Chloronitrobenzene hydrogenation catalyst and preparation method thereof

Abstract

The invention relates to the technical field of chloronitrobenzene hydrogenation catalysts, in particular to a chloronitrobenzene hydrogenation catalyst and a preparation method thereof.The method comprises the steps that 1, after an active metal source, a carbon source, a template agent and a solvent are mixed, the solvent is removed, and a solid is obtained; (2) roasting the solid obtained in the step (1) in an inert gas atmosphere to obtain a roasted product; and (3) contacting the roasted product with an acid solution, separating, washing and drying to obtain the hydrogenation catalyst. The active metal source is soluble salt of active metal, and the active metal is selected from one or more of Fe, Co, Ni, Cu and Zn; the template agent is selected from one or more of magnesium-containing compounds. According to the preparation method of the hydrogenation catalyst, the non-noble metal is selected, the pickling solution can be recycled, the catalyst is environment-friendly, the production and recovery cost is reduced, and the catalyst is excellent in performance and has no dechlorination phenomenon when being used for preparing chloroaniline through hydrogenation of chloronitrobenzene.

Description

Technical Field

[0001] The invention relates to the technical field of chloronitrobenzene hydrogenation catalysts, and in particular to a chloronitrobenzene hydrogenation catalyst and a preparation method thereof. Background Art

[0002] Chloroaniline is an important organic synthesis intermediate, widely used in the synthesis of dyes, agricultural chemicals, pharmaceuticals, polymers, etc., and occupies an important position in the fine chemicals industry. Chloroaniline is usually prepared by reducing the corresponding chloroaromatic nitro compounds. The common methods for industrial production mainly include iron powder reduction method, alkali sulfide reduction method, hydrazine hydrate reduction method and catalytic hydrogenation reduction method. Among them, the iron powder reduction method is the earliest method for preparing chloroaniline, but due to its large amount of iron powder, high production cost, serious pollution, low selectivity and yield, it has been eliminated by the market; the alkali sulfide reduction method and the hydrazine hydrate reduction method have too long production time, and the presence of a large number of other impurities in the product directly affects the production process and product quality; the catalytic hydrogenation reduction method is environmentally friendly, has stable product quality, and has advanced technology, becoming a trend in the development of green chemistry. However, this green process generally has the problem of hydrogenation dechlorination, mainly because the C-Cl on the chloroaniline undergoes hydrogenation dechlorination side reaction under the action of the catalyst, resulting in a low yield of chloroaniline, and the generated aniline and hydrochloric acid will cause equipment corrosion, catalyst deactivation and other problems.

[0003] CN109939713A discloses a method for preparing a nitrogen-doped activated carbon-supported Pt / Zn bimetallic catalyst. The method uses two metal salts, noble metal and non-noble metal, which is relatively costly. In addition, a large amount of nitric acid and hydrochloric acid are used in the activated carbon treatment during the preparation process, which increases the cost of subsequent wastewater treatment. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a chloronitrobenzene nitro hydrogenation catalyst which is environmentally friendly, reduces production costs, has high activity and selectivity, and the prepared hydrogenation catalyst can inhibit dechlorination. The preparation method uses non-precious metals and can recycle pickling liquid, is environmentally friendly, reduces production and recovery costs, and has excellent catalyst performance.

[0005] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a chloronitrobenzene hydrogenation catalyst, the method comprising:

[0006] (1) mixing an active metal source, a carbon source, a template, and a solvent, and removing the solvent to obtain a solid;

[0007] (2) calcining the solid obtained in step (1) under an inert gas atmosphere to obtain a calcined product;

[0008] (3) acid-washing, separating, washing, and drying the calcined product to obtain a hydrogenation catalyst;

[0009] The active metal source is a soluble salt of an active metal, and the active metal is selected from one or more of Fe, Co, Ni, Cu, and Zn;

[0010] The template is selected from one or more magnesium-containing compounds.

[0011] The second aspect of the present invention provides a chloronitrobenzene hydrogenation catalyst prepared by the preparation method of the present invention.

