Preparation method and application of sulfur-modified activated carbon-supported highly dispersed noble metal catalyst for selective hydrogenation of halogenated nitrobenzene

Abstract

The invention discloses a preparation method and application of a sulfur-modified activated carbon-loaded highly dispersed noble metal catalyst for selective hydrogenation of halogenated nitrobenzene. The present invention loads Pd onto a sulfur-modified activated carbon carrier to obtain a sulfur-modified activated carbon-loaded highly dispersed noble metal catalyst, wherein the sulfur-modified activated carbon-loaded highly dispersed noble metal catalyst comprises Pd, and Pd accounts for 0.5-1wt% of the sulfur-modified activated carbon carrier, and the mass content of S in the sulfur-modified activated carbon carrier is 2-5wt%. The present invention greatly improves the dispersion of the metal due to the addition of a dispersant lignin sulfonate and doped S on the surface of the carrier during the preparation process, increases the electronic effect between the noble metal and S, and exhibits excellent selectivity and stability.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst preparation, and in particular to a preparation method and application of a sulfur-modified activated carbon-loaded highly dispersed noble metal catalyst for selective hydrogenation of halogenated nitrobenzene. Background Art

[0002] Chloroaniline (CAN) is an important organic chemical intermediate, which is widely used in the fields of medicine, pesticides, dyes, etc. CAN is mainly prepared by reduction method using CNB. The preparation of CAN from CNB is often accompanied by dechlorination side reactions. The by-products generated by excessive hydrogenation not only affect the quality and quality of the product, but HCl will corrode the reaction equipment and pipelines, and will also deactivate the catalyst. At present, some technologies can be used to catalytically modify traditional supported precious metal catalysts to overcome this defect and expand its scope of application. Since o-CNB is sensitive to changes in metal particle size and is prone to form by-products during hydrogenation, heteroatoms are needed to regulate the electronic effect of precious metals to improve their selectivity.

[0003] Conventional CAN preparation is mainly prepared by using CNB through reduction method. Common reduction methods include chemical reduction, electrochemical reduction, and catalytic hydrogenation reduction. Catalytic hydrogenation reduction method refers to dissolving chloronitrobenzene in a solvent such as ethanol, loading a palladium catalyst on a carbon carrier, introducing hydrogen at a certain temperature for catalytic hydrogenation to reduce the nitro group to an amino group, and finally filtering and washing the reaction product to obtain halogenated aniline.

[0004] Supported palladium catalyst is one of the commonly used catalysts for hydrogenation of halogenated nitrobenzene. The catalyst selectivity is closely related to the preparation method and reaction conditions. The characteristics of supported palladium catalyst are high hydrogenation activity and low selectivity. Generally, the loading amount of palladium is about 0.5-1wt%. The greater the loading amount, the worse the dispersion. Therefore, the sulfur-modified carbon-supported noble metal catalyst prepared by the isovolumetric impregnation method is conducive to the high dispersion of the metal, thereby improving the performance of the catalyst.

[0005] In addition, there are many studies on sulfur-doped catalysts at home and abroad, but few studies have been conducted on the effects of dispersants on catalyst performance. Therefore, it is very necessary to study the performance of dispersants in the preparation process of sulfur-doped carbon-supported noble metal catalysts. Summary of the invention

[0006] In view of the problems existing in the prior art, the object of the present invention is to provide a preparation method and application of a sulfur-modified activated carbon-loaded highly dispersed precious metal catalyst for selective hydrogenation of halogenated nitrobenzene.

[0007] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0008] In a first aspect, the present invention provides a method for preparing a sulfur-modified activated carbon-supported highly dispersed precious metal catalyst for selective hydrogenation of halonitrobenzene, wherein the precious metal in the sulfur-modified activated carbon-supported highly dispersed precious metal catalyst is Pd, and Pd accounts for 0.5-1wt% of the sulfur-modified activated carbon carrier, and the mass content of S in the sulfur-modified activated carbon carrier is 2-5wt%; the preparation method comprises the following specific steps:

[0009] (1) First, prepare a precursor aqueous solution: dissolve palladium chloride powder in a hydrochloric acid solution, dilute with deionized water, mix well and set aside;

[0010] (2) Dissolve an appropriate amount of sulfur precursor in deionized water, add activated carbon, and stir to mix evenly; the sulfur precursor is NaHSO 3 ;

[0011] (3) vacuum drying the mixture of step (2) and calcining it under inert gas at a temperature of 500-600° C. for a time of 2.5-4 h to obtain a sulfur-modified activated carbon carrier;

