Toluene hydrogenation catalyst used at room temperature and normal pressure, and preparation method and application thereof

Abstract

The invention discloses a toluene hydrogenation catalyst used at room temperature and normal pressure as well as a preparation method and application thereof, oxidation modified carbon nanofibers are adopted as a carrier, and face-centered cubic Ru is loaded on the oxidation modified carbon nanofibers in the form of nanoparticles through solvothermal reaction to obtain the toluene hydrogenation catalyst. The catalyst provided by the invention can efficiently catalyze toluene hydrogenation to generate methylcyclohexane under the conditions of room temperature and normal hydrogen pressure. Compared with a traditional catalyst, the carbon oxide nanofiber supported ruthenium catalyst not only can work under relatively mild conditions, but also can keep relatively high activity in long-time use, and provides a key support for low cost of an organic liquid hydrogen storage technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of toluene hydrogenation catalysts, in particular to a toluene hydrogenation catalyst used at room temperature and normal pressure, a preparation method and application thereof. BACKGROUND

[0002] Hydrogen energy, as a green and low-carbon secondary energy source with a wide range of sources, is considered as one of the core directions of global energy transformation. However, the low-density characteristics of hydrogen gas result in high storage and transportation costs, accounting for 20%-40% of the terminal sales cost, which becomes a key bottleneck restricting the large-scale application of hydrogen energy. Liquid organic hydrogen carrier (LOHCs) technology has become an important path to solve this problem due to its high hydrogen storage density, long-period storage capacity and compatibility with existing oil and gas infrastructure. Among them, the toluene (TOL)-methylcyclohexane (MCH) system is considered as one of the most promising LOHCs solutions due to its hydrogen storage density of 6.2% (mass ratio), low medium cost and excellent cycle stability. Through reversible hydrogenation / dehydrogenation reactions, toluene can store and release hydrogen under mild conditions, and its liquid state supports transoceanic transportation and pipeline transportation, which can significantly reduce the storage and transportation costs by 50%-80% for medium and long distances.

[0003] Although toluene hydrogenation to prepare methylcyclohexane has significant advantages in theory, its actual application still faces the challenges of harsh hydrogenation conditions and low catalytic efficiency. Traditional aromatic hydrogenation reactions are limited by the stable π-conjugated structure of the benzene ring, and usually need to be carried out under high temperature (> 150°C) and high pressure (> 3 MPa) conditions, resulting in high energy consumption and high equipment cost. Achieving fast hydrogenation of LOHCs under mild reaction conditions is the basis for promoting the large-scale application of this technology, and the key to solving this problem lies in the development of excellent performance catalysts.

[0004] The currently reported ruthenium (Ru)-based catalysts have low hydrogenation efficiency under mild conditions, and usually use carbon nanotubes or graphene to support ruthenium, but the support oxidation modification is insufficient, the surface functional groups are few, and it is difficult to form strong metal-support electron interaction (EMSI). The poisoning effect of adsorbate between toluene and hydrogen atoms and Ru leads to slow reaction kinetics. The current Ru-based catalysts are usually hexagonal close-packed (hcp) structures, while the metastable face-centered cubic (fcc)-Ru has unique electronic structure and higher density of active sites, which makes it have higher catalytic activity. How to synthesize metastable fcc-Ru catalysts is still a challenge.

[0005] Therefore, how to develop excellent performance catalysts is a problem to be solved. SUMMARY

[0006] The present application aims to solve the problems of harsh conditions, low activity and poor stability of toluene hydrogenation at present, and provides a toluene hydrogenation catalyst for room temperature and normal pressure, a preparation method and application.

[0007] In order to achieve the above technical purpose, the technical scheme provided by the present application is: The preparation method of the toluene hydrogenation catalyst for room temperature and normal pressure adopts oxidized modified nanometer carbon fiber as a carrier, and through a solvothermal reaction, face-centered cubic Ru is loaded on the oxidized modified nanometer carbon fiber in the form of nanoparticles to obtain the toluene hydrogenation catalyst.

[0008] Further, before the solvothermal reaction, the ruthenium acetylacetonate solution and the oxidized modified nanometer carbon fiber need to be stirred for 0.5-24h and dispersed by ultrasonic for 4-6h to obtain a ruthenium acetylacetonate / oxidized modified nanometer carbon fiber precursor solution, and the mass ratio of ruthenium acetylacetonate to oxidized modified nanometer carbon fiber is 10:1-1:50.

