Acetylene hydrochlorination copper-based catalyst and preparation method and application thereof
阅读说明：本技术 一种乙炔氢氯化铜基催化剂及其制备方法和应用 (Acetylene hydrochlorination copper-based catalyst and preparation method and application thereof ) 是由 王旭 牛强 朱瑞波 徐小雷 解荣永 赵长森 于 2021-07-21 设计创作，主要内容包括：本发明提供了一种乙炔氢氯化铜基催化剂及其制备方法和应用,属于有机合成领域。所述的催化剂由载体、活性组分、助剂三部分组成,催化剂所用的载体是活性炭,催化剂所用的活性组分是Cu的金属盐,所用助剂是由一种或多种不同种类离子液体组成。该催化剂具有制备工艺简单、反应活性高、使用寿命长、易于工业化生产等优点。(The invention provides an acetylene hydrochlorination copper-based catalyst and a preparation method and application thereof, belonging to the field of organic synthesis. The catalyst consists of three parts, namely a carrier, an active component and an auxiliary agent, wherein the carrier used by the catalyst is activated carbon, the active component used by the catalyst is a metal salt of Cu, and the auxiliary agent consists of one or more ionic liquids of different types. The catalyst has the advantages of simple preparation process, high reaction activity, long service life, easy industrial production and the like.)
1. The copper-based catalyst for acetylene hydrochlorination is characterized in that: the preparation method comprises the following steps:
(1) taking wood activated carbon, coconut shell activated carbon or coal activated carbon as a carrier, carrying out nitrogen doping treatment on the carrier, and carrying out pretreatment for 2-10h at normal temperature by using hydrochloric acid to obtain a pretreated precursor;
(2) preparing a mixed solution of an ionic liquid auxiliary agent and a metal copper salt, adding the pretreated precursor, soaking at normal temperature in an equal volume, standing for 1h, rotationally evaporating and drying at 60 ℃ for 2h, and then drying in an oven at 120 ℃ overnight to obtain the acetylene hydrochlorination copper-based catalyst.
2. Copper-based catalyst for acetylene hydrochlorination according to claim 1 characterized in that: the nitrogen doping treatment in the step (1) comprises the following steps: dipping the activated carbon in a solution containing N for 5-10h, and drying at 120 ℃ to obtain activated carbon 1; then adding activated carbon 1 in N2Carbonizing at 500-600 ℃ for 2-6h in the atmosphere, and then activating at 800 ℃ for 1-3 h by using mixed gas of water vapor and carbon dioxide with the volume ratio of 1:1 to obtain nitrogen-doped activated carbon;
the solution containing N is selected from one or more of urea, melamine and ethylenediamine.
3. Copper-based catalyst for acetylene hydrochlorination according to claim 1 characterized in that: the ionic liquid auxiliary agent in the step (2) is selected from one of N-methyl pyrrolidone, N-ethyl-2-pyrrolidone, 1-butyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1-butyl-3-methylimidazole dicyanamide salt and 1-butyl-3-methylimidazole chloride salt.
4. Copper-based acetylene hydrochlorination catalyst according to claim 3 characterized in that: the ionic liquid auxiliary agent in the step (2) is selected from N-methylformamide or N-hydroxyethyl-2-pyrrolidone.
5. Copper-based catalyst for acetylene hydrochlorination according to claim 1 characterized in that: the metallic copper salt in the step (2) is selected from one or more of chloride, nitrate and sulfate of copper.
6. Copper-based acetylene hydrochlorination catalyst according to claim 5 characterized in that: the copper salt of the metal in the step (2) is selected from hydrated copper chloride.
7. Copper-based catalyst for acetylene hydrochlorination according to claim 1 characterized in that: the volume ratio of the ionic liquid to the metal copper salt in the step (2) is 1: 2-15; preferably, the volume ratio of the ionic liquid to the metal copper salt is 1:15,1:5,1:3 or 7: 15.
8. Copper-based catalyst for acetylene hydrochlorination according to claim 1 characterized in that: the mass of the copper ions accounts for 5-15% of the weight of the catalyst.
9. Copper-based catalyst for acetylene hydrochlorination according to claim 1 characterized in that: the mass of the ionic liquid accounts for 1-10% of the weight of the catalyst.
10. Use of a copper-based catalyst for the hydrochlorination of acetylene according to any one of claims 1 to 9 in the catalysis of the hydrochlorination of acetylene.
Technical Field
The invention belongs to the field of organic synthesis, and particularly relates to an acetylene hydrochlorination copper-based catalyst taking an ionic liquid as an auxiliary agent, and a preparation method and application thereof.