[0012] Through the above technical scheme, the preparation method of the hydrogenation catalyst of the present invention uses non-precious metals and can recycle pickling liquid, which is environmentally friendly and reduces production and recovery costs. The catalyst has excellent performance and is used for hydrogenating chloronitrobenzene to prepare chloroaniline without dechlorination. DETAILED DESCRIPTION

[0013] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0014] The present invention provides a method for preparing a chloronitrobenzene hydrogenation catalyst, the method comprising:

[0015] (1) mixing an active metal source, a carbon source, a template, and a solvent, and removing the solvent to obtain a solid;

[0016] (2) calcining the solid obtained in step (1) under an inert gas atmosphere to obtain a calcined product;

[0017] (3) acid-washing, separating, washing, and drying the calcined product to obtain a hydrogenation catalyst;

[0018] The active metal source is a soluble salt of the active metal, and the active metal is selected from one or more of Fe, Co, Ni, Cu, and Zn; and the template agent is selected from one or more of magnesium-containing compounds.

[0019] The preparation method of the hydrogenation catalyst of the present invention uses non-precious metals and can recycle pickling liquid, is environmentally friendly, reduces production and recycling costs, and has excellent catalyst performance.

[0020] According to one embodiment of the present invention, the mass ratio of the active metal source to the carbon source is 0.1-1:10; preferably 0.4-1:10; more preferably 0.6-1:10.

[0021] According to one embodiment of the present invention, the mass ratio of the carbon source to the template is 10:2-50; preferably 10:5-30; more preferably 10:8-20.

[0022] In the present invention, the pickling liquid can be recycled. According to one embodiment of the present invention, the preparation method of the chloronitrobenzene hydrogenation catalyst further comprises:

[0023] (4) Measure the content of active metal and the content of template in the solution after pickling in step (3), add active metal source and template, and repeat step (1).

[0024] In the present invention, the optional range of types of active metal sources is relatively wide, and materials containing the aforementioned active metals Fe, Co, Ni, Cu, and Zn can be used in the present invention. The following exemplary description is not intended to limit the scope of the present invention. According to one embodiment of the present invention, the active metal source is selected from one or more of chlorides, sulfates, acetates, and nitrates of active metals; preferably, the active metal source is selected from one or more of cobalt chloride hexahydrate, cobalt nitrate hexahydrate, cobalt sulfate heptahydrate, cobalt acetate, nickel chloride hexahydrate, nickel sulfate hexahydrate, nickel nitrate, nickel acetate, copper nitrate trihydrate, copper chloride, copper sulfate pentahydrate, copper acetate, ferric chloride hexahydrate, ferric sulfate, ferric nitrate nonahydrate, ferric acetate, zinc chloride hexahydrate, zinc sulfate, zinc nitrate, and zinc acetate.

[0025] In the present invention, the magnesium-containing compound may be, for example, a soluble Mg salt, magnesium oxide, etc.; according to a preferred embodiment of the present invention, the soluble magnesium salt is selected from one or more of magnesium chloride, magnesium acetate, magnesium citrate and magnesium sulfate.

[0026] According to a preferred embodiment of the present invention, the template is magnesium acetate and / or magnesium citrate.

[0027] In the present invention, the type of solvent has special requirements, and the main purpose is to form a uniform mixture, for example, the solvent is water.

[0028] In the present invention, the optional range of carbon source types is relatively wide. According to a preferred embodiment of the present invention, the carbon source is selected from one or more of amino acids, nitrogen-containing polymers, and biomass materials.

[0029] According to a preferred embodiment of the present invention, the nitrogen-containing polymer is selected from one or more of polyacrylonitrile, polyurethane and polyacrylamide; the biomass material is selected from one or more of soybean meal, soybean powder, sawdust, coconut shell, rice shell and fruit shell.

[0030] According to a preferred embodiment of the present invention, the amino acid is selected from aspartic acid and / or methionine.

[0031] According to a preferred embodiment of the present invention, the carbon source is selected from one or more of soybean meal, soybean powder, aspartic acid and methionine.