[0012] (4) mixing the precursor aqueous solution prepared in step (1) with a certain amount of lignin sulfonate, and then adding the sulfur-modified activated carbon support obtained in step (4) for equal volume impregnation;

[0013] (5) After the immersion in step (4) for 10-24 hours, place it in a drying oven at 60-90°C for 8-12 hours, and then place it in a N 2 Calcinate at 500-600℃ for 3-4h under atmosphere;

[0014] (6) reducing the catalyst calcined in step (5) at 300-400° C. for 2-5 h in a mixed atmosphere of hydrogen and nitrogen, and obtaining a solid which is a sulfur-modified activated carbon-supported highly dispersed precious metal catalyst.

[0015] Preferably, in step (2), the feed ratio of the sulfur precursor to the activated carbon is 0.3-0.9:5.

[0016] Preferably, in step (2), the stirring and mixing is carried out at room temperature for 8-16 hours.

[0017] Preferably, in step (3), the vacuum drying conditions are: vacuum drying at 70-120° C. for 5-12 hours.

[0018] Preferably, in step (4), the lignin sulfonate is sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) or calcium lignin sulfonate (C 20H 24 CaO 10 S 2 ), the amount of which added is 5-10wt% of the mass of the sulfur-modified activated carbon carrier.

[0019] Preferably, in step (4), the precursor aqueous solution and the sulfur-modified activated carbon carrier have a palladium loading of 0.5-1 wt%.

[0020] In a second aspect, the present invention provides the use of a sulfur-modified activated carbon-supported highly dispersed noble metal catalyst prepared according to the above method in the selective hydrogenation of halogenated nitrobenzenes to prepare halogenated anilines.

[0021] The application comprises the following specific steps:

[0022] Halonitrobenzene is dissolved in a solvent to obtain a reaction solution, a sulfur-modified activated carbon-supported highly dispersed noble metal catalyst is added to the reaction solution, and a continuous hydrogenation reaction is performed under a hydrogen atmosphere and stirring conditions to generate halogenated aniline. The hydrogenation product is quantitatively analyzed for product components using a gas chromatograph.

[0023] In a specific embodiment of the present invention, the halogenated nitrobenzene is o-chloronitrobenzene (o-CNB) which is sensitive to metal particle size, the solvent is ethanol, the reaction temperature is 60-100°C, the hydrogen pressure is 0.5-1.5MPa, and the mechanical stirring rate is controlled at 680-1000r·min -1 .

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The technical solution of the present invention is used to load Pd onto a sulfur-modified carbon carrier activated carbon-supported highly dispersed precious metal catalyst prepared on a CS carrier. The addition of a dispersant lignin sulfonate and the doped S on the surface of the carrier greatly improve the dispersion of the metal, increase the electronic effect between the precious metal and S, and show excellent selectivity and stability;

[0026] 2) Compared with the traditional noble metal supported catalyst, the present invention not only uses lignin sulfonate to make the metal dispersion better during the catalyst preparation process, but also stabilizes the S doped on the carrier. The catalyst of the present invention is applied to the halogenated nitrobenzene hydrogenation reaction. Under the premise of 100% conversion rate, the product selectivity is greater than 99.9%.

[0027] 3) Compared with general activated carbon carrier-supported noble metal catalysts, the catalyst of the present invention maintains a relatively high activity on the one hand due to the doping of sulfur with moderate valence in the sulfur precursor, and on the other hand, the interaction between the catalyst and the noble metal is enhanced, the outer electrons of the noble metal are shifted, and the selectivity for o-chloroaniline is significantly increased, thereby achieving dual optimization of activity and selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 and Figure 2 TEM image and XRD of the catalyst prepared in Example 1 of the present invention at 20 nm. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific examples, but the scope of protection of the present invention is not limited to the scope described above. The activated carbon used in the examples is powdered activated carbon produced by Fujian Xinsen Carbon Industry Co., Ltd.

[0030] Example 1

[0031] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0032] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0033] 2) Take 0.331 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0034] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0035] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0036] 5) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0037] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0038] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 1 to be prepared.

[0039] The prepared catalyst 1 was analyzed and found to have a Pd loading of 0.5 wt %, a S content of 1.8 wt %, a particle size of 2.55 nm, and very uniform dispersion.

[0040] 2. Application of Catalyst 1 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0041] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0042] Example 2

[0043] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0044] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0045] 2) Take 0.5019 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0046] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0047] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0048] 5) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0049] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0050] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 2 to be prepared.

