A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropene and application thereof

Abstract

This invention discloses a method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene and its application. The preparation method includes the following steps: (1) mixing the active component of the support, the pore expander, and the binder, and transferring the mixture to a kneader after uniform mixing. Nitric acid solution is added to the mixture to form a binder. The binder is kneaded, extruded, and cut by the kneader, and then dried and calcined to obtain the support. The active component of the support is composed of at least one of magnesium dihydrogen phosphate, zirconium oxychloride, and zinc oxide, along with titanium oxide and aluminum oxide. (2) Using an equal-volume impregnation method, the auxiliary component and the active component are loaded separately. (3) Reduction is performed to obtain the catalyst. The catalyst exhibits high activity, good stability, and good product selectivity when preparing 1,2,3,3,3-pentafluoropropylene.

Description

Technical Field

[0001] This invention belongs to the field of 1,2,3,3,3-pentafluoropropylene preparation technology, specifically relating to a method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene and its application. Background Technology

[0002] Hydrofluorocarbons (HFCs), as third-generation refrigerants, have been widely used in refrigerants, polishing agents, and chemical solvents due to their excellent performance. However, their high global warming potential (GWP) may have a certain impact on the environment, thus necessitating the development of alternatives. Hydrofluoroolefins (HFOs), as a new generation of environmentally friendly alternatives to HFCs, possess excellent properties such as low toxicity, high refrigeration capacity, and non-flammability. Therefore, utilizing HFCs to produce HFOs has certain social benefits.

[0003] The defluorination of hydrofluoroalkanes (HFCs) to prepare hydrofluoroolefins (HFOs) is a relatively ideal synthetic route with good application prospects. Patent CN 115322071A discloses a method for co-producing trifluoropropylene and tetrafluoropropylene using 1,1,1,2,3-pentafluoropropane as a raw material. This patent uses composite metal oxides such as Mg, Al, and Cr as catalysts, achieving a conversion rate of up to 90%, but Cr metal causes significant environmental pollution. Patent CN104710270A discloses a method for preparing hydrofluoroolefins by cracking hydrofluoroalkanes. This method uses a mixture of HF and hydrofluoroalkanes as reactants and fluorinated zinc chromium oxide as a catalyst. However, its hydrofluoroolefin yield is less than 60%, and the HF raw material is highly hazardous, while chromium oxide causes some environmental pollution. Most of the published methods use chromium-containing compounds as catalyst components, which will cause environmental pollution. Hydrofluoroolefins (HFOs) are prone to polymerization and coking at high temperatures, covering the active sites of the catalyst and leading to catalyst deactivation. Preventing coking is a problem that must be solved in the preparation of high-performance catalysts. Therefore, it is essential to develop a new type of environmentally friendly and efficient hydrofluoroalkane cracking catalyst. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene and its application. The catalyst exhibits high activity, good stability, and good product selectivity in the preparation of 1,2,3,3,3-pentafluoropropylene.

[0005] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst comprises a support, an active component supported on the support, and an auxiliary component. The catalyst, by weight (100%), comprises the following components: active component 0.5-10%, auxiliary component 0.1-10%, with the remainder being the support. The active component is one or two of iron, molybdenum, cobalt, nickel, platinum, and palladium; the auxiliary component is one or two of lanthanum, potassium, barium, tin, manganese, and niobium.

[0006] The method for preparing the catalyst includes the following steps:

[0007] (1) Stir and mix the carrier active ingredients, pore expander and binder, and transfer the mixture to a kneader after it is evenly mixed. Add nitric acid solution to form an adhesive. Knead the adhesive through the kneader, extrude it into strips and cut it. Then dry and calcine it to obtain the carrier. The carrier active ingredients are composed of at least one of magnesium dihydrogen phosphate, zirconium oxychloride and zinc oxide, along with titanium oxide and aluminum oxide.

