, in particular to a double-hydrophobic platinum-containing catalyst material, and a preparation method and application thereof.

Background

Global energy shortages are one of the major challenges facing the development of human society. With respect to the current reserves and production volumes, various fossil energy sources are facing to be exhausted, according to prediction, petroleum is exhausted after more than 40 years, natural gas is exhausted after more than 60 years, and coal is only enough to be exploited and used for more than 150 years. Besides, the fossil energy has high consumption and also faces serious problems of environmental pollution, climate influence and the like. Nuclear fission provides abundant energy, does not emit greenhouse gases, and is one of the important components of world energy. Nuclear fusion is a promising energy source, and has attracted much attention due to its high energy density, cleanness and reliability. In the nuclear fusion reaction, the energy released by the deuterium-tritium fusion reaction is large, the reaction condition is the mildest, and the deuterium-tritium fusion reaction is considered as the controllable nuclear fusion reaction which is most hopefully realized at the present stage.

Although nuclear energy has the characteristics of cleanness, economy and the like, a large number of problems still face to be solved after long-term use, wherein hydrogen explosion and nuclear fusion radioactive tritium leakage caused by hydrogen leakage in a nuclear power station are threats related to safe operation of the nuclear power station. In nuclear fission power stations or future nuclear fusion power stations, hydrogen isotope removal systems are critical to greatly reduce the risk of nuclear fission hydrogen explosions and nuclear fusion radioactive tritium leaks. Therefore, an effective hydrogen isotope removal system is essential for safe operation and environmental protection of nuclear power plants.

Catalytic oxidation is a common method in hydrogen isotope removal systems when treating high space velocity gases, and the nature of the catalyst has an important influence on the enrichment and removal of hydrogen isotopes. Tritium removal catalysts are generally required to have some of the following characteristics: high tritium conversion rate, high stability, low catalytic reaction temperature and strong tritium irradiation resistance. The tritium removal catalysts that are commonly used are mainly of the following three types: oxidants, including CuO, MnO₂AgO, hopcalite oxidant, and the like; noble metal (Pt, Pd) catalysts. The advantage of the oxidant for tritium removal is that the material is simple and easy to obtain, and can be used for tritium removal in inert atmosphere and air atmosphere. But the use temperature is high, the deep tritium removal capability is limited, and the reactivation temperature is high.

Currently, noble metal catalysts have attracted extensive research interest due to their high catalytic efficiency and low energy consumption. The noble metal supported catalyst has the main advantages that the reaction temperature is low, and the catalyst can work at room temperature; the catalytic reaction rate is sensitive to temperature change, and the conversion rate and the oxidation rate can be greatly improved by properly increasing the temperature during treatment of a large amount of tritium-containing gas or emergency treatment; the catalytic reaction is not influenced by reaction balance, and deep tritium removal can be realized. However, when the temperature is lower than 100 ℃, water easily adheres to the surface of the noble metal, preventing the catalyst from contacting the hydrogen isotope. In addition, because the three-stage containing system is operated by pumping gas into the glove box through the pump, substances such as engine oil and the like can enter the glove box, and in addition, because polluted gas is pumped into a catalytic bed in an accident, some petroleum and organic matters can enter the catalytic bed along with the polluted gas, so that an active center is occupied, the catalytic efficiency and the service life are reduced, and the restarting performance of the catalyst is influenced. Therefore, the development of a double-hydrophobic tritium removal catalyst which can be hydrophobic and oleophobic is very important for the development and application of nuclear energy.

Disclosure of Invention

Aiming at the problem of poor hydrophobic and oleophobic properties of a noble metal catalyst in the prior art, the invention designs and synthesizes a novel noble metal catalyst by taking nano silicon and fluoride functionalized materials as carriers. Due to the hydrophobic and oleophobic properties, the catalyst shows excellent hydrogen isotope catalytic oxidation performance at room temperature, and has good restarting performance and service life.

The invention aims to provide a double-hydrophobic platinum-containing catalyst material, a preparation method and application thereof, and solves the problems that in the prior art, a noble metal catalyst is poor in hydrophobic and oleophobic properties, so that the catalytic efficiency is reduced, the service life is prolonged, and the restarting performance of the catalyst is influenced.