[0051] 2. Application of Catalyst 2 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0052] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0053] Example 3

[0054] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0055] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0056] 2) Take 0.6774 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0057] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0058] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0059] 5) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0060] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0061] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 3 to be prepared.

[0062] 2. Application of Catalyst 3 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0063] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0064] Example 4

[0065] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0066] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0067] 2) Take 0.8557 g NaHSO 3The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0068] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0069] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0070] 5) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0071] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0072] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 4 to be prepared.

[0073] 2. Application of Catalyst 4 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0074] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0075] Example 5

[0076] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0077] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0078] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0079] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0080] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0081] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0082] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcinate at 600 °C for 3 h under atmosphere;

[0083] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 5 to be prepared.

[0084] 2. Application of Catalyst 5 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0085] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0086] Example 6

[0087] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0088] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0089] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0090] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0091] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0092] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0093] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcinate at 500 °C for 3 h under atmosphere;

[0094] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The reaction mixture was reduced at 300 °C for 3 h in an atmosphere of , and the obtained solid was the catalyst 6 to be prepared.

[0095] 2. Application of Catalyst 6 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0096] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0097] Example 7

[0098] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0099] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0100] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0101] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0102] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0103] 5) Take 322 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0104] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0105] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1The reaction mixture was reduced at 300 °C for 3 h in an atmosphere of , and the obtained solid was the catalyst 7 to be prepared.

[0106] 2. Application of Catalyst 7 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0107] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0108] Example 8

[0109] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0110] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0111] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0112] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0113] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0114] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0115] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and2 Calcination at 550 °C for 3 h under atmosphere;

[0116] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 8 to be prepared.

[0117] 2. Application of Catalyst 8 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0118] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0119] Example 9

[0120] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0121] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0122] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0123] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0124] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0125] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.1 g of sodium lignin sulfonate (C 20 H 24Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0126] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0127] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The reaction mixture was reduced at 300 °C for 3 h in an atmosphere of , and the obtained solid was the catalyst 9 to be prepared.

[0128] 2. Application of Catalyst 9 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0129] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0130] Example 10

[0131] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0132] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0133] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0134] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0135] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0136] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of calcium lignin sulfonate (C 20 H 24 CaO 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0137] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0138] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 10 to be prepared.

[0139] 2. Application of catalyst 10 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0140] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0141] Embodiment 11

[0142] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0143] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0144] 2) Take 0.8557 g NaHSO 3The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0145] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0146] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0147] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.1 g of calcium lignin sulfonate (C 20 H 24 CaO 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0148] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0149] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 11 to be prepared.

[0150] 2. Application of catalyst 11 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0151] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0152] Example 12

[0153] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO prepared in Example 3 3The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 60°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0154] Embodiment 13

[0155] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO prepared in Example 3 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 100°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0156] Embodiment 14

[0157] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO prepared in Example 3 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 0.5 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0158] Embodiment 15

[0159] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO prepared in Example 3 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min.-1 , H 2 The pressure was controlled at 1.5 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0160] Comparative Example 1

[0161] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0162] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0163] 2) Take 1.2215 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0164] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0165] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0166] 5) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0167] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0168] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 12 to be prepared.

[0169] 2. Application of catalyst 12 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0170] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. Subsequently, the air in the autoclave was repeatedly replaced with H2 to check the air tightness of the autoclave. The reaction was carried out at 80 °C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0171] Comparative Example 2

[0172] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0173] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0174] 2) Take 0.331 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0175] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0176] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0177] 5) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0178] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0179] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 13 to be prepared.

[0180] 2. Application of catalyst 13 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0181] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0182] Table 1 Effect of different S loadings on catalyst performance

[0183] variable Conversion rate (%) Selectivity (%) Example 1 <![CDATA[2wt%NaHSO 3 ]]> 100 99.9 Example 2 <![CDATA[3wt%NaHSO 3 ]]> 100 99.9 Example 3 <![CDATA[4wt%NaHSO 3 ]]> 100 99.9 Example 4 <![CDATA[5wt%NaHSO 3 ]]> 100 99.9 Comparative Example 1 <![CDATA[7wt%NaHSO 3 ]]> 98 95 Comparative Example 2 <![CDATA[0.5wt%NaHSO 3 ]]> 98 96 Comparative Example 9 <![CDATA[0wt%NaHSO 3 ]]> 98 84.6

[0184] Comparative Example 3

[0185] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0186] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0187] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0188] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0189] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0190] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.4 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0191] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0192] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 14 to be prepared.

