Preparation of Pt-based intermetallic compound and application of Pt-based intermetallic compound in conversion of high-value chemicals from straw derivatives

Abstract

The invention belongs to the technical field of biomass resource conversion, and discloses preparation of a Pt-based intermetallic compound and application of the Pt-based intermetallic compound in conversion of straw derivatives into high-value chemicals. The supported Pt-Sb intermetallic compound catalyst with controllable components is designed and prepared by adopting a co-impregnation method aiming at the problems of more byproducts and low selectivity of the existing catalyst in unsaturated aldehyde hydrogenation. The geometric and electronic structures of the Pt active center are modulated by Sb, so that Pt has an electron-rich characteristic, and the catalytic performance is remarkably improved. Under a mild condition, an ethanol-water mixed solvent is taken as a solvent, and the conversion rate of 99% of cinnamyl aldehyde and the selectivity of 91% of cinnamyl alcohol are realized by preferably selecting the catalyst Pt3Sb2 / C, which are far better than those of the traditional Pt / C catalyst. Meanwhile, the catalyst has excellent cycle stability, the reaction process is environment-friendly, and the raw material utilization rate is high. The method provided by the invention provides an efficient catalysis technical support for high-value utilization of straw resources and synthesis of green bio-based chemicals, and has a relatively good industrial application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass resource conversion, and relates to the preparation of a Pt-based intermetallic compound and its application in the conversion of straw derivatives into high-value chemicals. Background Art

[0002] Using biomass to produce bioenergy can reduce fossil fuel consumption and carbon emissions that contribute to global climate change. The main component of agricultural straw is lignocellulose (content reaches 60-80%). Its three major components—cellulose, hemicellulose, and lignin—can be depolymerized into platform compounds (such as furfural, 5-hydroxymethylfurfural, cinnamaldehyde, vanillin, citral, etc.) through thermochemical or biological methods, and then synthesized into high-value-added chemicals. Cinnamaldehyde (hereinafter referred to as CAL), as a lignin depolymerization product, can be extracted from p-coumaryl alcohol / coniferyl alcohol derived from straw lignin through the phenylpropane pathway. Its hydrogenation product, cinnamyl alcohol (hereinafter referred to as COL), is a core raw material for precious spices, medicines, and functional polymer monomers. The global annual demand exceeds 100,000 tons, with a market value of US$5 billion. As an important phenolic compound derived from nature, the research value of vanillyl alcohol lies in its multiple application potentials: it is a highly effective natural antioxidant that can significantly improve the preservation ability of food; it has potential anti-inflammatory and neuroprotective biological activities, providing direction for the development of health products; in the field of daily chemicals, it can be used as a cosmetic active ingredient and drug transdermal penetration enhancer; at the same time, it is a key intermediate in the synthesis of high-end flavors (such as ethyl vanillin) in the spice industry, and serves as a model compound for lignin biodegradation. These biomass-derived unsaturated aldehydes have great application and research value. The development of efficient and green unsaturated aldehyde hydrogenation technology is of great significance to increasing the added value of agricultural straw and extending the biomass industry chain. For the selective hydrogenation reaction of CAL, industrially used catalysts often face problems such as a large number of by-products, difficulty in product separation, and low yield of the target product during the hydrogenation of unsaturated aldehydes.

[0003] Chinese patent CN112410764A reports a method for preparing cinnamyl alcohol by selective hydrogenation of CAL using a nickel foam-supported cobalt phosphide nanosheet catalyst (CoP / NF), achieving a high conversion of cinnamaldehyde of 98.2% and a cinnamyl alcohol selectivity of 61.3%. However, its low selectivity, high by-product count, and poor biomass tolerance limit its application. Chinese patent CN114377712A reports a method for continuously hydrogenating cinnamaldehyde to cinnamyl alcohol in a tubular reactor, using a Pt-Sn / Al2O3 catalyst loaded in a fixed bed. At 80°C, 2.0 MPa H2, and a liquid phase space velocity of 0.8 h-1, a cinnamyl alcohol yield of 78% was achieved. However, there are disadvantages such as catalyst pulverization, poor cyclic stability, and weak raw material adaptability. Chinese patent CN115337945A proposes a Pt1-Fe1 / NC diatomic catalyst (Pt loading 0.2wt.%), which achieves a COL selectivity of 95.3% and a conversion rate of 99% at 70°C and 1.0MPaH2. Although this solution has a good catalytic effect, it has the problems of complex and difficult catalyst preparation scheme, low universality, poor hydrothermal stability, and weak sulfur resistance. Chinese patent CN115445713A reports a method of using Ru / MIL-101(Cr) catalyst in a supercritical CO2 medium to convert cinnamaldehyde into hydrocinnamic acid in one step (yield 88%), although it circumvents the problem of COL separation. However, the main product is hydrocinnamic acid (HCAL) of relatively low value, and the reaction conditions are relatively harsh.

