Pt nanoparticle supported porous SiC catalyst and its application in cinnamaldehyde hydrogenation reaction
By preparing a porous SiC carrier by chemical etching and vacuum rotary evaporation of polycrystalline silicon carbide, combined with the uniform dispersion of Pt nanoparticles, the problem of low selectivity of cinnamyl alcohol in the selective hydrogenation reaction of cinnamaldehyde was solved, and a cinnamaldehyde hydrogenation reaction with high selectivity and high yield was achieved.
Patent Information
- Application Number
- CN202411826937.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-10-10
- Estimated Expiration
- 2044-12-12
AI Technical Summary
In the prior art, the selectivity of cinnamyl alcohol in the selective hydrogenation reaction of cinnamaldehyde is relatively low and is difficult to reach above 90%.
Polycrystalline silicon carbide was chemically etched using a mixed acid formed by hydrofluoric acid and concentrated nitric acid to prepare a porous SiC carrier. Pt nanoparticles were evenly dispersed on the porous SiC carrier through vacuum rotary evaporation and a reducing agent method. The hydrogen overflow intensity on the catalyst surface was regulated to achieve a uniform distribution of Pt nanoparticles.
The selectivity of the cinnamaldehyde hydrogenation reaction and the yield of cinnamyl alcohol were significantly improved, the catalytic activity was more excellent, and high selectivity and high yield of cinnamyl alcohol in the selective hydrogenation reaction of cinnamaldehyde were achieved.
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Figure CN119633863B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of cinnamaldehyde hydrogenation reaction, and in particular to a Pt nanoparticle-loaded porous SiC catalyst and application thereof in cinnamaldehyde hydrogenation reaction. Background Art
[0002] Cinnamyl alcohol is an important chemical raw material and synthetic intermediate, widely used in flavors and fragrances, organic synthesis, and healthcare. Selective hydrogenation of cinnamaldehyde is a green method for synthesizing cinnamyl alcohol and holds great promise for future applications. However, cinnamaldehyde contains both a C=C bond and a C=O bond, which are reducible functional groups. The C=C bond has a lower bond energy than the C=O bond, making selectively controlling the hydrogenation of the C=O bond while preserving the C=C bond a challenging problem.
[0003] Hydrogen spillover is a common phenomenon in important chemical processes such as catalysis and hydrogen storage. It primarily refers to the migration of active hydrogen from the metal to the support after hydrogen dissociates on the metal surface, significantly affecting catalytic performance. Regulating this hydrogen spillover effect can effectively alter the catalytic activity and hydrogenation selectivity of the catalyst itself. For example, Gao Z et al. enhanced hydrogen spillover on the Pt / SBA-15 surface by modifying the support surface with organic matter, thereby effectively improving its catalytic performance in the hydrogenation of cinnamaldehyde (ACS Catal. 2023, 13, 4003-4011).
[0004] SiC is a typical non-oxide semiconductor material with excellent thermal and electrical conductivity, high temperature resistance, and acid-base corrosion resistance, making it a promising catalyst support material. SiC-based metal catalysts are used in various hydrogenation reactions and exhibit significant hydrogen spillover on their surfaces. However, regulating the intensity of hydrogen spillover on SiC-based metal catalyst surfaces is difficult to achieve. Summary of the Invention
[0005] The problem with the prior art is that the selectivity for cinnamyl alcohol in conventional cinnamaldehyde selective hydrogenation reactions is low, and it is difficult to achieve a selectivity of more than 90%. To address the above technical problems, the present invention provides a Pt nanoparticle-loaded porous SiC catalyst, the preparation method of which comprises the following steps:
[0006] (1) chemically etching polycrystalline silicon carbide using a mixed acid formed by hydrofluoric acid and concentrated nitric acid, washing with water, drying, and then calcining in air at 700-1100° C. for at least 3 hours. After the calcination, the calcined product is immersed in hydrofluoric acid to remove silicon dioxide, and finally washed with water until neutral and dried to obtain a porous silicon carbide support;
[0007] (2) adding the porous silicon carbide support and chloroplatinic acid to deionized water, stirring evenly, placing the mixture in a rotary evaporator, and vacuum evaporating the mixture at room temperature for at least 30 minutes. After the evaporation is completed, adding the lysine solution dropwise to the rotary evaporator, stirring the mixture for at least 30 minutes, and then adding the reducing agent aqueous solution and hydrochloric acid dropwise to the rotary evaporator in sequence. After the addition is completed, stirring the mixture for at least 24 hours. After the reaction is completed, filtering the reaction solution, washing it with deionized water at least 3 times, washing it with ethanol aqueous solution at least 3 times, and drying the reaction solution to obtain a porous SiC catalyst.
