Catalyst for preparing N-(1-ethyl propyl)-3, 4-dimethylaniline through continuous catalytic hydrogenation as well as preparation method and application of catalyst
By loading a catalyst with specific auxiliary components onto an activated carbon support, the problems of cumbersome operation and high cost in the preparation of N-(1-ethylpropyl)-3,4-dimethylaniline in the prior art have been solved, realizing a highly efficient and environmentally friendly catalytic hydrogenation preparation process that is suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN CATALYST NEW MATERIALS CO LTD
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies for preparing N-(1-ethylpropyl)-3,4-dimethylaniline suffer from problems such as cumbersome operation, high cost of precious metal catalysts, incomplete reaction, and wastewater generation, which affect product quality and economic benefits.
A catalyst with high catalytic activity and selectivity was prepared by using a catalyst including an activated carbon support and specific auxiliary components, through alkaline treatment, modification, and impregnation of active components, for continuous catalytic hydrogenation reaction in a fixed-bed reactor.
It achieves continuous and automated control of the reaction, reduces the generation of waste, improves the yield of the target product and the life of the catalyst, is suitable for industrial production, and has good economic benefits.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalytic hydrogenation technology, specifically relating to a catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, its preparation method, and its application. Background Technology
[0002] Pendimethalin belongs to the dinitroaniline class of selective herbicides. It is characterized by low toxicity, low residue, and high safety for humans, animals, and the environment, and is therefore widely recognized as a green herbicide. Pendimethalin is widely used for root control and shoot suppression of weeds in cereal, peanut, corn, and tobacco fields. N-(1-ethylpropyl)-3,4-dimethylaniline (DMA) is a key intermediate in the synthesis of pendimethalin.
[0003] Patent CN 118515567A discloses a method for producing N-(1-ethylpropyl)-3,4-dimethylaniline. This patent uses a batch reactor for preparation, and the steps include dissolving the mixture, adding the main catalyst and auxiliary agents, hydrogenation reaction, sampling and detection, cooling and discharging, replacing hydrogen in the reactor, separation of the liquid and the distillation process. This invention uses platinum-carbon, palladium-carbon, rhodium-carbon, and ruthenium-carbon catalysts, and controls the reaction temperature and pressure in two stages, making the operation relatively cumbersome. Patent CN 104250215A discloses a method for synthesizing N-(1-ethylpropyl)-3,4-dimethylaniline. This patent uses 3,4-dimethylnitrobenzene and 3-pentanone as raw materials, and reacts under the action of multiple catalysts, including a platinum-carbon catalyst and a phosphate-sodium dihydrogen phosphate buffer solution, with a platinum mass fraction of 2.5%-3.5%. This method uses a batch reactor synthesis, and the acid buffer solution also needs to be separated from the product. Moreover, the catalyst has a high content of precious metals, resulting in high cost. Patent application CN 101302168 A discloses a method for synthesizing N-(1-ethylpropyl)-3,4-dimethylaniline. This patent uses o-xylene as a starting material, nitrifies it under a catalyst to obtain 3,4-dimethylnitrobenzene, and then hydrogenates and condenses it with 3-pentanone under a catalyst to prepare N-(1-ethylpropyl)-3,4-dimethylaniline. However, this technique may lead to incomplete reaction in the early stages of hydrogenation due to excessively low reaction temperatures, ultimately affecting product quality. Furthermore, this method easily generates wastewater, increasing costs. Therefore, developing a green, environmentally friendly, simple, and safe process is of great significance. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, its preparation method, and its application. The catalyst exhibits high catalytic activity and product selectivity, as well as good stability.
[0005] A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising a support, and an active component platinum and an auxiliary component supported on the support, wherein the auxiliary component is at least one selected from sodium citrate, disodium ethylenediaminetetraacetate, sodium metavanadate, oxalic acid, zirconium oxychloride, yttrium nitrate, or sodium carbonate; the active component and the auxiliary component each account for 0.1-10% of the catalyst mass.
[0006] Preferably, the carrier is activated carbon.
[0007] Preferably, the active component accounts for 0.5-2.5% of the catalyst mass, and the auxiliary component accounts for 0.5-5% of the catalyst mass.