[0004] Although single-atom (Pt, Ru) catalysts have high activity, they struggle to achieve high selectivity for unsaturated alcohols. Therefore, designing and optimizing catalysts to improve selectivity for unsaturated alcohols has become a current research hotspot. In summary, the development and research of a catalyst with simple preparation methods, high catalyst stability, mild reaction conditions, low cost, high catalyst atom utilization, and high selectivity for unsaturated alcohols has great research value and promising industrial application prospects. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems of the difficulty in catalytically converting biomass derivatives into high-value chemicals and the difficulty in preparing unstable catalysts mentioned above. A preparation method and hydrogenation application of a highly dispersed Pt-based intermetallic compound catalyst supported on carbon black is proposed, which uses a second metal Sb to regulate the electronic state and geometric structure of the active sites of Pt.

[0006] The technical solution of the present invention:

[0007] A method for preparing a Pt-based intermetallic compound comprises the following steps:

[0008] (1) First, the carbon black is pretreated and calcined at 300℃~400℃ for 2~3h to remove some impurities and moisture.

[0009] (2) According to the mass ratio determined by the metal phase diagram, weigh chloroplatinic acid hexahydrate and antimony chloride and dissolve them in anhydrous ethanol, stir to mix them thoroughly, add carbon black, and continue stirring for more than 20 hours to ensure that the metal is completely impregnated in the carbon black.

[0010] (3) After being evaporated and dried by a rotary evaporator, the product was placed in a vacuum oven and dried overnight. After being ground, the product was placed in a tube furnace and calcined at 400°C to 600°C in an atmosphere of Ar and H2 with a volume ratio of 4:1 to obtain a Pt-based intermetallic compound.

[0011] The Pt-based intermetallic compounds prepared by the impregnation method are Pt3Sb2 / C, PtSb / C, and PtSb2 / C intermetallic compound catalysts with a metal Pt loading of 1 wt.% prepared by adjusting the ratio of Pt to Sb according to the Pt-Sb metal phase diagram.

[0012] The invention discloses an application of a Pt-based intermetallic compound as a catalyst in the conversion of straw derivatives into high-value chemicals. The method comprises the following steps: using an autoclave reactor, taking unsaturated aldehydes (such as cinnamaldehyde, furfural, 5-hydroxymethylfurfural, vanillin, and citral) as raw materials, and catalyzing the selective hydrogenation of unsaturated aldehydes (such as cinnamaldehyde, furfural, 5-hydroxymethylfurfural, vanillin, and citral) to produce unsaturated alcohols in a solvent and hydrogen atmosphere using the Pt-based intermetallic compound as a catalyst, at a reaction temperature of 40 to 60° C., a reaction pressure of 1 to 3 MPa, and a reaction time of 1 to 5 hours.

[0013] The solvent is ethanol, isopropanol, ethanol+10% volume fraction of H2O, and isopropanol+10% volume fraction of H2O.

[0014] The mass ratio of the Pt-based intermetallic compound to the unsaturated aldehyde is 0.125-0.25, and the mass concentration of the unsaturated aldehyde solution in the reaction system is 0.8-2 wt.%.

[0015] Beneficial effects of the present invention:

[0016] (1) The present invention uses low-value renewable biomass derivatives of unsaturated aldehydes (cinnamaldehyde, furfural, 5-hydroxymethylfurfural, vanillin, citral, etc.) to produce high-value chemical unsaturated alcohols. The raw material source is abundant and the cost is low.

[0017] (2) The present invention uses a mild co-impregnation method to prepare the catalyst. The conditions are mild and the catalyst preparation process is simple and controllable. By controlling the input ratio of the metal pre-salt and the calcination temperature, catalysts with different geometric structures can be formed. Unlike the face-centered cubic Pt, the addition of Sb forms orthorhombic Pt3Sb2 / C, hexagonal PtSb / C, and cubic PtSb2 / C. The prepared catalyst has high stability.