[0008] The ratio of the porous silicon carbide support to chloroplatinic acid, deionized water, lysine solution, reducing agent aqueous solution, and hydrochloric acid is 290-295 mg:15-17 mg:30 mL:20 mL:10 mL:10 mL;
[0009] The lysine solution is a solution with a concentration of 0.5-0.55 mol / L formed by dissolving lysine in deionized water;
[0010] The reducing agent aqueous solution is a solution having a concentration of 0.3-0.4 mol / L obtained by adding the reducing agent to deionized water;
[0011] The concentration of the hydrochloric acid is 0.25-0.35 mol / L.
[0012] Preferably, the reducing agent is sodium borohydride.
[0013] Preferably, the volume ratio of hydrofluoric acid to nitric acid in the mixed acid is 3:1, the mass concentration of hydrofluoric acid is 40%, and the mass concentration of nitric acid is 65-68%.
[0014] Preferably, the etching temperature in step (1) is in the range of 60-120°C.
[0015] Preferably, the etching time in step (1) is 1-4 hours.
[0016] Preferably, the etching time in step (1) is 3 hours.
[0017] An application of a Pt nanoparticle-loaded porous SiC catalyst comprises the following steps:
[0018] The porous SiC catalyst is placed in a stainless steel autoclave, an alcohol solvent and cinnamaldehyde are added, the autoclave is sealed and purged with hydrogen three times, and then hydrogen is filled into the autoclave to a pressure of 0.4-0.8 MPa. The autoclave is then heated to 30-60°C while being magnetically stirred, and the reaction is carried out with constant stirring for 30-90 minutes. After the reaction is completed, cinnamyl alcohol is obtained after purification.
[0019] Preferably, the alcohol solvent includes at least one of ethanol, isopropanol, methanol and a mixed solvent of ethanol and water.
[0020] Preferably, the alcohol solvent is a mixed solvent formed by ethanol and water.
[0021] Preferably, the volume ratio of ethanol to water in the alcohol solvent is 9-9.5:0.5-1. More preferably, the volume ratio of ethanol to water in the alcohol solvent is 9:1.
[0022] The present invention has the following beneficial effects:
[0023] (1) The present invention etches polycrystalline silicon carbide to obtain a porous structure by an acid etching method, and adopts a vacuum rotary evaporation method to first uniformly disperse Pt ions into the pore structure of polycrystalline silicon carbide, and then uses a reducing agent to in situ reduce the Pt ions in the pore structure of polycrystalline silicon carbide to obtain Pt nanoparticles. This method makes the Pt nanoparticles more and more evenly distributed in the pore structure of polycrystalline silicon carbide, and the catalytic activity of the obtained catalyst is more excellent, which is conducive to further improving the selectivity of the cinnamaldehyde hydrogenation reaction and significantly improving the yield of cinnamyl alcohol;
[0024] (2) The present invention has found that the catalytic activity of the porous SiC catalyst obtained by the present invention is not only related to the uniform dispersion of Pt ions in the pore structure of polycrystalline silicon carbide by the vacuum rotary evaporation method, but is also affected by the acid etching time of polycrystalline silicon carbide. The experimental results show that, for the method of the present invention, when the acid etching time is 3h, the catalytic activity of the porous SiC catalyst obtained is better than that of the porous SiC catalyst obtained with other etching times;
[0025] (3) The present invention utilizes an acid etching method to perform porous modification on polycrystalline SiC, and enhances the hydrogen overflow concentration on the surface of the obtained catalyst Pt / SiC by regulating the Si / C ratio on its surface. The Pt nanoparticles in the pores can preferentially adsorb and activate C=O bonds due to the steric effect, thereby achieving high activity of the obtained catalyst in the cinnamaldehyde hydrogenation reaction and high selectivity for the cinnamyl alcohol product. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 : HRTEM images of the catalyst supports in Example 1 and Comparative Examples 1-2 of the present invention.
