Alumina-supported ruthenium-erbium-cerium trimetallic catalyst for acetylene hydrochlorination reaction, its preparation and application

Abstract

This invention discloses an alumina-supported ruthenium-erbium-cerium trimetallic catalyst for the hydrochlorination of acetylene, its preparation, and its application. The catalyst comprises a support and a metal active component supported on the support, wherein the support is porous alumina. The alumina-supported ruthenium-erbium-cerium trimetallic catalyst is prepared by the following method: a salt solution containing ruthenium, erbium, and cerium salts is uniformly adsorbed onto the support by wet impregnation, followed by drying and calcination in air to obtain the alumina-supported ruthenium-erbium-cerium trimetallic catalyst. This invention provides the application of the catalyst in the hydrochlorination of acetylene. The alumina-supported ruthenium-erbium-cerium trimetallic catalyst of this invention, when applied to the hydrochlorination of acetylene, exhibits high acetylene conversion, high selectivity for vinyl chloride, and good catalyst stability.

Description

(I) TECHNICAL FIELD

[0001] The application belongs to the technical field of catalysts, and particularly relates to an alumina-supported ruthenium-erbium-cerium trimetallic catalyst for acetylene hydrochlorination reaction, a preparation method thereof and application of the catalyst in acetylene hydrochlorination reaction. (II) BACKGROUND

[0002] Polyvinyl chloride (PVC) is one of the five major engineering plastics in the world and has a universal application in the chemical industry. Vinyl chloride (VCM) is a monomer for the synthesis of PVC, and the annual demand for PVC is 400 million tons, resulting in that VCM is a very important chemical raw material, and about 90% of VCM is used to produce PVC. There are mainly three chemical synthesis processes for vinyl chloride, namely, C2H2 method, C2H4 method and C2H6 method. The calcium carbide acetylene method will be the main process for the production of vinyl chloride in China, that is, the reaction of acetylene and hydrogen chloride catalyzed by mercuric chloride to generate vinyl chloride. The activity and selectivity of the catalyst are relatively high, but the thermal stability is poor, and the use process will cause the loss of mercury in the catalyst, thereby affecting the activity, and more seriously, the highly toxic mercuric chloride will cause serious pollution to the environment. At present, many scholars are actively exploring how to replace the mercury catalyst in the acetylene hydrochlorination reaction and seeking a green and efficient technical route, and people gradually focus on mercury-free chlorides with metal chlorides as active components, among which, noble metal chlorides show the best catalytic activity, such as gold, palladium, ruthenium and copper as active components, which are reported to have higher catalytic activity than mercury.

[0003] Among them, the Au-based mercury-free catalyst has better activity and stability, and is the most promising non-mercury catalyst for industrial application. However, the gold-based catalyst is expensive, and there are many problems to be solved in industrialization. The price of ruthenium is much lower than that of gold, and its excellent catalyst performance has attracted much attention and research. However, low-content ruthenium catalysts have low activity, unstable ruthenium trichloride aqueous solution, easy agglomeration during the reaction, weak interaction with the carrier and easy coke deposition and other problems. In view of the above problems of ruthenium catalysts, many studies have been conducted from the aspects of changing the valence state and compound of ruthenium, adding auxiliary compounds, ligand complex coordination, ionic liquid, preparation method and carrier modification.

[0004] Therefore, it has great application prospect to design a ruthenium-based catalyst with high activity and high stability for acetylene hydrochlorination reaction. (III) SUMMARY

[0005] The purpose of the present application is to provide an alumina-supported ruthenium-erbium-cerium trimetallic catalyst, a preparation method thereof and application of the catalyst in acetylene hydrochlorination reaction, so as to solve the problems of low activity and poor stability of the ruthenium-based catalyst in the synthesis of vinyl chloride by acetylene hydrochlorination reaction.

[0006] To achieve the above object, the present application adopts the following technical solutions.

