Hydrogenation catalyst, preparation method and application thereof, and aromatic nitro compound hydrogenation method

Abstract

The present invention relates to the field of catalysts, and provides a hydrogenation catalyst preparation method, which comprises: mixing a cobalt source, a nitrogen source, a phosphorus source, an activator and active carbon powder to form a dispersion liquid, evaporating the dispersion liquid, drying, and roasting. The invention provides the catalyst prepared by the method provided by the invention. The invention provides application of the catalyst in catalyzing hydrogenation reaction of an aromatic nitro compound to generate a functionalized amino compound. The invention provides a hydrogenation method of an aromatic nitro compound, and in the presence of the catalyst and a solvent, the aromatic nitro compound is subjected to a hydrogenation reaction to generate a functionalized amino compound. The method is simple, efficient, low in cost, convenient and reliable, the hydrogenation catalyst with good stability can be prepared, and the hydrogenation catalyst has high activity and selectivity and particularly has high activity and selectivity when being used for hydrogenation of aromatic nitro compounds.

Description

Technical Field

[0001] The present invention relates to the field of catalysis, and particularly relates to a hydrogenation catalyst, a preparation method and an application thereof, and a method for hydrogenating an aromatic nitro compound. Background Art

[0002] Aromatic amines are important organic synthesis intermediates, which are widely used in the synthesis of dyes, agrochemicals, pharmaceuticals, polymers, etc., and occupy an important position in the fine chemicals industry. Aromatic amines are usually prepared by reducing the corresponding aromatic nitro compounds. Common industrial production methods mainly include iron powder reduction method, sodium sulfide reduction method, hydrazine hydrate reduction method, catalytic hydrogenation reduction method, etc. Among them, the iron powder reduction method is the earliest method for preparing chloroaniline, but due to its large consumption of iron powder, high production cost, serious pollution, low selectivity and yield, etc., it has been eliminated by the market; the production time of the sodium sulfide reduction method and the hydrazine hydrate reduction method is too long, and a large amount of other impurities in the product directly affect this production process and product quality. At present, the catalytic hydrogenation reduction method of aromatic nitro compounds is the main production method, and the key technical problem is to develop a highly efficient, inexpensive and stable hydrogenation catalyst. Therefore, the research on hydrogenation catalysts for aromatic nitro compounds has important theoretical value and practical significance.

[0003] The liquid-phase catalytic hydrogenation catalyst system of aromatic nitro compounds is mainly divided into Cu-based, Ni-based, Pd-based, Pt-based, Au-based and multi-metal catalysts according to the types of their different active sites. In addition, there are also metal catalysts such as Ag, Ru, Ir, Rh, etc. The above catalysts have their own advantages and disadvantages. For example, high catalytic reaction temperature, low selectivity or high catalyst cost limit their large-scale industrial application.

[0004] CN106236232B uses the catalyst Pt-Sb / TiO 2 in the process of catalytic hydrogenation of 3-nitrostyrene to prepare the corresponding amino compound. When using the catalyst, it needs to be pre-activated at a high temperature of 450 °C with H 2 The preparation conditions are relatively harsh and the risk is high, which greatly limits its application.

[0005] CN108409579A uses an aqueous solution of chloroplatinic acid as an electrolyte and makes it loaded on carbon onions by discharging to prepare a catalyst. The carrier is relatively special and not universal, and it loses more catalysts during the catalytic hydrogenation process and has a higher cost. Therefore, it is greatly limited in its industrial application. Summary of the Invention

[0006] The object of the present invention is to overcome the problems existing in the existing hydrogenation catalysts, such as too high catalytic reaction temperature, low selectivity, high catalyst cost, more catalyst loss and higher cost, and to provide a preparation method of a hydrogenation catalyst. The preparation method is simple, efficient, low-cost, convenient, reliable and good in stability. The prepared hydrogenation catalyst has high activity and selectivity at a relatively low reaction temperature, especially has high activity and selectivity for the hydrogenation of aromatic nitro compounds.