[0008] (2) Using the equal volume impregnation method, the carrier is added to the impregnation solution containing the auxiliary component and impregnated at room temperature for 5-20 hours. After filtration, drying and calcination, the carrier impregnated with the auxiliary component is obtained. The carrier impregnated with the auxiliary component is then added to the impregnation solution containing the active component and impregnated at room temperature for 5-20 hours. After filtration, drying and calcination, the catalyst precursor is obtained.

[0009] (3) The catalyst precursor is reduced to obtain the catalyst.

[0010] Preferably, the active component is one or two of iron, molybdenum, and cobalt.

[0011] Preferably, the active ingredient of the carrier is 100% by weight, and the content of each component is as follows: titanium oxide 5-40%, aluminum oxide 10-70%, and the balance is at least one of magnesium dihydrogen phosphate, zirconium oxychloride, and zinc oxide.

[0012] Preferably, the mass of the pore-expanding agent is 0.1-5% of the active ingredient of the carrier, and the mass of the adhesive is 0.05%-3% of the active ingredient of the carrier.

[0013] Preferably, the pore-expanding agent is any one of carbon powder, starch, urea, and hexamethylenetetramine, and the binder is any one of guar gum, guar gum, methylcellulose, and carboxymethylcellulose.

[0014] Preferably, the concentration of the nitric acid solution is 0.5-30 wt%. More preferably, the concentration of the nitric acid solution is 5-10 wt%.

[0015] Preferably, the kneading is performed at 20-50℃ for 1-20 hours.

[0016] Preferably, in step (1), the drying conditions are vacuum drying at 80-130℃ for 8-24 hours, and the calcination conditions are calcination at 400-1000℃ for 3-20 hours; in step (2), the drying conditions are vacuum drying at 80-120℃ for 8-24 hours, and the calcination conditions are calcination at 400-600℃ for 3-8 hours.

[0017] Preferably, the reduction is carried out under a hydrogen atmosphere at 200-400°C for 2-10 hours, with a hydrogen flow rate of 100-500 mL / min. -1 .

[0018] A method for synthesizing 1,2,3,3,3-pentafluoropropene: a catalyst is packed into a quartz tube in a fixed-bed reactor, and 1,1,2,3,3,3-hexafluoropropane is used as the raw material, nitrogen is used as the carrier gas, and the reaction is carried out at 350-550°C and atmospheric pressure; the catalyst is prepared by the method described in this invention.

[0019] Preferably, the space velocity of the 1,1,2,3,3,3-hexafluoropropane is 300-500 h⁻¹. -1 The volume ratio of nitrogen to 1,1,2,3,3,3-hexafluoropropane is 2-10.

[0020] Advantages of this invention:

[0021] (1) This invention uses a combination of components with synergistic and complementary properties to prepare a catalyst support. Titanium oxide has good resistance to poisoning and carbon deposition, and moderate acidity, while alumina has good acidity and good activity for the cracking of hydrofluoroalkanes. The support is modified with additives and then synergistically catalyzed with the active components, resulting in a catalyst with higher activity, selectivity, and stability.

[0022] (2) The catalyst of the present invention does not contain chromium compounds, and the metal compounds are inexpensive and readily available, thus the production cost of the catalyst is low;

[0023] (3) The catalyst provided by the present invention is used in the continuous catalytic synthesis of 1,1,2,3,3,3-hexafluoropropane into 1,2,3,3,3-pentafluoropropylene. The yield of the target product is high and the catalyst life is good. This application provides guidance for the later industrial production. Implementation

[0024] Example 1

[0025] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst comprises a support, an active component Fe supported on the support, and auxiliary components La and Sn. The content of each component, based on 100% weight of the catalyst, is as follows: Fe 5%, La 1.5%, Sn 1%, with the balance being the support.