The first purpose of the invention is to provide a preparation method of a double hydrophobic platinum-containing catalyst material, which comprises the following steps:

(1) constructing a plurality of silicon hydroxyl groups on the surface of a silicon-containing porous substrate material;

(2) under the condition of 20-30 ℃, growing nano silicon dioxide particles on the surface of the porous substrate material with a plurality of silicon hydroxyl groups built by using a mixed solution containing a silicate compound, a silicate hydrolysis catalyst and water, and obtaining the roughened porous substrate material after the reaction is finished;

(3) activating the roughened porous substrate material by using an aminosilane coupling agent solution at the temperature of 20-30 ℃, and obtaining the activated porous substrate material after the reaction is finished;

(4) performing functionalization treatment on the activated porous substrate material by using a solution containing an aromatic silane compound and a fluoroalkylsilane compound at the temperature of 20-30 ℃, and obtaining a amphiphobic porous substrate material after the reaction is finished;

(5) nanometer platinum particles grow on the surface of the amphiphobic porous substrate material to obtain the amphiphobic platinum-containing catalyst material.

The beneficial effects of the technical scheme at least comprise: the preparation method comprises the steps of constructing a plurality of silicon hydroxyl groups on the surface of a silicon-containing porous substrate material to roughen the silicon hydroxyl groups, and carrying out activation treatment, functionalization treatment and nano platinum particle growth to realize hydrophobic and oleophobic effects, so that a double-hydrophobic platinum-containing catalyst material is finally obtained, the catalytic performance and the restarting performance of a noble metal catalyst are improved, the obtained double-hydrophobic platinum-containing catalyst material has both hydrophobic property and oleophobic property, and has higher catalytic efficiency and service life when catalyzing for oxidation tritium removal, and has good restarting performance.

Further, in the step (5), nano platinum particles are grown on the surface of the amphiphobic porous substrate material by adopting a method comprising the following steps:

(S1) adsorbing the acetone solution containing chloroplatinic acid in the amphiphobic porous substrate material, and drying the amphiphobic porous substrate material adsorbed with the acetone solution containing chloroplatinic acid to obtain the amphiphobic porous substrate material attached with chloroplatinic acid;

(S2) reducing the amphiphobic porous substrate material attached with chloroplatinic acid by using reducing gas at the temperature of 180-275 ℃, and obtaining the amphiphobic platinum-containing catalyst material after the reaction is finished. According to the method, the gas reduction method is adopted to grow the nano platinum particles on the surface of the amphiphobic porous substrate material, the nano platinum particles grown by the gas reduction method are uniformly distributed on the surface of the amphiphobic porous substrate material, and the reduction degree is high.

Further, in the step (5), the particle size of the nano platinum particles is less than 6nm, and is mainly concentrated to about 3 nm. The proper particle size of the nano platinum particles can expose more active sites, greatly increase the contact probability of the active sites and hydrogen, and improve the catalytic efficiency.

Further, in the step (2), the silicate compound comprises one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate; the silicate ester hydrolysis catalyst comprises one or more of ammonia water, hydrofluoric acid, hydrochloric acid, ammonia water, sulfuric acid and acetic acid. Wherein, when preparing the mixed solution, the volume fraction of the silicate ester hydrolysis catalyst is 4.6-15.4%, and the volume ratio of the silicate ester compound to the silicate ester hydrolysis catalyst is 1: 0.6 to 1: 2.1.

further, in the step (2), the particle size of the nano silica particles is in the range of 50 to 500 nm. The appropriate particle size of the nanosilica particles enables the material to be roughened, greatly enhancing the hydrophobic effect.

Further, in the step (3), the aminosilane coupling agent comprises one or more of KH-550, KH-540 and (2-aminoisopropyl) triethoxysilane, and the solvent in the aminosilane coupling agent solution comprises one or more of alcohols, esters, ethers and aromatic solvents.