[0007] To achieve the above object, the first aspect of the present invention provides a method for preparing a hydrogenation catalyst, the method comprising: mixing a cobalt source, a nitrogen source, a phosphorus source, an activator and activated carbon powder to form a dispersion liquid, evaporating the dispersion liquid, and then drying and calcining.

[0008] The second aspect of the present invention provides a catalyst prepared by the method of the present invention.

[0009] The third aspect of the present invention provides the application of the catalyst of the present invention in the catalytic hydrogenation reaction of aromatic nitro compounds to produce functionalized amino compounds.

[0010] The fourth aspect of the present invention provides a method for hydrogenating aromatic nitro compounds. In the presence of the catalyst of the present invention and in the presence of a solvent, the aromatic nitro compounds are hydrogenated to produce functionalized amino compounds.

[0011] The method of the present invention is simple, efficient, low-cost, convenient, reliable and can prepare a hydrogenation catalyst with good stability. The hydrogenation catalyst has high activity and selectivity, especially has high activity and selectivity for the hydrogenation of aromatic nitro compounds. Detailed Embodiments

[0012] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0013] The present invention provides a method for preparing a hydrogenation catalyst, the method comprising: mixing a cobalt source, a nitrogen source, a phosphorus source, an activator and activated carbon powder to form a dispersion liquid, evaporating the dispersion liquid, and then drying and calcining. The method of the present invention mixes a cobalt source, a nitrogen source, a phosphorus source, an activator and activated carbon powder to form a dispersion liquid, evaporates the dispersion liquid, and then dries and calcines. The method is simple, efficient, low-cost, convenient, reliable and can prepare a hydrogenation catalyst with good stability. The prepared hydrogenation catalyst has high activity and selectivity, especially has high activity and selectivity for the hydrogenation of aromatic nitro compounds.

[0014] In the present invention, the object of the present invention can be achieved according to the foregoing technical solutions. The dosage range of each substance can be selected relatively widely. The following is a demonstration, but it does not limit the scope of the present invention. The mass ratio of the dosage of activated carbon powder, cobalt source, nitrogen source, phosphorus source, and activator is 1:(0.001 - 0.2):(1 - 5):(1 - 5):(1 - 10), preferably 1:(0.1 - 0.15):(2 - 3):(2 - 3):(1.5 - 5). By adopting the foregoing preferred technical solution, the activity and selectivity of the catalyst can be further improved.

[0015] In the present invention, it is only necessary to form a dispersion liquid, and there are no special requirements for the specific amounts of solute and solvent in the dispersion liquid. The following is a demonstration, but it does not limit the scope of the present invention. The solute content of the dispersion liquid is 20 - 40 wt%. In the present invention, substances other than those used as solvents are all called solutes, including liquid activators, etc. By adopting the foregoing preferred technical solution, the activity and selectivity of the catalyst can be further improved.

[0016] In the present invention, the types of the activator can be selected within a relatively wide range. For the present invention, the preferred activator is hydrogen peroxide, and more preferably the concentration of hydrogen peroxide is 10 - 40 wt%, preferably 20 - 35 wt%. By adopting the foregoing preferred technical solution, the activity and selectivity of the catalyst can be further improved.

[0017] In the present invention, the evaporation conditions can be selected within a relatively wide range. The following is a demonstration, but it does not limit the scope of the present invention. The evaporation conditions include: the evaporation temperature is 90 - 110 °C, such as 90 °C, 100 °C, 110 °C. In the examples, 100 °C is used to exemplify the advantages of the present invention.

[0018] In the present invention, the drying conditions can be selected within a relatively wide range. Commonly used drying conditions can be used for the present invention. For the present invention, for example, the drying conditions include: the temperature is 90 °C - 120 °C, such as 90 °C, 100 °C, 110 °C, 120 °C. In the examples, 100 °C is used to exemplify the advantages of the present invention; and / or the time is 2 - 12 h, such as 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h. In the examples, 3 h is used to exemplify the advantages of the present invention.

[0019] In the present invention, the calcination conditions can be selected within a relatively wide range. Commonly used calcination conditions can be used for the present invention. For the present invention, for example, the calcination conditions include: the temperature is 600 - 900 °C, preferably 800 - 850 °C; and / or the time is 1 - 10 h, preferably 2 - 3 h. By adopting the foregoing preferred technical solution, the activity and selectivity of the catalyst can be further improved.