[0026] The method for preparing the catalyst includes the following steps:

[0027] (1) 28g titanium dioxide, 45g aluminum oxide, 18g magnesium dihydrogen phosphate, 9g zirconium oxychloride, 2.5g urea and 1.3g guar gum were stirred and mixed. After being mixed evenly, the mixture was transferred to a kneader. 1wt% nitric acid solution was added to the mixture. After acid dissolution, an adhesive was formed. The adhesive was kneaded in the kneader at 30°C for 3 hours, extruded into strips, cut, and then vacuum dried at 100°C for 12 hours. Finally, it was placed in a muffle furnace and calcined at 900°C for 6 hours to obtain the carrier.

[0028] (2) Weigh lanthanum nitrate and stannous chloride according to the weight ratio of La and Sn in the catalyst. Dissolve lanthanum nitrate and stannous chloride in 2g of concentrated hydrochloric acid, then add 60g of pure water. After dissolving, add the carrier to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the filtered solid at 100℃ for 12h. Then place it in a muffle furnace and calcine at 450℃ for 3h to obtain a carrier impregnated with the auxiliary component. Weigh ferric nitrate according to the weight ratio of Fe in the catalyst. Dissolve ferric nitrate in 60g of pure water and add the carrier impregnated with the auxiliary component to the solution. Impregnate at room temperature for 12h. Filter the solution and vacuum dry the filtered solid at 100℃ for 12h. Then place it in a muffle furnace and calcine at 450℃ for 3h to obtain the catalyst precursor.

[0029] (3) The catalyst was reduced at 300°C for 3 hours in a hydrogen atmosphere with a hydrogen flow rate of 100 mL / min to obtain the catalyst.

[0030] Example 2

[0031] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst is composed of a support, an active component Co supported on the support, and auxiliary components La and Sn. The content of each component is as follows, based on 100% weight of the catalyst: Co 3%, La 3%, Sn 1.5%, with the balance being the support.

[0032] The method for preparing the catalyst includes the following steps:

[0033] (1) Mix 40g titanium dioxide, 35g aluminum oxide, 10g magnesium dihydrogen phosphate, 15g zirconium oxychloride, 3g urea and 1g guar gum. After mixing evenly, transfer to a kneader and add 1.5wt% nitric acid solution. After acid dissolution, an adhesive is formed. Knead the adhesive in the kneader at 30°C for 5h, extrude it into strips, cut it, and then vacuum dry it at 120°C for 12h. Then place it in a muffle furnace and calcine it at 960°C for 3h to obtain the carrier.

[0034] (2) Weigh lanthanum nitrate and stannous chloride according to the weight ratio of La and Sn in the catalyst. Dissolve lanthanum nitrate and stannous chloride in 2g of concentrated hydrochloric acid, then add 60g of pure water. After dissolving, add the support to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the filtered solid at 100℃ for 12h. Then calcine it in a muffle furnace at 450℃ for 3h to obtain a support impregnated with the promoter component. Weigh cobalt nitrate according to the weight ratio of Co in the catalyst. Dissolve cobalt nitrate in 60g of pure water and add the support impregnated with the promoter component to the solution. Impregnate at room temperature for 12h. Filter the solution and vacuum dry the filtered solid at 100℃ for 12h. Then calcine it in a muffle furnace at 500℃ for 3h to obtain the catalyst precursor.

[0035] (3) The catalyst was reduced at 350°C for 2 hours in a hydrogen atmosphere with a hydrogen flow rate of 100 mL / min to obtain the catalyst.

[0036] Example 3

[0037] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst is composed of a support, an active component Mo supported on the support, and auxiliary components K and Mn. The content of each component is as follows, based on 100% weight of the catalyst: Mo 5%, K 3%, Mn 1%, with the balance being the support.

[0038] The method for preparing the catalyst includes the following steps:

[0039] (1) Mix 15g titanium dioxide, 60g aluminum oxide, 25g magnesium dihydrogen phosphate, 1g hexamethylenetetramine and 3g guar gum. After mixing evenly, transfer to a kneader and add 0.5wt% nitric acid solution. After acid dissolution, an adhesive is formed. Knead the adhesive in the kneader at 30°C for 8 hours, extrude it, cut it, and then vacuum dry it at 120°C for 12 hours. Then place it in a muffle furnace and calcine it at 750°C for 6 hours to obtain the carrier.