Further, in the step (4), the aromatic silane compound includes a compound represented by the formula (1), and the fluoroalkyl silane compound includes a compound represented by the formula (2):

wherein R is₁Is phenyl, phenylaminomethyl or phenethyl; r₂One selected from hydrogen, C1-C3 alkyl; r₃One selected from hydrogen, C1-C3 alkyl; and m is 0-11. The appropriate chain length of the fluoroalkyl chain is beneficial to the amphiphobic effect, so that the inactivation effect of water vapor and oil gas on the catalytic active sites is reduced, and the catalytic efficiency is improved. C1-C3 alkyl such as methyl, ethyl or isopropyl.

The invention also provides a preparation method of the double-hydrophobic platinum-containing catalyst material, which comprises the following steps of preparing a porous substrate containing silicon element, wherein nano metal platinum, a hydrophobic group and an oleophobic group are attached to the surface of the porous substrate, and the double-hydrophobic platinum-containing catalyst material is prepared by the preparation method of the double-hydrophobic platinum-containing catalyst material.

The third purpose of the invention is to provide the application of the double hydrophobic platinum-containing catalyst material in the hydrogen isotope removal by gas oxidation.

Further, the method for applying the double-hydrophobic platinum-containing catalyst material in the hydrogen isotope removal by gas oxidation comprises the following steps: under the condition of 25-75 ℃, the gas to be treated with the hydrogen isotope gas content of 100-^-1Through a bis-hydrophobic platinum-containing catalyst material.

By adopting the technical scheme of the invention, the invention has the following beneficial effects:

the invention provides a hydrophobic and oleophobic platinum-based catalyst with high catalytic efficiency and good restarting performance, which can be used for catalytic oxidation of hydrogen isotopes. The catalyst takes a porous substrate as a carrier, achieves high hydrophobicity and oleophobicity by utilizing nano-silicon and fluorine-containing compounds through surface functionalization, and reduces the interference of water vapor and polluted gas, thereby improving the catalytic performance and the restarting performance of the material, and enabling the catalyst to realize the efficient catalytic oxidation of hydrogen isotopes in the practical application process.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following description is made with reference to the preferred embodiments of the present invention and the accompanying detailed drawings.

Drawings

FIG. 1 is a process flow diagram of a method for preparing a double hydrophobic platinum-containing catalyst material according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a flow process for preparing a amphiphobic porous substrate material provided by an embodiment of the invention;

FIG. 3 is an SEM image of a surface of a silicon-containing porous substrate material after an acidizing treatment and roughening provided by embodiments of the present invention;

FIG. 4 is a water phase and oil phase contact angle test chart of the silicon-containing porous substrate material after the acidizing treatment and the amphiphobic porous substrate material obtained after the functionalization treatment provided by the embodiment of the invention;

FIG. 5 is a TEM image of the surface of a double hydrophobic platinum-containing catalyst material provided by an embodiment of the present invention;

FIG. 6 is a graph illustrating the catalytic performance and the restart performance of a double hydrophobic platinum-containing catalyst material according to an embodiment of the present invention;

fig. 7 is a comparison graph of performance tests of the double hydrophobic platinum-containing catalyst material provided by the embodiment of the invention and a commercial catalyst material in a simulated atmosphere.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Referring to fig. 1 and fig. 2, an embodiment of the present invention provides a method for preparing a double-phobic platinum-containing catalyst material, including the following steps: constructing a plurality of silicon hydroxyl groups on the surface of a silicon-containing porous substrate material; under the condition of 20-30 ℃, growing nano silicon dioxide particles on the surface of the porous substrate material with a plurality of silicon hydroxyl groups built by using a mixed solution containing a silicate compound, a silicate hydrolysis catalyst and water, and obtaining the roughened porous substrate material after the reaction is finished; activating the roughened porous substrate material by using an aminosilane coupling agent solution at the temperature of 20-30 ℃, and obtaining the activated porous substrate material after the reaction is finished; performing functionalization treatment on the activated porous substrate material by using a solution containing an aromatic silane compound and a fluoroalkylsilane compound at the temperature of 20-30 ℃, and obtaining a amphiphobic porous substrate material after the reaction is finished; nanometer platinum particles grow on the surface of the amphiphobic porous substrate material to obtain the amphiphobic platinum-containing catalyst material.

