Application of zirconium hydroxide as catalyst for catalyzing semi-hydrogenation of phenylacetylene to styrene

Abstract

The application belongs to the technical field of organic synthesis, and particularly relates to application of zirconium hydroxide as a catalyst to catalyze preparation of styrene from phenylacetylene. The application finds that zirconium hydroxide can be used as a catalyst to catalyze reduction reaction of phenylacetylene to synthesize styrene; the zirconium hydroxide catalyst can be directly purchased or prepared by using a simple precipitation method with a zirconium salt precursor as a raw material, and has low price; the method is simple to operate, has low production cost, high yield, and is easy to be industrialized.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to the application of zirconium hydroxide or a composition containing zirconium hydroxide as a catalyst for the semi-hydrogenation of phenylacetylene to styrene. Background Technology

[0002] Styrene is an important monomer for the production of polystyrene, styrene-butadiene rubber, and other products, as well as a crucial raw material for the production of coatings and dyes. As a monomer in the industrial production of polystyrene, styrene typically contains trace amounts of phenylacetylene impurities. These impurities can poison and deactivate polymerization catalysts and must be eliminated to acceptable thresholds according to relevant industry standards.

[0003] The traditional industrial catalyst for the reduction of phenylacetylene to styrene is the Lindlar catalyst, which consists of palladium adsorbed onto a support (calcium carbonate or barium sulfate) with the addition of a small amount of inhibitor (lead acetate or quinoline). However, this catalyst is inefficient, causes severe pollution, and poses serious safety hazards. In recent years, researchers have developed many new catalysts for the reduction of phenylacetylene to styrene, which have attracted widespread attention due to their simple process and excellent yield. Reported studies have shown that by loading atomic palladium onto α-Fe₂O₃(012) to construct unit Pd-Fe pairs, the adsorption and dissociation of H₂ are accelerated, and the desorption of key products at Pd sites is allowed, thereby improving the yield of styrene (see Journal of the American Chemical Society, 2022, Vol. 144, No. 1, 573-581). Wang et al. proposed a synthesis method for Pd-based bimetallic nanoclusters based on porous nitrogen-doped carbon supports, ensuring the formation of bimetallic nanoclusters and thus improving styrene yield (see *Journal of Catalysis*, 2020, Vol. 389, pp. 297-304). However, existing catalytic systems suffer from drawbacks such as the use of precious metals, over-reduction, and poor catalyst reusability, which are detrimental to industrial applications and the environment. With the increasing demand for styrene both domestically and internationally, the use of inexpensive and environmentally friendly non-precious metal catalysts for the reduction synthesis of styrene from phenylacetylene has broad application prospects and significant practical implications. Summary of the Invention

[0004] This invention discovers that zirconium hydroxide or a composition containing zirconium hydroxide can be used as a catalyst to catalytically reduce phenylacetylene to styrene. Therefore, this invention provides a novel, low-cost, green, and efficient method for the catalytic reduction of phenylacetylene to styrene. This method is simple, low-cost, safe, and achieves a high synthesis rate. Specifically, it includes the following:

[0005] In a first aspect, the present invention provides an application of zirconium hydroxide as a catalyst for the catalytic semi-hydrogenation of phenylacetylene to styrene. The catalyst, zirconium hydroxide or a composition containing zirconium hydroxide, can be a treated commercial formulation or prepared using the following three methods:

[0006] (1) Precipitation method: A certain amount of zirconium salt is added to deionized water, a certain concentration of precipitant is added, and after stirring for a certain time, the precipitate is filtered, washed, dried and calcined to obtain the desired catalyst.

[0007] (2) Hydrothermal method: The alkaline solution and zirconium compound are reacted in an aqueous solution to generate zirconium hydroxide precipitate under hydrothermal conditions. After filtration, washing and drying, zirconium hydroxide is obtained.

[0008] (3) Sol-gel method: Precursors such as zirconium chloride or zirconium nitrate are hydrolyzed and polymerized in solution to obtain a gel-like substance, which is then heat-treated and calcined to generate zirconium hydroxide.

[0009] In addition to the methods described above, all other methods for preparing zirconium hydroxide or compositions containing zirconium hydroxide should be included here.

[0010] Preferably, the catalyst is a commercially available, treated zirconium hydroxide formulation.

[0011] In a first aspect, the present invention provides an application of zirconium hydroxide as a catalyst for the catalytic semi-hydrogenation of phenylacetylene to styrene.