[0040] (2) Weigh potassium carbonate and manganese sulfate according to the weight ratio of K and Mn in the catalyst. Add potassium carbonate and manganese sulfate to 60g of pure water and dissolve them. Add the carrier to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 100℃ for 12h. Then place the solid in a muffle furnace and calcine at 550℃ for 2h to obtain a carrier impregnated with the auxiliary component. Weigh ammonium molybdate according to the weight ratio of Mo in the catalyst. Dissolve ammonium molybdate in 2g of concentrated hydrochloric acid and then dissolve it in 60g of pure water. Add the carrier impregnated with the auxiliary component to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 100℃ for 12h. Then place the solid in a muffle furnace and calcine at 450℃ for 3h to obtain the catalyst precursor.

[0041] (3) The catalyst was reduced at 200°C for 8 hours in a hydrogen atmosphere with a hydrogen flow rate of 100 mL / min to obtain the catalyst.

[0042] Example 4

[0043] The carriers are different; they are prepared using the following methods:

[0044] 27g titanium dioxide, 50g aluminum oxide, 3g magnesium dihydrogen phosphate, 20g zirconium oxychloride, 2g urea, and 2.5g guar gum were stirred and mixed evenly, and then transferred to a kneader. A 5wt% nitric acid solution was added to the mixture, and after acid dissolution, an adhesive was formed. The adhesive was kneaded in the kneader at 30°C for 10 hours, extruded, and cut. Then, it was vacuum dried at 100°C for 12 hours and then calcined in a muffle furnace at 700°C for 10 hours to obtain the carrier.

[0045] Everything else is the same as in Example 1.

[0046] Example 5

[0047] The carriers are different; they are prepared using the following methods:

[0048] 30g titanium dioxide, 50g aluminum oxide, 20g magnesium dihydrogen phosphate, 20g zirconium oxychloride, 2g urea, and 3g carboxymethyl cellulose were stirred and mixed evenly, and then transferred to a kneader. A 3wt% nitric acid solution was added to the mixture, and after acid dissolution, an adhesive was formed. The adhesive was kneaded in the kneader at 30°C for 7 hours, extruded, and cut. Then, it was vacuum dried at 100°C for 12 hours and then calcined in a muffle furnace at 800°C for 7 hours to obtain the carrier.

[0049] Everything else is the same as in Example 1.

[0050] Example 6

[0051] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst comprises a support, an active component Fe supported on the support, and auxiliary components Ba and Mn. The content of each component, based on 100% weight of the catalyst, is as follows: Fe 3%, Ba 5%, Mn 0.5%, with the balance being the support; the support is the same as in Example 1.

[0052] The method for preparing the catalyst includes the following steps:

[0053] (1) Same as step (1) in Example 1;

[0054] (2) Weigh barium nitrate and manganese sulfate according to the weight ratio of Ba and Mn in the catalyst. Add barium nitrate and manganese sulfate to 60g of pure water and dissolve them. Add the carrier to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 120℃ for 10h. Then place it in a muffle furnace and calcine at 400℃ for 8h to obtain a carrier impregnated with the auxiliary component. Weigh ferric nitrate according to the weight ratio of Fe in the catalyst. Dissolve ferric nitrate in 60g of pure water and add the carrier impregnated with the auxiliary component to the solution. Impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 100℃ for 12h. Then place it in a muffle furnace and calcine at 600℃ for 3h to obtain the catalyst precursor.

[0055] (3) Same as step (3) in Example 1.

[0056] Example 7

[0057] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst comprises a support, an active component Fe supported on the support, and auxiliary components Ba and Nb. The content of each component, based on 100% weight of the catalyst, is as follows: Fe 8%, Ba 3%, Nb 1%, with the balance being the support; the support is the same as in Example 1.