[0008] The method for preparing the catalyst for the continuous catalytic hydrogenation to N-(1-ethylpropyl)-3,4-dimethylaniline includes the following steps: (1) Carrier pretreatment: Add the carrier to an alkaline solution, boil for 1-5 hours, centrifuge, wash with water until neutral, and dry to obtain an alkaline-treated carrier; (2) Carrier modification: Add a modifying agent to the alkali-treated carrier, stir at 100-200℃ for 1-5 hours, cool, centrifuge, wash with an organic solvent, dry, and calcine under an inert atmosphere to obtain the modified carrier; wherein, the modifying agent is one or two of octadecyl chloride, dodecylbenzenesulfonic acid, hexadecylacrylamide, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; the organic solvent is one or two of methanol, ethanol, acetone, 3-pentanone, and toluene; (3) Impregnation: Dissolve the precursor and auxiliary components of the active component in water, place the modified carrier in the water for 9-12 hours for adsorption, filter, dry and reduce.
[0009] Preferably, the alkaline solution is a 5-10 wt% aqueous solution of sodium hydroxide, potassium hydroxide, or ammonia.
[0010] Preferably, the mass of the alkaline solution is 2-5 times the mass of the carrier.
[0011] Preferably, the mass of the modified reagent is 2-5 times the mass of the carrier.
[0012] Preferably, the drying temperature is 100-120℃; the calcination is carried out in an inert atmosphere at 300-500℃ for 2-5 hours, with an inert gas flow rate of 50-500 mL·min. -1 The reduction is carried out in an H2 atmosphere at 200-400℃ for 1-5 hours, with an H2 flow rate of 100-500 mL / min. -1 .
[0013] Preferably, the active component is any one of platinum nitrate, potassium hexachloroplatinate, or chloroplatinic acid hexahydrate.
[0014] A method for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline: a catalyst is loaded into a fixed-bed reactor, hydrogen and raw materials are introduced, and the reaction is carried out at a reaction temperature of 60-160℃ and a reaction pressure of 0.5-5MPa. The raw materials are 3,4-dimethylnitrobenzene and 3-pentanone in a molar ratio of 1:(2-6), and the catalyst is the catalyst described in this invention.
[0015] Preferably, the total molar ratio of hydrogen to 3,4-dimethylnitrobenzene and 3-pentanone is 10-20; the mass hourly space velocity (WHSV) of the 3,4-dimethylnitrobenzene is 0.1-2 h⁻¹. -1 .
[0016] The beneficial effects of this invention are: First, the activated carbon support is treated with an alkaline reagent to remove residual carbon powder and impurities from the pores of the support, and to neutralize the acidic groups on the activated carbon, thus facilitating the modification of the support. Then, a modifying reagent is used to modify the support, introducing hydrophobic groups to promote the rapid desorption of water generated in the reaction and avoid hindering the contact between the reaction substrate and the active sites. In industrial production, the raw material 3-pentanone is generally in excess, and the unreacted pentanone is recovered after the reaction. Modifying the support can reduce the impact of water from the recovered 3-pentanone on the catalytic activity, thereby improving the catalyst activity and reaction stability. The active component and the auxiliary component are mixed and impregnated. The auxiliary component can promote the dispersion of active metal, making the active metal loading more uniform and firm, and giving the catalyst higher activity, selectivity and lifetime. 3. The catalyst of this invention is applied to the catalytic hydrogenation of N-(1-ethylpropyl)-3,4-dimethylaniline in a fixed-bed reactor. The reaction can be continuously and automatically controlled, with better safety performance, less waste, high yield of target product, and good catalyst life. It is suitable for industrial production and has good economic and social benefits. Detailed Implementation Example 1
[0017] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum supported on the support, and an auxiliary component sodium citrate, wherein the active component and the auxiliary component account for 1% and 1.2% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 97.8g of carrier was added to 280g of 10wt% sodium hydroxide solution, boiled for 2h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 200g of dodecylbenzenesulfonic acid was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 180℃ for 3h, cooled to room temperature, centrifuged, washed 5 times with 3-pentanone, dried at 120℃, and then processed at a flow rate of 200 mL·min. -1 The modified support was obtained by calcining in N2 at 400℃ for 2 hours. (3) Impregnation: Dissolve 10 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 1.2 g of sodium citrate in 250 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 200 mL·min -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 1%Pt+1.2%sodium citrate / C. Example 2
