CN116651445A - Ruthenium-silver/carbon catalyst, preparation method and application - Google Patents

Abstract

The invention discloses a ruthenium-silver/carbon catalyst, a preparation method and an application thereof, and belongs to the technical field of catalyst preparation. The ruthenium-silver/carbon catalyst provided by the invention consists of a carrier and ruthenium-silver alloy nanoparticles loaded on the carrier, wherein the carrier is activated carbon, the loading of ruthenium is 1wt%-5wt%, and the ratio of ruthenium to silver loading is 1:1‑1:4. The catalyst provided above uses activated biochar as a carrier, supports ruthenium-silver alloy nanoparticles on the carrier, disperses the catalytically active species ruthenium with cheaper silver, and uses the catalyst to catalyze the hydrogenation of phenol to prepare cyclohexanol with high efficiency and selectivity. Good performance, mild reaction conditions, reusable catalyst and other advantages.

Description

Ruthenium-silver/carbon catalyst and its preparation method and application

technical field

The invention relates to the technical field of catalyst preparation, in particular to a ruthenium-silver/carbon catalyst, a preparation method and an application.

Background technique

As an essential chemical intermediate in modern industry, cyclohexanol is widely used in rubber preparation, emulsifier, plasticizer and resin and other chemical fields. It is mainly used in the production of adipic acid, hexamethylenediamine, cyclohexanone, and caprolactam. It can also be used as a stabilizer for soap, to make disinfectant soap and detergent emulsion, and to be used as rubber, resin, nitrocellulose, metal soap, and oil. , solvents for esters and ethers, admixtures for paints, degreasing agents for leather, film release agents, dry cleaning agents, and polishing agents. Cyclohexanol is also a raw material for fiber finishing agents, pesticides, and plasticizers. The production methods of cyclohexanol are mainly phenol hydrogenation method and cyclohexane oxidation method.

At present, nickel catalysts are generally used for hydrogenation of phenol. The reaction temperature is 150° C., the pressure is 2.5 MPa, the yield is close to the theoretical value, the product is of high purity, and the reaction is stable. In view of the price of raw materials, the cyclohexane oxidation method has gradually replaced the phenol hydrogenation method. The oxidation reaction of cyclohexane is more complicated. It first generates cyclohexyl hydroperoxide, and then decomposes into cyclohexanol and cyclohexanone. Cyclohexanol and cyclohexanone are more easily oxidized than cyclohexane; most cyclohexanone is formed by oxidation of cyclohexanol, which in turn produces various oxidation by-products.

In view of the existence of the above problems, it is necessary to provide a ruthenium-silver/carbon catalyst and its preparation method and application.

Contents of the invention

The object of the present invention is to provide a kind of ruthenium-silver/carbon catalyst and preparation method and application in order to overcome the defective that above-mentioned prior art exists.

The present invention solves its technical problems by adopting the following technical solutions.

The invention provides a ruthenium-silver/carbon catalyst, which is composed of a carrier and ruthenium-silver alloy nanoparticles loaded on the carrier, wherein the carrier is activated carbon, the loading of ruthenium is 1wt%-5wt%, and the loading ratio of ruthenium and silver is 1:1-1:4.

The present invention also provides a preparation method of the above-mentioned ruthenium-silver/carbon catalyst, comprising: mixing activated carbon with ruthenium salt solution and silver salt solution, and then using a reducing agent to reduce ruthenium metal ions and silver metal ions in the solution to ruthenium-silver Silver alloy nanoparticles are loaded on activated carbon to obtain ruthenium-silver/carbon catalyst.

The present invention also provides an application of the above-mentioned ruthenium-silver/carbon catalyst in the preparation of cyclohexanol by catalytic hydrogenation of phenol.

