Nitrogen, phosphorus, boron and iron co-doped coconut shell activated carbon carrier as well as preparation method and application thereof

Abstract

The invention discloses a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier and a preparation method and application thereof, the method comprises the following steps: S1, crushing coconut shell activated carbon, and carrying out Ar / water vapor activation treatment to obtain pretreated activated carbon; s2, after the chitosan solution and the urea solution are mixed, phytic acid is added, the pH is adjusted to 5.5-6.0, stirring is conducted, and a wetting agent is obtained; s3, adding a wetting agent into the pretreated activated carbon, heating, stirring, filtering, washing, and drying in vacuum to obtain pre-activated activated carbon containing nitrogen and phosphorus; and S4, dissolving ammonium ferric citrate and sodium citrate in deionized water, adding ethylene glycol, stirring, then adding the pre-activated activated carbon containing nitrogen and phosphorus, heating, stirring again, then dropwise adding a potassium borohydride mixed solution, and roasting to obtain the nitrogen, phosphorus, boron and iron co-doped coconut shell activated carbon carrier. After the nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier provided by the invention is loaded with the metal catalyst, the common problems of low conversion rate and poor selectivity in nitro hydrogenation reaction can be solved.

Description

Technical Field

[0001] This invention relates to the field of novel carbon materials technology, specifically to a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier, its preparation method, and its application. Background Technology

[0002] Activated carbon, a porous carbonaceous material with a long history and wide application, has become a classic choice in the field of catalyst supports due to its well-developed pore structure, high specific surface area, excellent chemical stability, and easy regeneration. It has mature applications in various catalytic reactions such as hydrogenation and oxidation. Its main component is carbon, containing small amounts of oxygen and hydrogen. The hydroxyl and carboxyl functional groups on its surface can provide active sites, enabling the loading and anchoring of metal catalysts. In the hydrogenation reaction of nitro compounds, traditional activated carbon supports enrich the substrate through physical adsorption, providing reaction sites for metal active centers (such as Pd, Ni, Pt, etc.), promoting the conversion of nitro groups (-NO2) to amino groups (-NH2). It is a key material for the preparation of aromatic amine fine chemical products and pharmaceutical intermediates.

[0003] However, conventional activated carbon supports have inherent limitations: their strong surface inertness results in insufficient specific adsorption capacity for polar nitro compounds, leading to low substrate mass transfer efficiency; the lack of active functional groups to regulate the electronic state of metal active centers easily leads to insufficient catalytic activity and increased side reactions; and the monoporous structure may cause product accumulation, affecting catalytic stability. Therefore, optimizing the structure and chemical properties of activated carbon supports has become a core research direction for improving the catalytic efficiency of nitro hydrogenation. Summary of the Invention

[0004] The main objective of this invention is to propose a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon support, its preparation method, and its application. The aim is to provide a catalyst support for the hydrogenation reaction of nitro compounds, solving the problems of low catalytic activity and poor selectivity in the prior art.

[0005] To achieve the above objectives, this invention proposes a method for preparing a co-doped coconut shell activated carbon carrier, comprising the following steps: S1. Coconut shell activated carbon is pulverized to 100-200 mesh and then activated by Ar / steam to obtain pretreated activated carbon; S2. Dissolve chitosan in acetic acid solution to obtain chitosan solution, mix with urea solution, add phytic acid, adjust pH to 5.5~6.0, continue stirring to obtain wetting agent; S3. Add the pretreated activated carbon to the wetting agent, heat, stir, then filter, wash, and vacuum dry to obtain nitrogen and phosphorus pre-activated activated carbon. S4. Dissolve ferric ammonium citrate and sodium citrate in deionized water, add ethylene glycol, stir, then add the nitrogen and phosphorus pre-activated activated carbon, heat, stir again, and then slowly add potassium borohydride mixed solution. After the addition is complete, continue stirring. After filtration, washing, and drying, the product is calcined under a nitrogen atmosphere to obtain nitrogen, phosphorus, boron, and iron co-doped coconut shell activated carbon carrier.

[0006] Preferably, in step S1, the volume ratio of Ar to H2O is (4~6):1; the activation temperature is 400~600℃, and the activation time is 30~60min.

[0007] Preferably, in step S2, the mass fraction of the urea solution is 4-6%, the mass fraction of the chitosan solution is 1-3%, and the volume ratio of the urea solution, chitosan solution, and phytic acid is (35-45):(180-220):1.