[0193] 2. Application of catalyst 14 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0194] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0195] Comparative Example 4

[0196] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0197] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0198] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0199] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0200] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0201] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.4 g of calcium lignin sulfonate (C 20 H 24 CaO 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0202] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0203] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 15 to be prepared.

[0204] 2. Application of catalyst 15 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0205] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0206] Comparative Example 5

[0207] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0208] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0209] 2) Take 0.8557 g NaHSO 3The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0210] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0211] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0212] 5) taking 404 μl of the precursor solution prepared in step 1), and then adding 2 g of the dry sulfur-modified carbon support material for equal volume impregnation;

[0213] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0214] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 16 to be prepared.

[0215] 2. Application of catalyst 16 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0216] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0217] Table 2 Effect of dispersant addition on catalyst

[0218]

[0219] Comparative Example 6

[0220] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0221] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0222] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0223] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0224] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0225] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 NaO 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0226] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 650 °C for 3 h under atmosphere;

[0227] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 17 to be prepared.

[0228] 2. Application of catalyst 17 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0229] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H2 And calculate the selectivity of o-CAN.

[0230] Table 3 Effect of calcination temperature on catalyst

[0231] Variable (℃) Conversion rate (%) Selectivity (%) Example 8 550 100 99.9 Example 5 600 100 99.9 Example 6 500 100 99.9 Comparative Example 6 650 98 99.9

[0232] Comparative Example 7

[0233] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0234] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0235] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0236] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0237] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0238] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 NaO 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0239] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0240] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 18 to be prepared.

[0241] 2. Application of Catalyst 18 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0242] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 50°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0243] Comparative Example 8

[0244] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0245] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0246] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0247] 3) After the mixture in step 2) is evenly mixed, the mixture is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0248] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0249] 5) Take 404 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 NaO 10 S 2 ) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0250] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0251] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 19 to be prepared.

[0252] 2. Application of catalyst 19 in selective catalytic hydrogenation of halogenated nitrobenzene:

[0253] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 0.4 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0254] Table 4 Effect of reaction conditions on the reaction

[0255] variable Conversion rate (%) Selectivity (%) Example 3 1MPa / 80℃ 100 99.9 Example 12 1MPa / 60℃ 100 99.9 Example 13 1MPa / 100℃ 100 99.9 Embodiment 14 0.5MPa / 80℃ 100 99.9 Embodiment 15 1.5MPa / 80℃ 100 99.9 Example 8 1MPa / 80℃ 100 99.9 Comparative Example 7 1MPa / 50℃ 83.6 97.2 Comparative Example 8 0.4MPa / 80℃ 68.7 99.9

[0256] Comparative Example 9

[0257] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0258] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0259] 2) Place 2 g of undoped activated carbon in a beaker and add deionized water dropwise with a dropper until the carrier is just saturated. Stop adding and record the amount of deionized water added;

[0260] 3) Take 201 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2 ) were mixed, and then 2 g of dry carbon support material was added for equal volume impregnation;

[0261] 4) After immersion in step 3) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0262] 5) The catalyst calcined in step 4) is heated to 400 °C.2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h under an atmosphere of , and the obtained solid was the catalyst 20 to be prepared.

[0263] 2. Application of Catalyst 20 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0264] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0265] Comparative Example 10

[0266] 1. A method for preparing a sulfur-modified carbon carrier-supported noble metal catalyst:

[0267] 1) Dissolve 8.3308 g of palladium chloride powder in 20 ml of concentrated hydrochloric acid, then dilute the solution to 100 mL with deionized water to obtain a Pd concentration of 0.05 g mL -1 The catalyst impregnation solution is allowed to stand for use;

[0268] 2) Take 0.8557 g NaHSO 3 The precursor and 5 g of activated carbon were dispersed in deionized water and stirred at room temperature for 12 h to make them evenly dispersed;

[0269] 3) After the mixture in step 2) is evenly mixed, it is dried in a vacuum drying oven at 110° C. for 6 h, and then calcined at 600° C. for 3 h under Ar to obtain a CS carrier;

[0270] 4) Place 2 g of the carrier from step 3) in a beaker, add deionized water dropwise with a dropper until the carrier is just saturated, stop adding and record the amount of deionized water added;

[0271] 5) Take 609 μl of the precursor solution prepared in step 1) and add 0.2 g of sodium lignin sulfonate (C 20 H 24 Na 2 O 10 S 2) were mixed, and then 2 g of dry sulfur-modified carbon support material was added for equal volume impregnation;

[0272] 6) After immersion in step 5) for 24 hours, place it in a drying oven at 90°C for 8 hours and 2 Calcination at 550 °C for 3 h under atmosphere;

[0273] 7) The catalyst calcined in step 6) is heated to 400 °C. 2 Flow rate: 5 ml min -1 , N 2 Flow rate: 95 ml min -1 The catalyst was reduced at 300 °C for 3 h in an atmosphere of , and the obtained solid was the catalyst 21 to be prepared.