The present invention has the following beneficial effects:

A kind of ruthenium-silver/carbon catalyst provided by the present invention and its preparation method and application, ruthenium-silver/carbon catalyst is made up of carrier and the ruthenium-silver alloy nanoparticle that is loaded on the carrier, the catalyst provided above uses activated carbon as carrier, The activated carbon carrier can play the role of dispersing and anchoring the ruthenium-silver alloy nanoparticles. At the same time, the relatively cheap silver is used to disperse the catalytically active center ruthenium species, which can give full play to the catalytic activity of the ruthenium species. The obtained ruthenium-silver/carbon catalyst can be used The hydrogenation of phenol to produce cyclohexanol has the advantages of high efficiency, good selectivity, mild reaction conditions, and reusable catalyst, which is obviously superior to the traditional production method of cyclohexanol.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Figure 1 is a TEM-mapping diagram of 2wt% ruthenium-6wt% silver/kitchen waste fermentation slag activated carbon _.

Detailed ways

In order to make the purpose, 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. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

A ruthenium-silver/carbon catalyst provided in an embodiment of the present invention, its preparation method and application are described in detail below.

In the first aspect, the embodiment of the present invention provides a ruthenium-silver/carbon catalyst, which is composed of a carrier and ruthenium-silver alloy nanoparticles loaded on the carrier, wherein the carrier is activated carbon, and the loading amount of ruthenium is 1wt%-5wt%. The loading ratio of ruthenium and silver is 1:1-1:4.

The embodiment of the present invention provides a ruthenium-silver/carbon catalyst, which is composed of a carrier and ruthenium-silver alloy nanoparticles loaded on the carrier. The catalyst provided above uses silver to disperse the catalytic active center ruthenium species, which can give full play to the catalytic performance of ruthenium. Active, the activated carbon carrier can play the role of dispersing and anchoring the ruthenium-silver alloy nanoparticles, and the catalyst obtained in this way is used for the hydrogenation of phenol to produce cyclohexanol, showing good catalytic activity.

In an optional embodiment, the loading amount of ruthenium is 2wt%-3wt%, and the loading ratio of ruthenium to silver is 1:1.5-1:2.

In an optional embodiment, the activated carbon is obtained by the following method: roasting biomass to obtain biochar, and then activating and roasting the biochar to obtain activated carbon;

Preferably, the biomass includes any one of fermented residue, plant biomass and animal biomass;

More preferably, the fermented slag is mainly produced by joint anaerobic fermentation of kitchen waste and anaerobic sludge;

More preferably, the animal biomass is selected from skin meal;

More preferably, the plant biomass is selected from birch flour.

It is worth noting that the preparation of activated carbon from fermentation residue can refer to the patent that the inventor has applied for: ZL202111564362. Particle loading and attachment.

In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned ruthenium-silver/carbon catalyst, comprising: mixing activated carbon with a ruthenium salt solution and a silver salt solution, and then using a reducing agent to reduce the ruthenium metal ions and silver metal ions in the solution to The ions are reduced to ruthenium-silver alloy nanoparticles and loaded on activated carbon to obtain ruthenium-silver/carbon catalyst.

In an optional embodiment, the following steps are included:

Roast and activate the biomass to obtain activated carbon, then mix the obtained activated carbon with ruthenium salt, silver salt and deionized water in proportion, and ultrasonically make the activated carbon evenly adsorb metal ions at room temperature.

Under ultrasonic conditions, adding a reducing agent to carry out the reduction reaction, after the reaction is completed, centrifuge washing and drying to obtain the ruthenium-silver/carbon catalyst.

In an optional embodiment, the ruthenium salt includes at least one of ruthenium chloride, ruthenium nitrate, potassium chlororuthenate, and chlororuthenic acid, and the silver salt is silver nitrate.

In an optional embodiment, the reducing agent includes at least one selected from NaBH ₄ , formaldehyde, glycine, and ethylene glycol solution;

Preferably, the reducing agent is selected from sodium borohydride, and the molar ratio of the total amount of metal used in sodium borohydride and ruthenium salt to silver salt is 3:1.

In an optional embodiment, the drying temperature is 60-110° C. and the drying time is 6-24 hours.

In a third aspect, an embodiment of the present invention provides an application of the above-mentioned ruthenium-silver/carbon catalyst in the catalytic hydrogenation of phenol to prepare cyclohexanol.

In an optional embodiment, the catalytic hydrogenation includes: reacting phenol in a water system under the action of a hydrogen atmosphere and a ruthenium-silver/carbon catalyst to obtain cyclohexanol.

