A hydrophobically modified activated carbon supported copper catalyst, its preparation method and application

Abstract

This invention belongs to the field of catalyst preparation technology, and relates to a hydrophobically modified activated carbon-supported copper catalyst, its preparation method, and its application. The catalyst includes a support, an active component, and a co-catalyst component; the support is activated carbon; the active component is a copper salt; and the co-catalyst component is an ionic liquid; the ionic liquid is an ionic liquid formed by the reaction of DBU with at least one of 4-methylimidazole, 2-ethylimidazole, and 4-hydroxyethylimidazole. The modified activated carbon of this invention can inhibit the migration of copper ions by water components in the feed gas, reducing the loss of copper active components. The ionic liquid creates a HCl-rich environment, inhibiting catalyst reduction and deactivation, and improving catalyst stability. The preparation method of this invention is simple and effective, significantly improving copper ion loss and water resistance, which is beneficial for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, and relates to a hydrophobically modified activated carbon supported copper catalyst, its preparation method and application. Background Technology

[0002] Vinyl chloride monomer (VCM) is the basic material for synthesizing polyvinyl chloride (PVC), which is one of the most widely used materials in the world. Since 1930, the hydrochlorination of acetylene to produce vinyl chloride has remained the main production method in coal-rich countries. The mercuric chloride catalysts previously used in industry are volatile and toxic, causing serious impacts on the local ecological environment and human health. Therefore, the development and promotion of mercury-free catalysts is urgently needed.

[0003] Catalysts prepared by supporting mercuric chloride or chloroauric acid on activated carbon have been extensively studied and have shown excellent catalytic performance in the hydrochlorination of acetylene. However, their industrialization has been limited by issues such as toxicity or high cost. Copper chloride, with its moderate standard electrode potential, low toxicity, and good thermal stability, has attracted widespread attention from researchers in recent years and is expected to become a new generation of mercury-free non-precious metal catalysts.

[0004] Carbon materials are widely used in energy conversion, CO2 adsorption and capture, and heterogeneous catalysts due to their high specific surface area and other properties. Currently, many studies improve the strength and water resistance of carbon materials through modification, thereby enhancing the stability and catalytic performance of catalysts. In industrial production processes, the water component in the raw gas can carry away gold, copper, and other elements from the catalyst, causing loss of active components or particle aggregation, which in turn leads to a decrease in catalyst activity. Chinese invention patent CN113634265A discloses a Cu-Ru acetylene hydrochlorination catalyst for the synthesis of vinyl chloride and its preparation method. The preparation method includes the following steps: (1) Pretreatment: immersing activated carbon in hydrochloric acid; (2) immersing the pretreated activated carbon in a mixed solution A, allowing it to stand, drying it, and calcining it to obtain the catalyst; wherein, the mixed solution A is prepared from active components and additives; the active components are Cu metal salts and Ru metal salts; the additives are non-precious metal salts and / or organic compounds. This invention uses precious metals as active ingredients, which increases the cost of the catalyst and is not conducive to large-scale production.

[0005] Chinese invention patent CN110743613A discloses a supported metal catalyst, its preparation method, and its application. In this catalyst, the metal is stabilized on the outer surface of the catalyst through coordination with an ionic liquid, reducing the impact of mass transfer and improving the metal dispersion. The ionic liquid is stabilized on the support surface through silanol groups, exhibiting higher stability and being less prone to leaching from the support surface. This invention is the first to introduce an external static electric field into the preparation of a metal-based catalyst supported on an ionic liquid, promoting the enrichment of metal active centers on the ionic liquid surface. Because the active metal centers of this catalyst are distributed on the ionic liquid surface, the influence of substrate diffusion is reduced, and the induction period of the catalyst disappears under the evaluated reaction conditions. This invention fundamentally solves the shortcomings of low gas metal dispersion and low mass transfer in supported ionic liquid catalyst systems. However, this invention uses an external static electric field, making the operation cumbersome; and the use of precious metal salts increases production costs.

