Preparation method and application of black phosphorus modified nitrogen-doped noble metal / carbon-based catalyst

Abstract

The application discloses a preparation method of a black phosphorus modified nitrogen-doped noble metal / carbon catalyst and relates to the technical field of catalytic hydrogenation. Black phosphorus, a nitrogen source and a carbon carrier are compounded in a ball milling mode, and a black phosphorus modified nitrogen-carbon composite is obtained after calcination under an inert atmosphere; the black phosphorus modified nitrogen-carbon composite is loaded with noble metal through a hot reflux method, and a black phosphorus modified nitrogen-doped noble metal / carbon catalyst is obtained after calcination; and the obtained black phosphorus modified nitrogen-doped noble metal / carbon catalyst is applied to a chloronitrobenzene hydrogenation reduction reaction. The application introduces black phosphorus to improve the bonding capacity of nitrogen-carbon bonds and increase the defects on the surface of nitrogen-carbon, and the synergistic effect among black phosphorus, nitrogen-carbon and noble metal is improved, the catalyst consumption is reduced, the catalytic performance is greatly improved, and the economic benefits of industrial production are improved.

Description

TECHNICAL FIELD

[0001] The application discloses a preparation method of a black phosphorus modified nitrogen doped noble metal / carbon-based catalyst and application thereof, and relates to the technical field of catalytic hydrogenation. BACKGROUND

[0002] Chloroaniline is an important organic chemical raw material and intermediate, widely used in dyes, pharmaceuticals, pesticides and fine chemicals, etc. In recent years, with the continuous expansion of the domestic and foreign market, chloroaniline has broad prospects in the fields of fine chemicals, pharmaceuticals, dyes, etc. The catalytic hydrogenation process of chloronitrobenzene has the advantages of low reaction temperature, few side reactions, large production capacity, good product stability, low investment, etc., and is widely used in industrial production.

[0003] Chloroaniline is prepared by catalytic hydrogenation of chloronitrobenzene, and the catalyst component is a noble metal. Ranry-Ni is used as the catalyst for the hydrogenation reduction of chloronitrobenzene for the first time. Pt is used as the catalyst active component by Kosak et al., and phosphorous acid is added as a dechlorination inhibitor. The activity of Pt / C catalyst is well adjusted by adding Fe and Ce as modifiers by Yan Xuhuan et al. At present, the process for preparing chloroaniline by catalytic hydrogenation of chloronitrobenzene in domestic industrial production mainly uses Pt catalyst with activated carbon as the carrier. Since the noble metal is expensive, the large-scale use of the catalyst will inevitably result in high production cost. Therefore, improving the hydrogen efficiency of the catalyst and reducing the catalyst usage are effective methods to reduce the production cost of enterprises. In the application, black phosphorus, a nitrogen source and a carbon carrier are compounded by ball milling, a nitrogen doped-noble metal / carbon-based catalyst is prepared by a hot reflux method, and the performance of the catalyst in the hydrogenation preparation of chloroaniline is investigated.

[0004] In the nitrogen doped carbon supported metal catalyst, the carbon carrier can maximize the loading, dispersion and exposure of metal atoms due to its large specific surface area, high porosity and high stability. The doping of N atoms in the carbon carrier can effectively regulate the coordination environment around the single atom, and can improve the activity, selectivity and stability of the catalytic reaction.

[0005] Black phosphorus has attracted widespread attention in the field of catalysis due to its unique structure, large specific surface area and the presence of lone electron pairs. A large number of studies have shown that black phosphorus has a unique activation effect on metals. By utilizing the strong adsorption and spontaneous bonding characteristics between black phosphorus and noble metals, the electronic structure of the catalyst can be regulated, which can greatly improve the activity, selectivity and service life of the catalyst while reducing the catalyst usage, and is conducive to improving the economic benefits of industrial production. The modification process is efficient, simple, green and pollution-free, which is conducive to large-scale industrial preparation [Adv. Energy Mater. 2023, 2302727]. SUMMARY

[0006] The present application combines black phosphorus, nitrogen source and carbon carrier by ball milling, and makes them combine firmly through calcination, and then prepares noble metal / carbon-based catalyst by using hot reflux method, so as to improve the conversion rate in the hydrogenation reaction of chloronitrobenzene, reduce the use amount of catalyst in production, and reduce the production cost of enterprises. The method has simple process and mild reaction conditions, and has a significant effect on improving the conversion rate of chloronitrobenzene hydrogenation.