In an optional embodiment, in catalytic hydrogenation, the molar ratio of ruthenium-silver/carbon catalyst to phenol is 25-150 mg:1 mmol; the ratio of phenol to water is 2.5 mmol:25 mL.

Preferably, the hydrogen pressure is 0.5-4MPa, more preferably 1-2MPa;

Preferably, the reaction temperature is 30-90°C, more preferably 50-70°C; the reaction time is 0.5-4h, more preferably 1-2h.

It can be seen from the above that the embodiment of the present invention provides a ruthenium-silver/carbon catalyst, which is composed of a carrier and ruthenium-silver alloy nanoparticles loaded on the carrier, wherein kitchen waste, tanning waste or agricultural and forestry waste is used as the catalyst The preparation of carbon-based catalyst carriers from raw materials can not only realize the utilization of solid waste resources, but also, if kitchen waste is used as raw material, due to the rich carbon and nitrogen elements in kitchen waste, nitrogen-containing catalysts with high specific surface area can be produced without adding nitrogen sources. Porous activated carbon carrier can play the role of dispersing and anchoring ruthenium-silver metal nanoparticles. In addition, dispersing the active metal ruthenium with cheaper silver can give full play to the catalytic activity of ruthenium. The inventors have also proved through many experiments that when the catalyst is used for the hydrogenation of phenol to prepare cyclohexanol, the conditions are milder and the reaction time is shorter. Short, good efficiency and selectivity of cyclohexanol, catalyst can be reused, obviously superior to the traditional production method of cyclohexanol.

The characteristics and performance of the present invention will be described in further detail below in conjunction with the examples.

The method provided by the present invention mainly prepares a carbon-based catalyst carrier from solid waste, loads ruthenium-silver alloy nanoparticles on the carrier, utilizes silver to disperse the active center ruthenium, and obtains a catalyst composed of ruthenium-silver/carbon. The catalyst can efficiently reduce phenol to cyclohexanol under mild conditions.

Example 1

Activated carbon preparation: Kitchen waste and anaerobic sludge were crushed separately to adjust the TSS to 20g/L, mixed at a ratio of 9:1, adjusted to pH 8 with sodium bicarbonate, anaerobic fermentation at room temperature for 8 days, washed several times, and collected by centrifugation The food waste fermented slag was obtained, and the yield of the fermented slag was 42.8%. The fermentation residue was roasted in a tube furnace at 450°C in a nitrogen atmosphere for 2 hours, and the obtained biochar was soaked in 4 mol/L KOH solution with a mass ratio of 4:1 for 12 hours, and then the mixture was dried, and the dried biochar was placed in Calcined in a tube furnace at 800°C in a nitrogen atmosphere for 2 hours, washed until neutral and then dried to obtain activated carbon.

②Catalyst preparation: Take (0.595mL of 0.1mol/L chlororuthenate solution, 1.670mL of 0.1mol/L _AgNO3 solution, 0.3g of activated carbon, 3mL of water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The water was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 6.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was performed at a temperature of 90°C 30min. According to the gas chromatography, the conversion rate of phenol was 99.9%, and the yield of cyclohexanol was 99.7%.

The TEM-mapping diagram of the ruthenium-silver/carbon catalyst prepared in the above embodiment 1 is referring to Fig. 1, as can be seen from Fig. 1: ruthenium and silver are uniformly dispersed on the activated carbon carrier, and the signals of ruthenium and silver overlap highly, forming ruthenium-silver The silver alloy nano-particles can give full play to the catalytic activity of the ruthenium species by using relatively cheap silver to disperse the catalytically active center ruthenium species.

Example 2

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.300mL of 0.1mol/L chlororuthenate solution, 0.840mL of 0.1mol/L _AgNO3 solution, 0.3g of activated carbon, 3mL of water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The water was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 1.0 wt% ruthenium and 3.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 150mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 3.0MPa, and the reaction was performed at a temperature of 70°C 120min. The conversion rate of phenol was 99.5% and the yield of cyclohexanol was 99.2% as measured by gas chromatography.