[0008] Preferably, in step S3, the heating temperature is 70~80℃, the stirring time is 4~5 h, the vacuum drying temperature is 75~85℃, and the vacuum drying time is 1.5~2.5 h.

[0009] Preferably, in step S4, the stirring temperature is 35~45℃, the stirring time is 30~40 min; the temperature is raised to 50~60℃, and the stirring time is 2~3 h; the concentration of the potassium borohydride solution is 20~50 mmol / L; and the stirring time is 30~40 min.

[0010] Preferably, in step S4, the ratio of the amount of ferric ammonium citrate, sodium citrate, ethylene glycol, nitrogen- and phosphorus-containing pre-activated activated carbon, and potassium borohydride is (1~2g):(3~5g):(0.5~1.5mL):(8~12g):(2~6mL).

[0011] Preferably, in step S4, the calcination temperature is 700~800℃.

[0012] The present invention also proposes a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier, which is prepared by the method described above.

[0013] The present invention also proposes a catalyst comprising a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon support as described above and a supported transition metal, wherein the transition metal includes at least one of Pt, Pd, and Au.

[0014] The present invention also proposes the application of the catalyst described above in the hydrogenation reaction of nitro compounds.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The method for preparing the nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon support provided by the present invention, through the synergistic treatment of activation pretreatment and doping process, yields a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon support with a high specific surface area and a multi-level interconnected pore structure, as well as strong active adsorption and catalytic stability. When used as a support to load metal catalysts, it can solve the common problems of "weak substrate adsorption, poor dispersion of active centers, and low product selectivity" in nitro hydrogenation reaction, and achieve simultaneous improvement in catalytic activity, selectivity and stability, providing high-performance material support for efficient hydrogenation catalysis. Furthermore, this preparation method does not require expensive raw materials and extreme reaction conditions, saves energy, and has industrialization feasibility.

[0016] (2) The method for preparing the nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier provided by the present invention firstly involves Ar / steam activation treatment. The hydroxyl radicals (·OH) generated by the dissociation of steam act on the surface of the activated carbon. The ·OH reacts with carbon radicals to introduce oxygen-containing groups such as hydroxyl (-OH) and carboxyl (-COOH), providing connection sites for the subsequent chemical bonding of N and P sources. It also creates defects and rough structures on the surface of the coconut shell activated carbon, providing more sites for the subsequent loaded metal active components and avoiding the agglomeration of metal particles. Then, it is pre-activated by impregnation with a wetting agent. The wetting agent uses chitosan and urea as multiple nitrogen sources and is combined with phytic acid to achieve N and P co-doping. Its electron-rich properties can enhance the activation ability of nitro groups. Subsequently, it is activated by Fe with iron ammonium citrate. 3+ It forms a complex with sodium citrate and ethylene glycol, and then forms an N-Fe coordination bond with the amino groups on activated carbon to fix iron ions. The addition of potassium borohydride can then partially remove the Fe... 3+ Reduced to Fe 2+ Fe 2+ / Fe 3+ Mixed state, in which Fe 2+ As an electron donor, Fe 3+ As electron acceptors, the two work synergistically to lower the activation energy of the nitro group (-NO2), thereby increasing the conversion rate of nitrobenzene. Simultaneously, the generated borate ions and the PO4 provided by phytic acid... 3- The formation of BOP bonds, which together with N-Fe bonds form a cooperative network, not only enhances the loading and doping of Fe, B, and P elements, but also provides important support for the high activity, high conversion rate, high selectivity, and long cycle life of subsequent hydrogenation reactions of nitro compounds. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The process flow diagram for preparing the nitrogen, phosphorus, boron, and iron co-doped coconut shell activated carbon carrier provided by the present invention is shown.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0022] Example 1 A method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier includes the following steps: (1) The coconut shell activated carbon is pulverized to 150 mesh and then activated at 500℃ with Ar / water steam for 50 min to obtain pretreated activated carbon; (2) Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a mass fraction of 2%. Mix 200 mL of chitosan solution with 40 mL of urea solution with a mass fraction of 5%, add 1 g of phytic acid, adjust the pH to 5.8, and continue stirring to obtain a wetting agent. (3) Add 10g of pretreated activated carbon to the wetting agent, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain nitrogen and phosphorus pre-activated activated carbon; (4) Dissolve 1.5g of ferric ammonium citrate and 4g of sodium citrate in 20mL of deionized water, add 1mL of ethylene glycol, stir at 40℃ for 35 min, then add 10g of nitrogen and phosphorus pre-activated activated carbon, heat to 50℃, stir again for 2.5h, then slowly add 4mL of potassium borohydride mixed solution, continue stirring for 35 min after the addition is complete, filter, wash, dry the product and calcine at 750℃ under nitrogen atmosphere to obtain nitrogen, phosphorus, boron and iron co-doped coconut shell activated carbon carrier.