[0007] The present application is realized by the following technical solutions:

[0008] A preparation method of black phosphorus modified nitrogen doped noble metal / carbon-based catalyst, the prepared black phosphorus modified nitrogen doped noble metal / carbon-based catalyst is a composite material of black phosphorus modified nitrogen doped carbon, and then loaded with noble metal to obtain a composite material. The method comprises the following steps:

[0009] (1) Black phosphorus, nitrogen source and carbon carrier are compounded by using ball milling, and then calcined in an inert atmosphere to obtain a black phosphorus modified nitrogen-carbon composite; calcination in an inert atmosphere is conducive to the full combination of black phosphorus, nitrogen source and carrier.

[0010] (2) noble metal loading process: under stirring, surface active agent, nitrogen doped phosphorus-carbon composite in step (1), base, reducing agent and noble metal salt solution are sequentially added in a solvent, and hot reflux reaction is carried out, then the solid is collected by centrifugation, dried and calcined in an inert atmosphere, and the product obtained is a black phosphorus modified nitrogen doped noble metal / carbon-based catalyst.

[0011] Preferably, the nitrogen source in step (1) is one or more of urea, ammonium sulfate, ammonium bisulfate, ammonium nitrate, ammonium carbonate and ammonium bicarbonate;

[0012] Preferably, the black phosphorus in step (1) is selected from one or more of black phosphorus powder, black phosphorus quantum dots, black phosphorus nanosheets and black phosphorus crystals; further preferably, it is black phosphorus powder; on the one hand, the incorporation of black phosphorus will produce P-C bond, and the C atom adjacent to the P atom will have more positive charge, thereby effectively enhancing the electronegativity and adsorbability of the carbon-based material, and being more conducive to the combination of nitrogen and carbon carrier. Compared with the traditional nitrogen doped modified carbon carrier, the introduction of black phosphorus is conducive to reducing the loss of metal and reducing the amount of catalyst. On the other hand, the modification of black phosphorus can also increase the defects on the surface of the nitrogen doped carbon carrier. The lone pair of electrons on the surface of black phosphorus makes it have active chemical properties. The empty orbit of noble metal can interact with black phosphorus through cation-pi bond, and a relatively stable structure is formed, which enhances the dispersion and stability of the active components such as metal components or metal oxides. Through the synergistic effect between black phosphorus, nitrogen doped carbon and noble metal, the activity and selectivity of the catalyst can be greatly improved, and the cost is greatly reduced.

[0013] Preferably, the carbon carrier in step (1) is one or more of porous carbon, carbon black, carbon nanotubes, carbon nanospheres, graphitized carbon nanocage and graphene.

[0014] Preferably, the surfactant in step (2) is one or more of amphoteric surfactant, nonionic surfactant, anionic surfactant, cationic surfactant; further preferably, the amphoteric surfactant is selected from one or more of Ddaps, the nonionic surfactant is selected from one or more of polyethylene glycol, polyvinylpyrrolidone, polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer, alkyl oxyethylene phenolic ether; the anionic surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium dodecyl sulfonate, sodium dodecyl sulfate; the cationic surfactant is selected from one or more of octadecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride.

[0015] Preferably, the base in step (2) includes one or more of urea, triethylamine, aqueous ammonia, sodium hydroxide, sodium methoxide, potassium ethoxide, sodium tert-butoxide and sodium amide; further preferably, the base includes one or more of urea, triethylamine, aqueous ammonia, sodium hydroxide.

[0016] Preferably, the reducing agent in step (2) includes one or more of formic acid, hydrazine hydrate and triphenylphosphine; further preferably, the reducing agent includes formic acid and hydrazine hydrate.