Background
Vinyl chloride is a raw material for synthesizing polyvinyl chloride, and there are 3 kinds of methods for synthesizing vinyl chloride, namely an acetylene method, an ethylene method and an ethane method, and currently, the acetylene method using coal as a raw material and the ethylene method using petroleum as a raw material are mainly industrialized. At present, the polyvinyl chloride produced by the acetylene method is commonly used as a mercury catalyst, mercury is volatile as a heavy metal, and the loss and volatilization of mercury in the use process of the mercury catalyst can cause serious pollution damage to the environment and people, so that the research and development of a mercury-free catalyst for replacing a mercury-containing catalyst are imperative.
The ionic liquid has the advantages of good solubility, ionic conductivity, wide operable temperature range, extremely low vapor pressure and the like, and can solve the problems of loss of active components of a metal catalyst and low reaction activity in acetylene hydrochlorination to a certain extent. Li et al]AuCl 4A 0.1% Au-IL/AC catalyst was prepared to stabilize Au3+At 180 deg.C, C2H2 GHSV is 370H-1,VHCl:VC2H2Under the reaction condition of 1.2, the acetylene conversion rate reaches 77.1 percent; yi Yu et al in CuCl2Imidazole ionic liquid is added into the catalyst to increase the synergistic effect with the metal active component, and the temperature is 140 ℃, and the C2H2 GHSV is 370H-1,VHCl:VC2H2Under reaction conditions of 1.2, Cu-IL exhibits a specific Cu-to-IL ratio2+Better catalytic activity; cao et al found [ BMIm ] by studying the effect of different types of ionic liquids on the activity of acetylene hydrochlorination]Cl increased acetylene conversion to 68%, and in addition, they studied ionic liquids for other metal chlorides (HgCl)2,MnCl4, H2[PtCl6]And H [ AuCl ]4]) Under the action of a mercury-free catalyst as an active component, the addition of the ionic liquid is found to effectively improve the acetylene conversion rate; zhang et al reported imidazole-based ionic liquids, [ BMIm]BF4, which can greatly improve the performance of Ru-based catalyst loaded on active carbon, although it is not a good catalyst; various studies have shown that IL can be amplified with metal catalysisThe catalyst has a synergistic effect and promotes the performance of the catalyst, and has a good application prospect in later-stage catalyst development and industrial application.
The research and development of the mercury-free catalyst are mainly two kinds of metal catalysts with noble metals such as Au, Pd, Ru and the like and non-noble metals such as Bi, Sn, Cu and the like as active centers. In patent CN112156809A, Au metal is compounded as an active component, and the initial activity of the catalyst can reach 71.2% by modifying with ionic liquid, but no stability test result exists. Compared with gold-based catalysts, the copper-based catalyst has low production cost and is beneficial to industrial production.
The patent CN 110743613B reduces the mass transfer effect by using different ionic liquids to stabilize metal ions and the ionic liquids on the outer surface layer of the catalyst in a coordinated manner. One or more metals of gold, ruthenium, rhodium and copper are mainly selected and loaded in a mode of an external electrostatic field, so that the problems of complex preparation method and the like exist.
Therefore, it is necessary to develop a method for preparing activated carbon by an impregnation method, which can greatly reduce the preparation difficulty and is beneficial to industrial production.
Disclosure of Invention
Based on the problems in the prior art, the invention aims to solve the problem of developing a copper-based catalyst for acetylene hydrochlorination with an industrial prospect, wherein the catalyst can meet the requirements and standards of the catalyst for acetylene hydrochlorination in industry.
The specific technical scheme of the invention is as follows:
the copper-based catalyst for acetylene hydrochlorination is prepared by the following method:
(1) taking wood activated carbon, coconut shell activated carbon or coal activated carbon as a carrier, carrying out nitrogen doping treatment on the carrier, and carrying out pretreatment for 2-10h at normal temperature by using hydrochloric acid to obtain a pretreated precursor;
(2) preparing a mixed solution of an ionic liquid auxiliary agent and a metal copper salt, adding the pretreated precursor, soaking at normal temperature in an equal volume, standing for 1h, rotationally evaporating and drying at 60 ℃ for 2h, and then drying in an oven at 120 ℃ overnight to obtain the acetylene hydrochlorination copper-based catalyst.