[0018] (3) The present invention is a noble metal Pt-based intermetallic compound that uses a secondary metal, Sb, to regulate the Pt geometry and electron center. Sb, acting as an electron donor, effectively modulates the electronic state of Pt, resulting in an electron-rich catalyst. The prepared catalyst exhibits high dispersibility, and the addition of metallic Sb significantly reduces catalyst cost.

[0019] (4) The catalyst of the present invention can be prepared under mild conditions, with a simple method and high universal applicability. It effectively reduces catalyst costs, has good catalyst recycling performance, and exhibits excellent corrosion resistance. It can efficiently catalyze the conversion of unsaturated aldehydes into high-value-added chemicals, unsaturated alcohols, under mild conditions, and can be used in large-scale industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The Pt3Sb2 / C catalyst with a different crystal structure - hexagonal system - was prepared using a mild impregnation method.

[0021] Figure 2 This is the reaction data diagram of different catalysts catalyzing the selective hydrogenation of cinnamaldehyde to produce cinnamyl alcohol within the same reaction time (4h). DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0023] Cinnamaldehyde was used as the raw material, and ethanol plus 10% by volume water was used as the solvent. Pt3Sb2 / C, PtSb / C, and PtSb2 / C intermetallic compound nanocatalysts were used as hydrogenation catalysts. Pt / C and Sb / C were used as comparison catalysts. Cinnamaldehyde was selectively catalyzed and hydrogenated to produce cinnamyl alcohol in an autoclave reactor at a reaction temperature of 40-60°C, a reaction pressure of 1-2 MPa, and a reaction time of 1-4 hours.

[0024] Example 1: Preparation of 1 wt.% Pt3Sb2 / C Catalyst

[0025] 0.0777g of H2PtCl6·6H2O and 0.0228g of SbCl3 metal precursor salt were dissolved and dispersed in 80mL of anhydrous ethanol and stirred for 1 hour to thoroughly mix. 2.9265g of carbon black (the theoretical Pt metal loading was 1 wt.%) was weighed and stirred for 20 hours to uniformly disperse the metal on the carbon black support. The ethanol solvent was evaporated on a rotary evaporator and then dried in an 80°C vacuum oven for 16 hours. After grinding, the mixture was placed in a tube furnace and calcined at 400°C for 3 hours in an Ar / H2 = 4:1 atmosphere. This yielded the catalyst. Before each reaction, the catalyst was pre-reduced in a tube furnace at 400°C for 2 hours under a pure hydrogen atmosphere and then passivated overnight with pure argon.

[0026] Example 2: Preparation of 1 wt.% PtSb / C Catalyst

[0027] 0.1036g of H2PtCl6·6H2O and 0.0456g of SbCl3 metal precursor salts were dissolved and dispersed in 80mL of anhydrous ethanol and stirred for 1 hour to thoroughly mix. 3.9020g of carbon black (the theoretical Pt metal loading was 1 wt%) was weighed and stirred for 20 hours to evenly disperse the metal on the carbon black support. The ethanol solvent was evaporated on a rotary evaporator and dried in a vacuum oven at 80°C for 16 hours. After grinding, the mixture was placed in a tube furnace and calcined at 400°C for 3 hours in an Ar / H2 atmosphere of 4:1. This yielded the catalyst. Before each reaction, the catalyst was pre-reduced in a tube furnace at 400°C for 2 hours under a pure hydrogen atmosphere and then passivated overnight with pure argon.

[0028] Example 3: Preparation of 1 wt.% PtSb2 / C Catalyst

[0029] 0.0.0531g of H2PtCl6·6H2O and 0.1033g of SbCl3 metal precursor salt were dissolved and dispersed in 80mL of anhydrous ethanol and stirred for 1 hour to thoroughly mix. 1.9800g of carbon black (the theoretical Pt metal loading was 1 wt%) was weighed and stirred for 20 hours to evenly disperse the metal on the carbon black support. The ethanol solvent was evaporated on a rotary evaporator and dried in a vacuum oven at 80°C for 16 hours. After grinding, the mixture was placed in a tube furnace and calcined at 400°C for 3 hours in an Ar / H2 = 4:1 atmosphere. This yielded the catalyst. Before each reaction, the catalyst was pre-reduced in a tube furnace at 400°C for 2 hours under a pure hydrogen atmosphere and then passivated overnight with pure argon.