[0017] Preferably, the noble metal salt in step (2) includes one or more of platinum chloride, silver chloride, potassium chloroplatinate, sodium chloroplatinate, ammonium chloroplatinate, potassium chloroplatous acid, palladium chloride, sodium chloropalladate, ammonium chloropalladate, ammonium tetrachloropalladate, chloroauric acid, chloroiridic acid, iridium trichloride and iridium tetrachloride, potassium chlororhodate, ruthenium chloride, osmium chloride, sodium osmate, potassium osmate; further preferably, the noble metal salt is potassium chloroplatinate; the concentration of the noble metal salt is 0.01 mol / L-2 mol / L.

[0018] Preferably, the solvent in step (2) includes one or more of water, alcohol solvent, amide solvent; further preferably, the solvent in step (2) is one or more of water, methanol, diethyl ether, acetone, ethanol, propanol, isopropanol, N, N-dimethylformamide.

[0019] Preferably, the mass ratio of the carbon carrier, black phosphorus, nitrogen source, surfactant, base, solvent, reducing agent, noble metal salt is 1:(0.0001-0.5):(0.0001-10):(0.0001-10):(0.0001-1):(1-1000):(0.001-1):(0.001-0.5).

[0020] Preferably, the rotation speed of the ball mill in step (1) is 300-500 rpm, and the ball milling time is 24-48 h.

[0021] Preferably, the inert atmosphere in step (1) is one or more of nitrogen and argon; the calcination temperature is 180-500℃, and the calcination time is 0.5-5 h; calcination in an inert atmosphere is conducive to the full combination of black phosphorus, nitrogen and the carrier, improves the bonding ability, and makes the black phosphorus not be oxidized.

[0022] Preferably, the heat reflux temperature in step (2) is 10-100℃, and the heat reflux time is 0.5-30 h.

[0023] Preferably, the inert atmosphere in step (2) is one or more of nitrogen and argon; the calcination temperature is 180-500℃, and the calcination time is 0.5-5 h; calcination in an inert atmosphere is conducive to improving the bonding ability of the modified carrier and noble metal.

[0024] Based on this, the application also includes the use of the prepared black phosphorus modified nitrogen doped noble metal / carbon-based catalyst for catalytic hydrogenation reduction of chloronitrobenzene.

[0025] The solution containing chloronitrobenzene is transferred to the inner liner of the autoclave, the black phosphorus modified nitrogen doped noble metal / carbon-based catalyst is added, nitrogen is introduced in a closed environment, hydrogen is continuously introduced after the nitrogen replaces the air, and the reduction product is obtained under the conditions of a pressure of 0.1-5 MPa and a temperature of 30℃-200℃ for 0.1-5 h.

[0026] Preferably, the chloronitrobenzene in step (3) includes p-chloronitrobenzene and o-chloronitrobenzene, and is preferably p-chloronitrobenzene.

[0027] Preferably, the mass ratio of the catalyst to chloronitrobenzene in step (3) is (0.001-0.5):(1-200).

[0028] Preferably, the solvent used in the solution of chloronitrobenzene in step (3) is one or more of methanol or ethanol.

[0029] Preferably, the mass concentration of chloronitrobenzene in step (3) is 1-80%.

[0030] The application greatly improves the catalytic performance and catalytic stability of the catalyst by the synergistic effect between the black phosphorus modified nitrogen carbon and the noble metal, while reducing the amount of noble metal, which is conducive to improving the economic benefits of industrial production. The application finally realizes the energy-saving, environment-friendly and efficient hydrogenation catalytic process of chloronitrobenzene. The method of the application has the characteristics of high efficiency, simplicity, green and pollution-free reaction process, and has high industrial application value. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 TEM picture of 1 wt% N-BP-Pt / C in Example 1; from Figure 1 It can be seen that the phosphorus-nitrogen-doped platinum nanoparticles (particle size about 1-2 nm) are uniformly distributed on the surface of the carbon carrier. DETAILED DESCRIPTION

[0032] The application provides a preparation method and application of a black phosphorus modified nitrogen-doped noble metal / carbon-based catalyst. The black phosphorus modified nitrogen-doped noble metal / carbon-based catalyst is a noble metal / carbon-based catalyst modified by black phosphorus, nitrogen and a carbon-based material and a noble metal. The application is the use of the black phosphorus modified nitrogen-doped noble metal / carbon-based catalyst in the hydrogenation of chloronitrobenzene to chloroaniline.