[0020] According to a preferred embodiment of the present invention, preferably, it is calcined in an inert atmosphere.

[0021] According to a preferred embodiment of the present invention, preferably, it is heated to the calcination temperature at a heating rate of 2-10 °C / min for calcination. For example, the heating rates are 2 °C / min, 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min, 10 °C / min. In the examples, a heating rate of 5 °C / min is used to exemplify the advantages of the present invention.

[0022] The present invention has no special requirements for the types of the cobalt source, activated carbon powder, nitrogen source, and phosphorus source. The following is a demonstration, but it does not limit the scope of the present invention.

[0023] For example, the cobalt source is selected from one or more of cobalt chloride hexahydrate, cobalt nitrate hexahydrate, cobalt sulfate heptahydrate, and cobalt acetate, and preferably cobalt chloride hexahydrate.

[0024] For example, the activated carbon powder is selected from one or more of wood activated carbon, fruit shell activated carbon, coconut shell activated carbon, and coal-based activated carbon, and preferably wood activated carbon.

[0025] For example, the nitrogen source is selected from one or more of nitric acid, ammonium sulfate, ammonium persulfate, ammonium bisulfate, ammonium carbonate, and ammonium bicarbonate, preferably nitric acid and / or ammonium sulfate, and more preferably ammonium sulfate.

[0026] For example, the phosphorus source is selected from one or more of phosphoric acid, ammonium dihydrogen phosphate, and ammonium phosphate, preferably phosphoric acid and / or ammonium dihydrogen phosphate.

[0027] In the present invention, there are no special requirements for the step of mixing the cobalt source, nitrogen source, phosphorus source, activator, and activated carbon powder to form a dispersion. In the specific operation process, the dispersion can be uniformly dispersed by using stirring, ultrasonic, mild heating, etc. The following demonstrates an operation process, but the present invention is not limited thereto. According to a preferred embodiment of the present invention, the method includes:

[0028] a) Forming solution A from the cobalt source;

[0029] b) Adding the nitrogen source, phosphorus source, activator, and activated carbon powder to solution A, optionally adding a solvent to submerge the activated carbon, and stirring to obtain a uniformly dispersed solution B;

[0030] c) Stirring and evaporating the uniformly dispersed solution B and drying to obtain solid C;

[0031] d) Grinding solid C into a powder and calcining to obtain a catalyst.

[0032] The present invention provides the catalyst prepared by the method described in the present invention.

[0033] The present invention provides an application of the catalyst described in the present invention in the catalytic hydrogenation reaction of aromatic nitro compounds to produce functionalized amino compounds.

[0034] The present invention provides a method for hydrogenating aromatic nitro compounds, which is characterized in that, in the presence of the catalyst described in the present invention and in the presence of a solvent, the aromatic nitro compounds are subjected to a hydrogenation reaction to produce functionalized amino compounds. The catalyst of the present invention has high activity and selectivity in the application of catalytically reacting aromatic nitro compounds with hydrogen to produce functionalized amino compounds.

[0035] The present invention has no special requirements for the hydrogenation reaction conditions, etc. For the present invention, preferably, the conditions of the hydrogenation reaction include: the temperature is 50 to 130 °C, preferably 100 - 120 °C, for example 100 °C, 110 °C, 120 °C, and in the examples, 120 °C is used as an example to illustrate the advantages of the present invention; and / or the pressure is 0.1 to 10 MPa, preferably 0.1 - 0.5 MPa, for example 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, and in the examples, 0.5 MPa is used as an example to illustrate the advantages of the present invention.

[0036] In the present invention, the range of the types of the solvent is relatively wide, and any solvent that can be applicable to the reaction of the present invention can be used in the present invention. The following demonstrates an operation process, but the present invention is not limited thereto. The solvent is one or more of ethanol, methanol, and water.

[0037] In the present invention, there are no special requirements for the types of the aromatic nitro compounds, and common aromatic nitro compounds can be used in the present invention. For the present invention, preferably, the aromatic nitro compound is nitrobenzene and / or substituted nitrobenzene.