[0030] Comparative Example 1: Preparation of 1 wt.% Pt / C catalyst

[0031] 0.0754g of the metal precursor salt H2PtCl6·6H2O was dissolved and dispersed in 50mL of anhydrous ethanol, stirred for 1 hour to thoroughly mix. 2.8136g of carbon black (the theoretical Pt metal loading was 1 wt%) was weighed and stirred for 20 hours to uniformly disperse the metal on the carbon black support. The ethanol solvent was evaporated on a rotary evaporator and then dried in an 80°C vacuum oven for 16 hours. After grinding, the mixture was placed in a tube furnace and calcined at 400°C for 3 hours in an Ar / H2 atmosphere of 4:1. This yielded the catalyst. Before each reaction, the catalyst was pre-reduced in a tube furnace at 400°C for 2 hours under a pure hydrogen atmosphere and then passivated overnight with pure argon.

[0032] Comparative Example 2: Preparation of 1 wt.% Sb / C Catalyst

[0033] 0.02281g of SbCl3 metal precursor salt was dissolved in 50mL of anhydrous ethanol and stirred for 1 hour to thoroughly mix. 1.2810g of carbon black (the theoretical Sb metal loading was 1 wt%) was weighed and stirred for 20 hours to evenly disperse the mixture on the carbon black support. The ethanol solvent was evaporated on a rotary evaporator and dried in an 80°C vacuum oven for 16 hours. After grinding, the mixture was placed in a tube furnace and calcined at 400°C for 3 hours in an Ar / H2 atmosphere of 4:1. This yielded the catalyst. Before each reaction, the catalyst was pre-reduced in a tube furnace at 400°C for 2 hours under a pure hydrogen atmosphere and then passivated overnight with pure argon.

[0034] Application Example 1: Selective Hydrogenation of Cinnamaldehyde over Pt3Sb2 / C Catalyst

[0035] 0.1 g of the Pt3Sb2 / C catalyst (metal loading of 1 wt.%) prepared in Example 1 was weighed and pre-reduced in a tubular furnace. The catalyst was then sealed with a solvent before removal to prevent oxidation of the catalyst by contact with oxygen. A hydrogenation experiment was conducted in an autoclave reactor. The reaction mixture contained 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, and 0.4 g of the internal standard n-octane. The reaction was carried out at a hydrogen pressure of 2 MPa, a reaction temperature of 50° C., and a reaction time of 4 h. The reaction mixture was cooled to room temperature and the catalyst was separated. Gas chromatographic analysis revealed a cinnamaldehyde (CAL) conversion of 99% and a cinnamyl alcohol (COL) selectivity of 91%.

[0036] The performance of the catalysts prepared in Examples 1-3 and Comparative Examples 1-2 was evaluated. The experimental protocol was identical to that of Application Example 1, except for the catalyst. The reaction mixture consisted of 0.1 g of catalyst, 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane, 2 MPa of hydrogen pressure, 50°C, and 4 h of reaction time. Specific experimental parameters and reaction yields are shown in Table 1.

[0037] Table 1 Effect of different catalyst compositions on catalytic activity

[0038]

[0039] Note: The overall mass of the reaction is conserved.

[0040] Application Example 4

[0041] 0.1 g of the Pt3Sb2 / C catalyst (metal loading of 1 wt.%) prepared in Example 1 was weighed and pre-reduced in a tubular furnace. The catalyst was then sealed with a solvent before removal to prevent oxidation of the catalyst by contact with oxygen. A hydrogenation experiment was conducted in an autoclave reactor. The reaction mixture contained 0.4 g of the substrate molecule cinnamaldehyde, 60 mL of cyclohexane, and 0.4 g of the internal standard n-octane. The reaction was carried out at a hydrogen pressure of 2 MPa, a reaction temperature of 50°C, and a reaction time of 4 h. The reaction mixture was cooled to room temperature and the catalyst was separated. Gas chromatographic analysis revealed that the conversion of cinnamaldehyde (CAL) was 34% and the selectivity of cinnamyl alcohol (COL) was 56%.

[0042] Application Examples 5-10

[0043] The performance of the Pt3Sb2 / C catalyst prepared in Example 1 was evaluated in different solvents. A batch reactor was used, and the experimental protocol was identical to that of Application Example 4, except for the different solvents. The experimental conditions were 0.1 g of catalyst, 0.4 g of the substrate molecule cinnamaldehyde, 60 mL of different solvents, 0.4 g of the internal standard n-octane, 2 MPa of hydrogen pressure, 50°C, and 4 h. Specific experimental parameters and reaction yields are shown in Table 2.