The nitrogen doping treatment in the step (1) comprises the following steps: dipping the activated carbon in a solution containing N for 5-10h, and drying at 120 ℃ to obtain activated carbon 1; then adding activated carbon 1 in N2Carbonizing at 500-600 ℃ for 2-6h in the atmosphere, and then activating at 800 ℃ for 1-3 h by using mixed gas of water vapor and carbon dioxide with the volume ratio of 1:1 to obtain nitrogen-doped activated carbon;
the solution containing N is selected from one or more of urea, melamine and ethylenediamine.
The ionic liquid auxiliary agent in the step (2) is selected from one of N-methyl pyrrolidone, N-ethyl-2-pyrrolidone, 1-butyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1-butyl-3-methylimidazole dicyanamide salt and 1-butyl-3-methylimidazole chloride salt;
the metal copper salt in the step (2) is selected from one or more of copper chloride, nitrate and sulfate;
preferably, the copper salt of a metal described in the above step (2) is selected from copper chloride hydrate.
The volume ratio of the ionic liquid to the metal copper salt in the step (2) is 1: 2-15; preferably, the volume ratio of the ionic liquid to the metal copper salt is 1:15,1:5,1:3 or 7: 15.
The mass of the copper ions accounts for 5-15% of the weight of the catalyst; the mass of the ionic liquid accounts for 1-10% of the weight of the catalyst;
the impregnation in the step (2) is a loading process of the active component, that is, the ionic liquid and the metal copper salt are prepared into an impregnation solution, and the impregnation solution is loaded on the active carbon by adopting an isometric impregnation method.
The invention provides application of the catalyst in catalyzing acetylene hydrochlorination.
The application condition is that T is 130-200 ℃; normal pressure; GHSV (C)2H2)＝30～90h-1；n(HCl):n(C2H2)＝1.05～1.45。
Compared with the prior art, the invention has the beneficial effects that:
cu metal is used as a catalytic active component, and ionic liquid is added as an auxiliary agent, so that the catalytic activity of the catalyst can be effectively improved, and the industrial preparation cost of the catalyst is reduced.
Detailed Description
The following is a more specific example description of the catalyst.
Basic embodiment
The nitrogen doping treatment steps are as follows:
dipping the activated carbon in a solution containing N for 5-10h, and drying at 120 ℃ to obtain activated carbon 1; then adding activated carbon 1 in N2Carbonizing at 500-600 ℃ for 2-6h in the atmosphere, and then activating at 800 ℃ for 1-3 h by using mixed gas of water vapor and carbon dioxide with the volume ratio of 1:1 to obtain nitrogen-doped activated carbon;
the solution containing N is selected from one or more of urea, melamine and ethylenediamine.
Example 1
(1) Weighing 100g of nitrogen-doped wood activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, weighing 24g of copper chloride hydrate and 1.8g of N-methylformamide, dissolving in 54mL of deionized water, dropwise adding into the nitrogen-doped activated carbon, soaking for half an hour, then moving to a flask, carrying out rotary drying at 60 ℃ for 2 hours, and transferring to an oven to be dried at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2The initial acetylene conversion rate is 95.5 percent, the vinyl chloride selectivity is more than 99.5 percent, the reaction is operated for 1000 hours, and the catalyst acetylene conversion rate is 85.5 percent.
Example 2
(1) Weighing 100g of nitrogen-doped wood activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, dissolving 24g of copper chloride hydrate and 1.8g of N-ethyl-2-pyrrolidone in 54mL of deionized water, dropwise adding the solution into nitrogen-doped activated carbon, dipping for half an hour, transferring the solution into a flask, carrying out rotary drying at 60 ℃ for 2 hours, transferring the solution into an oven, and drying at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2When HCl is 1:1.08, the initial acetylene conversion rate is 87.3%, the selectivity of chloroethylene is more than 99.5%, the reaction is operated for 1000h, and the catalyst acetylene conversion rate is 73.5%.
Example 3
(1) Weighing 100g of nitrogen-doped wood activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, dissolving 24g of copper chloride hydrate and 1.8g of 1-butyl-2-pyrrolidone in 54mL of deionized water, dropwise adding the solution into nitrogen-doped activated carbon, dipping for half an hour, transferring the solution into a flask, carrying out rotary drying at 60 ℃ for 2 hours, transferring the solution into an oven, and drying at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2HCl 1:1.08, initial acetylene conversion 87, vinyl chloride selectivity greater than 99.5%, reaction run 1000h, catalyst acetylene conversion 69.8%.