[0007] In a first aspect, the present application provides an alumina-supported ruthenium-erbium-cerium trimetallic catalyst for acetylene hydrochlorination reaction, which comprises a carrier and a metal active component supported on the carrier, wherein the carrier is porous alumina; and the alumina-supported ruthenium-erbium-cerium trimetallic catalyst is prepared by the following method: uniformly adsorbing a salt solution containing ruthenium salt, erbium salt and cerium salt onto the carrier by wet impregnation, and then drying and calcining in air atmosphere to obtain the alumina-supported ruthenium-erbium-cerium trimetallic catalyst.

[0008] Preferably, the average particle size of the porous alumina is between 3-4 mm, and the specific surface area is 1000-1200 m 2 / g.

[0009] Preferably, the feeding ratio of the ruthenium salt, the erbium salt and the cerium salt is 10%:25-35%:55-65% in terms of the mass ratio of the metal elements ruthenium, erbium and cerium contained therein, and more preferably 10%:29-31%:59-61%.

[0010] Preferably, in the alumina-supported ruthenium-erbium-cerium trimetallic catalyst, the loading amount of ruthenium (relative to the carrier) is 0.5-0.6 wt%.

[0011] Preferably, the wet impregnation is to immerse the carrier into a salt solution containing ruthenium salt, erbium salt and cerium salt, and immerse in a fume hood at room temperature for 6-8 hours.

[0012] Preferably, the drying condition is to dry in an oven at 100℃-110℃ for 20-24 hours.

[0013] Preferably, the calcination temperature is 1000-1100℃, and the calcination time is 5-6h.

[0014] In a second aspect, the present application provides a preparation method of the alumina-supported ruthenium-erbium-cerium trimetallic catalyst of the first aspect, which comprises the following steps:

[0015] Step one: mixing and dissolving ruthenium salt, erbium salt and cerium salt in a solvent according to a certain proportion to prepare a salt solution;

[0016] Step two: immersing the carrier into the salt solution, and then drying and calcining in air atmosphere to obtain the alumina-supported ruthenium-erbium-cerium trimetallic catalyst for acetylene hydrochlorination reaction.

[0017] Preferably, in step one, the ruthenium salt is anhydrous ruthenium chloride, the erbium salt is Er(NO3)3·5H2O, the cerium salt is Ce(NO3)2·6H2O, and the solvent is deionized water.

[0018] As preferred, the impregnation condition in step two is impregnation in a fume hood at room temperature for 6-8 hours.

[0019] As preferred, the drying condition in step two is drying in an oven at 100-110℃ for 20-24 hours.

[0020] As preferred, the calcination condition in step two is calcination in an air atmosphere at 1000-1100℃ using a muffle furnace with a heating rate of 5-10℃ / min for 5-6 hours.

[0021] In a third aspect, the present application provides the use of the alumina-supported ruthenium-erbium-cerium trimetallic catalyst in the acetylene hydrochlorination reaction.

[0022] Specifically, the use is as follows: the alumina-supported ruthenium-erbium-cerium trimetallic catalyst is loaded into a fixed bed reactor, raw gas HCl and C2H2 are introduced, the reaction temperature is controlled at 120-200℃, the reaction pressure is controlled at 0.01-2MPa, and chloroethylene is generated.

[0023] Further, the amount-of-substance ratio of the raw gas is n(HCl):n(C2H2)=1:1-1.2:1, and the acetylene volume space velocity is 5-500h-1. -1 .

[0024] Compared with the prior art, the present application has the following advantages:

[0025] (1) The present application uses porous alumina instead of commonly used activated carbon as the carrier, and the prepared catalyst has high catalytic activity and mechanical strength, and good stability; the use of a trimetallic catalyst makes the catalyst have better catalytic activity; thereby solving the problems of low activity and poor stability of the ruthenium catalyst.

[0026] (2) The reagents used in the catalyst preparation method of the present application are easy to obtain, the cost is low, the process is simple, and the method has good application prospect.