Preferably, the silicon-containing porous substrate material may include one of a molecular sieve, a zeolite, or cordierite, and the method for forming the plurality of silicon hydroxyl groups on the surface of the silicon-containing porous substrate material may include: acidizing the silicon-containing porous substrate material by using an aqueous solution of oxidizing acid to construct a plurality of silicon hydroxyl groups on the surface of the silicon-containing porous substrate material; further preferably, the aqueous solution of an oxidizing acid is an oxidizing acid comprising nitric acid.

Based on the technical scheme in the embodiment, the double-hydrophobic platinum-containing catalyst material is finally obtained by constructing a plurality of silicon hydroxyl groups on the surface of the silicon-containing porous substrate material, roughening treatment, activating treatment, functionalizing treatment and nano platinum particle growth, and the obtained double-hydrophobic platinum-containing catalyst material has both hydrophobicity and oleophobicity, has high catalytic efficiency and service life when catalyzing oxidation tritium removal, and has good restarting performance.

In some embodiments, nano platinum particles are grown on the surface of the amphiphobic porous substrate material by a method comprising: adsorbing an acetone solution containing chloroplatinic acid in a amphiphobic porous substrate material, and drying the amphiphobic porous substrate material adsorbed with the acetone solution containing chloroplatinic acid to obtain the chloroplatinic acid-attached amphiphobic porous substrate material; and (3) carrying out reduction treatment on the amphiphobic porous substrate material attached with chloroplatinic acid by using reducing gas at the temperature of 180-275 ℃, and obtaining the amphiphobic platinum-containing catalyst material after the reaction is finished. The beneficial effects brought by the fact that the nano platinum particles are grown on the surface of the amphiphobic porous substrate material by preferably adopting a gas reduction method at least comprise the following steps: the nano platinum particles grown by the gas reduction method are uniformly distributed on the surface of the amphiphobic porous substrate material, and the reduction degree is higher. Preferably, the method for adsorbing the acetone solution containing chloroplatinic acid in the amphiphobic porous substrate material can comprise the following steps: dripping an acetone solution containing chloroplatinic acid on the surface of the amphiphobic porous substrate material, and immersing the amphiphobic porous substrate material; further preferably, the reducing gas may include hydrogen.

In some embodiments, the particle size of the nano-platinum particles is less than 6nm, centered primarily around 3 nm. The proper particle size of the nano platinum particles can expose more active sites, greatly increase the contact probability of the active sites and hydrogen, and improve the catalytic efficiency.

In some embodiments, the silicate-based compound comprises one or more combinations of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate; the silicate ester hydrolysis catalyst comprises one or more of ammonia water, hydrofluoric acid, hydrochloric acid, ammonia water, sulfuric acid and acetic acid.

In some embodiments, the nanosilica particles have a particle size in the range of 50-500 nm. The appropriate particle size of the nanosilica particles enables the material to be roughened, greatly enhancing the hydrophobic effect.

In some embodiments, the aminosilane coupling agent comprises one or more combinations of KH-550, KH-540, and (2-aminoisopropyl) triethoxysilane, and the solvent in the aminosilane coupling agent solution comprises one or more combinations of alcohols, esters, ethers, and aromatic solvents. Preferably, KH-550 may be used as the aminosilane coupling agent, and ethanol may be used as the solvent for KH-550.

In some embodiments, the arylsilane compound comprises a compound of formula (1) and the fluoroalkylsilane compound comprises a compound of formula (2):

wherein R is₁Is phenyl, phenylaminomethyl or phenethyl; r₂One selected from hydrogen, C1-C3 alkyl; r₃One selected from hydrogen, C1-C3 alkyl; and m is 0-11. The appropriate chain length of the fluoroalkyl chain is beneficial to the amphiphobic effect, so that the inactivation effect of water vapor and oil gas on the catalytic active sites is reduced, and the catalytic efficiency is improved. Preferably, R₁Is a benzene ring, R₂Is ethyl, R₃When the parameters are preferably adopted, the raw materials are easy to obtain, the cost is low, the stability is high, the hydrophobicity is good, and the catalytic efficiency is highest.