[0032] According to a preferred embodiment of the present invention, in step (1), the solvent is removed by drying. Preferably, the drying conditions include: a temperature of 90°C-120°C.

[0033] In the present invention, there is no particular limitation on the amount of the solvent used, which is only used to mix the carbon source, the template and the active metal source.

[0034] According to a preferred embodiment of the present invention, step (1) comprises:

[0035] The active metal source is dissolved in water to obtain solution A; then a carbon source and a template are added according to a mass ratio, and the mixture is stirred sufficiently to form a uniform dispersion; the dispersion is heated and dried at 90-120° C. to form a solid.

[0036] According to a preferred embodiment of the present invention, in the above step (1), the drying is performed while being heated and stirred so as to remove the moisture as evenly as possible.

[0037] In the present invention, grinding is performed as needed before calcination, thereby achieving sufficient calcination.

[0038] In the present invention, the purpose of the present invention can be achieved by calcining in an inert atmosphere, and there is no special requirement for the type of inert gas, for example, it can be selected from nitrogen and / or argon.

[0039] In the present invention, there are no special requirements for the roasting conditions and steps, and they can be commonly used roasting steps and conditions. The following exemplary description is not intended to limit the scope of the present invention. According to one embodiment of the present invention, the roasting conditions include: a roasting temperature of 600-900°C and a time of 1-4h; preferably, the temperature is increased to 600-900°C and roasted at a heating rate of 2-10°C / min.

[0040] In the present invention, there is no special requirement for pickling. The following is an exemplary description, but it does not limit the scope of the present invention. According to one embodiment of the present invention, in step (3), the pickling conditions include: a temperature of 70-90°C and a contact time of 6-10h.

[0041] In the present invention, the acid solution can be selected according to the anion of the template, and preferably the acid solution of the same kind as the anion of the template is used, for example, the acid solution is one or more of hydrochloric acid, acetic acid aqueous solution, citric acid aqueous solution and sulfuric acid.

[0042] According to a preferred embodiment of the present invention, the concentration of the acid solution is 0.5-2 mol / L.

[0043] In the present invention, after acid washing, the solid is separated and washed to neutrality.

[0044] The second aspect of the present invention provides a chloronitrobenzene hydrogenation catalyst prepared by the preparation method of the present invention. The hydrogenation catalyst of the present invention is used for hydrogenating chloronitrobenzene to prepare chloroaniline without dechlorination.

[0045] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0046] In order to more clearly explain the present invention, the following embodiments are given, but the present invention can be implemented in a manner not limited to the scope of the embodiments.

[0047] In the following examples and comparative examples, the evaluation method of the hydrogenation catalyst includes:

[0048] In the hydrogenation reactor, the mass ratio of chloronitrobenzene to catalyst was 3:1. Under the condition of hydrogen pressure of 0.5 MPa, the reaction was carried out at 100°C with a stirring speed of 500 r / min for 3 hours.

[0049] Hydrogenation reaction test method: Use a disposable syringe to take the reaction solution, then connect a filter membrane to the outlet of the needle tube, and transfer the solution to a chromatographic injection bottle; use gas chromatography for evaluation, and use the area normalization method to obtain the conversion rate and selectivity based on the peak area of ​​each component;

[0050]

[0051]

[0052] G represents the correction factor;

[0053] A represents the peak area.

[0054] Example 1

[0055] (1) Dissolve 0.6 g of cobalt acetate tetrahydrate in 5 ml of water to obtain solution 1;

[0056] (2) Add 10 g of soybean powder to solution 1, add 30 mL of deionized water, stir until the soybean powder is evenly dispersed, then add 16 g of magnesium acetate tetrahydrate, stir until it is completely dissolved, and obtain dispersion 2;

[0057] (3) The dispersion 2 is heated while being stirred until the water is completely evaporated and then placed in an oven at 100° C. to dry to obtain a solid 3;