[0009] In the preparation of the ruthenium acetylacetonate solution, the amount of ruthenium acetylacetonate is calculated according to the target ruthenium loading amount, and the ruthenium acetylacetonate is added into a mixed solution of ethanol and acetone and is dissolved by ultrasonic.

[0010] Further, the solvothermal reaction is as follows: the ruthenium acetylacetonate / oxidized modified nanometer carbon fiber precursor solution is heated at 100℃-280℃ for 1-6h, and after being cooled to ambient temperature, the solid product is collected by centrifugation at 1000-11000 rpm for 1-15 min, washed with ethanol and acetone, and dried at 50℃ under vacuum for 1-10h to obtain the toluene hydrogenation catalyst.

[0011] Specifically, the present application synthesizes Ru nanoparticles with metastable face-centered cubic structure by using a simple solvothermal method, without the need for a template or a specific substrate support, and is a kind of universal metastable fcc-Ru synthesis method.

[0012] Further, the preparation method of the oxidized modified nanometer carbon fiber includes mixing and ultrasonic dispersing carbon nanofiber and concentrated nitric acid, stirring, heating to 60-150℃, heating and refluxing for 1-10h, cooling to room temperature, and collecting the lower layer product by centrifugation; the lower layer product is washed with deionized water for multiple times, and after the upper clear liquid of the centrifugation is colorless and transparent, the product is extracted and filtered, and continues to be washed with deionized water until the surface is neutral; and the oxidized modified nanometer carbon fiber is obtained after freeze drying.

[0013] Specifically, by oxidizing the nanometer carbon fiber, abundant defects and oxygen-containing functional groups are introduced on the surface, and Ru nanoparticles are better anchored, so that the Ru particles are uniformly dispersed and strongly bonded with the carrier, the active Ru metal nanoparticles on the surface of the prepared catalyst have high dispersity, the atomic utilization rate is improved, and deactivation in the use process is avoided.

[0014] The application further provides a toluene hydrogenation catalyst.

[0015] Further, the carrier is an oxidized modified nanometer carbon fiber, and the active component is a face-centered cubic ruthenium nanoparticle, and the ruthenium loading is 1-50 wt%.

[0016] Further, the oxidized modified nanometer carbon fiber has a diameter of 100-400 nm and a length of 5-10 microns, and the surface is rich in defects and oxygen-containing functional groups; and the face-centered cubic ruthenium nanoparticle has a size of 3-6 nm.

[0017] The application further provides an application of the toluene hydrogenation catalyst under room temperature and normal pressure in toluene hydrogenation.

[0018] Specifically, in order to realize toluene hydrogenation under mild conditions, an electron-deficient Ru catalyst is constructed, the strong EMSI effect is utilized to weaken the chemical adsorption strength of Ru and toluene and hydrogen atoms, the reaction energy barrier required for toluene hydrogenation to form a new C-H bond is reduced, and the hydrogen overflow effect is promoted; the hydroxyl groups on the surface of the carrier stabilize part of toluene molecules through hydrogen bonds, and the active hydrogen atoms migrated to the surface of the carrier cooperatively catalyze toluene hydrogenation, and a toluene hydrogenation catalyst with high activity and high stability under room temperature and normal pressure is developed.