[0012] Preferably, the calcination temperature of the catalyst is 100℃-500℃.

[0013] Preferably, the calcination temperature of the catalyst is 100℃-300℃.

[0014] Preferably, the calcination temperature of the catalyst is 100℃-200℃.

[0015] Preferably, the calcination temperature of the catalyst is 150°C.

[0016] Preferably, the structural formula of the phenylacetylene is shown in formula (I), and the structural formula of the styrene is shown in formula (II):

[0017]

[0018] Secondly, the present invention provides a method for preparing styrene, wherein the method comprises: using phenylacetylene as shown in formula (I) as raw material, using an organic solvent as a reaction solvent, using zirconium hydroxide as a catalyst, and reacting for a certain time under a certain hydrogen pressure and temperature to catalytically synthesize styrene as shown in formula (II).

[0019]

[0020] Preferably, the organic solvent is ethanol, cyclohexane, acetonitrile, mesitylene, N,N-dimethylformamide, dichloromethane, and methanol, but is not limited thereto.

[0021] Preferably, the reaction solvent is acetonitrile.

[0022] Preferably, the ratio of the catalyst to phenylacetylene is 1-150 g: 1 mol.

[0023] Preferably, the ratio of the catalyst to phenylacetylene is 10-100 g: 1 mol.

[0024] Preferably, the ratio of the catalyst to phenylacetylene is 40-60 g: 1 mol.

[0025] Preferably, the ratio of the catalyst to phenylacetylene is 50g:1mol.

[0026] The ratio of the organic solvent to phenylacetylene is 0.1-20 L: 1 mol.

[0027] The ratio of the organic solvent to phenylacetylene is 1-15 L: 1 mol.

[0028] The ratio of the organic solvent to phenylacetylene is 8-13 L: 1 mol.

[0029] The ratio of the organic solvent to phenylacetylene is 10 L: 1 mol.

[0030] Preferably, the reaction temperature is 60-300℃.

[0031] Preferably, the reaction temperature is 100-160℃.

[0032] Preferably, the reaction temperature is 150°C.

[0033] Preferably, the reaction pressure is 0.5-7 MPa.

[0034] Preferably, the reaction pressure is 4-6 MPa.

[0035] Preferably, the reaction pressure is 5 MPa.

[0036] Preferably, the reaction time is 1-24 hours.

[0037] Preferably, the reaction time is 10 hours.

[0038] Compared with existing technologies, the method for the partial hydrogenation of phenylacetylene to styrene catalyzed by zirconium hydroxide according to the present invention has the following advantages:

[0039] (1) This invention innovatively uses inexpensive zirconium hydroxide as a catalyst, which not only has high activity and good selectivity, but can also be directly purchased as a commercial product or prepared by a simple precipitation method. Compared with the precious metal catalysts used in traditional methods, this significantly reduces the cost of the catalyst and is environmentally friendly.

[0040] (2) The phenylacetylene used in this invention is a basic raw material commonly used in industry, and is cheap and readily available.

[0041] (3) The method described in this invention can catalytically reduce phenylacetylene to the corresponding styrene, with good specificity and a high yield of the target product. Attached Figure Description

[0042] Figure 1 Mass spectrum of styrene synthesized by the method described in Example 1;

[0043] Figure 2 Mass spectrum of styrene synthesized by the method described in Example 2;

[0044] Figure 3 Mass spectrum of styrene synthesized by the method described in Example 3;

[0045] Figure 4 Mass spectrum of styrene synthesized by the method described in Example 4;

[0046] Figure 5 Mass spectrum of styrene synthesized by the method described in Example 5;

[0047] Figure 6 Mass spectrum of styrene synthesized by the method described in Example 6; Detailed Implementation

[0048] The present invention will be further described in detail below with reference to specific embodiments. The scope of protection of the present invention is not limited thereto. Unless otherwise specified, all raw materials used in the following embodiments can be purchased commercially.

[0049] Example 1: Synthesis of styrene using catalysts at different calcination temperatures

[0050] 1. Add 5g of zirconium hydroxide catalyst calcined at 100℃ to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0051] 2. Add 5g of zirconium hydroxide catalyst calcined at 150℃ to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 150℃ for 10h. Then, after filtration, extraction and distillation, obtain the product styrene.