The embodiment of the invention also provides a double-sparse platinum-containing catalyst material, which comprises a porous substrate containing silicon elements, wherein nano metal platinum, a hydrophobic group and an oleophobic group are attached to the surface of the porous substrate, and the double-sparse platinum-containing catalyst material is prepared by the preparation method of the double-sparse platinum-containing catalyst material in the embodiment.

The embodiment of the invention also provides an application of the double-sparse platinum-containing catalyst material in the embodiment in removing hydrogen isotopes by gas oxidation.

In some embodiments, the method for using the double-hydrophobic platinum-containing catalyst material in the hydrogen isotope removal by gas oxidation comprises the following steps: under the condition of 25-75 ℃, the gas to be treated with the hydrogen isotope gas content of 100-^-1Through a bis-hydrophobic platinum-containing catalyst material.

Example 1

Preparing a double-hydrophobic platinum-containing catalyst material by taking cordierite as a silicon-containing porous substrate material:

(a) acidification (building of the silicon hydroxyl group): the cordierite was divided into a cylindrical shape having a length of 20mm and a diameter of 14mm, and the divided cordierite was immersed in a 20 wt.% nitric acid aqueous solution and heated at 120 ℃ for 2 hours. After 24 hours the cordierite was washed with deionized water to neutrality and then dried overnight in a vacuum oven at 130 c to yield acidified Cordierite (CDH).

(b) Surface roughening: 2.8582g of CDH (2 pieces) were placed in an Erlenmeyer flask, and 234.023mL of absolute ethanol and 25.724mL of H were added in that order₂O、13.211mL NH₃·H₂O and 12.862mL TEOS, the solution gradually changed from colorless to milky white. Stirring for 24h at room temperature, taking out cordierite, washing with absolute ethyl alcohol for 3 times, washing with ultrapure water continuously until the filtrate is neutral, transferring the cordierite into a vacuum drying oven at 80 ℃, and drying for 24h to obtain cordierite CDSi-1 with roughened surface. In addition, according to table 1, the ammonia water ratio can be adjusted and the cordierite (CDSi1-3) modified by nano-silica with different sizes can be synthesized.

TABLE 1 feed ratio for CDSi synthesis

The morphology of CDH and CDSi was observed by Scanning Electron Microscopy (SEM), and the results are shown in fig. 3. FIG. 3(A) is an acidCordierite (CDH), FIG. 3(B) is CDSi-1; FIG. 3(C) is CDSi-2; FIG. 3(D) is a scanning electron micrograph of CDSi-3. As can be seen from FIG. 3, as the volume fraction of ammonia water increases from 4.62% to 15.41%, the particle size of the nano-silica increases from 91nm to 394 nm. The surface of the acidified cordierite CDH is smooth. When tetraethyl orthosilicate is hydrolyzed by ammonia water, nano silicon dioxide grows on the surface of cordierite, and the surface of cordierite becomes rough. With increasing NH₃·H₂The concentration of O and the diameter of the nano-silica are increased from 91nm to 177nm and 394nm (shown in figures 3B-D), the agglomeration of the nano-silica is gradually reduced, the roughness of the surface of cordierite is reduced, and the experimental result shows that NH can be regulated and controlled₃·H₂The concentration of O thereby regulates the roughness of the cordierite surface.

(c) Surface functionalization: 2.8198g CDSi (2 blocks) was placed in an Erlenmeyer flask, 187.987mL absolute ethanol was added, stirring was performed at room temperature for 20min, and 1.503mL KH-550 was added for activation for 1 h. After the activation, 1.503mL of ATPS and 1.503mL of FAS-17 were added, and after stirring at room temperature for 24 hours, the functionalized cordierite was taken out, washed 3 times with absolute ethanol, and then dried in a vacuum oven at 80 ℃ for 24 hours to obtain a hydrophobic and oleophobic substrate material (CDM).