[0018] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component disodium ethylenediaminetetraacetate supported on the support, wherein the active component and the auxiliary component account for 1.5% and 3% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 95.5g of carrier was added to 200g of 8wt% ammonia solution, boiled for 1h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 300 g of octadecyl chloride was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 150 °C for 5 h, cooled to room temperature, centrifuged, then washed 5 times with 3-pentanone, dried at 120 °C, and then processed at a flow rate of 200 mL·min. -1 The modified support was obtained by calcining in N2 at 350℃ for 2 hours. (3) Impregnation: Dissolve 15 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 3 g of disodium ethylenediaminetetraacetate in 200 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 300 mL·min -1 The catalyst was obtained by reduction at 240°C for 3 hours in an H2 atmosphere, and was denoted as 1.5%Pt+3%disodium ethylenediaminetetraacetate / C. Example 3
[0019] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component sodium metavanadate supported on the support, wherein the active component and the auxiliary component each account for 0.5% of the catalyst mass; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 99g of carrier was added to 300g of 5wt% potassium hydroxide solution, boiled for 5h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 300 g of hexadecylacrylamide was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 200 °C for 1 h, cooled to room temperature, centrifuged, washed 5 times with 3-pentanone, dried at 120 °C, and then processed at a flow rate of 300 mL·min. -1 The modified support was obtained by calcining in N2 at 450℃ for 3 hours. (3) Impregnation: Dissolve 5 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 0.5 g of sodium metavanadate in 300 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 300 mL·min -1 The catalyst was obtained by reduction at 400°C for 1 hour in an H2 atmosphere, and was denoted as 0.5%Pt+0.5%sodium metavanadate / C. Example 4
[0020] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum supported on the support, and an auxiliary component sodium citrate, wherein the active component and the auxiliary component account for 2.5% and 1% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 96.5g of carrier was added to 400g of 5wt% sodium hydroxide solution, boiled for 3h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 350g of N,N-dimethylformamide was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 200℃ for 3h, cooled to room temperature, centrifuged, washed 5 times with 3-pentanone, dried at 120℃, and then processed at a flow rate of 300 mL·min. -1 The modified support was obtained by calcining in N2 at 500℃ for 2 hours. (3) Impregnation: Dissolve 25 mL of a platinum nitrate solution with a platinum concentration of 0.1 g / mL and 1 g of sodium citrate in 300 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 300 mL·min -1 The catalyst was obtained by reduction at 300°C for 3 hours in an H2 atmosphere, and was denoted as 2.5%Pt+1%sodium citrate / C. Example 5
[0021] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component sodium carbonate supported on the support, wherein the active component and the auxiliary component account for 1.5% and 5% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 93.5g of carrier was added to 250g of 10wt% sodium hydroxide solution, boiled for 3h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 300g of octadecyl chloride was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 150℃ for 2h, cooled to room temperature, centrifuged, washed 5 times with ethanol, dried at 120℃, and then processed at a flow rate of 50 mL·min. -1 The modified support was obtained by calcining in N2 at 300℃ for 5 hours. (3) Impregnation: Dissolve 15 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 5 g of sodium carbonate in 300 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 200 mL·min -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 1.5%Pt+5%sodium carbonate / C. Example 6
[0022] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component disodium ethylenediaminetetraacetate supported on the support, wherein the active component and the auxiliary component each account for 0.5% of the catalyst mass; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 99g of carrier was added to 250g of 10wt% sodium hydroxide solution, boiled for 3h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 280g of dodecylbenzenesulfonic acid was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 180℃ for 2h, cooled to room temperature, centrifuged, washed 5 times with toluene, dried at 120℃, and then processed at a flow rate of 100mL·min. -1 The modified support was obtained by calcining in N2 at 350℃ for 4 hours. (3) Impregnation: Dissolve 5 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 0.5 g of disodium ethylenediaminetetraacetate in 300 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 200 mL·min -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 0.5%Pt+0.5%disodium ethylenediaminetetraacetate / C. Example 7