[0033] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in detail below in combination with the drawings and examples. It should be pointed out that the specific examples described herein are only used to explain the present application, and are not intended to limit the embodiments of the present application. Any changes, modifications, combinations, simplifications or substitutions made without departing from the spirit and principles of the present application shall be equivalent replacement methods and shall fall within the scope of protection of the present application.

[0034] Example 1

[0035] (1) 1 mg of urea, 2 mg of black phosphorus powder and 2 g of carbon black were mixed and added to a ball mill jar, the rotation speed was 300 rpm, and the ball milling was carried out for 24 h to obtain a uniform phosphorus-nitrogen-carbon composite material;

[0036] (2) The obtained phosphorus-nitrogen-carbon composite material was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a black phosphorus modified nitrogen-doped carbon composite material;

[0037] (3) A certain amount of K2PtCl4 was dissolved in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0038] (4) 0.05 g of F127, 30 μL of ammonia water, 0.1 g of the black phosphorus modified nitrogen-doped carbon composite material of step (2), 100 μL of the K2PtCl4 solution of step (3) and 0.1 g of formic acid were sequentially added to 25 mL of water, and the metal platinum was loaded onto the black phosphorus modified nitrogen-doped carbon composite material by a hot reflux method under stirring at 70°C for 12 h until the stirring was uniform;

[0039] (5) The product obtained in step (4) was centrifuged and washed to obtain a solid;

[0040] (6) The obtained solid was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a product marked as 1 wt% BP-N-Pt / C.

[0041] In another embodiment of the present application, the mass of black phosphorus added in step (1) is 6 mg, and other steps are the same as above, then the product obtained is 3 wt‰ BP-N-Pt / C.

[0042] In another embodiment of the present application, the mass of black phosphorus added in step (1) is 10 mg, and other steps are the same as above, then the product obtained is 5 wt‰ BP-N-Pt / C.

[0043] In another embodiment of the present application, the mass of black phosphorus added in step (1) is 20 mg, and other steps are the same as above, then the product obtained is 1 wt% BP-N-Pt / C. Figure 1 It is a TEM picture of 1 wt‰ N-BP-Pt / C in Example 1; from Figure 1 It can be seen that the phosphorus and nitrogen doped platinum nanoparticles (particle size about 1-2 nm) are uniformly distributed on the surface of the carbon carrier.

[0044] In another embodiment of the present application, no black phosphorus is added in step (1), and other steps are the same as above, then the product obtained is N-Pt / C.

[0045] The performance of the above catalysts (1 wt‰ BP-N-Pt / C, 3 wt‰ BP-N-Pt / C, 5 wt‰ BP-N-Pt / C, 1 wt% BP-N-Pt / C and N-Pt / C) is evaluated by taking the catalytic hydrogenation of p-chloronitrobenzene as a model reaction. 20 g of p-chloronitrobenzene, 40 mL of methanol and 50 mg of the above catalyst are added to a high-pressure reaction kettle, the air in the reaction system is replaced with nitrogen for 3 times, then heated, the temperature is raised to 80 ℃, the rotation speed is adjusted to 600 r·min -1 , hydrogen gas with a pressure of 0.8 Mpa is introduced into the kettle, the reaction time is 1 h, after the reaction is completed, the reaction kettle is cooled to room temperature, the material is discharged, and the sample is analyzed by using a gas chromatograph, the conversion rate and the yield of p-chloroaniline are shown in Table 1.

[0046] The 1 wt‰ BP-N-Pt / C is used to catalyze the hydrogenation of p-chloronitrobenzene to prepare p-chloroaniline, and the recycling test is carried out. The test steps are as follows: after the above catalytic reaction is carried out once, the separated catalyst is washed with methanol, and then is filled in the high-pressure reaction kettle again to carry out the recycling catalytic reaction of p-chloronitrobenzene to prepare p-chloroaniline, and the yield obtained is shown in Table 2.