(d) A 1 wt.% chloroplatinic acid-acetone solution was prepared for use. CDM (1.3g,3mL) was placed in a 5mL beaker, and 1.2mL of a 1 wt.% chloroplatinic acid-acetone solution was added dropwise to immerse the CDM. Due to the porous nature of cordierite, the solution is able to enter the carrier. The excess acetone solution can be rapidly volatilized by drying with an infrared baking lamp. Transferring the dried sample to a tube furnace H₂As reducing gas, a temperature-raising program is set for reduction (in the first stage, the temperature is raised from 25 ℃ to 180 ℃ within 30min, in the second stage, the temperature is uniformly raised to 275 ℃ in 6h, and in the third stage, the temperature is kept for 16 h). After reduction is complete, N is used at 200 DEG C₂And blowing the cordierite for 2h to remove water vapor on the surface. Different concentrations of NH₃·H₂O hydrolyzed CDM minus platinum 4g/L, actual minus platinum amount was tested by ICP-OES (see Table 2).

TABLE 2 platinum content of Pt @ CDM

To examine the hydrophobic and oleophobic properties of the catalyst support, the contact angles of the surfaces of CDH and CDM materials in this example were tested with deionized water and n-hexadecane as shown in fig. 4(a) - (D), respectively. FIG. 4(A) is the result of the water contact angle test for CDH, FIG. 4(B) is the result of the n-hexadecane contact angle test for CDH, FIG. 4(C) is the result of the water contact angle test for CDM-1, and FIG. 4(D) is the result of the n-hexadecane contact angle test for CDM-1. Fig. 4(a) - (B) show that the acidified cordierite shows excellent hydrophilicity and lipophilicity (WCA ═ 0 °, OCA ═ 0 °). The functionalized catalyst carrier CDM-1 exhibits excellent hydrophobicity with water contact angles as high as 129.9 ° (fig. 4 (C)). Meanwhile, the surface of the n-hexadecane also has a certain repelling effect, and the contact angle of the n-hexadecane reaches 118.4 degrees, which proves that the n-hexadecane also has excellent oil repellency (figure 4 (D)).

Therefore, the cordierite treatment method provided by the embodiment can effectively enable cordierite to have both water repellency and oil repellency.

The crystal form and the size of Pt @ CDM-1 surface platinum nanoparticles are characterized by a high-resolution transmission electron microscope. As shown in FIG. 5, FIGS. 5(A) - (C) show the TEM, HRTEM and SAED characterization results of Pt @ CDM-1 in sequence. As can be seen from FIG. 5(A), Pt @ CDM-1 has a large number of Pt nanoparticles less than 6nm distributed on the surface. Fig. 5(B) - (C) are HRTEM images and corresponding SAED mode images of platinum nanoparticles on Pt @ CDM-1, respectively, indicating the presence of (111) and (200) facets in the Pt crystals on the surface of the double thinning catalyst material by lattice spacings (d values) of 0.226nm and 0.198 nm.

Example 2

The catalyst material containing the amphiphobic platinum provided in the embodiment 1 of the invention is used for carrying out catalytic oxidation experiments of hydrogen and isotopes thereof:

(a) the test method comprises the following steps:

H₂the effect of the initial concentration on the catalysis was carried out as follows: the catalyst (2 pieces of 3mL solid catalyst, not ground, totaling 6mL catalyst) was placed in the catalytic bed, maintaining the flow rate of the inlet at 900mL/min and the catalytic experiment was carried out at 35 ℃. By regulating MFC₁And MFC₂Obtaining hydrogen gas mixture with different concentrations for two H₂The reading of the detector is stable, the concentration of the air inlet and the air outlet is recorded, and the conversion rate f is calculated.

In an experiment to investigate the effect of different temperatures on catalytic efficiency, a catalyst (2 3mL solid catalyst, 6mL total) was placed in the catalytic bed for catalytic testing, maintaining the inlet H₂The concentration is 1000ppm, the flow rate is 900mL/min, the temperature is adjusted, and when the reading of the detector at the air outlet is stable, the H of the air outlet is recorded₂The conversion f is calculated.