[0023] Example 2 A method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier includes the following steps: (1) Coconut shell activated carbon is pulverized to 100 mesh and then activated at 400℃ by Ar / water steam for 30 min to obtain pretreated activated carbon; (2) Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a mass fraction of 1%. Mix 200 mL of chitosan solution with 40 mL of urea solution with a mass fraction of 4%, add 1 g of phytic acid, adjust the pH to 5.8, and continue stirring to obtain a wetting agent. (3) Add 10g of pretreated activated carbon to the wetting agent, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain nitrogen and phosphorus pre-activated activated carbon; (4) Dissolve 1g of ferric ammonium citrate and 3g of sodium citrate in 20mL of deionized water, add 0.5mL of ethylene glycol, stir at 35℃ for 30 min, then add 8g of nitrogen and phosphorus pre-activated activated carbon, heat to 50℃, stir again for 2h, then slowly add 2mL of potassium borohydride mixed solution, continue stirring for 30 min after the addition is complete, filter, wash, dry the product and calcine at 700℃ under nitrogen atmosphere to obtain nitrogen, phosphorus, boron and iron co-doped coconut shell activated carbon carrier.

[0024] Example 3 A method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier includes the following steps: (1) Coconut shell activated carbon is pulverized to 200 mesh and then activated at 600℃ with Ar / water steam for 60 min to obtain pretreated activated carbon; (2) Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a mass fraction of 3%. Mix 200 mL of chitosan solution with 40 mL of urea solution with a mass fraction of 6%, add 1 g of phytic acid, adjust the pH to 5.8, and continue stirring to obtain a wetting agent. (3) Add 10g of pretreated activated carbon to the wetting agent, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain nitrogen and phosphorus pre-activated activated carbon; (4) Dissolve 2g of ferric ammonium citrate and 5g of sodium citrate in 20mL of deionized water, add 1.5mL of ethylene glycol, stir at 45℃ for 40 min, then add 12g of nitrogen and phosphorus pre-activated activated carbon, heat to 60℃, stir again for 3h, then slowly add 6mL of potassium borohydride mixed solution, continue stirring for 40 min after the addition is complete, filter, wash, dry the product and calcine at 800℃ under nitrogen atmosphere to obtain nitrogen, phosphorus, boron and iron co-doped coconut shell activated carbon carrier.

[0025] Comparative Example 1 A method for preparing a phosphorus-boron-iron co-doped coconut shell activated carbon carrier includes the following steps: (1) The coconut shell activated carbon is pulverized to 150 mesh and then activated at 500℃ with Ar / water steam for 50 min to obtain pretreated activated carbon; (2) Add 10g of pretreated activated carbon to 1g of phytic acid, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain phosphorus-containing preactivated activated carbon. (3) Dissolve 1.5g of ferric ammonium citrate and 4g of sodium citrate in 20mL of deionized water, add 1mL of ethylene glycol, stir at 40℃ for 35 min, then add 10g of phosphorus-containing pre-activated activated carbon, heat to 50℃, stir again for 2.5h, then slowly add 4mL of potassium borohydride mixed solution, continue stirring for 35 min after the addition is complete, filter, wash, dry the product and calcine at 750℃ under nitrogen atmosphere to obtain co-doped coconut shell activated carbon carrier.