[0019] The application has the following beneficial effects: The application prepares a metastable fcc-Ru nanometer catalyst through a simple solvothermal reduction method, stabilizes Ru in an electron-deficient state based on metal-support electron interaction, adjusts the adsorption strength of toluene and hydrogen atoms, and can efficiently catalyze toluene hydrogenation to generate methylcyclohexane under room temperature (≤30℃) and normal hydrogen pressure. Compared with traditional catalysts, the oxidized carbon nanometer fiber loaded ruthenium catalyst can not only work under relatively mild conditions, but also can maintain high activity in long-time use, and provides key support for low-cost organic liquid hydrogen storage technology. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 TEM image of the 18Ru / O-CNFs catalyst in Example 1; Figure 2 XRD pattern of the 18Ru / CNFs, commercial 5 wt.% Ru / C, 28Ru / O-CNFs, 24Ru / O-CNFs, 13Ru / O-CNFs and 18Ru / O-CNFs catalysts in Examples 1, 5, 6, 7 and 8; Figure 3 Hydrogenation performance graph of the 18Ru / O-CNFs catalyst in Examples 1, 3 and 4 under different temperature conditions; Figure 4(a) is a TEM image of the catalyst after recycling in Example 11. Figure 4 (b) is a graph showing the stability test data of the catalyst in Example 11; Figure 5 TEM image of catalyst 18Ru / CNFs in Example 8; Figure 6 The graphs show the hydrogenation performance of the catalysts in Examples 2, 8 and Comparative Example 2. Figure 7 The graphs show the hydrogenation performance of the catalysts in Examples 2, 5, 6, and 7. Figure 8 The XRD patterns of Ru nanocatalysts with fcc structures synthesized using different supports in Example 10 are shown below. Figure 9 The XRD patterns are of the Ru nanocatalysts synthesized in Example 1 and Comparative Examples 3 and 4. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0022] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] Example 1 35.86 mg of ruthenium acetylacetone was added to a mixture of 30 ml ethanol and 30 ml acetone. After sonication to dissolve, 7 ml of the solution was added to a 10 ml sample vial along with 3 mg of carbon oxide nanofibers. The mixture was stirred for 12 h and then sonicated for 4 h to form a uniformly dispersed ruthenium acetylacetone / carbon oxide nanofiber precursor solution. Next, the solution was transferred to a Teflon-lined steel autoclave, sealed, and heated at 200 °C for 4 h to reduce and prepare the carbon oxide nanofiber-supported nanoparticle catalyst. The autoclave was then cooled to ambient temperature inside the furnace, and the solid product was collected by centrifugation at 9000 rpm for 10 min. Finally, the product was washed twice with ethanol and acetone and vacuum dried at 50 °C for 4 h to obtain the carbon oxide nanofiber-supported nanoparticle catalyst. The ruthenium loading was 17.56 wt.%, denoted as 18Ru / O-CNFs. Its transmission electron microscopy (TEM) image is shown below. Figure 1 As shown in the figure, Ru nanoparticles with a size of 5.66 ± 0.68 nm are uniformly distributed on the support surface. The XRD pattern is shown in the figure. Figure 2 As shown, the crystal form is a metastable face-centered cubic structure.

[0024] Toluene hydrogenation experiment: The catalyst performance test was carried out using a 10 ml conical ground reaction tube. 106 μΐ of toluene, 3 mg of 18Ru / O-CNFs catalyst and 5 ml of reaction solvent (isopropanol) were added into the 10 ml conical ground reaction tube. The hydrogenation reaction was carried out under normal pressure H2bubbling and 30 °C with strong magnetic stirring. The reaction mixture was sampled at certain time intervals. After 7 h 30 min of reaction, the reaction product composition was analyzed by gas chromatography, and the yield of methylcyclohexane was 100%.

[0025] Example 2 According to the operation of Example 1, all other conditions were unchanged, the only difference was that the reaction time of toluene hydrogenation experiment was 6 h. After the reaction, the reaction product composition was analyzed by gas chromatography, and the yield of methylcyclohexane was 80.9%.

[0026] Example 3 According to the operation of Example 1, all other conditions were unchanged, the only difference was that the reaction temperature of toluene hydrogenation experiment was 20 °C. After 13 h 30 min of reaction, the reaction product composition was analyzed by gas chromatography, and the yield of methylcyclohexane was 100%, as shown in Figure 3

[0027] Example 4 According to the operation of Example 1, all other conditions were unchanged, the only difference was that the reaction temperature of toluene hydrogenation experiment was 40 °C. After 6 h of reaction, the reaction product composition was analyzed by gas chromatography, and the yield of methylcyclohexane was 100%, as shown in Figure 3 It can be seen that under the mild conditions of 20-40 °C, the rate of 18Ru / O-CNFs catalyzed toluene hydrogenation is accelerated with the increase of temperature.