[0027] Figure 2 : HRTEM image of Pt / SiC-3 obtained in Example 1 of the present invention.
[0028] Figure 3 : XRD patterns of the catalysts obtained in Example 1 and Comparative Examples 1-3 of the present invention. DETAILED DESCRIPTION
[0029] The application will be described in detail below with reference to the embodiments. However, it should be understood that the following embodiments are only examples of the implementation of the application, and are not intended to limit the scope of the application.
[0030] Example 1
[0031] A Pt nanoparticle loaded porous SiC catalyst is prepared as follows:
[0032] (1) 3g of polycrystalline silicon carbide is chemically etched using a mixed acid formed by 30mL of hydrofluoric acid and concentrated nitric acid. After the etching is completed, water washing, drying, and then calcination in air at 700℃ for 3h are performed. After the calcination is completed, the calcination product is immersed in hydrofluoric acid to remove silicon dioxide. Finally, water washing to neutral and drying are performed to obtain a porous silicon carbide carrier;
[0033] (2) The porous silicon carbide carrier and chloroplatinic acid hexahydrate are added to deionized water, stirred uniformly, and then placed in a rotary evaporator flask. Vacuum rotary evaporation is performed at room temperature for 30min. After the rotary evaporation is completed, lysine solution is added dropwise into the rotary evaporator flask. After the dropwise addition is completed, stirring is performed for 30min. Then, a reducing agent aqueous solution and hydrochloric acid are sequentially added dropwise into the rotary evaporator flask. After the dropwise addition is completed, stirring is performed for 24h. After the reaction is completed, the reaction liquid is sequentially subjected to suction filtration, deionized water washing for 3 times, ethanol aqueous solution washing for 3 times, and drying to obtain a porous SiC catalyst (denoted as Pt / SiC-3), which has a specific surface area of 135m 2 / g and a surface Si / C ratio of 0.997.
[0034] The amount ratio of the porous silicon carbide carrier, chloroplatinic acid hexahydrate, deionized water, lysine solution, reducing agent aqueous solution, and hydrochloric acid is 294mg:3.99mg:30mL:20mL:10mL:10mL;
[0035] The lysine solution is a solution formed by dissolving lysine in deionized water, and has a concentration of 0.53mol / L;
[0036] The reducing agent aqueous solution is a solution formed by adding a reducing agent to deionized water, and has a concentration of 0.35mol / L;
[0037] The concentration of the hydrochloric acid is 0.3mol / L.
[0038] The reducing agent is sodium borohydride.
[0039] The volume ratio of hydrofluoric acid to nitric acid in the mixed acid is 3:1. The mass concentration of the hydrofluoric acid is 40%, and the mass concentration of the nitric acid is 65%.
[0040] The etching temperature in step (1) ranges from 100℃.
[0041] The etching time in step (1) is 3 h.