[0038] In the present invention, the object of the present invention can be achieved by carrying out according to the foregoing steps. The mass ratio of the aromatic nitro compound to the catalyst can be flexibly adjusted according to the reaction requirements. The following demonstrates an implementation manner, but the scope of the present invention is not limited thereby. Preferably, the mass ratio of the aromatic nitro compound to the catalyst is 1 to 15, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and in the examples, 10 is used as an example to illustrate the advantages of the present invention.

[0039] The method of the present invention is simple, and the prepared catalyst has high activity and selectivity in the catalytic hydrogenation reaction to produce functionalized amino compounds.

[0040] The present invention will be described in detail below through examples.

[0041] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. 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, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered specifically disclosed herein.

[0042] For the experimental methods without specific conditions noted in the examples, they are generally carried out according to the conventional conditions and the conditions described in the manuals, or according to the conditions recommended by the manufacturers; for the general equipment, materials, reagents, etc. used, if there is no special description, they can all be obtained commercially.

[0043] Example 1

[0044] Dissolve 0.12 g of cobalt chloride hexahydrate in 5 ml of water, then add 2 g of ammonium sulfate, 2 g of ammonium dihydrogen phosphate, 1.8 g of hydrogen peroxide (concentration 30 wt%), and 1 g of powdered woody activated carbon. Add 10 ml of deionized water to submerge the activated carbon powder. After stirring for 2 h to disperse the activated carbon evenly, stir at 400 r / min at 100 °C until the water is evaporated to dryness. Place it in an oven at 100 °C and dry for 3 h. Then, thoroughly grind the dried solid into a powder, load it into a porcelain boat, cover it with another porcelain boat of the same size, and then place it in a tube furnace. Then, under a nitrogen purge of 300 ml / min, heat it up to 800 °C at a rate of 5 °C / min and keep it at a constant temperature for 2 h to obtain the catalyst product; 2 Purge with nitrogen at a rate of 5 °C / min to 800 °C and keep it at a constant temperature for 2 h to obtain the catalyst product;

[0045] Catalytic test

[0046] Catalytic application of the catalyst of Example 1

[0047] 1.1 Add 0.8 g of nitrobenzene and 0.08 g of the catalyst to a 500 ml autoclave, add 50 ml of absolute ethanol, stir to dissolve it, then add 50 ml of deionized water, and ultrasonically disperse it evenly. Tighten the reaction kettle. First, displace the air with high-purity nitrogen three times at room temperature, and then use H 2 After displacing 3 times with H 2 Pressurize to 0.5 MPa and react at 120 °C for 3 h. After completion, analyze the reaction solution by gas chromatography.

[0048] The conversion rate of nitrobenzene was measured to be 100%, and the selectivity of the target product aniline was 99.97%.

[0049] 1.2 It is mainly the same as 1.1, except that nitrobenzene is replaced with p-chloronitrobenzene.

[0050] The conversion rate of p-chloronitrobenzene was measured to be 100%, and the selectivity of the target product p-chloroaniline was 99.27%. This shows that the catalyst has excellent performance and high selectivity.

[0051] 1.3 is mainly the same as 1.1, except that nitrobenzene is replaced by p-fluoronitrobenzene.

[0052] The conversion rate of p-fluoronitrobenzene was measured to be 100%, and the selectivity of the target product p-fluoroaniline was 99.35%. This shows that the catalyst has excellent performance and high selectivity.

[0053] 1.4 is mainly the same as 1.1, except that nitrobenzene is replaced by p-nitrostyrene.

[0054] The conversion rate of p-nitrostyrene was measured to be 100%, and the selectivity of the target product p-vinyl aniline was 99.30%. This shows that the catalyst has excellent performance and high selectivity.

[0055] 1.5 is mainly the same as 1.1, except that nitrobenzene is replaced by p-nitrotoluene.

[0056] The conversion rate of p-nitrotoluene was measured to be 100%, and the selectivity of the target product p-methylaniline was 99.44%. This shows that the catalyst has excellent performance and high selectivity.