Example 3

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.1mol/L chlororuthenate solution 0.595mL, 0.1mol/L AgNO ₃ solution 1.115mL, 0.3g activated carbon, 3mL water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 4.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was performed at a temperature of 70°C 90min. According to gas chromatography, the conversion rate of phenol was 99.7%, and the yield of cyclohexanol was 99.5%.

Example 4

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (1.485mL of 0.1mol/L chlororuthenate solution, 1.390mL of 0.1mol/L _AgNO3 solution, 0.3g of activated carbon, 3mL of water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The water was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 5.0 wt% ruthenium and 5.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 25mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 1.5MPa, and the reaction was performed at a temperature of 70°C 60min. The conversion rate of phenol was 84.9% and the yield of cyclohexanol was 84.5% as measured by gas chromatography.

Example 5

①The preparation of activated carbon is the same as that described in Example 1.

②Catalyst preparation: Take (0.595 mL of 0.1 mol/L chlororuthenate solution, 2.225 mL of 0.1 mol/L AgNO ₃ solution, 0.3 g of activated carbon, and 3 mL of water) into a 50 mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The water was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 8.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 75mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was kept at 4.0MPa, and the reaction was performed at a temperature of 50°C 120min. According to the gas chromatography, the conversion rate of phenol was 99.9%, and the yield of cyclohexanol was 99.7%.

Example 6

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.895 mL of 0.1 mol/L chlororuthenate solution, 1.255 mL of 0.1 mol/L AgNO ₃ solution, 0.3 g of activated carbon, and 3 mL of water) into a 50 mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 3.0 wt% ruthenium and 4.5 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 150mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 4.0MPa, and the reaction was performed at a temperature of 30°C 240min. The conversion rate of phenol was 86.5% and the yield of cyclohexanol was 86.1% as measured by gas chromatography.

Example 7

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.1mol/L chlororuthenate solution 0.595mL, 0.1mol/L AgNO ₃ solution 1.115mL, 0.3g activated carbon, 3mL water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 4.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was kept at 0.5MPa, and the reaction was performed at a temperature of 70°C 240min. The conversion rate of phenol was 96.5% and the yield of cyclohexanol was 96.1% as measured by gas chromatography.

Example 8

①Activated carbon preparation: birch powder was calcined in a tube furnace at 450°C in a nitrogen atmosphere for 2 hours, and the obtained biochar was soaked in 4mol/L KOH solution at a mass ratio of 4:1 for 12 hours, and then the mixture was dried, and the dried The biochar was calcined in a tube furnace at 800 °C in a nitrogen atmosphere for 2 h, washed until neutral and then dried to obtain activated carbon.

② Catalyst preparation: Take (0.595mL of 0.1mol/L chlororuthenic acid solution, 1.115mL of 0.1mol/L AgNO ₃ solution, 0.3g of birch activated carbon, 3mL of water) into a 50mL centrifuge tube, and place in an ultrasonic cleaner at 20°C Ultrasound left and right for 2 hours to mix activated carbon and metal ions evenly. After sonication, centrifuge and wash three times with secondary water in a high-speed refrigerated centrifuge to ensure that the supernatant is colorless. After centrifugal washing, add 1.5 mL of 5 mg/mL NaBH ₄ solution to the centrifuge tube, and sonicate again for 1 hour. After sonication, centrifuge and wash three times again. After the end, dry the water in an oven at 105°C to obtain a loading capacity of 2.0 wt% ruthenium, 4.0 wt% silver ruthenium-silver/carbon catalyst.

③ Catalytic hydrogenation of phenol: 2.5 mmol of phenol, 100 mg of ruthenium-silver/carbon catalyst, 25 mL of water, hydrogen pressure of 2.0 MPa, temperature of 70°C, and reaction time of 60 min. According to the gas chromatography, the conversion rate of phenol was 99.9%, and the yield of cyclohexanol was 99.7%.

Example 9

①Preparation of activated carbon: waste skin powder from tanning was calcined in a tube furnace at 450 °C in a nitrogen atmosphere for 2 h, and the obtained biochar was soaked in 4 mol/L KOH solution at a mass ratio of 4:1 for 12 h, then the mixture was dried, and the The dried biochar was calcined in a tube furnace at 800 °C in a nitrogen atmosphere for 2 h, washed until neutral and then dried to obtain activated carbon.