To investigate the effect of different space velocities on the catalytic efficiency, an equal volume of catalyst was placed in a 35 ℃ catalyst bed, keeping the inlet H, as in the above procedure₂The concentration is 1000ppm, and the flow meter MFC is adjusted₃Thereby obtaining the flow rates (300 mL/min-3000 mL/min) of different air inlets, and recording the H of the air outlet when the reading of the air outlet detector is stable₂The conversion f is calculated.

In the formula (1), f represents the conversion, C_inRepresents the inlet hydrogen concentration, C_outRepresenting the outlet hydrogen concentration; in the formula (2), S_vRepresents space velocity, Q represents gas mixture flow, and V represents catalyst volume.

(b) The catalytic performance is as follows:

because the tritium concentration in the third layer of safe containment system is lower, H below 2000ppm is selected in the catalytic experiment₂Concentration catalytic performance study (water vapor concentration C in mixed atmosphere)_H2O<1 ppm). At H₂At a concentration of 200-2000ppm, the conversion of hydrogen gas was always maintained at 100% in the experiment using Pt @ CDM-2 and Pt @ CDM-3 provided in example 1 as catalysts, indicating that the catalytic capabilities of Pt @ CDM-2 and Pt @ CDM-3 are almost the same in the low concentration rangeIs free from H₂Influence of initial concentration. In addition, although the experiment was performed with Pt @ CDM-1 as the catalyst in a hydrogen concentration of 1000ppm, the hydrogen conversion rate was slightly decreased, but still 99.9% (FIG. 6A).

Temperature is an important factor in catalyst activity. As shown in FIG. 6(B), H increases as the temperature increases₂The conversion rate is obviously improved. At 35 ℃, the space velocity is 9000h^-1H with Pt @ CDM-1 as catalyst₂The conversion rate reaches 99.9 percent. H with Pt @ CDM-1 as catalyst when the temperature is raised to 45 deg.C₂The conversion reached 100%. The increase in temperature increases the rate of diffusion of the gas over the catalyst and to some extent reduces the interference of moisture with the catalyst. Therefore, the double-hydrophobic platinum-containing catalyst material provided by the embodiment of the invention has wide temperature adaptability when being applied to a catalyst for removing hydrogen isotopes by gas oxidation.

In practical application scenarios, the gas oxidation dehydrogenation isotopic catalyst is often placed at a high space velocity for catalytic reaction. Therefore, it is a challenge to be able to adapt to high space velocity in practical application of such catalysts. As shown in FIG. 6(C), at 6000h^-1Hereinafter, H of all catalysts₂The conversion rate of (A) reaches 100%. However, when the airspeed is as high as 30000h^-1When the catalyst was used, the conversion rates of the catalysts Pt @ CDM-1, Pt @ CDM-2 and Pt @ CDM-3 were reduced, but still more than 90%. This indicates that the reduction of H formed by the reaction is achieved by virtue of the hydrophobic double surface of the catalyst₂O poisons the catalyst, and the double-hydrophobic platinum-containing catalyst material provided by the embodiment of the invention can realize H poisoning at low space velocity₂Can ensure higher H when facing application scenes with high airspeed₂And (4) conversion rate.

(c) Restart performance of catalyst:

control H₂The concentration is 1000ppm, and the space velocity is 9000h^-1Pt @ CDM-1 was placed in a 35 ℃ catalytic bed and operated continuously for 24 h. After the operation is finished, the catalyst is kept on the catalytic bed, and the catalytic device is closed for 24 hours. After the start-stop step, the equipment is restarted, the catalysis is carried out for 1h according to the catalysis conditions, and then the equipment is stoppedRun for 1h, five cycles. After five cycles the plant was stopped for another 12 h. And then restarting the equipment, carrying out catalytic reaction for 2 hours, stopping the reaction for 2.5 hours, starting the reaction for 2 hours after determining that the catalytic performance has not changed, stopping the reaction for 2 hours, and repeatedly carrying out three start-stop cycles. In each process, the stabilized outlet detector reading is recorded. The restart performance of the catalyst was explored through 83.5h of continuous operation and start-stop. The results of the experiment are shown in FIG. 6D.