[0006] Therefore, it is of practical significance to study a catalyst that is low in cost, has good performance, and has prospects for industrial application. Summary of the Invention

[0007] Terminology and Declarations of this Invention:

[0008] 1. Articles “a,” “a kind,” and “the”: These include plural objects unless otherwise explicitly specified as a single (kind) object.

[0009] 2. Numerical Range: Unless otherwise expressly stated, all ranges or ratios disclosed herein shall be construed as including any and all subranges or subratios contained herein. For example, a stated range or ratio of 1 to 30 shall be considered to be included between the minimum value of 1 and the maximum value of 30, and includes any subranges or subratios, integers, decimals, or subranges or subratios consisting of integers or decimals, including the endpoints.

[0010] To address the technical problems of high cost and difficulty in industrial production of existing technologies, the purpose of this invention is to provide a hydrophobically modified activated carbon-supported copper catalyst, its preparation method, and its application. The catalyst of this invention has industrial application prospects and can meet the requirements and standards for acetylene hydrochlorination catalysts in industry.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] This invention provides a copper-supported catalyst on hydrophobically modified activated carbon, comprising a support, an active component, and a co-catalytic component; wherein the support is activated carbon; the active component is a copper salt; and the co-catalytic component is an ionic liquid; wherein the ionic liquid is an ionic liquid formed by reacting 1,8-diazabicyclo[5.4.0]undec-7-ene with at least one of 4-methylimidazole, 2-ethylimidazole, and 4-hydroxyethylimidazole.

[0013] Furthermore, the activated carbon is obtained by modifying wood-based activated carbon as a carrier.

[0014] Furthermore, the modification uses a silane reagent, which is at least one of trimethylchlorosilane, trimethoxychlorosilane, methyltriethoxysilane, and octadecyltrichlorosilane.

[0015] Furthermore, the wood-based activated carbon is at least one of coconut shell activated carbon, apricot shell activated carbon, walnut shell activated carbon, and peach shell activated carbon.

[0016] Furthermore, the wood-based activated carbon is coconut shell activated carbon.

[0017] Furthermore, the copper salt is at least one of copper chloride, copper sulfate, and copper nitrate.

[0018] Furthermore, the Cu content in the active component accounts for 5-20% of the total mass of the catalyst, and the co-catalytic component accounts for 1-10% of the total mass of the catalyst.

[0019] Furthermore, the ionic liquid is an ionic liquid generated by reacting 1,8-diazabicyclo[5.4.0]undec-7-ene with 4-methylimidazolium, 2-ethylimidazolium and 4-hydroxyethylimidazolium in a molar ratio of 1:0.5-2.

[0020] Furthermore, the ionic liquid is an ionic liquid generated by reacting 1,8-diazabicyclo[5.4.0]undec-7-ene with 4-methylimidazolium, 2-ethylimidazolium and 4-hydroxyethylimidazolium in a molar ratio of 1:1-2.

[0021] The present invention also provides a method for preparing the above-mentioned catalyst, comprising the following steps:

[0022] S1. Add the silane solution to the activated carbon, stir, dry, and calcine to obtain the modified activated carbon;

[0023] S2. Prepare the active component solution and the co-catalytic component solution, impregnate them into the modified activated carbon described in step S1 according to the formula, stir, let stand for aging and dry to obtain the catalyst.

[0024] Furthermore, in the silane solution described in step S1, the mass fraction of the silane reagent is 5-60%.

[0025] Furthermore, the silane solution described in step S1 is obtained by adding a silane reagent to a hexane solvent.

[0026] Furthermore, the mass fraction of the silane reagent is 10-50% for trimethylchlorosilane, 10-50% for trimethoxychlorosilane, 20-60% for methyltriethoxysilane, and 10-50% for octadecyltrichlorosilane.

[0027] Further, the mass ratio of activated carbon to silane solution in step S1 is 1:5-15.