[0042] 30 mg of Pt / SiC-3 was weighed and placed in a stainless steel autoclave. 9.5 mL of anhydrous ethanol, 0.5 mL of water, and 1 mmol of cinnamaldehyde were added. The autoclave was sealed and purged with hydrogen three times. Then, hydrogen was filled into the autoclave to a pressure of 0.4 MPa. The autoclave was then heated to 40°C while magnetically stirring. The reaction was stirred at this constant temperature for 75 minutes. After the reaction was completed, the conversion rate of cinnamaldehyde was detected to be 98%, and the selectivity of cinnamyl alcohol was 96.7%.
[0043] Comparative Example 1 is the same as Example 1, except that the catalyst preparation method in Comparative Example 1 is as follows:
[0044] Polycrystalline silicon carbide and chloroplatinic acid hexahydrate were added to deionized water, stirred evenly, and placed in a rotary evaporator. Vacuum rotary evaporation was performed at room temperature for 30 minutes. After the rotary evaporation was completed, lysine solution was added dropwise to the rotary evaporator. After the addition was completed, the mixture was stirred for 30 minutes. Then, a reducing agent aqueous solution and hydrochloric acid were added dropwise to the rotary evaporator. After the addition was completed, the mixture was stirred for 24 hours. After the reaction was completed, the reaction solution was filtered, washed with deionized water 3 times, washed with ethanol aqueous solution 3 times, and dried to obtain Pt / SiC-0, which had a specific surface area of 27 m 2 / g, and the surface Si / C ratio is 0.885.
[0045] The ratio of the polycrystalline silicon carbide to chloroplatinic acid hexahydrate, deionized water, lysine solution, reducing agent aqueous solution, and hydrochloric acid is 294 mg:3.99 mg:30 mL:20 mL:10 mL:10 mL;
[0046] The lysine solution is a solution with a concentration of 0.53 mol / L formed by dissolving lysine in deionized water;
[0047] The reducing agent aqueous solution is a solution having a concentration of 0.35 mol / L obtained by adding a reducing agent to deionized water;
[0048] The concentration of the hydrochloric acid is 0.3 mol / L.
[0049] The reducing agent is sodium borohydride.
[0050] The volume ratio of hydrofluoric acid to nitric acid in the mixed acid is 3:1, the mass concentration of hydrofluoric acid is 40%, and the mass concentration of nitric acid is 68%.
[0051] 30 mg of Pt / SiC-0 was weighed and placed in a stainless steel autoclave. 9.5 mL of ethanol, 0.5 mL of water, and 1 mmol of cinnamaldehyde were added. The autoclave was sealed and purged with hydrogen three times. Then, hydrogen was filled into the autoclave to a pressure of 0.4 MPa. The autoclave was then heated to 40°C while magnetically stirring. The reaction was stirred at this constant temperature for 75 minutes. After the reaction was completed, the conversion rate of cinnamaldehyde was detected to be 60.9%, and the selectivity of cinnamyl alcohol was 70.4%.
[0052] Comparative Example 2 is the same as Example 1, except that the etching time in step (1) of Comparative Example 2 is 2 h. The obtained catalyst is recorded as Pt / SiC-2. Its specific surface area is 79 m 2 / g, and the surface Si / C ratio is 0.983.
[0053] 30 mg of Pt / SiC-2 was weighed and placed in a stainless steel autoclave. 9.5 mL of anhydrous ethanol, 0.5 mL of water, and 1 mmol of cinnamaldehyde were added. The autoclave was sealed and purged with hydrogen three times. Hydrogen was then filled into the autoclave to a pressure of 0.4 MPa. The autoclave was then heated to 40°C while magnetically stirring. The reaction was stirred at this constant temperature for 75 minutes. After the reaction was completed, the conversion rate of cinnamaldehyde was detected to be 79.6%, and the selectivity of cinnamyl alcohol was 91%.
[0054] Comparative Example 3 is the same as Example 1, except that the etching time in step (1) of Comparative Example 3 is 4 h. The obtained catalyst is recorded as Pt / SiC-4. Its specific surface area is 27 m 2 / g, and the surface Si / C ratio is 0.968.