[0047] Table 1

[0048]

[0049] Table 2 Catalyst reuse performance

[0050]

[0051] Example 2

[0052] (1) 1 mg of ammonium sulfate, 2 mg of black phosphorus powder, and 2 g of carbon black were mixed and added to a ball mill tank, the rotation speed was 300 rpm, and the ball milling was performed for 24 h to obtain a uniform phosphorus-nitrogen-carbon composite material;

[0053] (2) The obtained phosphorus-nitrogen-carbon composite material was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a black phosphorus modified nitrogen-doped carbon composite material;

[0054] (3) A certain amount of K2PtCl4 was dissolved in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0055] (4) 0.05 g of F127, 30 μL of ammonia water, 0.1 g of the black phosphorus modified nitrogen-doped carbon composite material of step (2), 100 μL of the K2PtCl4 solution of step (3), and 0.1 g of formic acid were sequentially added to 25 mL of water, and under stirring, the metal platinum was loaded onto the black phosphorus modified nitrogen-doped carbon composite material by a hot reflux method, and the reaction was performed at 70°C for 12 h, and the stirring was uniform;

[0056] (5) The product obtained in step (4) was centrifuged and washed to obtain a solid;

[0057] (6) The obtained reduced solid was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a product marked as (NH4)2SO4-BP-Pt / C.

[0058] In another embodiment of the present application, in step (1), the nitrogen source added is ammonium nitrate, and the other steps are the same as above, and the obtained product is NH4NO3-BP-Pt / C.

[0059] In another embodiment of the present application, in step (1), the nitrogen source added is ammonium carbonate, and the other steps are the same as above, and the obtained product is (NH4)2CO3-BP-Pt / C.

[0060] In another embodiment of the present application, in step (1), the nitrogen source added is ammonium bicarbonate, and the other steps are the same as above, and the obtained product is NH4HCO3-BP-Pt / C.

[0061] The performance of the above catalysts ((NH4)2SO4-BP-Pt / C, NH4NO3-BP-Pt / C, (NH4)2CO3-BP-Pt / C and NH4HCO3-BP-Pt / C) is evaluated by taking the catalytic hydrogenation of p-chloronitrobenzene as a model reaction. 20 g of p-chloronitrobenzene, 40 mL of methanol and 50 mg of the above catalyst are added to a high-pressure reaction kettle, the air in the reaction system is replaced with nitrogen for 3 times, then heated, the temperature is raised to 80 ℃, the rotation speed is adjusted to 600 r·min -1 , the hydrogen pressure in the kettle is 0.8 Mpa, the reaction time is 1 h, after the reaction is completed, the reaction kettle is cooled to room temperature, the material is discharged, and the sample is analyzed by a gas chromatograph, the conversion rate and the yield of p-chloroaniline are shown in Table 3.

[0062] Table 3

[0063]

[0064] Example 3

[0065] (1) 1 mg of urea, 2 mg of black phosphorus powder and 2 g of carbon black are mixed and added to a ball mill jar, the rotation speed is 300 rpm, and the ball milling is carried out for 24 h to obtain a uniform phosphorus-nitrogen-carbon composite material;

[0066] (2) The obtained phosphorus-nitrogen-carbon composite material is calcined at 300 ℃ for 3 h in a tube furnace under a nitrogen atmosphere to obtain a black phosphorus modified nitrogen-doped carbon composite material;

[0067] (3) A certain amount of K2PtCl4 is dissolved in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0068] (4) 0.05 g of F127, 30 μL of ammonia water, 0.1 g of the black phosphorus modified nitrogen-doped carbon composite material of step (2), 100 μL of the K2PtCl4 solution of step (3) and 0.1 g of hydrazine hydrate are sequentially added to 25 mL of water, and the metal platinum is loaded on the black phosphorus modified nitrogen-doped carbon composite material by a hot reflux method under stirring at 70 ℃ for 12 h, and the stirring is uniform;

[0069] (5) The product obtained in step (4) is centrifuged and washed to obtain a solid;

[0070] (6) The obtained reduced solid is calcined at 300 ℃ for 3 h in a tube furnace under a nitrogen atmosphere to obtain a product marked as N2H4·H2O-BP-N-Pt / C.

[0071] In another embodiment of the application, a triphenylphosphine is added as a reducing agent in step (1), and other steps are the same as above, and the product obtained is C 18 H15 P-BP-N-Pt / C.