[0044] Table 2 Effect of different reaction solvents on catalytic activity

[0045]

[0046] Note: The overall reaction material conservation. Others are some high molecular weight substances, such as cinnamyl alcohol ester

[0047] Application Example 11

[0048] 0.1 g of the Pt3Sb2 / C catalyst (metal loading of 1 wt.%) prepared in Example 1 was weighed and pre-reduced in a tubular furnace. The catalyst was then sealed with a solvent before removal to prevent oxidation of the catalyst by contact with oxygen. A hydrogenation experiment was conducted in an autoclave reactor. The reaction mixture contained 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, and 0.4 g of the internal standard n-octane. The reaction was carried out at a hydrogen pressure of 2 MPa, a reaction temperature of 50° C., and a reaction time of 1 h. The reaction was cooled to room temperature, the catalyst was separated, and gas chromatographic analysis revealed a cinnamaldehyde (CAL) conversion of 43% and a cinnamyl alcohol (COL) selectivity of 82%.

[0049] Application Examples 12-15

[0050] The performance of the Pt3Sb2 / C catalyst prepared in Example 1 was evaluated for different reaction times. A batch reactor was used, and the experimental protocol was identical to that of Application Example 11, except for the reaction time. The reaction mixture consisted of 0.1 g of catalyst, 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane, 2 MPa of hydrogen pressure, 50°C of reaction temperature, and 2-5 h of reaction time. Specific experimental parameters and reaction yields are shown in Table 3.

[0051] Table 3 Effect of different reaction times on catalytic activity

[0052]

[0053] Note: The overall mass of the reaction is conserved.

[0054] Application Example 16

[0055] 0.1 g of the Pt3Sb2 / C catalyst (metal loading of 1 wt.%) prepared in Example 1 was weighed and pre-reduced in a tube furnace. Before removing the catalyst, it was sealed with a solvent to prevent the catalyst from being oxidized by oxygen. A hydrogenation experiment was carried out in an autoclave reactor. 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane were weighed, the hydrogen pressure was 1 MPa, the reaction temperature was 50°C, the reaction time was 4 h, and the reaction was cooled to room temperature. The catalyst was separated and analyzed by gas chromatography. The conversion rate of cinnamaldehyde (CAL) was 81%, and the selectivity of cinnamyl alcohol (COL) was 91%.

[0056] Application Examples 17-20

[0057] The performance of the Pt3Sb2 / C catalyst prepared in Example 1 was evaluated at different hydrogen pressures. A batch reactor was used, and the experimental protocol was identical to that of Application Example 16, except for the different hydrogen pressures. The experimental composition consisted of 0.1 g of catalyst, 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane, and a hydrogen pressure of 1.5-3 MPa, a reaction temperature of 50°C, and a reaction time of 4 h. Specific experimental parameters and reaction yields are shown in Table 4.

[0058] Table 4 Effect of different hydrogen pressures on catalytic activity

[0059]

[0060] Note: The overall mass of the reaction is conserved.

[0061] Application Example 21

[0062] 0.1 g of the Pt3Sb2 / C catalyst (metal loading of 1 wt.%) prepared in Example 1 was weighed and pre-reduced in a tube furnace. Before removing the catalyst, it was sealed with a solvent to prevent the catalyst from being oxidized by oxygen. A hydrogenation experiment was carried out in an autoclave reactor. 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane were weighed, the hydrogen pressure was 2 MPa, the reaction temperature was 40°C, the reaction time was 4 h, and the reaction was cooled to room temperature. The catalyst was separated and analyzed by gas chromatography. The conversion rate of cinnamaldehyde (CAL) was 71%, and the selectivity of cinnamyl alcohol (COL) was 93%.

[0063] Application Examples 22-25

[0064] The performance of the Pt3Sb2 / C catalyst prepared in Example 1 was evaluated at different reaction temperatures. A batch reactor was used, and the experimental protocol was identical to that of Application Example 21, except for the different temperatures. The reaction mixture consisted of 0.1 g of catalyst, 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane, a hydrogen pressure of 2 MPa, a reaction temperature of 45-70°C, and a reaction time of 4 h. Specific experimental parameters and reaction yields are shown in Table 5.

[0065] Table 5 Effect of different reaction temperatures on catalytic activity

[0066]

[0067] Note: The overall mass of the reaction is conserved.