[0026] Comparative Example 2 A method for preparing a nitrogen-boron-iron co-doped coconut shell activated carbon carrier includes the following steps: (1) The coconut shell activated carbon is pulverized to 150 mesh and then activated at 500℃ with Ar / water steam for 50 min to obtain pretreated activated carbon; (2) Chitosan was dissolved in acetic acid solution to obtain a chitosan solution with a mass fraction of 2%. 200 mL of chitosan solution was mixed with 40 mL of urea solution with a mass fraction of 5%. The pH was adjusted to 5.8 and stirring was continued to obtain a wetting agent. (3) Add 10g of pretreated activated carbon to the wetting agent, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain nitrogen and phosphorus pre-activated activated carbon; (4) Dissolve 1.5g of ferric ammonium citrate and 4g of sodium citrate in 20mL of deionized water, add 1mL of ethylene glycol, stir at 40℃ for 35 min, then add 10g of nitrogen and phosphorus pre-activated activated carbon, heat to 50℃, stir again for 2.5h, then slowly add 4mL of potassium borohydride mixed solution, continue stirring for 35 min after the addition is complete, filter, wash, dry the product and calcine at 750℃ under nitrogen atmosphere to obtain co-doped coconut shell activated carbon carrier.

[0027] Comparative Example 3 A method for preparing a nitrogen-phosphorus-boron co-doped coconut shell activated carbon carrier includes the following steps: (1) The coconut shell activated carbon is pulverized to 150 mesh and then activated at 500℃ with Ar / water steam for 50 min to obtain pretreated activated carbon; (2) Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a mass fraction of 2%. Mix 200 mL of chitosan solution with 40 mL of urea solution with a mass fraction of 5%, add 1 g of phytic acid, adjust the pH to 5.8, and continue stirring to obtain a wetting agent. (3) Add 10g of pretreated activated carbon to the wetting agent, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain nitrogen and phosphorus pre-activated activated carbon; (4) Dissolve 4g of sodium citrate in 20mL of deionized water, add 1mL of ethylene glycol, stir at 40℃ for 35 min, then add 10g of nitrogen and phosphorus pre-activated activated carbon, heat to 50℃, stir again for 2.5h, then slowly add 4mL of potassium borohydride mixed solution, continue stirring for 35 min after the addition is complete, filter, wash, dry the product and calcine at 750℃ under nitrogen atmosphere to obtain co-doped coconut shell activated carbon carrier.

[0028] Comparative Example 4 A method for preparing a nitrogen-phosphorus-iron co-doped coconut shell activated carbon carrier includes the following steps: (1) The coconut shell activated carbon is pulverized to 150 mesh and then activated at 500℃ with Ar / water steam for 50 min to obtain pretreated activated carbon; (2) Dissolve chitosan in acetic acid solution to obtain a chitosan solution with a mass fraction of 2%. Mix 200 mL of chitosan solution with 40 mL of urea solution with a mass fraction of 5%, add 1 g of phytic acid, adjust the pH to 5.8, and continue stirring to obtain a wetting agent. (3) Add 10g of pretreated activated carbon to the wetting agent, heat to 75°C, stir for 4.5 h, then filter, wash, and vacuum dry at 80°C for 2 h to obtain nitrogen and phosphorus pre-activated activated carbon; (4) Take 1.5g of ferric ammonium citrate and 4g of sodium citrate and dissolve them in 20mL of deionized water. Add 1mL of ethylene glycol and stir at 40℃ for 35 min. Then add 10g of nitrogen and phosphorus pre-activated activated carbon, heat to 50℃, and stir again for 2.5h. After filtration, washing, and drying, the product is calcined at 750℃ under a nitrogen atmosphere to obtain co-doped coconut shell activated carbon carrier.

[0029] Application Examples 1-7 1 g of co-doped coconut shell activated carbon support prepared in Examples 1-3 and Comparative Examples 1-4 were added to 10 mL of deionized water to prepare a slurry. The slurry was heated to 80 °C in a water bath, and 10 mL of 0.05 mol / L PdCl2 solution was slowly added dropwise under magnetic stirring for 60 min. Then, 6 mL of 0.1 mol / L sodium acetate solution was added and stirred for 60 min. An alkaline solution, namely NaOH solution, was added dropwise to adjust the pH to 7-9, and stirring was continued for 60 min. Subsequently, 60 μL of 37 wt% formaldehyde solution was added dropwise for reduction and maintained for 60 min. Then, the temperature was lowered to room temperature, filtered, and the filter cake was washed with deionized water and vacuum dried to obtain the palladium catalyst supported on the co-doped coconut shell activated carbon support of Examples 1-7.