[0072] The performance of the above catalysts (N2H4·H2O-BP-N-Pt / C and C 18 H 15 P-BP-N-Pt / C) was evaluated by taking the catalytic hydrogenation of p-chloronitrobenzene as a model reaction. 20 g of p-chloronitrobenzene, 40 mL of methanol, and 50 mg of the above catalyst were added to a high-pressure reaction kettle, the air in the reaction system was replaced with nitrogen for 3 times, then heated, the temperature was raised to 80 ℃, the rotation speed was adjusted to 600 r·min -1 , hydrogen gas with a pressure of 0.8 Mpa was introduced into the kettle, the reaction time was 1 h, after the reaction was completed, the reaction kettle was cooled to room temperature, the material was discharged, and the sample was analyzed by gas chromatography. The conversion rate and p-chloroaniline yield are shown in Table 4.

[0073] Table 4

[0074]

[0075] Example 4

[0076] (1) 1 mg of urea, 2 mg of black phosphorus powder, and 2 g of carbon black were mixed and added to a ball mill jar, the rotation speed was 300 rpm, and the ball milling was carried out for 24 h to obtain a uniform phosphorus-nitrogen-carbon composite material;

[0077] (2) The obtained phosphorus-nitrogen-carbon composite material was calcined at 300 ℃ for 3 h in a tube furnace under nitrogen atmosphere to obtain a black phosphorus modified nitrogen-doped carbon composite material;

[0078] (3) A certain amount of K2PtCl4 was dissolved in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0079] (4) 0.05 g of F127, 0.1 g of urea, 0.1 g of the black phosphorus modified nitrogen-doped carbon composite material of step (2), 100 μL of the K2PtCl4 solution of step (3), and 0.1 g of formic acid were sequentially added to 25 mL of water, and the metal platinum was loaded onto the black phosphorus modified nitrogen-doped carbon composite material by hot reflux method under stirring at 70 ℃ for 12 h;

[0080] (5) The product obtained in step (4) was centrifuged and washed to obtain a solid;

[0081] (6) The obtained reduced solid was calcined at 300 ℃ for 3 h in a tube furnace under nitrogen atmosphere to obtain a product marked as CO(NH2)2-BP-N-Pt / C.

[0082] In another embodiment of the present application, the precipitant added in step (1) is sodium hydroxide, and other steps are the same as above, then the product obtained is NaOH-BP-N-Pt / C. 15 N-BP-N -Pt / C, NaOH-BP-N-Pt / C and NaHCO3-BP-N-Pt / C.

[0083] In another embodiment of the present application, the precipitant added in step (1) is sodium hydroxide, and other steps are the same as above, then the product obtained is NaOH-BP-N-Pt / C.

[0084] In another embodiment of the present application, the precipitant added in step (1) is sodium hydroxide, and other steps are the same as above, then the product obtained is NaOH-BP-N-Pt / C.

[0085] The performance of the above catalysts (CO(NH2)2-BP-N-Pt / C, C6H 15 N-BP-N -Pt / C, NaOH-BP-N-Pt / C and NaHCO3-BP-N-Pt / C) was evaluated by taking the catalytic hydrogenation of p-chloronitrobenzene as a model reaction. 20 g of p-chloronitrobenzene, 40 mL of methanol and 50 mg of the above catalyst were added to a high-pressure reaction kettle, the air in the reaction system was replaced with nitrogen for 3 times, then heated, the temperature was raised to 80 ℃, the rotation speed was adjusted to 600 r·min -1 , hydrogen gas with a pressure of 0.8 Mpa was introduced into the kettle, the reaction time was 1 h, after the reaction was completed, the reaction kettle was cooled to room temperature, the material was discharged, and gas chromatography was used for sample analysis, the conversion rate and p-chloroaniline yield are shown in Table 5.

[0086] Table 5

[0087]

[0088] The specific embodiment of Comparative Example 1 is:

[0089] (1) A certain amount of K2PtCl4 was dissolved in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0090] (2) 0.05 g of F127, 30 μL of ammonia water, 0.1 g of carbon black, 100 μL of the K2PtCl4 solution of step (1), and 0.1 g of formic acid were sequentially added to 25 mL of water, and under stirring conditions, the metal platinum was loaded on the carbon black by a hot reflux method, and the reaction was carried out at 70 ℃ for 12 h, and the stirring was uniform;

[0091] (3) The product obtained in step (2) was centrifuged and washed to obtain a solid;

[0092] (4) The obtained solid was calcined in a tube furnace under a nitrogen atmosphere at 300 ℃ for 3 h to obtain a platinum / carbon composite.