[0028] Example 5 The catalyst was prepared according to the method of Example 1, the only difference was that the amount of ruthenium acetylacetone was 59.76 mg. 59.76 mg of ruthenium acetylacetone was added into 30 ml of ethanol and 30 ml of acetone mixed solution, and 7 ml of the solution was taken after ultrasonic dissolution, and 3 mg of oxidized carbon nanofiber was added into a 10 ml sample bottle for ultrasonic dispersion, to obtain a loading of 28.22 wt.%, which was denoted as 28Ru / O-CNFs. It can be seen that the Ru nanoparticles with a size of 5.85 ± 0.39 nm are uniformly distributed on the surface of the carrier. The XRD pattern is shown in Figure 2 Figure 7 It can be seen that under the mild conditions of 20-40 °C, the rate of 18Ru / O-CNFs catalyzed toluene hydrogenation is accelerated with the increase of temperature.

[0028] Example 5 The catalyst was prepared according to the method of Example 1, the only difference was that the amount of ruthenium acetylacetone was 59.76 mg. 59.76 mg of ruthenium acetylacetone was added into 30 ml of ethanol and 30 ml of acetone mixed solution, and 7 ml of the solution was taken after ultrasonic dissolution, and 3 mg of oxidized carbon nanofiber was added into a 10 ml sample bottle for ultrasonic dispersion, to obtain a loading of 28.22 wt.%, which was denoted as 28Ru / O-CNFs. It can be seen that the Ru nanoparticles with a size of 5.85 ± 0.39 nm are uniformly distributed on the surface of the carrier. The XRD pattern is shown in Figure 2 Figure 7 It can be seen that under the mild conditions of 20-40 °C, the rate of 18Ru / O-CNFs catalyzed toluene hydrogenation is accelerated with the increase of temperature.

[0029] Example 6 The catalyst was prepared according to the method of Example 1 with the difference that the amount of ruthenium acetylacetonate was 47.81 mg. 47.81 mg of ruthenium acetylacetonate was added to a mixture of 30 ml of ethanol and 30 ml of acetone, and after ultrasonic dissolution, 7 ml of the solution was added to 3 mg of oxidized carbon nanofibers in a 10 ml sample bottle and ultrasonically dispersed to obtain a loading of 24.32 wt.%, denoted as 24Ru / O-CNFs. Ru nanoparticles with a size of 5.27 ± 0.82 nm were uniformly distributed on the surface of the support. The XRD pattern is shown in Figure 2 , and the crystal form was a metastable face-centered cubic structure. The operation according to Example 1 was followed, with the difference that 24Ru / O-CNFs was used as the catalyst, and the other conditions were unchanged. After 6 h 30 min of reaction, the composition of the reaction products was analyzed by gas chromatography, and the toluene conversion was 100%, as shown in Figure 7 .

[0030] Example 7 The catalyst was prepared according to the method of Example 1 with the difference that the amount of ruthenium acetylacetonate was 23.90 mg. 23.9 mg of ruthenium acetylacetonate was added to a mixture of 30 ml of ethanol and 30 ml of acetone, and after ultrasonic dissolution, 7 ml of the solution was added to 3 mg of oxidized carbon nanofibers in a 10 ml sample bottle and ultrasonically dispersed to obtain a loading of 13.39 wt.%, denoted as 13Ru / O-CNFs. Ru nanoparticles with a size of 5.71 ± 0.83 nm were uniformly distributed on the surface of the support. The XRD pattern is shown in Figure 2 , and the crystal form was a metastable face-centered cubic structure. The operation according to Example 1 was followed, with the difference that 13Ru / O-CNFs was used as the catalyst, and the other conditions were unchanged. After 16 h of reaction, the composition of the reaction products was analyzed by gas chromatography, and the toluene conversion was 100%, as shown in Figure 7 . It can be seen that as the loading increases, the catalytic speed of the catalyst for toluene accelerates, but considering the problem of atom economy, the 18Ru / O-CNFs catalyst with a loading of 17.56 wt.% is preferred.

[0031] Example 8 The catalyst was prepared according to the method of Example 1 with the difference that unoxidized carbon nanofibers were used as the support, and the loading of ruthenium was 18.4 wt.%, denoted as 18Ru / CNFs. Ru nanoparticles were obviously agglomerated, as shown in Figure 5 . The XRD pattern is shown in Figure 2The crystal form is a metastable face-centered cubic structure. The procedure of Example 1 was followed, except that 18Ru / CNFs was used as catalyst, and other conditions were unchanged. After 24 h of reaction, the composition of the reaction product was analyzed by gas chromatography, and the conversion of toluene was 59.8%, as shown in Figure 6 .