[0027] (3) The alumina-supported ruthenium-erbium-cerium trimetallic catalyst described in the present application is used in the acetylene hydrochlorination reaction, the acetylene conversion rate is high, the selectivity of chloroethylene is high, and the catalyst stability is good. (Four) Specific Embodiment

[0028] The present application will be described in detail below with specific examples. It is necessary to point out that the examples are only used to further illustrate the present application, but cannot be understood as limiting the scope of protection of the present application, and the present application is not limited in any way. Those skilled in the art can make some non-essential improvements and adjustments according to the content of the above-mentioned application.

[0029] Example 1

[0030] In a beaker, 2.7 g of Ce(N03)3-6H20 was dissolved in 20 mL of deionized water. Then, 0.3 g of RuCl3and 1.2 g of Er(N03)3-5H20 promoter salt were added into the beaker to mix with the cerium nitrate solution, which was magnetically stirred at 100 r / min for 30 min at room temperature. 25 g of alumina balls with an average diameter of 4 mm (specific surface area 1117.2549 m2 / g, total pore volume 0.607815 cc / g, same below) were immersed in the prepared metal salt solution, and placed in a fume hood for impregnation for 8 h. After impregnation, the catalyst was placed in an oven at 100 °C for drying for 24 h, and then calcined at 1000 °C in an air atmosphere using a muffle furnace at a temperature rising rate of 10 °C / min for 6 h to obtain a catalyst with a metal loading ratio of Ru:Er:Ce of 10 wt%:30 wt%:60 wt%, wherein the Ru loading amount was 0.5 wt%, which was recorded as catalyst 1. 2 2) / g, total pore volume 0.607815 cc / g, same below) were immersed in the prepared metal salt solution, and placed in a fume hood for impregnation for 8 h. After impregnation, the catalyst was placed in an oven at 100 °C for drying for 24 h, and then calcined at 1000 °C in an air atmosphere using a muffle furnace at a temperature rising rate of 10 °C / min for 6 h to obtain a catalyst with a metal loading ratio of Ru:Er:Ce of 10 wt%:30 wt%:60 wt%, wherein the Ru loading amount was 0.5 wt%, which was recorded as catalyst 1.

[0031] Application of catalyst 1 in acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction evaluation was carried out on a fixed bed reactor device, and the reaction conditions were as follows: temperature 140 °C, reaction pressure 0.01 MPa, n(HCl):n(C2H 2) = 1.1:1, acetylene space velocity 15 h -1 -1. The initial acetylene conversion rate was 99.2%, and the vinyl chloride selectivity was 98.8%. After 1000 h of reaction, the acetylene conversion rate was 84.13%, and the vinyl chloride selectivity was 97.0%.

[0032] Example 2

[0033] In a beaker, 2.5 g of Ce(N03)3-6H20 was dissolved in 20 mL of deionized water. Then, 0.3 g of RuCl3and 1.33 g of Er(N03)3-5H20 promoter salt were added into the beaker to mix with the cerium nitrate solution, which was magnetically stirred at 100 r / min for 30 min at room temperature. 25 g of alumina balls with an average diameter of 4 mm were immersed in the prepared metal salt solution, and placed in a fume hood for impregnation for 8 h. After impregnation, the catalyst was placed in an oven at 100 °C for drying for 24 h, and then calcined at 1000 °C in an air atmosphere using a muffle furnace at a temperature rising rate of 10 °C / min for 6 h to obtain a catalyst with a metal loading ratio of Ru:Er:Ce of 10 wt%:30 wt%:60 wt%, wherein the Ru loading amount was 0.5 wt%, which was recorded as catalyst 1.

[0034] Application of catalyst 2 in acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction evaluation was carried out on a fixed bed reactor device, and the reaction conditions were as follows: temperature 140 °C, reaction pressure 0.01 MPa, n(HCl):n(C2H 2)= 1.1 : 1, acetylene space velocity 15 h -1 The conversion of acetylene was 97.4% and the selectivity of vinyl chloride was 97.6% at the beginning of the reaction. After 1000 hours of reaction, the conversion of acetylene was 70.6% and the selectivity of vinyl chloride was 93.4%.