[0023] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component sodium metavanadate supported on the support, wherein the active component and the auxiliary component account for 2.5% and 5% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 92.5g of carrier was added to 300g of 10wt% sodium hydroxide solution, boiled for 2h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 300g of dodecylbenzenesulfonic acid was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 180℃ for 2h, cooled to room temperature, centrifuged, washed 5 times with toluene, dried at 120℃, and then processed at a flow rate of 300mL·min. -1 The modified support was obtained by calcining in N2 at 300℃ for 5 hours. (3) Impregnation: Dissolve 25 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 5 g of sodium metavanadate in 300 g of deionized water, add the modified carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 100 mL·min -1 The catalyst was obtained by reduction at 200°C for 5 hours in an H2 atmosphere, and was denoted as 2.5%Pt+5%sodium metavanadate / C. Example 8
[0024] 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component zirconium oxychloride supported on the support, wherein the active component and the auxiliary component account for 10% and 0.1% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 89.9g of carrier was added to 450g of 5wt% sodium hydroxide solution, boiled for 1h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Carrier modification: 450g of dimethyl sulfoxide was added to the alkali-treated carrier, placed in a reaction vessel, stirred at 100℃ for 3h, cooled to room temperature, centrifuged, washed 5 times with 3-pentanone, dried at 100℃, and then processed at a flow rate of 500mL·min. -1 The modified support was obtained by calcining in N2 at 300℃ for 5 hours. (3) Impregnation: Dissolve 100 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 0.1 g of zirconium oxychloride in 250 g of deionized water, add the modified carrier, impregnate and adsorb for 12 h, filter, dry at 100 °C, and place in a container with a flow rate of 500 mL·min -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 10%Pt+0.1%zirconium oxychloride / C. Example 9
[0025] A catalyst for the continuous catalytic hydrogenation to prepare N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component yttrium nitrate supported on the support, wherein the active component and the auxiliary component account for 0.1% and 10% of the catalyst mass, respectively. The catalyst was prepared using the same method as in Example 1, and the resulting catalyst was denoted as 0.1%Pt+10%Yttrium Nitrate / C.
[0026] Comparative Example 1 A platinum-carbon catalyst includes a supported activated carbon and an active component, platinum, supported on the support, wherein the active component constitutes 1% of the catalyst mass. The catalyst is prepared as follows: Dissolve 10 mL of a 0.1 g / mL platinum-containing chloroplatinic acid hexahydrate solution in 250 g of deionized water, add 99 g of activated carbon carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a flow rate of 200 mL / min. -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 1%Pt / CO.
[0027] Comparative Example 2 A catalyst for the continuous catalytic hydrogenation to prepare N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum, and an auxiliary component sodium citrate supported on the support, wherein the active component and the auxiliary component account for 1% and 1.2% of the catalyst mass, respectively. The catalyst is prepared as follows: Dissolve 10 mL of chloroplatinic acid hexahydrate solution (0.1 g / mL platinum concentration) and 1.2 g of sodium citrate in 250 g of deionized water. Add 97.8 g of activated carbon support and impregnate for 10 h. Filter, dry at 120 °C, and place in a container with a flow rate of 200 mL / min. -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 1%Pt+1.2%sodium citrate / CO.
[0028] Comparative Example 3 1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, the catalyst comprising an activated carbon support, an active component platinum supported on the support, and an auxiliary component sodium citrate, wherein the active component and the auxiliary component account for 1% and 1.2% of the catalyst mass, respectively; 2. The catalyst is prepared as follows: (1) Carrier pretreatment: 97.8g of carrier was added to 280g of 10wt% sodium hydroxide solution, boiled for 2h, centrifuged, washed with water until neutral, and dried at 120℃ to obtain alkali-treated carrier; (2) Impregnation: Dissolve 10 mL of chloroplatinic acid hexahydrate solution with a platinum concentration of 0.1 g / mL and 1.2 g of sodium citrate in 250 g of deionized water, add the alkali-treated carrier, impregnate and adsorb for 10 h, filter, dry at 120 °C, and place in a container with a flow rate of 200 mL / min. -1 The catalyst was obtained by reduction at 300°C for 2 hours in an H2 atmosphere, and was denoted as 1%Pt+1.2%sodium citrate / CO.