[0028] Further, the mass ratio of activated carbon to silane solution in step S1 is 1:5-10.

[0029] Furthermore, the stirring described in step S1 is carried out at a temperature of 30-60°C for 3-10 hours.

[0030] Furthermore, the stirring described in step S1 is carried out at a temperature of 40-60°C for 5-10 hours.

[0031] Furthermore, the drying process described in step S1 is carried out at a temperature of 100-140°C for 6-12 hours.

[0032] Furthermore, the drying process described in step S1 is carried out at a temperature of 120°C for 8-12 hours.

[0033] Furthermore, the calcination described in step S1 is carried out at a temperature of 400-800℃ in a N2 atmosphere for 3-6 hours.

[0034] Furthermore, the calcination described in step S1 is carried out at a temperature of 400-600℃ in a N2 atmosphere for 4-5 hours.

[0035] Furthermore, the stirring in step S2 lasts for 10-20 minutes; the static aging in step S2 lasts for 5-10 hours; and the drying in step S2 lasts for 6-12 hours at a temperature of 100-140°C.

[0036] The present invention also provides the application of the catalyst in the acetylene hydrochlorination reaction.

[0037] Furthermore, at T = 120-180℃, normal pressure, and space velocity = 30-360h... -1 The catalyst was evaluated under the condition that the molar ratio of the feed gas n(C2H2):n(HCl) = 1:1.05-1.25.

[0038] Hydrophobic modification of activated carbon involves linking hydrophobic groups in silane reagents to hydroxyl groups on the surface of activated carbon. This inhibits the contact between moisture in the feed gas and active sites, prevents the loss of metal components, and thus improves catalyst stability.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] In this invention, activated carbon is modified with silane reagent, copper chloride is used as the catalytic active component, and ionic liquid is added as a co-catalytic component. The modified activated carbon is hydrophobic, which can inhibit the migration of copper ions by water components in the feed gas and reduce the loss of copper active components. The ionic liquid creates an HCl-rich environment, inhibits the reduction and deactivation of the catalyst, and improves the stability of the catalyst. Detailed Implementation

[0041] The present invention will be further described below with reference to the embodiments. Unless otherwise specified, all chemical reagents used in the present invention are obtained through conventional commercial means.

[0042] Example 1

[0043] A copper-supported catalyst on activated carbon.

[0044] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0045] S1. Prepare a 30% trimethylchlorosilane solution: Add 90g of trimethylchlorosilane to 210g of n-hexane;

[0046] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0047] S3. Weigh 0.7g of 4-methylimidazole and 1.1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, mix well, add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0048] Catalyst performance evaluation:

[0049] At a temperature of 150℃, normal pressure, and a space velocity of 90 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 94.1% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 90.3%.

[0050] Example 2

[0051] A copper-supported catalyst on activated carbon.

[0052] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0053] S1. Prepare a 30% trimethoxychlorosilane solution: Add 90g of trimethoxychlorosilane to 210g of n-hexane;

[0054] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethoxychlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0055] S3. Weigh 0.8g of 2-ethylimidazole and 1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, then add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0056] Catalyst performance evaluation:

[0057] At a temperature of 150℃, normal pressure, and a space velocity of 90 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 89.8% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 78.4%.

[0058] Example 3

[0059] A copper-supported catalyst on activated carbon.

[0060] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0061] S1. Prepare a 30% methyltriethoxysilane solution: Add 90g of methyltriethoxysilane to 210g of n-hexane;

[0062] S2. Mix 50g of wood-based activated carbon with a prepared 30% methyltriethoxysilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0063] S3. Weigh 0.85g of 4-hydroxyethylimidazolium and 0.95g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, then add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0064] Catalyst performance evaluation:

[0065] At a temperature of 150℃, normal pressure, and a space velocity of 60 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 92.3% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 85.2%.

[0066] Example 4

[0067] A copper-supported catalyst on activated carbon.