[0093] (5) 2 mg black phosphorus powder and the platinum / carbon composite obtained in step (4) were added into a ball mill tank, the rotation speed was 300 rpm, and ball milling was performed for 24 h to obtain a uniform phosphorus-platinum / carbon composite;

[0094] (6) The obtained phosphorus-platinum / carbon composite was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a black phosphorus modified platinum / carbon composite, which was marked as 1 wt% BP-Pt / C.

[0095] The embodiment of Comparative Example 2 is as follows:

[0096] (1) 1 mg of urea was mixed with 2 g of carbon black, and the mixture was added into a ball mill tank, the rotation speed was 300 rpm, and ball milling was performed for 24 h to obtain a uniform nitrogen / carbon composite material;

[0097] (2) The obtained nitrogen / carbon composite material was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a nitrogen-doped carbon material;

[0098] (3) A certain amount of K2PtCl4 was dissolved in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0099] (4) 0.05 g of F127, 30 μL of ammonia water, 0.1 g of the nitrogen-doped carbon material obtained in step (2), 100 μL of the K2PtCl4 solution obtained in step (3), and 0.1 g of formic acid were sequentially added into 25 mL of water, and the mixture was stirred under reflux at 70°C for 12 h to load platinum onto the nitrogen-doped carbon material;

[0100] (5) The product obtained in step (4) was centrifuged and washed to obtain a solid;

[0101] (6) 2 mg of black phosphorus powder and the solid obtained in step (5) were added into a ball mill tank, the rotation speed was 300 rpm, and ball milling was performed for 24 h to obtain a uniform phosphorus-platinum / nitrogen / carbon composite;

[0102] (7) The obtained phosphorus-platinum / nitrogen / carbon composite was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a product, which was marked as 1 wt% Pt / N-C-BP.

[0103] The embodiment of Comparative Example 3 is as follows:

[0104] (1) 1 mg of urea was mixed with 2 g of carbon black, and the mixture was added into a ball mill tank, the rotation speed was 300 rpm, and ball milling was performed for 24 h to obtain a uniform nitrogen / carbon composite material;

[0105] (2) The obtained nitrogen / carbon composite material was calcined at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a nitrogen-doped carbon material;

[0106] (3) Dissolve a certain amount of K2PtCl4 in deionized water to prepare a K2PtCl4 solution with a concentration of 1 mol / L;

[0107] (4) Add 0.05 g of F127, 30 μL of ammonia water, 0.1 g of the nitrogen-doped carbon material of step (2), 2 mg of black phosphorus powder, 100 μL of the K2PtCl4 solution of step (3), and 0.1 g of formic acid into 25 mL of water in sequence under stirring, and then load the black phosphorus modified platinum onto the nitrogen-doped carbon material by using a hot reflux method at 70°C for 12 h;

[0108] (5) Centrifuge and wash the product obtained in step (4) to obtain a solid;

[0109] (6) Calcine the obtained solid at 300°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a product marked as 1wt‰ BP-Pt / N-C.

[0110] The performance of the above catalysts (1wt‰ BP-Pt / C, 1wt‰ Pt / N-C-BP, and 1wt‰ BP-Pt / N-C) was evaluated by taking the catalytic hydrogenation of p-chloronitrobenzene as a model reaction. 20 g of p-chloronitrobenzene, 40 mL of methanol, and 50 mg of the above catalyst were added into a high-pressure reaction kettle, the air in the reaction system was replaced with nitrogen for 3 times, and then heated to 80°C with a rotation speed of 600 r·min-1. Hydrogen with a pressure of 0.8 MPa was introduced into the kettle, and the reaction lasted for 1 h. After the reaction, the reaction kettle was cooled to room temperature, and the sample was analyzed by using a gas chromatograph. The conversion rate and the yield of p-chloroaniline are shown in Table 6. -1