[0032] Example 9 The catalyst was prepared according to the method of Example 1 for toluene solvent-free hydrogenation experiments: a 5-ml conical flask was used for catalyst performance testing. 1 ml of toluene and 9 mg of 18Ru / O-CNFs catalyst were added to the 5-ml conical flask. The hydrogenation reaction was carried out under normal pressure H2bubbling and 30°C with strong magnetic stirring. The reaction mixture was sampled at certain time intervals. After 24 h of reaction, the composition of the reaction product was analyzed by gas chromatography, and the composition of methylcyclohexane was 100%.

[0033] Example 10 The catalyst was prepared according to the method of Example 1, except that magnesium oxide (MgO), aluminum oxide (Al2O3), titanium oxide (TiO2), silicon oxide (SiO2), and graphene oxide (GO) were used as carriers. The XRD pattern is shown in Figure 8 The crystal form of the Ru nanoparticle catalyst supported on different carriers prepared by the hydrothermal method of the present application is a metastable face-centered cubic structure, indicating that the method is universal.

[0034] Example 11 The procedure of Example 1 was followed, and other conditions were unchanged, except that the reaction catalyst was a recovered catalyst, and the stability of the catalyst was tested. After each reaction, the catalyst was allowed to settle, the supernatant was poured out, and then a large amount of anhydrous ethanol was used for cleaning. After centrifugation, the supernatant was poured out. The above cleaning-centrifugation-pouring out of the supernatant process was repeated three times, and then the recovered catalyst was dried in a 50°C vacuum drying oven for 4 hours. Then the recycling reaction test was carried out according to the steps of Example 1, and the reaction time was 7 hours, and this was repeated 10 times. After each reaction, the composition of the reaction product was analyzed by gas chromatography, and the stability test data of the catalyst were obtained as shown in Figure 4 (b), and the performance of the catalyst did not decrease significantly. The transmission electron micrograph of the catalyst after recycling is shown in Figure 4 (a), and the morphology of the catalyst did not change significantly.

[0035] Comparative Example 1 The catalyst was prepared according to the method of Example 1, with the only difference that no noble metal ruthenium nanoparticles were loaded, i.e. the pure support was applied for toluene hydrogenation, denoted as O-CNFs. The reaction was carried out according to the procedure of Example 1, with the only difference that O-CNFs was used as catalyst, and other conditions were the same. After the reaction, the composition of the reaction products was analyzed by gas chromatography, and the toluene conversion was 0%.

[0036] Comparative Example 2 The reaction was carried out according to the procedure of Example 1, with the only difference that 12 mg of commercial 5 wt.% Ru / C was used as catalyst, and other conditions were the same. The XRD pattern of the commercial 5 wt.% Ru / C catalyst is shown in Figure 2 , and the crystal form was hexagonal close-packed structure. After the reaction, the composition of the reaction products was analyzed by gas chromatography, and the toluene conversion was 0%, as shown in Figure 6 . It can be seen that the prepared Ru nanoparticle catalyst with fcc phase realized the hydrogenation of toluene at room temperature and normal pressure, and the catalytic performance was greatly improved after the support was modified by oxidation.

[0037] Comparative Example 3 Unlike Example 1, the carbon nanofiber supported Ru nanoparticle catalyst was prepared by using the Joule rapid synthesis technology, and the XRD pattern is shown in Figure 9 . The crystal form of the Ru nanoparticle catalyst prepared by using this method was stable hexagonal structure.

[0038] Comparative Example 4 Unlike Example 1, the carbon nanofiber supported Ru nanoparticle catalyst was prepared by using the sodium borohydride chemical reduction technology, and the XRD pattern is shown in Figure 9 . The crystal form of the Ru nanoparticle catalyst prepared by using this method was stable hexagonal structure.