[0068] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0069] S1. Prepare 30% octadecyltrichlorosilane by mass: Add 90g of octadecyltrichlorosilane to 210g of n-hexane;

[0070] S2. Mix 50g of wood-based activated carbon with a prepared 30% octadecyltrichlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 5h to obtain modified activated carbon.

[0071] S3. Weigh 0.7g of 4-methylimidazole and 1.1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, then add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0072] Catalyst performance evaluation:

[0073] At a temperature of 150℃, normal pressure, and a space velocity of 60 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 83.9% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 78.3%.

[0074] Example 5

[0075] A copper-supported catalyst on activated carbon.

[0076] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0077] S1. Prepare a 30% trimethylchlorosilane solution: Add 90g of trimethylchlorosilane to 210g of n-hexane;

[0078] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0079] S3. Weigh 0.85g of 4-hydroxyethylimidazolium and 0.95g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, then add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0080] Catalyst performance evaluation:

[0081] At a temperature of 150℃, normal pressure, and a space velocity of 60 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 92.8% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 77.9%.

[0082] Comparative Example 1

[0083] The difference between this comparative example and Example 1 is that the activated carbon was not modified with a silane reagent for hydrophobicity.

[0084] A copper-supported catalyst on activated carbon.

[0085] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0086] S1. Weigh 0.7g of 4-methylimidazole and 1.1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution;

[0087] S2. Weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution. Mix well and add it dropwise to 25g of modified activated carbon. Stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0088] Catalyst performance evaluation:

[0089] At a temperature of 150℃, normal pressure, and a space velocity of 60 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 86.7% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 50.1%.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 1 is that ionic liquids are not used as co-catalytic components.

[0092] A copper-supported catalyst on activated carbon.

[0093] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0094] S1. To prepare a 30% trimethylchlorosilane solution, add 90g of trimethylchlorosilane to 210g of n-hexane;

[0095] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0096] S3. Weigh 10g of copper chloride dihydrate and add it to 20g of deionized water to prepare a solution. Add the solution dropwise to 25g of modified activated carbon, stir for 15min, let it stand and age for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0097] Catalyst performance evaluation:

[0098] At a temperature of 150℃, normal pressure, and a space velocity of 60 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 75.6%, the vinyl chloride selectivity is greater than 99.5%, and after 800 hours of reaction operation, the catalyst acetylene conversion rate is 54.2%.

[0099] Comparative Example 3

[0100] The difference between this comparative example and Example 1 is that the ionic liquid is replaced with the ionic liquid in Example 1 of CN110743613A. Specifically, the ionic liquid is composed of 1-butyl-3-methylimidazolium hexafluorophosphate and 1-propyl-3-butylimidazolium tetrafluoroborate in a mass ratio of 1:4.

[0101] A copper-supported catalyst on activated carbon.

[0102] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0103] S1. Prepare a 30% trimethylchlorosilane solution: Add 90g of trimethylchlorosilane to 210g of n-hexane;

[0104] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0105] S3. Weigh 0.36g of 1-butyl-3-methylimidazolium hexafluorophosphate and 1.44g of 1-propyl-3-butylimidazolium tetrafluoroborate and dissolve them in 20g of water to obtain an ionic liquid solution. Weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution. Mix well and add it dropwise to 25g of modified activated carbon. Stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0106] Catalyst performance evaluation:

[0107] At a temperature of 150℃, normal pressure, and a space velocity of 90 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 83.8% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 59.9%.

[0108] Comparative Example 4:

[0109] The difference between this comparative example and Example 1 is that the mass ratio of silane reagent to activated carbon is different; specifically, the mass ratio is 20:1.

[0110] A copper-supported catalyst on activated carbon.