[0035] Example 3

[0036] In a beaker, 2.95 g of Ce(N03)3-6H20 was dissolved in 20 mL of deionized water. Then, 0.3 g of RuCl3and 0.96 g of Er(N03)3-5H20 promoter salt were added into the beaker to mix with the cerium nitrate solution, which was magnetically stirred at 100 r / min for 30 min at room temperature. 25 g of alumina balls with an average diameter of 4 mm were immersed in the prepared metal salt solution, and placed in a fume hood for 8 h of impregnation. After impregnation, the catalyst was dried in an oven at 100 °C for 24 h, and then calcined at 1000 °C in an air atmosphere using a muffle furnace at a heating rate of 10 °C / min for 6 h to obtain a catalyst with a metal loading ratio of Ru:Er:Ce of 10 wt%:25 wt%:65 wt%, wherein the Ru loading was 0.5 wt%, which was recorded as catalyst 3.

[0037] Application of catalyst 3 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated on a fixed bed reactor device under the reaction conditions of a temperature of 140 °C, a reaction pressure of 0.01 MPa, n(HCl):n(C2H 2) = 1.1 : 1, acetylene space velocity 15 h -1 The conversion of acetylene was 96.2% and the selectivity of vinyl chloride was 97.8% at the beginning of the reaction. After 1000 hours of reaction, the conversion of acetylene was 72.88% and the selectivity of vinyl chloride was 94.5%.

[0038] Comparative example 1

[0039] Comparative example 1 is used to illustrate that the three-metal catalyst system has a key influence on the catalytic activity of the catalyst by comparison with example 1.

[0040] In a beaker, 2.7 g of Ce(N03)3-6H20 was dissolved in 20 mL of deionized water. Then, 0.3 g of RuCl3was added to mix with the cerium nitrate solution, which was magnetically stirred at 100 r / min for 30 min at room temperature. 25 g of alumina balls with an average diameter of 4 mm were immersed in the prepared metal salt solution, and placed in a fume hood for 8 h of impregnation. After impregnation, the catalyst was dried in an oven at 100 °C for 24 h, and then calcined at 1000 °C in an air atmosphere using a muffle furnace at a heating rate of 10 °C / min for 6 h to obtain a catalyst with a Ru loading of 0.5 wt%, which was recorded as catalyst 4.

[0041] Application of catalyst 4 in acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction evaluation was carried out on a fixed bed reactor device, and the reaction conditions were as follows: temperature 140℃, reaction pressure 0.01 MPa, n(HCl):n(C2H 2) = 1.1:1, acetylene space velocity 15h -1 In the initial stage of the reaction, the acetylene conversion rate was 95.8%, and the vinyl chloride selectivity was 96.9%; after 1000 hours of reaction, the acetylene conversion rate was 66.4%, and the vinyl chloride selectivity was 93.4%.

[0042] Comparative example 2

[0043] Comparative example 2 is to illustrate that the three-metal catalyst system has a key influence on the catalytic activity of the catalyst by comparing with example 1.

[0044] In a beaker, 0.3g RuCl3 and 1.2g Er(NO3)3·5H2O were dissolved in 20mL deionized water and mixed, then magnetically stirred at 100r / min for 30min at room temperature, 25g of alumina balls with an average diameter of 4mm were immersed in the prepared metal salt solution, placed in a fume hood for 8h of immersion, after immersion, the catalyst was placed in a 100℃ oven for drying for 24h, then calcined in an air atmosphere at 1000℃ using a muffle furnace with a heating rate of 10℃ / min for 6h, to obtain a catalyst with a Ru loading of 0.5wt%, denoted as catalyst 5.