[0111] Table 6

[0112] ​

Claims

1. The application of black phosphorus-modified nitrogen-doped noble metal / carbon-based catalyst in the catalytic hydrogenation reduction of chloronitrobenzene, characterized in that, The preparation method of black phosphorus modified nitrogen-doped noble metal / carbon-based catalyst includes the following steps: under the condition of adding black phosphorus, the nitrogen source and carbon support are combined by ball milling, and after the first step of calcination, noble metal loading is performed, and after drying and the second step of calcination, the black phosphorus modified nitrogen-doped noble metal / carbon-based catalyst is obtained. The precious metal loading process includes adding solvent, surfactant, alkali and reducing agent to the product after the first calcination step, then adding a precious metal salt solution, and carrying out a hot reflux reaction under stirring conditions. The hot reflux temperature is 10-100℃ and the hot reflux time is 0.5-30h. The product after reaction is collected by centrifugation, dried and then calcined in an inert atmosphere to obtain the target product.

2. The application according to claim 1, characterized in that, The raw materials for black phosphorus are selected from one or more of black phosphorus powder, black phosphorus quantum dots, black phosphorus nanosheets, and black phosphorus crystals; the nitrogen source includes one or more of urea, ammonium salts, and nitrates; the carbon carrier includes one or more of porous carbon, carbon black, carbon nanotubes, carbon spheres, graphitized carbon nanocages, and graphene.

3. The application according to claim 1, characterized in that, The ball milling speed is 300-500 rpm, and the ball milling time is 24-48 h; the inert atmosphere is one or more of nitrogen or argon; the calcination temperature is 180-500℃, and the calcination time is 0.5-5 h.

4. The application according to claim 1, characterized in that, The solvent includes one or more of water, methanol, diethyl ether, acetone, ethanol, propanol, isopropanol, and N,N-dimethylformamide; the surfactant includes one or more of Ddaps, polyethylene glycol, polyvinylpyrrolidone, polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer, alkyloxyethylene phenolic ether, sodium dodecylbenzenesulfonate, sodium dodecyl sulfonate, sodium dodecyl sulfate, octadecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and dodecyldimethylbenzylammonium chloride; the alkali includes one or more of urea, triethylamine, sodium hydroxide, and sodium bicarbonate; the reducing agent includes one or more of formic acid, hydrazine hydrate, and triphenylphosphine; the concentration of the noble metal salt is 0.01 mol / L to 2 mol / L, and the noble metal salt includes one or more of platinum chloride, chloroplatinate, palladium chloride, chloropalladium salt, chloroauric acid, silver chloride, chloroiridium acid, iridium trichloride and iridium tetrachloride, potassium rhodium chloride, ruthenium chloride, osmium chloride, and osmium tetroxide.

5. The application according to claim 4, characterized in that, The inert atmosphere is one or more of nitrogen or argon; the calcination temperature is 180-500℃, and the calcination time is 0.5-5h.

6. The application according to any one of claims 1-5, characterized in that, The prepared black phosphorus-modified nitrogen-doped noble metal / carbon-based catalyst is a composite material of black phosphorus-modified nitrogen-doped carbon, which is then loaded with noble metal to obtain the composite material.

7. The application according to claim 1, characterized in that, A method for the catalytic hydrogenation reduction of chloronitrobenzene using a black phosphorus-modified nitrogen-doped noble metal / carbon-based catalyst includes the following steps: The solution containing chloronitrobenzene was transferred to the lining of a high-pressure reactor, and a black phosphorus-modified nitrogen-doped noble metal / carbon-based catalyst was added. Under a closed environment, nitrogen gas was introduced to replace the air, and then hydrogen gas was continuously introduced. The reaction was carried out for 0.1-5 h at a pressure of 0.1-5 MPa and a temperature of 30℃-200℃ to obtain the reduction product.

8. The application according to claim 1, characterized in that, The chloronitrobenzene includes p-chloronitrobenzene and o-chloronitrobenzene; the mass ratio of the catalyst to the chloronitrobenzene is (0.001-0.5):(1-200).

9. The application according to claim 8, characterized in that, The solvent used in the chloronitrobenzene solution is selected from C1-C4 alcohol solvents, and the mass concentration of chloronitrobenzene is 1-80%.

10. The application according to claim 8, characterized in that, The chloronitrobenzene mentioned is p-chloronitrobenzene.

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