[0111] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0112] S1. Prepare a 30% (w / w) trimethylchlorosilane solution: Add 300g of trimethylchlorosilane to 700g of n-hexane;

[0113] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0114] S3. Weigh 0.7g of 4-methylimidazole and 1.1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, mix well, add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0115] Catalyst performance evaluation:

[0116] At a temperature of 150℃, normal pressure, and a space velocity of 90 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 87.7% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 51.6%.

[0117] Comparative Example 5

[0118] The difference between this comparative example and Example 1 is that the Cu content in the active component is different as a percentage of the total mass of the catalyst.

[0119] A copper-supported catalyst on activated carbon.

[0120] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0121] S1. Prepare a 30% trimethylchlorosilane solution: Add 90g of trimethylchlorosilane to 210g of n-hexane;

[0122] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0123] S3. Weigh 0.7g of 4-methylimidazole and 1.1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 20g of copper chloride dihydrate and add it to the prepared ionic liquid solution, mix well, add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0124] Catalyst performance evaluation:

[0125] At a temperature of 150℃, normal pressure, and a space velocity of 90 h⁻¹ -1Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 93.1% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 61.5%.

[0126] Comparative Example 6

[0127] The difference between this comparative example and Example 1 lies in the different molar ratio of DBU to 4-methylimidazole in the co-catalytic component.

[0128] A copper-supported catalyst on activated carbon.

[0129] A method for preparing a copper-supported catalyst on activated carbon includes the following steps:

[0130] S1. Prepare a 30% trimethylchlorosilane solution: Add 90g of trimethylchlorosilane to 210g of n-hexane;

[0131] S2. Mix 50g of wood-based activated carbon with a prepared 30% trimethylchlorosilane solution, stir at 40℃ for 5h, wash with ethanol 5 times, dry at 120℃ for 12h, and calcine at 500℃ under N2 atmosphere for 4h to obtain modified activated carbon.

[0132] S3. Weigh 1.5g of 4-methylimidazole and 1.1g of 1,8-diazabicyclo[5.4.0]undec-7-ene and dissolve them in 20g of water to obtain an ionic liquid solution; weigh 10g of copper chloride dihydrate and add it to the prepared ionic liquid solution, mix well, add it dropwise to 25g of modified activated carbon, stir for 15min, let it stand for aging for 5 hours, and then transfer it to an oven to dry at 120℃ for 12h to obtain the catalyst.

[0133] Catalyst performance evaluation:

[0134] At a temperature of 150℃, normal pressure, and a space velocity of 90 h⁻¹ -1 Under the condition that the molar ratio of raw gas C2H2:HCl = 1:1.08, the initial acetylene conversion rate is 81.3% and the vinyl chloride selectivity is greater than 99.5%; after 800 hours of reaction operation, the catalyst acetylene conversion rate is 63.2%.

[0135] Table 1 Comparison of catalyst performance between Examples 1-5 and Comparative Examples 1-6

[0136] Testing items Vinyl chloride selectivity Acetylene conversion rate Acetylene conversion rate after 800 hours Example 1 ≥99.5％ 94.1％ 90.3％ Example 2 ≥99.5％ 89.8％ 78.4％ Example 3 ≥99.5％ 92.3％ 85.2％ Example 4 ≥99.5％ 83.9％ 78.3％ Example 5 ≥99.5％ 92.8％ 77.9％ Comparative Example 1 ≥99.5％ 86.7％ 50.1％ Comparative Example 2 ≥99.5％ 75.6％ 54.2％ Comparative Example 3 ≥99.5％ 83.8％ 59.9％ Comparative Example 4 ≥99.5％ 87.7％ 51.6％ Comparative Example 5 ≥99.5％ 93.1％ 61.5％ Comparative Example 6 ≥99.5％ 81.3％ 63.2％

[0137] Table 1 shows the comparison results of catalyst performance between Examples 1-5 and Comparative Examples 1-6. The following conclusions can be drawn from the comparison between Examples 1-5 and Comparative Examples 1-6:

[0138] A comparison of Example 1 and Comparative Example 1 shows that the catalyst prepared without hydrophobic modification has high initial activity, but the conversion rate decreases more severely than in Example 1.