Example 4
(1) Weighing 100g of nitrogen-doped coal-based activated carbon, immersing the activated carbon for 4h by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8h at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, dissolving 24g of copper chloride hydrate and 1.8g of N-hydroxyethyl-2-pyrrolidone in 54mL of deionized water, dropwise adding the solution into the nitrogen-doped activated carbon, dipping for half an hour, transferring the solution into a flask, carrying out rotary drying at 60 ℃ for 2 hours, transferring the solution into an oven, and drying at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst was evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2When HCl is 1:1.08, the initial acetylene conversion rate is 91%, the selectivity of chloroethylene is more than 99.5%, the reaction is operated for 1000h, and the catalyst acetylene conversion rate is 80.4%.
Example 5
(1) Weighing 100g of nitrogen-doped wood activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, weighing 24g of copper chloride hydrate and 1.8g of 2-pyrrolidone, dissolving in 54mL of deionized water, dropwise adding into nitrogen-doped activated carbon, soaking for half an hour, transferring to a flask, carrying out rotary drying at 60 ℃ for 2 hours, transferring to an oven, and drying at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The raw material gas C2H2: HCl is 1:1.08, the initial acetylene conversion rate is 71%, the vinyl chloride selectivity is more than 99.5%, the reaction is operated for 1000H, and the catalyst acetylene conversion rate is 67.9%.
Example 6
(1) Weighing 100g of nitrogen-doped wood activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, weighing 24g of copper chloride hydrate and 1.8g of 1-butyl, 3-methylimidazol dicyanamide salt, dissolving in 54mL of deionized water, dropwise adding into nitrogen-doped activated carbon, dipping for half an hour, transferring to a flask, carrying out rotary drying at 60 ℃ for 2 hours, transferring to an oven, and drying at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2The initial acetylene conversion rate is 74 percent, the vinyl chloride selectivity is more than 99.5 percent, the reaction is operated for 1000 hours, and the catalyst acetylene conversion rate is 64.1 percent.
Example 7
(1) Weighing 100g of nitrogen-doped coconut shell activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃ to obtain a pretreated precursor;
(2) weighing 40g of pretreated activated carbon, dissolving 24g of copper chloride hydrate and 1.8g of 1-butyl, 3-methylimidazolium chloride in 54mL of deionized water, dropwise adding the solution into the nitrogen-doped activated carbon, dipping for half an hour, transferring the solution into a flask, carrying out rotary drying at 60 ℃ for 2 hours, and transferring the solution into an oven to be dried at 120 ℃ for 12 hours to obtain the catalyst.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2The initial acetylene conversion rate is 75 percent, the vinyl chloride selectivity is more than 99.5 percent, the reaction is operated for 1000 hours, and the catalyst acetylene conversion rate is 63.2 percent.
Comparative example 1
Weighing 100g of nitrogen-doped wood activated carbon, immersing the activated carbon for 4 hours by using 500mL of 5% wt hydrochloric acid solution, washing the activated carbon with deionized water after filtering until the pH value of the aqueous solution is close to 5, and drying the activated carbon for 8 hours at 90 ℃; and then 38g of hydrochloric acid pretreated activated carbon is taken, 24g of hydrated copper chloride is weighed and dissolved in 52mL of deionized water, the mixture is dropwise added into the nitrogen-doped activated carbon, the mixture is immersed for half an hour and then moved to a flask, the mixture is rotationally dried for 2 hours at the temperature of 60 ℃, and the mixture is transferred to an oven to be dried for 12 hours at the temperature of 120 ℃, so that the catalyst can be obtained.
The catalyst is evaluated at a temperature of 150 ℃ and a space velocity of 90h-1The feed gas C2H2The initial acetylene conversion is 68 percent, the vinyl chloride selectivity is more than 99.5 percent, the reaction is operated for 1000 hours, and the catalyst acetylene conversion is 53.5 percent.
Effect experiment: catalyst Performance testing
See table 1 for details.
Table 1 comparison of catalyst Performance between examples 1-7 and comparative example 1
The following conclusions can be drawn by comparing examples 1 to 7 with comparative example 1: comparison of example 1 with comparative examples 1-7 yields: the catalyst is lack of ionic liquid auxiliary agent, only metallic copper ions are taken as active components, and the activity of acetylene hydrochlorination reaction is obviously reduced.
The technical scheme of the invention is not limited to the technical means disclosed by the technical means, and also comprises the technical scheme formed by any combination of the technical features. While the foregoing is directed to embodiments of the present invention, it will be appreciated by those skilled in the art that various changes may be made in the embodiments without departing from the principles of the invention, and that such changes and modifications are intended to be included within the scope of the invention.