The Pt @ CDM-1 catalyst material provided by the embodiment 1 of the invention can still maintain the catalytic performance of 98.2% after continuous operation for 24 hours. After a pause of 24h, the plant was restarted, maintaining the same catalytic conditions, with a conversion increasing from 91.7% to 95.1%. After 9 start-stop cycles, the catalyst still maintains over 90% of catalytic efficiency. With the prolonging of time, the double hydrophobic surfaces repel the water vapor on the surfaces, so that the activity of the nano Pt on the surfaces is maintained, the service life of the catalyst is prolonged to a certain extent, and the double hydrophobic platinum-containing catalyst material provided by the embodiment of the invention has excellent restarting performance.

(d) The catalytic performance of hydrogen and deuterium under simulated atmosphere:

the water vapor concentration of the self-made simulated air is about 700 ppm. 6mL of Pt @ CDM-3 was placed in the catalyst bed and passed through a mass flow meter MFC₁And MFC₂The flow rates of 10% hydrogen-argon mixture and simulated air were controlled to prepare a mixture having a hydrogen (deuterium) concentration of about 1000ppm, which was then passed through a MFC (mass flow controller)₃The flow rate of the inlet of the catalytic bed is controlled, and two hydrogen (deuterium) analyzers record the concentration of hydrogen (deuterium) at the inlet and outlet. The resistance of the catalyst to water vapor interference was evaluated by comparison with the catalytic performance under dry conditions.

At 9000h^-1Next, the conversion of Pt @ CDM-3 was still 100% as the hydrogen concentration increased to 2000ppm, and was not affected by the increase in concentration (FIG. 7A). As the temperature increased, the catalyst was less affected by moisture and was able to maintain conversion at 100% consistently well above the commercial catalyst (fig. 7B). At 15000h^-1In the following simulated air, the initial concentration of about 1000ppm hydrogen is completely converted into water, and the conversion rate is up to100%, which indicates that at low space velocity, 700ppm of water vapor has negligible interference with Pt @ CDM-3. But with the increase of the airspeed, when the airspeed reaches 30000h^-1Although the conversion decreased somewhat, 95.1% was still present, whereas the conversion of the commercial catalyst was only 36.1% at this point (FIG. 7C).

9000h at different deuterium concentrations and different temperatures compared to the conversion of hydrogen in a simulated atmosphere^-1At space velocity, Pt @ CDM-3 consistently exhibited excellent catalytic performance with 100% conversion (FIGS. 7D-E). At 30000h^-1At the space velocity, the commercial catalyst has almost no catalytic capability to deuterium gas, and the conversion rate of Pt @ CDM-3 to deuterium gas is still 93%, which is far better than the commercial catalyst. And below 15000h^-1At space velocity, there was 100% deuterium conversion of Pt @ CDM-3 (FIG. 7F). In fig. 7, the conditions for the respective tests are: fig. 7 (a): c_H2O＝700ppm,T＝35℃，S_V＝9000h^-1(ii) a Fig. 7 (B): c_H2＝1000ppm,C_H2O＝700ppm,S_V＝9000h^-1(ii) a Fig. 7 (C): c_H2＝1000ppm,C_H2O700ppm, 35 ℃ T; fig. 7 (D): c_H2O＝700ppm,T＝35℃，S_V＝9000h^-1(ii) a Fig. 7 (E): c_H2＝1000ppm,C_H2O＝700ppm,S_V＝9000h^-1(ii) a Fig. 7 (F): c_H2＝1000ppm,C_H2O＝700ppm,T＝35℃。

The above results show that the double hydrophobic platinum-containing catalyst material provided by the embodiment of the invention has better catalytic efficiency than the commercial catalyst material in an environment containing water vapor, and the double hydrophobic platinum-containing catalyst material provided by the embodiment of the invention has far better adaptability to hydrogen (and its isotope gas) concentration, temperature and space velocity than the commercial catalyst material in an environment containing water vapor.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.