[0039] From the above experimental results, it can be seen that metastable face-centered cubic Ru nanoparticle catalysts are prepared by a simple hydrothermal synthesis method. The commonly used Joule rapid synthesis and sodium borohydride chemical reduction method cannot synthesize metastable face-centered cubic Ru nanoparticles. Compared with the commercial Ru / C catalyst, the fcc phase Ru nanoparticle catalyst can realize the hydrogenation reaction of toluene at room temperature and normal pressure. And after the oxidation modification of the carrier, the catalytic performance is greatly improved. The oxidation modification of the carbon fiber carrier helps to make the ruthenium atoms stably adhere to the surface through strong metal-carrier interaction, and stabilize the active metal Ru in the electron-deficient state, adjust the binding energy of Ru active sites and reaction intermediates, and significantly improve the catalytic activity. With the increase of Ru loading, the catalytic speed of the catalyst for toluene is accelerated, however, considering the problem of atom economy, the 18Ru / O-CNFs catalyst with a loading of 17.56 wt.% is preferred. In the mild temperature range of 20-40℃, the rate of 18Ru / O-CNFs catalytic hydrogenation of toluene increases with the increase of temperature. The ruthenium catalyst supported by the oxidized carbon nanofiber proposed in the application not only has good hydrogenation performance at room temperature and normal pressure, but also can maintain high activity in long-term use, and the performance does not decrease obviously after 10 cycles. It provides key support for the low-cost of organic liquid hydrogen storage technology.

[0040] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

[0041] The above detailed description is a detailed description of the present application, and cannot be considered as limiting the specific embodiments of the present application to these descriptions. For ordinary skilled in the art to which the present application belongs, several simple deductions and substitutions can be made without departing from the concept of the present application, and all of them should be considered as belonging to the protection scope of the present application.

Claims

1. A process for the preparation of a catalyst for the hydrogenation of toluene at room temperature and atmospheric pressure, characterized in that, The catalyst for toluene hydrogenation is prepared by loading face-centered cubic Ru nanoparticles on oxidized nanocarbon fibers as carriers through a solvothermal reaction.

2. The method for preparing a catalyst for the hydrogenation of toluene at room temperature and atmospheric pressure according to claim 1, characterized in that, Before the solvothermal reaction, the solution of ruthenium acetylacetone and the oxidized nanocarbon fibers are stirred for 0.5-24 h and dispersed by ultrasonic for 4-6 h to obtain a solution of the precursor of ruthenium acetylacetone / oxidized nanocarbon fibers, and the mass ratio of ruthenium acetylacetone to oxidized nanocarbon fibers is 10:1-1:

50.

3. The method for preparing a catalyst for the hydrogenation of toluene at room temperature and atmospheric pressure according to claim 2, characterized in that, The solvothermal reaction is carried out by heating the solution of the precursor of ruthenium acetylacetone / oxidized nanocarbon fibers at 100-280 ℃ for 1-6 h, collecting the solid product by centrifugation at 1000-11000 rpm for 1-15 min after cooling to ambient temperature, washing with ethanol and acetone, and drying at 50 ℃ under vacuum for 1-10 h to obtain the catalyst for toluene hydrogenation.

4. The method for preparing a catalyst for the hydrogenation of toluene at room temperature and atmospheric pressure according to claim 1, characterized in that, The preparation method of the oxidized nanocarbon fibers comprises the following steps: mixing and ultrasonic dispersing carbon nanofibers and concentrated nitric acid, stirring, heating to 60-150 ℃, heating and refluxing for 1-10 h, cooling to room temperature, and collecting the lower product by centrifugation; washing the lower product with deionized water for multiple times, and performing suction filtration after the upper clear liquid obtained by centrifugation is colorless and transparent, and continuing to wash with deionized water until the surface is neutral; and obtaining the oxidized nanocarbon fibers by freeze drying.

5. A catalyst for toluene hydrogenation prepared by the method according to any one of claims 1-4.

6. The catalyst according to claim 5, characterized in that, The carrier is oxidized nanocarbon fibers, and the active component is face-centered cubic Ru nanoparticles, and the loading amount of Ru is 1-50 wt%.

7. The toluene hydrogenation catalyst according to claim 6, characterized in that, The oxidized nanocarbon fibers have a diameter of 100-400 nm and a length of 5-10 μm, and the surface is rich in defects and oxygen-containing functional groups; and the size of the face-centered cubic Ru nanoparticles is 3-6 nm.

8. The catalyst for toluene hydrogenation according to any one of claims 5-7 is used in toluene hydrogenation.

Images