[0068] Application Example 26

[0069] 0.1 g of the Pt3Sb2 / C catalyst (metal loading of 1 wt.%) prepared in Example 1 was weighed and pre-reduced in a tube furnace. Before removing the catalyst, it was sealed with a solvent to prevent the catalyst from being oxidized by oxygen. A hydrogenation experiment was carried out in an autoclave reactor. 0.4 g of the substrate molecule cinnamaldehyde, 57 mL of ethanol + 3 mL of water, 0.4 g of the internal standard n-octane were weighed, the hydrogen pressure was 2 MPa, the reaction temperature was 50°C, the reaction time was 4 h, and the reaction was cooled to room temperature. The catalyst was separated and analyzed by gas chromatography. The conversion rate of cinnamaldehyde (CAL) was 99%, and the selectivity of cinnamyl alcohol (COL) was 91%.

[0070] Application Examples 27-30

[0071] The Pt3Sb2 / C catalyst prepared in Example 1 was evaluated for its performance with different unsaturated aldehyde substrates. A batch reactor was used, and the experimental protocol was identical to that of Application Example 26, except for the different substrates. The reaction mixture consisted of 0.1 g of catalyst, 0.4 g of substrate molecules (furfural, citral, crotonaldehyde, vanillin), 57 mL of ethanol + 3 mL of water, 0.4 g of n-octane as the internal standard, a hydrogen pressure of 2 MPa, a reaction temperature of 50°C, and a reaction time of 4 h. Specific experimental parameters and reaction yields are shown in Table 6.

[0072] Table 6 Catalyst hydrogenation performance for different substrate molecules

[0073]

[0074] Note: The overall mass of the reaction is conserved.

[0075] Based on all the above reaction data, we used the secondary metal Sb to effectively control the electronic state and geometric structure of the Pt active site, resulting in a series of supported Pt-Sb intermetallic compound catalysts (Pt3Sb2 / C, PtSb / C, and PtSb2 / C) with controllable composition, adjustable ratio, high dispersion, and high stability. This significantly reduced the reaction temperature and energy consumption, greatly improving the selectivity of a series of biomass-derived unsaturated aldehydes for unsaturated alcohols, achieving high conversion rates and extremely high yields. These studies provide clear ideas and strong experimental evidence for the design and development of the next generation of high-performance selective hydrogenation catalysts.

[0076] The description of the above embodiments is only used to help understand the method of the present invention and its core concept. It should be pointed out that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention. These improvements and modifications should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a Pt-based intermetallic compound, characterized in that: Here are the steps: (1) First, pretreat the carbon black and calcine it at 300℃~400℃ for 2~3h; (2) According to the mass ratio determined by the metal phase diagram, weigh chloroplatinic acid hexahydrate and antimony chloride and dissolve them in anhydrous ethanol, stir to mix them thoroughly, add carbon black, and continue stirring for more than 20 hours to ensure that the metal is completely impregnated in the carbon black; (3) After being evaporated and dried by a rotary evaporator, the product was placed in a vacuum oven and dried overnight. After being ground, the product was placed in a tube furnace and calcined at 400°C to 600°C in an atmosphere of Ar and H2 with a volume ratio of 4:1 to obtain a Pt-based intermetallic compound.

2. The preparation method according to claim 1, characterized in that The Pt-based intermetallic compounds prepared by the impregnation method are Pt3Sb2 / C, PtSb / C, and PtSb2 / C intermetallic compound catalysts with a metal Pt loading of 1 wt.% prepared by adjusting the ratio of Pt to Sb according to the Pt-Sb metal phase diagram.

3. Use of a Pt-based intermetallic compound obtained by the preparation method according to claim 1 or 2 as a catalyst in the conversion of straw derivatives into high-value chemicals, characterized in that: The steps are as follows: using a high-pressure autoclave reactor, unsaturated aldehyde as raw material, using a Pt-based intermetallic compound as a catalyst in a solvent and hydrogen atmosphere, the unsaturated aldehyde is selectively hydrogenated to produce unsaturated alcohol under mild conditions of a reaction temperature of 40-60°C, a reaction pressure of 1-3 MPa, and a reaction time of 1-5 hours.

4. The use according to claim 3, characterized in that The unsaturated aldehydes are cinnamaldehyde, furfural, 5-hydroxymethylfurfural, vanillin and citral.

5. The use according to claim 3, characterized in that The solvent is ethanol, isopropanol, ethanol+10% volume fraction of H2O, and isopropanol+10% volume fraction of H2O.

6. The use according to claim 3, characterized in that The mass ratio of the Pt-based intermetallic compound to the unsaturated aldehyde is 0.125-0.25, and the mass concentration of the unsaturated aldehyde solution in the reaction system is 0.8-2 wt.%.

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