[0030] Test methods and results In a 500 mL stainless steel reactor, 50 g of o-chloronitrobenzene and 300 mL of ethanol were added, followed by 0.5 g of the palladium catalyst co-doped with coconut shell activated carbon as described in Application Examples 1-7. The reactor was then closed, and the air inside was replaced three times with hydrogen. The temperature was raised to 100°C and the hydrogen pressure to 1 MPa. Stirring was started at a rate of 700 r / min, and the reaction was carried out for 6 h. The reaction was then stopped, and after the temperature cooled to room temperature, the reaction solution was removed, filtered to remove the catalyst, and the filtrate was analyzed by gas chromatography. The experimental results are shown in Table 1.

[0031] Table 1. Catalytic hydrogenation performance of palladium catalysts supported on different co-doped coconut shell activated carbon supports. Group Conversion rate (%) Selectivity (%) Application Example 1 100 99.99 Application Example 2 99.98 98.97 Application Example 3 100 99.76 Application Example 4 94.53 96.57 Application Example 5 94.78 97.21 Application Example 6 91.57 93.89 Application Example 7 90.34 93.26 As shown in Table 1, the catalysts prepared by supporting transition metals on activated carbon provided in Examples 1-3 of this invention have better conversion rates and selectivity for catalytic hydrogenation compared to the catalysts prepared in Comparative Examples 1-4.

[0032] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier, characterized in that, Includes the following steps: S1. Coconut shell activated carbon is pulverized to 100-200 mesh and then activated by Ar / steam to obtain pretreated activated carbon; S2. Dissolve chitosan in acetic acid solution to obtain chitosan solution, mix with urea solution, add phytic acid, adjust pH to 5.5~6.0, continue stirring to obtain wetting agent; S3. Add the pretreated activated carbon to the wetting agent, heat, stir, then filter, wash, and vacuum dry to obtain nitrogen and phosphorus pre-activated activated carbon. S4. Dissolve ferric ammonium citrate and sodium citrate in deionized water, add ethylene glycol, stir, then add the nitrogen and phosphorus pre-activated activated carbon, heat, stir again, and then slowly add potassium borohydride mixed solution. After the addition is complete, continue stirring. After filtration, washing, and drying, the product is calcined under a nitrogen atmosphere to obtain nitrogen, phosphorus, boron, and iron co-doped coconut shell activated carbon carrier.

2. The method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier according to claim 1, characterized in that, In step S1, the volume ratio of Ar to H2O is (4~6):1; the activation temperature is 400~600℃, and the activation time is 30~60min.

3. The method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier according to claim 1, characterized in that, In step S2, the mass fraction of the urea solution is 4-6%, the mass fraction of the chitosan solution is 1-3%, and the volume ratio of the urea solution, chitosan solution, and phytic acid is (35-45):(180-220):

1.

4. The method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier according to claim 1, characterized in that, In step S3, the heating temperature is 70~80℃, the stirring time is 4~5 h, the vacuum drying temperature is 75~85℃, and the vacuum drying time is 1.5~2.5 h.

5. The method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier according to claim 1, characterized in that, In step S4, the stirring temperature is 35~45℃, and the stirring time is 30~40 min; the temperature is raised to 50~60℃, and the stirring time is 2~3 h; the concentration of the potassium borohydride solution is 20~50 mmol / L; and the stirring time is continued for 30~40 min.

6. The method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier according to claim 1, characterized in that, In step S4, the ratio of the amounts of ferric ammonium citrate, sodium citrate, ethylene glycol, nitrogen- and phosphorus-containing pre-activated activated carbon, and potassium borohydride is (1~2g):(3~5g):(0.5~1.5mL):(8~12g):(2~6mL).

7. The method for preparing a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier according to claim 1, characterized in that, In step S4, the calcination temperature is 700~800℃.

8. A nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon carrier, characterized in that, The nitrogen, phosphorus, boron, and iron co-doped coconut shell activated carbon carrier is prepared by the method described in any one of claims 1 to 7.

9. A catalyst, characterized in that, The catalyst comprises a nitrogen-phosphorus-boron-iron co-doped coconut shell activated carbon support as described in claim 8 and a supported transition metal, wherein the transition metal includes at least one of Pt, Pd, and Au.

10. The application of the catalyst as described in claim 9 in the hydrogenation reaction of nitro compounds.

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