[0274] 2. Application of Catalyst 21 in Selective Catalytic Hydrogenation of Halonitrobenzene:

[0275] Take 30g o-chloronitrobenzene (o-CNB), 0.3g Pd / C-NaHSO 3 The catalyst was placed in a 250 ml beaker, 200 ml of ethanol solvent was added and mixed, and then transferred to a 0.6 L autoclave. 2 Repeatedly replace the air in the reactor to check the air tightness of the reactor. The reaction was carried out at 80°C and the mechanical stirring rate was controlled at 720 r / min. -1 , H 2 The pressure was controlled at 1 MPa. During the reaction, H 2 And calculate the selectivity of o-CAN.

[0276] Table 5 Effect of Pd content on catalyst

[0277] variable Conversion rate Selectivity Example 4 0.5wt%Pd 100％ ＞99.9％ Example 7 0.75wt%Pd 100％ ＞99.9％ Example 8 1.00wt%PD 100％ ＞99.9％ Comparative Example 10 1.5wt%Pd 98％ 99.40％

Claims

1. A method for preparing a sulfur-modified activated carbon-supported highly dispersed noble metal catalyst for selective hydrogenation of halogenated nitrobenzene, characterized in that: In the sulfur-modified activated carbon-supported highly dispersed precious metal catalyst, the precious metal is Pd, and Pd accounts for 0.5-1 wt % of the sulfur-modified activated carbon carrier. In the sulfur-modified activated carbon carrier, the mass content of S is 2-5 wt %; the preparation method comprises the following specific steps: (1) First, prepare a precursor aqueous solution: dissolve palladium chloride powder in hydrochloric acid solution, dilute with deionized water, mix well and set aside; (2) dissolving an appropriate amount of sulfur precursor in deionized water, adding activated carbon, and stirring to mix evenly; the sulfur precursor is NaHSO3; (3) vacuum drying the mixture of step (2) and calcining it under inert gas at a temperature of 500-600° C. for a time of 2.5-4 h to obtain a sulfur-modified activated carbon carrier; (4) mixing the precursor aqueous solution prepared in step (1) with a certain amount of lignin sulfonate, and then adding the sulfur-modified activated carbon carrier obtained in step (4) for equal volume impregnation; the lignin sulfonate is sodium lignin sulfonate or calcium lignin sulfonate, and the amount thereof added is 5-10 wt % of the mass of the sulfur-modified activated carbon carrier; (5) After the impregnation in step (4) for 10-24 h, the mixture is placed in a drying oven at 60-90 °C for 8-12 h, and then calcined at 500-600 °C for 3-4 h in a N2 atmosphere; (6) The catalyst calcined in step (5) is reduced at 300-400° C. for 2-5 h in a mixed atmosphere of hydrogen and nitrogen to obtain a solid which is a sulfur-modified activated carbon-supported highly dispersed precious metal catalyst.

2. The preparation method according to claim 1, characterized in that: In step (2), the feed ratio of the sulfur precursor to the activated carbon is 0.3-0.9:

5.

3. The preparation method according to claim 1, characterized in that: In step (2), the stirring and mixing is carried out at room temperature for 8-16 hours.

4. The preparation method according to claim 1, characterized in that: In step (3), the vacuum drying conditions are: vacuum drying at 70-120° C. for 5-12 hours.

5. Use of the sulfur-modified activated carbon-supported highly dispersed noble metal catalyst prepared according to the preparation method of claim 1 in the selective hydrogenation of halogenated nitrobenzenes to prepare halogenated anilines.

6. The use according to claim 5, characterized in that: The application comprises the following specific steps: Halonitrobenzene is dissolved in a solvent to obtain a reaction solution, a sulfur-modified activated carbon-loaded highly dispersed noble metal catalyst is added to the reaction solution, and a continuous hydrogenation reaction is carried out in a hydrogen atmosphere and under stirring conditions to generate halogenated aniline.

7. The use according to claim 6, characterized in that: The halogenated nitrobenzene is o-chloronitrobenzene, the solvent is ethanol, the reaction temperature is 60-100 °C, the hydrogen pressure is 0.5-1.5 MPa, and the mechanical stirring rate is controlled at 680-1000 r·min -1 .

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