[0057] Through the catalytic applications 1.1 - 1.5 of the catalyst in Example 1, it can be seen that for the catalyst prepared in Example 1, the conversion rates of nitrobenzene, p-chloronitrobenzene, p-fluoronitrobenzene, p-nitrostyrene, and p-nitrotoluene, as well as the selectivities of the target products, are all very high, indicating that the catalyst has good performance and a wide range of applications.

[0058] Example 2

[0059] It is mainly the same as Example 1, except that the amount of cobalt chloride hexahydrate is adjusted to 0.04 g, and the prepared catalyst is used for the catalytic application of nitrobenzene, with the operation being the same as 1.1.

[0060] The conversion rate of nitrobenzene was measured to be 97.43%, and the selectivity of the target product aniline was 99.75%.

[0061] Example 3

[0062] It is mainly the same as Example 1, except that 2 g of ammonium sulfate is replaced by 1.8 g of nitric acid, and the prepared catalyst is used for the catalytic application of nitrobenzene, with the operation being the same as 1.1.

[0063] The conversion rate of nitrobenzene was measured to be 98.67%, and the selectivity of the target product aniline was 99.68%.

[0064] Example 4

[0065] Basically the same as Example 1, except that 2 g of ammonium dihydrogen phosphate is replaced with 1.7 g of phosphoric acid. The prepared catalyst is used for the catalytic application of nitrobenzene, and the operation is the same as 1.1.

[0066] The conversion rate of nitrobenzene was measured to be 98.78%, and the selectivity of the target product aniline was 99.83%.

[0067] Example 5

[0068] Basically the same as Example 1, except that the amount of cobalt chloride hexahydrate is adjusted to 0.002 g. The prepared catalyst is used for the catalytic application of nitrobenzene, and the operation is the same as 1.1.

[0069] The conversion rate of nitrobenzene was measured to be 56.67%, and the selectivity of the target product aniline was 99.32%.

[0070] Example 6

[0071] Basically the same as Example 1, except that the amount of cobalt chloride hexahydrate is adjusted to 0.008 g. The prepared catalyst is used for the catalytic application of nitrobenzene, and the operation is the same as 1.1.

[0072] The conversion rate of nitrobenzene was measured to be 83.55%, and the selectivity of the target product aniline was 99.74%.

[0073] Example 7

[0074] Basically the same as Example 1, except that ammonium sulfate is replaced with 1.8 g of nitric acid, and 2 g of ammonium dihydrogen phosphate is replaced with 1.7 g of phosphoric acid. The prepared catalyst is used for the catalytic application of nitrobenzene, and the operation is the same as 1.1.

[0075] The conversion rate of nitrobenzene was measured to be 49.94%, and the selectivity of the target product aniline was 99.41%.

[0076] Example 8

[0077] Basically the same as Example 1, except that the calcination temperature in Example 1 is changed to 700 °C. The prepared catalyst is used for the catalytic application of nitrobenzene, and the operation is the same as 1.1.

[0078] The conversion rate of nitrobenzene was measured to be 76.23%, and the selectivity of the target product aniline was 99.12%.

[0079] Example 9

[0080] Basically the same as Example 1, except that the calcination temperature in Example 1 is changed to 900 °C. The prepared catalyst is used for the catalytic application of nitrobenzene, and the operation is the same as 1.1.

[0081] The conversion rate of nitrobenzene was measured to be 86.42%, and the selectivity of the target product aniline was 99.33%.

[0082] Example 10

[0083] It is mainly the same as Example 1, except that the concentration of hydrogen peroxide is 10 wt%.

[0084] The prepared catalyst was used for the catalytic application of nitrobenzene, and the operation was the same as that in 1.1.

[0085] The conversion rate of nitrobenzene was measured to be 84.42%, and the selectivity of the target product aniline was 98.13%.

[0086] Example 11

[0087] It is mainly the same as Example 1, except that the concentration of hydrogen peroxide is 40 wt%.

[0088] The prepared catalyst was used for the catalytic application of nitrobenzene, and the operation was the same as that in 1.1.

[0089] The conversion rate of nitrobenzene was measured to be 80.42%, and the selectivity of the target product aniline was 97.06%.