[0058] (4) Grind solid 3 into powder, put it into a porcelain boat, cover it with a porcelain boat of the same size, and put it into a tube furnace. Then, flow N at 400 ml / min (glass rotor flowmeter).2 Pass the mixture into the tube furnace for 15 min to ensure that the air in the tube furnace has been completely replaced; then maintain N 2 The flow rate was 400 ml / min, and the temperature was raised to 800 °C at a rate of 5 °C / min under a nitrogen atmosphere, and the mixture was calcined at this constant temperature for 2 h to obtain a black solid powder 4;

[0059] (5) Prepare 200 ml of 0.5 mol / L acetic acid solution and place it in a beaker, transfer the black solid powder 4 into the acetic acid solution, heat and stir at 90° C. for 8 h, filter with suction, retain the acid washing solution for later use, wash the filter cake with water until it is neutral, and then dry to obtain the catalyst product 1-A1;

[0060] (6) The pickling stock solution obtained in step (5) is tested for the cobalt and magnesium contents by ICP, and cobalt acetate tetrahydrate and magnesium acetate tetrahydrate are added in the amounts used in step (1), and the above steps (1) to (5) are repeated to obtain catalyst product 1-A2.

[0061] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0062] Example 2

[0063] The method of Example 1 is followed, except that in step (1), cobalt acetate tetrahydrate is replaced by copper acetate; the remaining conditions are the same as those of Example 1, to obtain catalyst product 2-A1.

[0064] The pickling stock solution was tested for copper and magnesium contents by ICP, and copper acetate and magnesium acetate tetrahydrate were added in the amounts used in step (1), and the above steps (1) to (5) were repeated to obtain catalyst product 2-A2.

[0065] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0066] Example 3

[0067] The method of Example 1 is followed, except that in step (1), cobalt acetate tetrahydrate is replaced by nickel acetate; the remaining conditions are the same as those of Example 1, to obtain catalyst product 3-A1.

[0068] The pickling stock solution was tested for nickel and magnesium contents by ICP, and nickel acetate and magnesium acetate tetrahydrate were added in the amounts used in step (1), and the above steps (1) to (5) were repeated to obtain catalyst product 3-A2.

[0069] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0070] Example 4

[0071] The method of Example 1 is followed, except that in step (2), soybean meal is replaced by soybean meal; the remaining conditions are the same as those of Example 1, to obtain catalyst product 4-A1.

[0072] The cobalt and magnesium contents of the pickling stock solution were tested by ICP. Cobalt acetate tetrahydrate and magnesium acetate tetrahydrate were added in the amounts used in step (1). The above steps (1) to (5) were repeated to obtain catalyst product 4-A2.

[0073] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0074] Example 5

[0075] The method of Example 1 is followed, except that in step (2), the soybean powder is replaced by coconut shell powder; the remaining conditions are the same as those of Example 1, to obtain catalyst product 5-A1.

[0076] The cobalt and magnesium contents of the pickling stock solution were tested by ICP. Cobalt acetate tetrahydrate and magnesium acetate tetrahydrate were added in the amounts used in step (1). The above steps (1) to (5) were repeated to obtain catalyst product 5-A2.

[0077] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0078] Example 6

[0079] (1) Dissolve 0.1 g of cobalt acetate tetrahydrate in 5 ml of water to obtain solution 1;

[0080] (2) Add 10 g of polyurethane powder to solution 1, add 30 ml of deionized water, stir until the soybean powder is evenly dispersed, then add 5 g of magnesium acetate tetrahydrate, stir until it is completely dissolved, and obtain dispersion 2;

[0081] (3) The dispersion 2 is heated while being stirred until the water is completely evaporated and then placed in an oven at 100° C. to dry to obtain a solid 3;

[0082] (4) Grind solid 3 into powder, put it into a porcelain boat, cover it with a porcelain boat of the same size, and put it into a tube furnace. Then, flow N at 400 ml / min (glass rotor flowmeter). 2 Pass the N into the tube furnace for 15 min to ensure that the air in the tube furnace has been completely replaced; then maintain N 2 The flow rate was 400 ml / min, and the temperature was raised to 800 °C at a rate of 5 °C / min under a nitrogen atmosphere, and the mixture was calcined at this constant temperature for 2 h to obtain a black solid powder 4;