[0029] Catalytic performance evaluation A method for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline: A catalyst is loaded into a fixed-bed reactor, hydrogen and feedstock are introduced, and the reaction is carried out at a reaction temperature of 60-160℃ and a reaction pressure of 0.5-5 MPa. The feedstock is 3,4-dimethylnitrobenzene and 3-pentanone, and the total molar ratio (hydrogen-feed ratio) of hydrogen to 3,4-dimethylnitrobenzene and 3-pentanone is 10-20; the mass hourly space velocity (WHSV) of 3,4-dimethylnitrobenzene is 0.1-2 h⁻¹. -1The molar ratio of 3,4-dimethylnitrobenzene to 3-pentanone (benzophenone molar ratio) is 1:(2-6); the specific reaction conditions and results are shown in Table 1. Table 1 Reaction conditions and results
[0030] Therefore, the catalyst prepared by the present invention has a high yield, high catalytic activity, and longer lifespan and stability when applied to the continuous catalytic hydrogenation to prepare N-(1-ethylpropyl)-3,4-dimethylaniline.
Claims
1. A catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, characterized in that: The catalyst includes a support, and an active component platinum and an auxiliary component supported on the support. The auxiliary component is at least one of sodium citrate, disodium ethylenediaminetetraacetate, sodium metavanadate, oxalic acid, zirconium oxychloride, yttrium nitrate, or sodium carbonate. The active component and the auxiliary component each account for 0.1-10% of the catalyst mass.
2. The catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 1, characterized in that: The carrier is activated carbon.
3. The catalyst for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 1, characterized in that: The active component accounts for 0.5-2.5% of the catalyst mass, and the auxiliary component also accounts for 0.5-5% of the catalyst mass.
4. The method for preparing the catalyst for the continuous catalytic hydrogenation to N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 1, characterized in that: Includes the following steps: (1) Carrier pretreatment: Add the carrier to an alkaline solution, boil for 1-5 hours, centrifuge, wash with water until neutral, and dry to obtain an alkaline-treated carrier; (2) Carrier modification: Add a modifying agent to the alkali-treated carrier, stir at 100-200℃ for 1-5 hours, cool, centrifuge, wash with an organic solvent, dry, and calcine under an inert atmosphere to obtain the modified carrier; wherein, the modifying agent is one or two of octadecyl chloride, dodecylbenzenesulfonic acid, hexadecylacrylamide, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; the organic solvent is one or two of methanol, ethanol, acetone, 3-pentanone, and toluene; (3) Impregnation: Dissolve the precursor and auxiliary components of the active component in water, place the modified carrier in the water for 9-12 hours for adsorption, filter, dry and reduce.
5. The method for preparing the catalyst for the continuous catalytic hydrogenation to N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 4, characterized in that: The alkaline solution is a 5-10 wt% aqueous solution of sodium hydroxide, potassium hydroxide, or ammonia.
6. The method for preparing the catalyst for the continuous catalytic hydrogenation to N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 4, characterized in that: The mass of the alkaline solution is 2-5 times the mass of the carrier.
7. The method for preparing the catalyst for the continuous catalytic hydrogenation to N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 4, characterized in that: The mass of the modified reagent is 2-5 times the mass of the carrier.
8. The method for preparing the catalyst for the continuous catalytic hydrogenation to N-(1-ethylpropyl)-3,4-dimethylaniline according to claim 4, characterized in that: The drying temperature is 100-120℃; the calcination is carried out in an inert atmosphere at 300-500℃ for 2-5 hours, with an inert gas flow rate of 50-500 mL / min. -1 The reduction is carried out in an H2 atmosphere at 200-400℃ for 1-5 hours, with an H2 flow rate of 100-500 mL / min. -1 .
9. A method for the continuous catalytic hydrogenation preparation of N-(1-ethylpropyl)-3,4-dimethylaniline, characterized in that: The catalyst is loaded into a fixed-bed reactor, and hydrogen and raw materials are introduced. The reaction is carried out at a reaction temperature of 60-160℃ and a reaction pressure of 0.5-5MPa. The raw materials are 3,4-dimethylnitrobenzene and 3-pentanone in a molar ratio of 1:(2-6). The catalyst is the catalyst described in claim 1.
10. The method for preparing N-(1-ethylpropyl)-3,4-dimethylaniline by continuous catalytic hydrogenation according to claim 9, characterized in that: The total molar ratio of hydrogen to 3,4-dimethylnitrobenzene and 3-pentanone is 10-20; the mass hourly space velocity (WHSV) of the 3,4-dimethylnitrobenzene is 0.1-2 h⁻¹. -1 .