[0045] Application of catalyst 5 in acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction evaluation was carried out on a fixed bed reactor device, and the reaction conditions were as follows: temperature 140℃, reaction pressure 0.01 MPa, n(HCl):n(C2H 2) = 1.1:1, acetylene space velocity 15h -1 In the initial stage of the reaction, the acetylene conversion rate was 95.8%, and the vinyl chloride selectivity was 96.9%; after 1000 hours of reaction, the acetylene conversion rate was 66.4%, and the vinyl chloride selectivity was 93.4%.

[0046] Comparative example 3

[0047] In a beaker, 0.3g RuCl3 was dissolved in 20mL deionized water, and magnetically stirred at 100r / min for 30min at room temperature, 25g of alumina balls with an average diameter of 4mm were immersed in the prepared metal salt solution, placed in a fume hood for 8h of immersion, after immersion, the catalyst was placed in a 100℃ oven for drying for 24h, then calcined in an air atmosphere at 1000℃ using a muffle furnace with a heating rate of 10℃ / min for 6h, to obtain a catalyst with a Ru loading of 0.5wt%, denoted as catalyst 6.

[0048] Application of catalyst 6 in ethyne hydrochlorination reaction: ethyne hydrochlorination reaction evaluation was carried out on a fixed bed reactor device, under the reaction conditions of temperature 140℃, reaction pressure 0.01 MPa, n(HCl):n(C2H 2) =1.1:1, ethyne space velocity 15h -1 In the initial stage of the reaction, ethyne conversion rate was 91.4%, and vinyl chloride selectivity was 95.7%; after 1000 hours of reaction, ethyne conversion rate was 56.9%, and vinyl chloride selectivity was 93.1%.

[0049] Comparative example 4

[0050] Comparative example 4 is to illustrate that alumina as a carrier can improve the stability of the catalyst by comparison with comparative example 3.

[0051] Select columnar medium activated carbon carrier 25g, wash with water to remove ash and dry for standby. In a beaker, 0.3g RuCl3 is dissolved in 20mL deionized water, and the solution is magnetically stirred at 100r / min for 30min at room temperature. 25g of columnar medium activated carbon with an average particle size of 4mm is immersed in the prepared metal salt solution, and placed in a fume hood for 8h of immersion. After immersion, the catalyst is placed in a 100℃ oven for drying for 24h, and then calcined in a muffle furnace at 1000℃ in air atmosphere with a heating rate of 10℃ / min for 6h to obtain a catalyst with Ru loading of 0.5wt%, which is recorded as catalyst 7.

[0052] Application of catalyst 7 in ethyne hydrochlorination reaction: ethyne hydrochlorination reaction evaluation was carried out on a fixed bed reactor device, under the reaction conditions of temperature 140℃, reaction pressure 0.01 MPa, n(HCl):n(C2H 2) =1.1:1, ethyne space velocity 15h -1 In the initial stage of the reaction, ethyne conversion rate was 90.6%, and vinyl chloride selectivity was 96.3%; after 1000 hours of reaction, ethyne conversion rate was 35.9%, and vinyl chloride selectivity was 92.2%.

[0053] Comparative example 5

[0054] Comparative example 5 is to illustrate that alumina as a carrier can improve the stability of the catalyst by comparison with example 1.

[0055] Select cylindrical medium activated carbon support 25 g, washed with water to remove ash and dried for later use. In a beaker, 2.7 g Ce(NO3)3·6H2O was dissolved in 20 mL deionized water. Then, 0.3 g RuCl3and 1.2 g Er(NO3)3·5H2O promoter salts were mixed with the cerium nitrate solution in the beaker, and stirred at 100 r / min for 30 min at room temperature. 25 g of cylindrical medium activated carbon with an average diameter of 4 mm was immersed in the prepared metal salt solution, and placed in a fume hood for 8 h of impregnation. After impregnation, the catalyst was dried in an oven at 100 °C for 24 h, and then calcined in an air atmosphere at 1000 °C using a muffle furnace with a heating rate of 10 °C / min for 6 h to obtain a catalyst with a metal loading ratio of Ru:Er:Ce of 10 wt%:30 wt%:60 wt%, wherein the Ru loading was 0.5 wt%, and was recorded as catalyst 8.