[0083] (5) Prepare 200 ml of 0.5 mol / L acetic acid solution and place it in a beaker, transfer the black solid powder 4 into the acetic acid solution, heat and stir at 70° C. for 10 h, filter with suction, retain the acid washing solution for later use, wash the filter cake with water until it is neutral, and then dry to obtain the catalyst product 6-A1;

[0084] (6) The pickling stock solution obtained in step (5) is tested for cobalt and magnesium contents by ICP, and cobalt acetate tetrahydrate and magnesium acetate tetrahydrate are added in the amounts used in step (1), and the above steps (1) to (5) are repeated to obtain catalyst product 6-A2.

[0085] Example 7

[0086] (1) Dissolve 1 g of cobalt acetate tetrahydrate in 5 ml of water to obtain solution 1;

[0087] (2) Add 10 g of methionine powder to solution 1, add 30 ml of deionized water, stir until the soybean powder is evenly dispersed, then add 8 g of magnesium acetate tetrahydrate, stir until it is completely dissolved, and obtain dispersion 2;

[0088] (3) The dispersion 2 is heated while being stirred until the water is completely evaporated and then placed in an oven at 100° C. to dry to obtain a solid 3;

[0089] (4) Grind solid 3 into powder, put it into a porcelain boat, cover it with a porcelain boat of the same size, and put it into a tube furnace. Then, flow N at 400 ml / min (glass rotor flowmeter). 2 Pass the mixture into the tube furnace for 15 min to ensure that the air in the tube furnace has been completely replaced; then maintain N 2 The flow rate was 400 ml / min, and the temperature was raised to 800 °C at a rate of 5 °C / min under a nitrogen atmosphere, and the mixture was calcined at this constant temperature for 2 h to obtain a black solid powder 4;

[0090] (5) Prepare 200 ml of 0.5 mol / L acetic acid solution and place it in a beaker, transfer the black solid powder 4 into the acetic acid solution, heat and stir at 80° C. for 8 h, filter with suction, retain the acid washing solution for later use, wash the filter cake with water until it is neutral, and then dry to obtain the catalyst product 7-A1;

[0091] (6) The pickling stock solution obtained in step (5) is tested for the cobalt and magnesium contents by ICP, and cobalt acetate tetrahydrate and magnesium acetate tetrahydrate are added in the amounts used in step (1), and the above steps (1) to (5) are repeated to obtain catalyst product 7-A2.

[0092] Example 8

[0093] The method of Example 1 is followed, except that in step (2), 16 g of magnesium oxide is added instead of magnesium acetate tetrahydrate; specifically:

[0094] (1) Dissolve 0.6 g of cobalt acetate tetrahydrate in 5 ml of water to obtain solution 1;

[0095] (2) Add 10 g of soybean powder to solution 1, add 30 mL of deionized water, stir until the soybean powder is evenly dispersed, then add 16 g of magnesium oxide, stir evenly, and obtain dispersion 2;

[0096] (3) The dispersion 2 is heated while being stirred until the water is completely evaporated and then placed in an oven at 100° C. to dry to obtain a solid 3;

[0097] (4) Grind solid 3 into powder, put it into a porcelain boat, cover it with a porcelain boat of the same size, and put it into a tube furnace. Then, flow N at 400 ml / min (glass rotor flowmeter). 2 Pass the mixture into the tube furnace for 15 min to ensure that the air in the tube furnace has been completely replaced; then maintain N 2 The flow rate was 400 ml / min, and the temperature was raised to 800 °C at a rate of 5 °C / min under a nitrogen atmosphere, and the mixture was calcined at this constant temperature for 2 h to obtain a black solid powder 4;

[0098] (5) Prepare 200 ml of 0.5 mol / L acetic acid solution and place it in a beaker, transfer the black solid powder 4 into the acetic acid solution, heat and stir at 90° C. for 8 h, filter with suction, retain the acid washing solution for later use, wash the filter cake with water until it is neutral, and then dry to obtain the catalyst product 8-A1;

[0099] (6) The pickling stock solution obtained in step (5) is tested for cobalt and magnesium contents by ICP, and cobalt acetate tetrahydrate and magnesium oxide are added in the amounts used in step (1), and the above steps (1) to (5) are repeated to obtain catalyst product 8-A2.