[0055] 30 mg of Pt / SiC-2 was weighed and placed in a stainless steel autoclave. 9.5 mL of anhydrous ethanol, 0.5 mL of water, and 1 mmol of cinnamaldehyde were added. The autoclave was sealed and purged with hydrogen three times. Then, hydrogen was filled into the autoclave to a pressure of 0.4 MPa. The autoclave was then heated to 40°C while magnetically stirring. The reaction was stirred at this constant temperature for 75 minutes. After the reaction was completed, the conversion rate of cinnamaldehyde was detected to be 85.9%, and the selectivity of cinnamyl alcohol was 94.8%.
[0056] The data obtained from the tests of Example 1 and Comparative Examples 1-3 are shown in Table 1.
[0057] Table 1
[0058]
[0059] Table 1 shows that the acid etching time significantly affects the catalyst's performance. With increasing etching time, the catalyst's specific surface area gradually increases, further facilitating the uniform dispersion and anchoring of Pt nanoparticles. Simultaneously, the Si / C ratio also changes. A higher Si atomic ratio enhances the catalyst's hydrogen overflow capacity and significantly improves its catalytic activity. When the etching time is 3 hours, the Pt / SiC-3 prepared exhibits optimal performance in the hydrogenation of cinnamaldehyde to cinnamyl alcohol.
[0060] The Pt / SiC-3 obtained in Example 1 was used as a catalyst in the cinnamaldehyde hydrogenation reaction to investigate the catalytic activity of Pt / SiC-3 in different alcohol solvents for 1 h. The test results are shown in Table 2.
[0061] Comparative Example 4 was the same as Example 1, except that the alcohol solvent in Comparative Example 4 was anhydrous ethanol. The cinnamaldehyde hydrogenation reaction was carried out for 1 hour. After the reaction, the conversion rate of cinnamaldehyde was detected to be 59.2%, and the selectivity of cinnamyl alcohol was 88.9%.
[0062] Comparative Example 5 was the same as Example 1, except that the alcohol solvent in Comparative Example 5 was isopropyl alcohol. The cinnamaldehyde hydrogenation reaction was carried out for 1 hour. After the reaction, the conversion rate of cinnamaldehyde was detected to be 29.2%, and the selectivity of cinnamyl alcohol was 81.6%.
[0063] Comparative Example 6 was the same as Example 1, except that the alcohol solvent in Comparative Example 6 was methanol. The cinnamaldehyde hydrogenation reaction was carried out for 1 hour. After the reaction, the conversion rate of cinnamaldehyde was detected to be 32.3%, and the selectivity of cinnamyl alcohol was 86%.
[0064] Comparative Example 7 was the same as Example 1, except that the alcohol solvent in Comparative Example 7 was methanol. The cinnamaldehyde hydrogenation reaction was carried out for 1 hour. After the reaction, the conversion rate of cinnamaldehyde was detected to be 32.3%, and the selectivity of cinnamyl alcohol was 86%.
[0065] Comparative Example 8 was the same as Example 1, except that the alcohol solvent in Comparative Example 8 was a mixed solution of anhydrous ethanol and water in a volume ratio of 9.5:0.5. The cinnamaldehyde hydrogenation reaction was carried out for 1 hour. After completion of the reaction, the conversion of cinnamaldehyde was detected to be 79.0%, and the selectivity of cinnamyl alcohol was 94.8%.
[0066] Comparative Example 9 was the same as Example 1, except that the alcohol solvent in Comparative Example 9 was a mixed solution of anhydrous ethanol and water in a volume ratio of 9:1. The cinnamaldehyde hydrogenation reaction was carried out for 1 hour. After completion of the reaction, the conversion rate of cinnamaldehyde was detected to be 83.7%, and the selectivity of cinnamyl alcohol was 91.7%.
[0067] Table 2
[0068]
[0069] It can be seen from Table 2 that the addition of a small amount of H2O is beneficial to the selective hydrogenation of cinnamaldehyde molecules, which can promote the hydrogen overflow effect and thus enhance the catalytic hydrogenation activity, but excessive water will lead to a decrease in the selectivity of cinnamyl alcohol.