[0058] The method for preparing the catalyst includes the following steps:

[0059] (1) Same as step (1) in Example 1;

[0060] (2) Weigh barium nitrate and niobium pentachloride according to the weight ratio of Ba and Nb in the catalyst. Add barium nitrate and niobium pentachloride to 2g of concentrated hydrochloric acid, then add to 60g of pure water. After dissolving, add the carrier to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 120℃ for 10h. Then place it in a muffle furnace and calcine at 400℃ for 8h to obtain a carrier impregnated with the auxiliary agent component. Weigh ferric nitrate according to the weight ratio of Fe in the catalyst. Dissolve ferric nitrate in 60g of pure water. Add the carrier impregnated with the auxiliary agent component to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 100℃ for 12h. Then place it in a muffle furnace and calcine at 450℃ for 3h to obtain the catalyst precursor.

[0061] (3) Same as step (3) in Example 1.

[0062] Example 8

[0063] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst comprises a support, active components Fe and Co supported on the support, and auxiliary components La and Sn, and the content of each component is as follows based on 100% weight of the catalyst: Fe 1.5%, Co 1.5%, La 1.5%, Sn 1%, with the balance being the support;

[0064] The method for preparing the catalyst includes the following steps:

[0065] (1) Same as step (1) in Example 1;

[0066] (2) Weigh lanthanum nitrate and stannous chloride according to the weight ratio of La and Sn in the catalyst. Dissolve lanthanum nitrate and stannous chloride in 2g of concentrated hydrochloric acid, then add 60g of pure water. After dissolving, add the carrier to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 100℃ for 12h. Then place the solid in a muffle furnace and calcine at 450℃ for 3h to obtain a carrier impregnated with the auxiliary component. Weigh ferric nitrate and cobalt nitrate according to the weight ratio of Fe and Co in the catalyst. Dissolve ferric nitrate and cobalt nitrate in 60g of pure water. Add the carrier impregnated with the auxiliary component to the solution and impregnate at room temperature for 12h. Filter the solution and vacuum dry the solid obtained by filtration at 100℃ for 12h. Then place the solid in a muffle furnace and calcine at 550℃ for 3h to obtain the catalyst precursor.

[0067] (3) Same as step (3) in Example 1.

[0068] Example 9

[0069] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst is composed of a support, an active component Ni supported on the support, and an auxiliary component La. The content of each component is as follows, based on 100% weight of the catalyst: Ni 10%, La 0.1%, with the balance being the support.

[0070] The method for preparing the catalyst includes the following steps:

[0071] (1) Mix 5g titanium dioxide, 70g aluminum oxide, 15g magnesium dihydrogen phosphate, 10g zinc oxide, 0.1g starch and 0.05g guar gum. After mixing evenly, transfer to a kneader and add 1wt% nitric acid solution. After acid dissolution, an adhesive is formed. Knead the adhesive in the kneader at 20°C for 20h, extrude it into strips, cut it, and then vacuum dry it at 80°C for 24h. Then place it in a muffle furnace and calcine it at 1000°C for 3h to obtain the carrier.

[0072] (2) Weigh lanthanum nitrate according to the weight ratio of La in the catalyst, dissolve lanthanum nitrate in 60g of pure water, add the carrier to it, impregnate at room temperature for 5h, filter, vacuum dry the filtered solid at 80℃ for 24h, and then calcine it in a muffle furnace at 400℃ for 8h to obtain a carrier impregnated with the auxiliary component; Weigh nickel nitrate according to the weight ratio of Ni in the catalyst, dissolve nickel nitrate in 60g of pure water, add the carrier impregnated with the auxiliary component to it, impregnate at room temperature for 12h, filter, vacuum dry the filtered solid at 80℃ for 24h, and then calcine it in a muffle furnace at 400℃ for 8h to obtain the catalyst precursor;

[0073] (3) The catalyst was reduced at 400°C for 2 hours in a hydrogen atmosphere with a hydrogen flow rate of 500 mL / min to obtain the catalyst.