[0139] A comparison of Example 1 and Comparative Example 2 shows that the ionic liquid formed by imidazole adjuvants and 1,8-diazabicyclo[5.4.0]undec-7-ene can improve catalyst conversion and slow down catalyst deactivation.

[0140] A comparison of Example 1 and Comparative Example 3 shows that changing the type of ionic liquid significantly reduces the conversion rate and makes the catalyst prone to deactivation.

[0141] A comparison of Example 1 and Comparative Example 4 shows that changing the mass ratio of silane reagent to activated carbon leads to a decrease in the stability of the prepared catalyst and a significant decrease in conversion rate.

[0142] A comparison of Example 1 and Comparative Example 5 shows that changing the mass fraction of the active component in the total mass of the catalyst leads to a decrease in the stability of the prepared catalyst, and the conversion rate decreases significantly after 800 hours.

[0143] A comparison of Example 1 and Comparative Example 6 shows that changing the molar ratio of imidazole promoters to 1,8-diazabicyclo[5.4.0]undec-7-ene in the co-catalytic component results in a decrease in the conversion rate and a deterioration in the stability of the prepared ionic liquid catalyst.

[0144] The present invention is not limited to the technical means disclosed above, but also includes technical solutions composed of any combination of the above technical features. The above descriptions are specific embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications are also considered within the scope of protection of the present invention.

Claims

1. A catalyst for supporting copper on hydrophobically modified activated carbon, characterized in that, Includes support, active component, and co-catalytic component; The carrier is modified activated carbon; the active component is a copper salt; and the co-catalytic component is an ionic liquid. The modified activated carbon is obtained by modifying wood-based activated carbon as a carrier; The modification involves adding a silane solution to wood-based activated carbon, stirring, drying, and calcining. The reagent used in the silane solution is a silane reagent; the silane reagent is at least one selected from trimethylchlorosilane, trimethoxychlorosilane, methyltriethoxysilane, and octadecyltrichlorosilane. The ionic liquid is generated by reacting 1,8-diazabicyclo[5.4.0]undec-7-ene with imidazole substances in a molar ratio of 1:0.5-2. The imidazole substance is at least one of 4-methylimidazole, 2-ethylimidazole and 4-hydroxyethylimidazole; The mass ratio of the wood-based activated carbon to the silane solution is 1:5-15.

2. The catalyst according to claim 1, characterized in that, The copper salt is at least one of copper chloride, copper sulfate, and copper nitrate.

3. The catalyst according to claim 1, characterized in that, The Cu content in the active component accounts for 5-20% of the total mass of the catalyst; the content of the co-catalytic component accounts for 1-10% of the total mass of the catalyst.

4. The method for preparing the catalyst according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Add silane solution to wood-based activated carbon, stir, dry, and calcine to obtain modified activated carbon; S2. Prepare the active component solution and the co-catalytic component solution, impregnate them into the modified activated carbon described in step S1 according to the formula, stir, let stand for aging and dry to obtain the catalyst.

5. The preparation method according to claim 4, characterized in that, The silane solution described in step S1 has a silane reagent mass fraction of 10-60%.

6. The preparation method according to claim 4, characterized in that, The stirring described in step S1 is carried out at a temperature of 30-60℃ for 3-10 hours. The drying process described in step S1 is carried out at a temperature of 100-140℃ for 6-12 hours. The calcination described in step S1 is carried out at a temperature of 400-800℃ in a N2 atmosphere for 3-6 hours. The stirring in step S2 shall take 10-20 minutes; The static aging process described in step S2 takes 5-10 hours. The drying process described in step S2 is carried out at a temperature of 100-140℃ for 6-12 hours.

7. The use of the catalyst according to any one of claims 1-3 or the catalyst prepared by the preparation method according to any one of claims 4-6 in the acetylene hydrochlorination reaction.