[0100] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0101] Comparative Example 1

[0102] The method of Example 1 is followed, except that in step (2), magnesium acetate tetrahydrate is not added; the remaining conditions are the same as those of Example 1, to obtain catalyst product 1-D1.

[0103] The catalyst was evaluated for the hydrogenation of chloronitrobenzene to produce chloroaniline. The test results are shown in Table 1.

[0104] Comparative Example 2

[0105] The method of Example 1 is followed, except that in step (2), no soybean powder is added; the remaining conditions are the same as those of Example 1, to obtain catalyst product 2-D1.

[0106] Table 1

[0107]

[0108]

[0109] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a chloronitrobenzene hydrogenation catalyst, It is characterized in that The method includes: (1) mixing an active metal source, a carbon source, a template, and a solvent, and removing the solvent to obtain a solid; (2) calcining the solid obtained in step (1) under an inert gas atmosphere to obtain a calcined product; (3) acid-washing, separating, washing, and drying the calcined product to obtain a hydrogenation catalyst; The active metal source is a soluble salt of an active metal, and the active metal is selected from one or more of Fe, Co, Ni, Cu, and Zn; The template is selected from one or more magnesium-containing compounds.

2. The preparation method according to claim 1, in, The mass ratio of the active metal source to the carbon source is 0.1-1:10; preferably 0.4-1:10; more preferably 0.6-1:10; and / or The mass ratio of the carbon source to the template is 10:2-50; preferably 10:5-30; more preferably 10:8-20.

3. The preparation method according to claim 1 or 2, in, The method further includes: Step (4): Measure the content of active metal and the content of template in the solution after pickling in step (3), add active metal source and template, and repeat step (1).

4. The preparation method according to claim 1 or 2, in, The active metal source is selected from one or more of chlorides, sulfates, acetates and nitrates of active metals; and / or The active metal is selected from Co and / or Ni.

5. The preparation method according to claim 1 or 2, in, The template agent is selected from one or more of soluble Mg salt and magnesium oxide; Preferably, the soluble magnesium salt is selected from one or more of magnesium chloride, magnesium acetate, magnesium citrate and magnesium sulfate.

6. The preparation method according to claim 1 or 2, in, The template is selected from magnesium acetate and / or magnesium citrate; and / or The solvent is water; and / or The carbon source is selected from one or more of amino acids, nitrogen-containing polymers, and biomass materials; Preferably, The nitrogen-containing polymer is selected from one or more of polyacrylonitrile, polyurethane and polyacrylamide; and / or The biomass material is selected from one or more of soybean meal, soybean powder, sawdust, coconut shell, rice shell, and fruit shell; and / or The amino acids are selected from aspartic acid and / or methionine.

7. The preparation method according to claim 1 or 2, in, In step (1), the solvent is removed by drying. Preferably, the drying conditions include: a temperature of 90°C-120°C.

8. The preparation method according to claim 1 or 2, in, In step (2), the inert gas is selected from nitrogen and / or argon; and / or The calcination conditions include: a calcination temperature of 600-900° C. and a calcination time of 1-4 hours; preferably, the calcination is performed at a heating rate of 2-10° C. / min to a temperature of 600-900° C.

9. The preparation method according to claim 1 or 2, in, In step (3), the pickling conditions include: temperature of 70-90°C and time of 6-10h; and / or The acid solution is one or more of hydrochloric acid, acetic acid aqueous solution, citric acid aqueous solution and sulfuric acid; Preferably, the acid concentration is 0.5-2 mol / L.

10. The chloronitrobenzene hydrogenation catalyst prepared by the preparation method according to any one of claims 1 to 9.

Images