[0074] Example 10

[0075] A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, wherein the catalyst is composed of a support, active components Pt and Pd supported on the support, and an auxiliary component La. The content of each component is as follows, based on 100% weight of the catalyst: Pt 0.3%, Pd 0.2%, La 10%, with the balance being the support.

[0076] The method for preparing the catalyst includes the following steps:

[0077] (1) Mix 40g titanium dioxide, 10g aluminum oxide, 25g magnesium dihydrogen phosphate, 25g zinc oxide, 5g carbon powder and 3g methylcellulose. After mixing evenly, transfer to a kneader and add 30wt% nitric acid solution. After acid dissolution, an adhesive is formed. Knead the adhesive in the kneader at 50℃ for 1h, extrude it into strips, cut it, and then vacuum dry it at 130℃ for 8h. Then place it in a muffle furnace and calcine it at 400℃ for 20h to obtain the carrier.

[0078] (2) Weigh lanthanum nitrate according to the weight ratio of La in the catalyst, dissolve lanthanum nitrate in 60g of pure water, add the support to the solution, impregnate at room temperature for 20h, filter, vacuum dry the filtered solid at 120℃ for 8h, and then calcine it in a muffle furnace at 400℃ for 8h to obtain a support impregnated with the auxiliary component; Weigh chloroplatinic acid and palladium nitrate according to the weight ratio of Pt and Pd in ​​the catalyst, dissolve chloroplatinic acid and palladium nitrate in 60g of pure water, add the support impregnated with the auxiliary component to the solution, impregnate at room temperature for 20h, filter, vacuum dry the filtered solid at 120℃ for 8h, and then calcine it in a muffle furnace at 400℃ for 8h to obtain the catalyst precursor;

[0079] (3) The catalyst was reduced at 200°C for 10 h in a hydrogen atmosphere with a hydrogen flow rate of 200 mL / min to obtain the catalyst.

[0080] Comparative Example 1

[0081] The carrier's active components consist only of titanium dioxide and aluminum oxide, in the same proportion as in Example 1. The carrier preparation is as follows:

[0082] 38.3g titanium dioxide, 61.6g aluminum oxide, 2.5g urea and 1.3g guar gum were stirred and mixed evenly, and then transferred to a kneader. 1wt% nitric acid solution was added to the mixture, and after acid dissolution, an adhesive was formed. The adhesive was kneaded in the kneader at 30℃ for 3h, extruded into strips, cut, and then vacuum dried at 100℃ for 12h. Finally, it was placed in a muffle furnace and calcined at 900℃ for 6h to obtain the carrier.

[0083] Everything else is the same as in Example 1.

[0084] Comparative Example 2

[0085] The carrier is a conventional alumina microsphere, and the rest is the same as in Example 1.

[0086] Comparative Example 3

[0087] The impregnation method differs during preparation; the auxiliary components and active components are impregnated simultaneously. Other aspects are the same as in Example 1. The preparation method is as follows:

[0088] (1) Same as step (1) in Example 1;

[0089] (2) Weigh ferric nitrate, lanthanum nitrate and stannous chloride according to the weight ratio of Fe, La and Sn in the catalyst. Dissolve ferric nitrate, lanthanum nitrate and stannous chloride in 2g concentrated hydrochloric acid, then add 60g pure water. After dissolving, add the support and impregnate at room temperature for 12h. Filter and vacuum dry the filtered solid at 100℃ for 12h. Then place it in a muffle furnace and calcine at 450℃ for 3h to obtain the catalyst precursor.

[0090] (3) Same as step (3) in Example 1.

[0091] Catalyst performance evaluation

[0092] A method for synthesizing 1,2,3,3,3-pentafluoropropene: A catalyst is packed into a quartz tube in a fixed-bed reactor; 1,1,2,3,3,3-hexafluoropropane is used as the raw material; nitrogen is used as the carrier gas; and the reaction is carried out at 350-550°C and atmospheric pressure; the space velocity of the 1,1,2,3,3,3-hexafluoropropane is 300-500 h⁻¹. -1 The volume ratio of nitrogen to 1,1,2,3,3,3-hexafluoropropane is 5. The specific reaction conditions and results are shown in Table 1. The stabilization period is the reaction time during which the conversion or selectivity decreases to below 90% of the initial value.