[0052] 3. Add 5g of zirconium hydroxide catalyst calcined at 200℃ to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0053] 4. Add 5g of zirconium hydroxide catalyst calcined at 300℃ to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0054] 5. Add 5g of zirconium hydroxide catalyst calcined at 400℃ to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0055] 6. Add 5g of zirconium hydroxide catalyst calcined at 500℃ to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0056] The yields of styrene obtained by the preparation methods described in 1-6 above were calculated, and the results are shown in Table 1 below:

[0057] Table 1. Process parameters and yield of styrene product of the preparation method described in Example 1.

[0058]

[0059]

[0060] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 1 As shown (the mass spectra of the main products of the above 6 reactions are the same, so only one mass spectrum is provided). The above results indicate that styrene can be catalytically synthesized from phenylacetylene using acetonitrile as the reaction solvent, zirconium hydroxide as the catalyst, at a reaction temperature of 150℃, a reaction pressure of 5MPa, and a reaction time of 10h. Furthermore, using zirconium hydroxide catalyst with a calcination temperature of 150-300℃, the yield of styrene obtained is above 75%, and when the calcination temperature is 150℃, the yield of styrene obtained is as high as 94%.

[0061] Example 2: Synthesis of styrene using different reaction solvents

[0062] 1. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of ethanol and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 150℃ for 10h. Then, through filtration, extraction and distillation, styrene is obtained.

[0063] 2. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of cyclohexane and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 150℃ for 10h. Then, through filtration, extraction and distillation, obtain the product styrene.

[0064] 3. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0065] 4. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of mesitylene and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0066] 5. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of N,N-dimethylformamide and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0067] 6. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of dichloromethane and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0068] 7. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of methanol and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0069] The yields of styrene obtained by the preparation methods described in 1-7 above were calculated, and the results are shown in Table 2 below:

[0070] Table 2. Process parameters and yield of styrene product of the preparation method described in Example 2.

[0071]

[0072] The mass spectrum of the product synthesized by the above reaction is shown below. Figure 2 As shown (the mass spectra of the main products of the above 7 reactions are the same, so only one mass spectrum is provided). The above results indicate that styrene can be catalytically synthesized from phenylacetylene using organic solvents (methanol, ethanol, acetonitrile, etc.) as reaction solvents, zirconium hydroxide as catalyst, a reaction temperature of 150℃, a reaction pressure of 5MPa, and a reaction time of 10h; among which, the yield of styrene synthesized using acetonitrile as the reaction solvent can reach 94%.

[0073] Example 3: Synthesis of styrene at different reaction temperatures

[0074] 1. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 100℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0075] 2. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 110℃ for 10h. Then, through filtration, extraction and distillation, styrene is obtained.

[0076] 3. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 120℃ for 10h. Then, through filtration, extraction, and distillation, obtain the product styrene.

[0077] 4. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 130℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0078] 5. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 140℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0079] 6. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0080] 7. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 160℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0081] The yields of styrene obtained by the preparation methods described in 1-7 above were calculated, and the results are shown in Table 3 below:

[0082] Table 3. Process parameters and styrene yield of the preparation method described in Example 3.

[0083]

[0084] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 3 As shown (the mass spectra of the main products of the above 7 reactions are the same, so only one mass spectrum is provided). The above results indicate that styrene can be catalytically synthesized from phenylacetylene at a reaction temperature of 100-160℃, using acetonitrile as the reaction solvent, zirconium hydroxide as the catalyst, a reaction time of 10 h, and a reaction pressure of 5 MPa; at a reaction temperature of 140-160℃, the yield of styrene obtained is above 65%; and at a reaction temperature of 150℃, the yield of styrene obtained can reach above 94%.

[0085] Example 4: Synthesis of styrene under different reaction pressures

[0086] 1. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 1MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0087] 2. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 2MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0088] 3. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 3MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0089] 4. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 4MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0090] 5. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0091] 6. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 6MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0092] 7. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 7MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0093] The yields of styrene obtained by the preparation methods described in 1-7 above were calculated, and the results are shown in Table 4 below:

[0094] Table 4. Process parameters and yield of styrene product of the preparation method described in Example 4.

[0095]

[0096] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 4 As shown (the mass spectra of the main products of the above 7 reactions are the same, so only one mass spectrum is provided). The above results indicate that styrene can be catalytically synthesized from phenylacetylene at a reaction pressure of 1-7 MPa, using acetonitrile as the reaction solvent, zirconium hydroxide as the catalyst, a reaction temperature of 150 °C, a reaction time of 10 h, and a reaction pressure of 5 MPa; at the same reaction time of 4-6 MPa, the yield of styrene obtained is above 50%; and at a reaction pressure of 5 MPa, the yield of styrene obtained can reach above 94%.