②Catalyst preparation: Take (0.595mL of 0.1mol/L chlororuthenic acid solution, 1.115mL of 0.1mol/L _AgNO3 solution, 0.3g skin powder activated carbon, 3mL water) into a 50mL centrifuge tube, and place in an ultrasonic cleaner for 20 Ultrasonic at around ℃ for 2 hours to mix activated carbon and metal ions evenly. After sonication, centrifuge and wash with secondary water three times in a high-speed refrigerated centrifuge to ensure that the supernatant is colorless. After centrifugal washing, add 1.5 mL of 5 mg/mL NaBH ₄ solution to the centrifuge tube, and sonicate again for 1 hour. After sonication, centrifuge and wash three times again. After the end, dry the water in an oven at 105°C to obtain a loading capacity of 2.0 wt% ruthenium, 4.0 wt% silver ruthenium-silver/carbon catalyst.

③ Catalytic hydrogenation of phenol: 2.5 mmol of phenol, 100 mg of ruthenium-silver/carbon catalyst, 25 mL of water, hydrogen pressure of 2.0 MPa, temperature of 70°C, and reaction time of 60 min. According to the gas chromatography, the conversion rate of phenol was 97.4%, and the yield of cyclohexanol was 97.1%.

Table 1

As can be seen from the above Table 1, the carbon-based catalyst carrier is prepared from kitchen waste (such as fermentation residue), tanning waste (skin powder) or agricultural and forestry waste (such as birch powder), and then loaded with ruthenium -Silver alloy nanoparticles, when it is used for catalytic hydrogenation of phenol, the conversion rate of phenol and the yield of cyclohexanol are very high, which is obviously better than the conversion rate of phenol and the yield of cyclohexanol using conventional metals as catalysts .

Comparative example 1

Similar to the steps of Example 1, the only difference is that the metal nanoparticles loaded on activated carbon do not contain silver, but only contain independent ruthenium nanoparticles. The experimental process and results are as follows:

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.595 mL of 0.1 mol/L chlororuthenic acid solution, 0.3 g of activated carbon, and 3 mL of water) into a 50 mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument to make the activated carbon fully adsorb metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a ruthenium/carbon catalyst with a loading amount of 2.0 wt% ruthenium.

③ Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was carried out at a temperature of 70°C for 60min. The conversion rate of phenol was 41.5% and the yield of cyclohexanol was 41.1% as measured by gas chromatography.

Comparative example 2

Similar to the steps of Comparative Example 1, the only difference is that the metal nanoparticles supported by activated carbon are separate palladium nanoparticles. The experimental process and results are as follows:

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Add (0.1mol/L K ₂ PdCl ₄ solution 0.565mL, 0.3g activated carbon, 3mL water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument to make the activated carbon fully adsorb metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a palladium/carbon catalyst with a loading capacity of 2.0 wt% palladium.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of palladium/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was carried out at a temperature of 70°C for 60min. According to the gas chromatography, the conversion rate of phenol was 2.3%, and the yield of cyclohexanol was 1.9%.

Comparative example 3

Similar to the steps of Comparative Example 1, the only difference is that the metal nanoparticles supported by activated carbon are separate platinum nanoparticles. The experimental process and results are as follows:

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Add (0.1mol/L H ₂ PtCl ₆ solution 0.310mL, 0.3g activated carbon, 3mL water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument to make the activated carbon fully adsorb metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a platinum/carbon catalyst with a platinum loading of 2.0 wt%.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of platinum/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was carried out at a temperature of 70°C for 60min. According to the gas chromatography, the conversion rate of phenol was 2.9%, and the yield of cyclohexanol was 2.5%.