[0056] Application of catalyst 8 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated on a fixed bed reactor device, under the reaction conditions of a temperature of 140 °C, a reaction pressure of 0.01 MPa, n(HCl):n(C2H2) = 1.1:1, an acetylene space velocity of 15 h 2) -1 The initial acetylene conversion rate was 99.0%, and the vinyl chloride selectivity was 98.1%. After 1000 h of reaction, the acetylene conversion rate was 68.92%, and the vinyl chloride selectivity was 95.5%.​

Claims

1. Use of an alumina-supported ruthenium-erbium-cerium trimetallic catalyst in the hydrochlorination of acetylene, characterized in that: The alumina-supported ruthenium-erbium-cerium trimetallic catalyst comprises a carrier and a metal active component supported on the carrier, wherein the carrier is porous alumina; and the alumina-supported ruthenium-erbium-cerium trimetallic catalyst is prepared by the following method: uniformly adsorbing a salt solution containing a ruthenium salt, an erbium salt and a cerium salt onto the carrier by wet impregnation, and then drying and calcining in an air atmosphere to obtain the alumina-supported ruthenium-erbium-cerium trimetallic catalyst.

2. Use according to claim 1, characterized in that: The average particle size of the porous alumina is between 3-4 mm, and the specific surface area is 1000-1200 m 2 / g.

3. The use according to claim 1, characterized in that: The feeding ratio of the ruthenium salt, the erbium salt and the cerium salt is 10%: 25-35%: 55-65% in terms of the mass ratio of the metal elements ruthenium, erbium and cerium contained therein.

4. Use according to claim 3, wherein: The feeding ratio of the ruthenium salt, the erbium salt and the cerium salt is 10%: 25-35%: 55-65% in terms of the mass ratio of the metal elements ruthenium, erbium and cerium contained therein.

5. The use according to claim 1, characterized in that: In the alumina-supported ruthenium-erbium-cerium trimetallic catalyst, the loading amount of ruthenium relative to the carrier is 0.5-0.6 wt%.

6. The use according to claim 1, characterized in that: The wet impregnation is to immerse the carrier in a salt solution containing a ruthenium salt, an erbium salt and a cerium salt, and immerse in a fume hood at room temperature for 6-8 hours.

7. The use according to claim 1, characterized in that: The drying condition is to dry in an oven at 100-110℃ for 20-24 hours.

8. The use according to claim 1, characterized in that: The calcination temperature is 1000-1100℃, and the calcination time is 5-6 h.

9. Use according to any one of claims 1 to 8, characterized in that: The preparation method of the alumina-supported ruthenium-erbium-cerium trimetallic catalyst comprises the following steps: Step one: mixing and dissolving the ruthenium salt, the erbium salt and the cerium salt in a solvent in a certain proportion to prepare a salt solution; Step two: immersing the carrier in the salt solution, drying and calcining in an air atmosphere after sufficient impregnation to obtain the alumina-supported ruthenium-erbium-cerium trimetallic catalyst for acetylene hydrochlorination reaction.

10. Use according to claim 9, wherein: In step one, the ruthenium salt is anhydrous ruthenium chloride, the erbium salt is Er(NO3)3·5H2O, the cerium salt is Ce(NO3)2·6H2O, and the solvent is deionized water.

11. The use according to claim 1, characterized in that: The application specifically refers to loading the alumina-supported ruthenium-erbium-cerium trimetallic catalyst into a fixed bed reactor, passing in raw gas HCl and C2H2, controlling the reaction temperature to be 120-200℃ and the reaction pressure to be 0.01-2 MPa to generate chloroethylene.

12. The use according to claim 11, characterized in that: The raw gas material has a mass ratio of n(HCl):n(C2H2) = 1:1 ~ 1.2:1, and the acetylene volume space velocity is 5 ~ 500 h -1 .