[0093] Table 1. Specific reaction conditions and results

[0094] .

Claims

1. A method for preparing a catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene, characterized in that: The catalyst comprises a support, an active component supported on the support, and an auxiliary component. The catalyst is based on 100% by weight, and the content of each component is as follows: active component 0.5-10%, auxiliary component 0.1-10%, and the balance is the support. The active component is one or two of iron, molybdenum, cobalt, nickel, platinum, and palladium, and the auxiliary component is one or two of lanthanum, potassium, barium, tin, manganese, and niobium. The method for preparing the catalyst includes the following steps: (1) Stir and mix the carrier active ingredients, pore expander and binder, and transfer the mixture to a kneader after it is evenly mixed. Add nitric acid solution to form an adhesive. Knead the adhesive through the kneader, extrude it into strips and cut it. Then dry and calcine it to obtain the carrier. The carrier active ingredients are composed of at least one of magnesium dihydrogen phosphate, zirconium oxychloride and zinc oxide, along with titanium oxide and aluminum oxide. (2) Using the equal volume impregnation method, the carrier is added to the impregnation solution containing the auxiliary component and impregnated at room temperature for 5-20 hours. After filtration, drying and calcination, the carrier impregnated with the auxiliary component is obtained. The carrier impregnated with the auxiliary component is then added to the impregnation solution containing the active component and impregnated at room temperature for 5-20 hours. After filtration, drying and calcination, the catalyst precursor is obtained. (3) The catalyst precursor is reduced to obtain the catalyst.

2. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 1, characterized in that: The active ingredient of the carrier is calculated by mass of 100%, and the content of each component is as follows: titanium oxide 5-40%, aluminum oxide 10-70%, and the balance is at least one of magnesium dihydrogen phosphate, zirconium oxychloride, and zinc oxide.

3. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 2, characterized in that: The mass of the pore-expanding agent is 0.1-5% of the active ingredient of the carrier, and the mass of the adhesive is 0.05%-3% of the active ingredient of the carrier.

4. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 3, characterized in that: The pore-expanding agent is any one of carbon powder, starch, urea, and hexamethylenetetramine, and the binder is any one of guar gum, guar gum, methylcellulose, and carboxymethylcellulose.

5. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 4, characterized in that: The concentration of the nitric acid solution is 0.5-30 wt%.

6. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 5, characterized in that: The kneading process involves kneading at 20-50℃ for 1-20 hours.

7. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 6, characterized in that: In step (1), the drying conditions are vacuum drying at 80-130℃ for 8-24 hours, and the calcination conditions are calcination at 400-1000℃ for 3-20 hours; in step (2), the drying conditions are vacuum drying at 80-120℃ for 8-24 hours, and the calcination conditions are calcination at 400-600℃ for 3-8 hours.

8. The method for preparing the catalyst for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 7, characterized in that: The reduction is under hydrogen atmosphere, 2-10h at 200-400℃, the flow rate of hydrogen is 100-500mL·min -1 .

9. A method for synthesizing 1,2,3,3,3-pentafluoropropylene, characterized in that: The catalyst was packed into a quartz tube in a fixed-bed reactor and reacted with 1,1,2,3,3,3-hexafluoropropane as the raw material and nitrogen as the carrier gas at 350-550°C and atmospheric pressure. The catalyst was prepared by the method described in claim 1.

10. The method for synthesizing 1,2,3,3,3-pentafluoropropylene according to claim 9, characterized in that: The space velocity of the 1,1,2,3,3,3-hexafluoropropane is 300-500 h -1 The volume ratio of the nitrogen and 1,1,2,3,3,3-hexafluoropropane is 2-10.