[0090] Comparative Example 1

[0091] It is mainly the same as Example 1, except that no activator is added.

[0092] The conversion rate of nitrobenzene was measured to be 46.58%, and the selectivity of the target product aniline was 97.13%.

[0093] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing a hydrogenation catalyst, characterized in that, the method comprises: mixing a cobalt source, a nitrogen source, a phosphorus source, an activator, and activated carbon powder to form a dispersion, evaporating the dispersion, and then drying and calcining.

2. The method according to claim 1, wherein, the mass ratio of the activated carbon powder, cobalt source, nitrogen source, phosphorus source, and activator is 1:(0.001 - 0.2):(1 - 5):(1 - 5):(1 - 10), preferably 1:(0.1 - 0.15):(2 - 3):(2 - 3):(1.5 - 5).

3. The method according to claim 1 or 2, wherein, the solute content of the dispersion is 20 - 40 wt%.

4. The method according to any one of claims 1 - 3, wherein, the activator is hydrogen peroxide, preferably the concentration of hydrogen peroxide is 10 - 40 wt%, more preferably 20 - 35 wt%.

5. The method according to any one of claims 1 - 4, wherein, the conditions for evaporation include: the evaporation temperature is 90 - 110 °C; and / or the conditions for drying include: the temperature is 90 °C - 120 °C, and / or the time is 2 - 12 h; and / or the conditions for calcining include: the temperature is 600 - 900 °C, preferably 800 - 850 °C; and / or the time is 1 - 10 h, preferably 2 - 3 h; preferably, calcining is carried out in an inert atmosphere, preferably heating to the calcination temperature at a heating rate of 2 - 10 °C / min for calcination.

6. The method according to any one of claims 1 - 5, wherein, the cobalt source is selected from one or more of cobalt chloride hexahydrate, cobalt nitrate hexahydrate, cobalt sulfate heptahydrate, and cobalt acetate, preferably cobalt chloride hexahydrate; and / or the activated carbon powder is selected from one or more of wood activated carbon, fruit shell activated carbon, coconut shell activated carbon, and coal-based activated carbon, preferably wood activated carbon; and / or the nitrogen source is selected from one or more of nitric acid, ammonium sulfate, ammonium persulfate, ammonium bisulfate, ammonium carbonate, and ammonium bicarbonate, preferably nitric acid and / or ammonium sulfate, more preferably ammonium sulfate; and / or the phosphorus source is selected from one or more of phosphoric acid, ammonium dihydrogen phosphate, and ammonium phosphate, preferably phosphoric acid and / or ammonium dihydrogen phosphate.

7. The method according to any one of claims 1 - 6, wherein, the method comprises: a) forming solution A from the cobalt source; b) adding the nitrogen source, phosphorus source, activator, and activated carbon powder to solution A, optionally adding a solvent to submerge the activated carbon, and stirring to obtain a homogeneous dispersion B; c) stirring and evaporating the homogeneous dispersion B, and drying to obtain solid C; d) grinding solid C into a powder form and calcining to obtain the catalyst.

8. A catalyst prepared by the method according to any one of claims 1 - 7.

9. Use of the catalyst according to claim 8 in the catalytic hydrogenation reaction of aromatic nitro compounds to produce functionalized amino compounds.

10. A method for hydrogenating an aromatic nitro compound, characterized in that, in the presence of the catalyst according to claim 8, in the presence of a solvent, the aromatic nitro compound undergoes a hydrogenation reaction to produce a functionalized amino compound; preferably, the conditions for the hydrogenation reaction include: The temperature is 50 to 130 °C, preferably 100 - 120 °C; and / or the pressure is 0.1 to 10 MPa, preferably 0.1 - 0.5 MPa; and / or The mass ratio of the aromatic nitro compound to the catalyst is 1 to 15; and / or The solvent is one or more of ethanol, methanol and water; Preferably, the aromatic nitro compound is nitrobenzene and / or substituted nitrobenzene, and the substituted nitrobenzene is one or more of p-chloronitrobenzene, p-fluoronitrobenzene, p-nitrostyrene, p-nitrotoluene.