[0070] The Pt / SiC-3 obtained in Example 1 was used as a catalyst in the cinnamaldehyde hydrogenation reaction to investigate the catalytic activity of Pt / SiC-3 in the cinnamaldehyde hydrogenation reaction at different hydrogenation pressures for 1 h. The test results are shown in Table 3.
[0071] Comparative Example 10 is the same as Example 1, except that the hydrogenation pressure in Comparative Example 10 is 0.4 MPa. The cinnamaldehyde hydrogenation reaction is carried out for 1 hour. After the reaction is completed, the conversion rate of cinnamaldehyde is detected to be 79%, and the selectivity of cinnamyl alcohol is 94.8%.
[0072] Comparative Example 11 is the same as Example 1, except that the hydrogenation pressure in Comparative Example 11 is 0.6 MPa. After the cinnamaldehyde hydrogenation reaction is completed for 1 hour, the conversion rate of cinnamaldehyde is detected to be 89.8%, and the selectivity of cinnamyl alcohol is 90.2%.
[0073] Comparative Example 12 is the same as Example 1, except that the hydrogenation pressure in Comparative Example 12 is 0.8 MPa. The cinnamaldehyde hydrogenation reaction is carried out for 1 hour. After the reaction is completed, the conversion rate of cinnamaldehyde is detected to be 95.2%, and the selectivity of cinnamyl alcohol is 89.8%.
[0074] Table 3
[0075] Hydrogen filling pressure (MPa) Conversion rate (%) Selectivity (%) 0.4 79 94.8 0.6 89.8 90.2 0.8 95.2 89.8
[0076] It can be seen from Table 3 that, under the same catalyst conditions, as the hydrogen pressure increases, the conversion rate of cinnamaldehyde gradually increases, but the selectivity for cinnamyl alcohol product decreases. Therefore, the optimal reaction pressure is 0.4 MPa.
[0077] Comparative Example 13 is the same as Example 1, except that the method of step (2) of Comparative Example 13 is as follows:
[0078] A porous silicon carbide support and chloroplatinic acid hexahydrate were added to deionized water, stirred evenly, and then lysine solution was added dropwise. After the addition was completed, the mixture was stirred for 30 minutes. Then, a reducing agent aqueous solution and hydrochloric acid were added dropwise to the reaction system in sequence. After the addition was completed, the mixture was stirred for 24 hours. After the reaction was completed, the reaction liquid was filtered, washed with deionized water 3 times, washed with ethanol aqueous solution 3 times, and dried to obtain a porous SiC catalyst.
[0079] 30 mg of porous SiC catalyst was weighed and placed in a stainless steel autoclave, 9.5 mL of anhydrous ethanol, 0.5 mL of water, and 1 mmol of cinnamaldehyde were added, the autoclave was sealed and purged with hydrogen three times, and then hydrogen was filled into the autoclave to a pressure of 0.4 MPa. Then, the temperature of the autoclave was heated to 40°C while magnetically stirring, and the reaction was stirred at a constant temperature for 75 minutes. After the reaction, the conversion rate of cinnamaldehyde was detected to be 96.9%, and the selectivity of cinnamyl alcohol was 80.7%.
[0080] The microscopic morphology of the catalyst supports in Example 1 and Comparative Examples 1-2 was studied using a high-resolution electron microscope (HRTEM). Figure 1 As shown in Figure 1, Figure a shows the morphology before etching, Figure b shows the morphology after etching for 2 hours, and Figure c shows the morphology after etching for 3 hours. As can be seen from the figure, with the increase of etching time, the pores on the SiC surface gradually increase, showing a clear porous structure.
[0081] HRTEM of Pt / SiC-3 is as shown in the attached instruction manual. Figure 2 As shown in the figure, it can be seen that Pt nanoparticles are uniformly dispersed on the porous SiC, with an average particle size of about 4 nm.