[0097] Example 5: Synthesis of styrene with different reaction times

[0098] 1. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 2 hours, and then obtain the product styrene through filtration, extraction and distillation.

[0099] 2. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 4 hours, and then obtain the product styrene through filtration, extraction and distillation.

[0100] 3. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 6 hours, and then obtain the product styrene through filtration, extraction and distillation.

[0101] 4. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 8 hours, and then obtain the product styrene through filtration, extraction and distillation.

[0102] 5. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0103] The yields of styrene obtained by the preparation methods described in 1-5 above were calculated, and the results are shown in Table 5 below:

[0104] Table 5. Process parameters and yield of styrene product of the preparation method described in Example 5.

[0105]

[0106] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 5 As shown (the mass spectra of the main products of the above 5 reactions are the same, so only one mass spectrum is provided). The above results indicate that acetonitrile can be catalytically synthesized into styrene at a reaction pressure of 5 MPa, a reaction temperature of 150 °C, and a reaction time of 2-10 h; and the yield of styrene obtained from the reaction is higher than 30% when the reaction time is 4-10 h; while the yield of styrene obtained from the reaction is as high as 94% when the reaction time is 10 h.

[0107] Example 6: Synthesis of phenylacetylene in excess styrene with different proportions.

[0108] 1. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile and 10.2g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, react at 150℃ for 10h, and then obtain the product styrene through filtration, extraction and distillation.

[0109] 2. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile, 9.36g of styrene, and 1.02g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 150℃ for 10h. Then, through filtration, extraction, and distillation, obtain the product styrene.

[0110] 3. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile, 9.88g of styrene, and 0.51g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 150℃ for 10h. Then, through filtration, extraction, and distillation, obtain the product styrene.

[0111] 4. Add 5g of zirconium hydroxide catalyst to a stainless steel autoclave, then add 1L of acetonitrile, 10.3g of styrene, and 0.12g of phenylacetylene. Increase the pressure inside the autoclave to 5MPa through a hydrogen cylinder, and react at 150℃ for 10h. Then, through filtration, extraction, and distillation, obtain the product styrene.

[0112] The yields of styrene obtained by the preparation methods described in 1-4 above were calculated, and the results are shown in Table 6 below:

[0113] Table 6. Process parameters and styrene yield of the preparation method described in Example 6.

[0114]

[0115] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 6 As shown (the mass spectra of the main products of the above four reactions are the same, so only one mass spectrum is provided). The above results indicate that acetonitrile can be catalytically synthesized into styrene in the presence of styrene using zirconium hydroxide as the reaction solvent, acetonitrile as the catalyst, 5 MPa as the reaction pressure, 10 h as the reaction time, and 150 °C as the reaction temperature, with yields all above 90%.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. The application of zirconium hydroxide as a catalyst for the semi-hydrogenation of phenylacetylene to styrene, characterized in that, Using phenylacetylene as shown in formula (I) as raw material, acetonitrile as solvent, hydrogen as hydrogen source, and zirconium hydroxide as catalyst, a semi-hydrogenation reaction was carried out under the following conditions: catalyst to phenylacetylene ratio of 40-60 g: 1 mol, acetonitrile to phenylacetylene ratio of 8-13 L: 1 mol, reaction temperature of 140-160℃, hydrogen pressure of 4-6 MPa, and reaction time of 6-10 h, to prepare styrene as shown in formula (II); 。 2. The application as described in claim 1, wherein the zirconium hydroxide is a treated commercial formulation; the calcination temperature is 150-300 °C.

3. The application as described in claim 1, characterized in that, The zirconium hydroxide is prepared by the following method: (1) Precipitation method: A certain amount of zirconium salt is added to deionized water, a certain concentration of precipitant is added, and after stirring for a certain time, the precipitate is filtered, washed, dried and calcined to obtain the desired catalyst. (2) Hydrothermal method: The alkaline solution and zirconium compound are reacted in an aqueous solution to generate zirconium hydroxide precipitate under hydrothermal conditions. After filtration, washing and drying, zirconium hydroxide is obtained. (3) Sol-gel method: The precursors of zirconium chloride or zirconium nitrate are hydrolyzed and polymerized in solution to obtain a gel-like substance, which is then heat-treated and calcined to generate zirconium hydroxide.

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