[0082] The XRD patterns of the catalysts obtained in Example 1 and Comparative Examples 1-3 are shown in the attached specification. Figure 3 As shown in the figure, the diffraction peaks at 35.6°, 41.4°, 60.0°, 71.8° and 75.5° correspond to the (111), (200), (220), (311) and (222) crystal planes of β-SiC, respectively. No obvious diffraction peak of Pt is seen, which may be because the Pt particles are small in size and evenly distributed.
[0083] With the above-described preferred embodiments of the present invention as inspiration, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.
Claims
1. A Pt nanoparticle-supported porous SiC catalyst, characterized in that: The preparation method comprises the following steps: (1) Chemically etching polycrystalline silicon carbide with a mixed acid formed by hydrofluoric acid and concentrated nitric acid. After etching, the polycrystalline silicon carbide is washed with water, dried, and then calcined in air at 700-1100°C for at least 3 hours. After calcination, the calcined product is immersed in hydrofluoric acid to remove silicon dioxide, and finally washed with water until neutral and dried to obtain a porous silicon carbide carrier; (2) The porous silicon carbide carrier and chloroplatinic acid were added to deionized water, stirred evenly, and placed in a rotary evaporator, and vacuum-evaporated at room temperature for at least 30 minutes. After the rotary evaporation was completed, lysine solution was added dropwise to the rotary evaporator. After the addition was completed, the mixture was stirred for at least 30 minutes. Then, a reducing agent aqueous solution and hydrochloric acid were added dropwise to the rotary evaporator in sequence. After the addition was completed, the mixture was stirred for at least 24 hours. After the reaction was completed, the reaction solution was filtered, washed with deionized water at least 3 times, washed with ethanol aqueous solution at least 3 times, and dried to obtain a porous SiC catalyst. The ratio of the porous silicon carbide support to chloroplatinic acid, deionized water, lysine solution, reducing agent aqueous solution, and hydrochloric acid is 290-295 mg:15-17 mg:30 mL:20 mL:10 mL:10 mL; The lysine solution is a solution with a concentration of 0.5-0.55 mol / L formed by dissolving lysine in deionized water; The reducing agent aqueous solution is a solution having a concentration of 0.3-0.4 mol / L obtained by adding the reducing agent to deionized water; The concentration of the hydrochloric acid is 0.25-0.35 mol / L; The volume ratio of hydrofluoric acid to nitric acid in the mixed acid is 3:1, the mass concentration of hydrofluoric acid is 40%, and the mass concentration of nitric acid is 65-68%; The etching temperature in step (1) is in the range of 60-120°C; The etching time in step (1) is 1-4 hours.
2. The Pt nanoparticle-supported porous SiC catalyst according to claim 1, characterized in that: The reducing agent is sodium borohydride.
3. The Pt nanoparticle-supported porous SiC catalyst according to claim 1, characterized in that: The etching time in step (1) is 3 h.
4. An application of a Pt nanoparticle-supported porous SiC catalyst, characterized in that: The following steps are involved: The porous SiC catalyst obtained according to any one of claims 1 to 3 is weighed and placed in a stainless steel high-pressure reactor, an alcohol solvent and cinnamaldehyde are added, the high-pressure reactor is sealed and purged with hydrogen three times, hydrogen is filled into the reactor to a pressure of 0.4-0.8 MPa, and then the temperature of the reactor is heated to 30-60° C. while magnetically stirring, and the reaction is carried out by constant temperature stirring for 30-90 minutes. After the reaction is completed, cinnamyl alcohol is obtained after purification; the alcohol solvent is a mixed solvent formed by ethanol and water.
5. The use of a Pt nanoparticle-supported porous SiC catalyst according to claim 4, characterized in that: The volume ratio of ethanol to water in the alcohol solvent is 9-9.5:0.5-1.