Comparative example 4

Similar to the steps of Example 1, the only difference is that the reaction condition parameters in the catalytic process are changed to: the ruthenium loading is 2.0wt%, the ruthenium-silver loading ratio is 1/1, the temperature is 70°C, the hydrogen pressure is 2MPa, The time is 1h, the experimental process and results are as follows:

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.595 mL of 0.1 mol/L chlororuthenate solution, 0.560 mL of 0.1 mol/L AgNO ₃ solution, 0.3 g of activated carbon, and 3 mL of water) into a 50 mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The moisture was dried to obtain a ruthenium-silver/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 2.0 wt% silver.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium-silver/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was performed at a temperature of 70°C 60min. According to the gas chromatography, the conversion rate of phenol was 60.7%, and the yield of cyclohexanol was 60.4%.

Comparative example 5

Similar to the steps of Comparative Example 4, the only difference is that the loaded bimetal is changed from ruthenium-silver bimetal to ruthenium-cobalt bimetal. The experimental process and results are as follows:

①The preparation of activated carbon is the same as that described in Example 1.

②Catalyst preparation: Take (0.595mL of 0.1mol/L chlororuthenic acid solution, 1.020mL of 0.1mol/L Co(NO ₃ ) ₂ solution, 0.3g activated carbon, 3mL water) into a 50mL centrifuge tube, Sonicate at room temperature for 2 hours to make the activated carbon fully adsorb metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The water was dried to obtain a ruthenium-cobalt/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 2.0 wt% cobalt.

③ Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium-cobalt/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was maintained at 2.0MPa, and the reaction was performed at a temperature of 70°C 60min. According to the gas chromatography, the conversion rate of phenol was 45.5%, and the yield of cyclohexanol was 45.2%.

Comparative example 6

Similar to the steps of Comparative Example 4, the only difference is that the loaded bimetal is changed from ruthenium-silver bimetal to ruthenium-nickel bimetal. The experimental process and results are as follows:

①The preparation of activated carbon is the same as that described in Example 1.

② Catalyst preparation: Take (0.595mL of 0.1mol/L chlororuthenate solution, 1.025mL of 0.1mol/L _NiCl2 solution, 0.3g of activated carbon, 3mL of water) into a 50mL centrifuge tube, and ultrasonicate at room temperature for 2 hours in an ultrasonic instrument. Activated carbon fully adsorbs metal ions. After sonication, centrifuge and wash three times with distilled water in a high-speed centrifuge, and remove the supernatant. After centrifugation and washing, add NaBH ₄ solution to the centrifuge tube so that the molar ratio of NaBH ₄ to metal is 3:1, and sonicate again for 1 hour. After sonication, centrifuge and wash three times. The water was dried to obtain a ruthenium-nickel/carbon catalyst with a loading capacity of 2.0 wt% ruthenium and 2.0 wt% nickel.

③Catalytic hydrogenation of phenol: 2.5mmol of phenol, 100mg of ruthenium-nickel/carbon catalyst, and 25mL of water were placed in a high-pressure reactor, and the air in the reactor was replaced with hydrogen, and the initial hydrogen pressure was kept at 2.0MPa, and the reaction was performed at a temperature of 70°C 60min. According to the gas chromatography, the conversion rate of phenol was 47.3%, and the yield of cyclohexanol was 46.9%.

Table 2

As can be seen from the above table 2: the ruthenium-silver/carbon carbon catalyst prepared in the comparative example is applied to the reaction of cyclohexanol in the hydrogenation of phenol, although the effect of ruthenium is better than palladium and platinum, but the single metal catalyst The effect of the bimetallic ruthenium-silver catalyst is much lower than that of the bimetallic ruthenium-silver catalyst. Meanwhile, the bimetallic catalyst has a better effect of dispersing ruthenium with silver. Ruthenium-silver/carbon-carbon demonstrates again that using the ruthenium-silver/carbon catalyst prepared by the embodiment of the present invention to disperse active metal ruthenium with cheaper silver, the efficiency and selectivity of catalyzing the hydrogenation of phenol to cyclohexanol with this catalyst Good, mild reaction conditions, and reusable catalysts.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a ruthenium-silver/carbon catalyst, is characterized in that, is made up of the ruthenium-silver alloy nano-particle loaded on carrier and carrier, and wherein, described carrier is gac, and the loading capacity of described ruthenium is 1wt%-5wt% , the loading ratio of ruthenium and silver is 1:1-1:4. 2. The ruthenium-silver/carbon catalyst according to claim 1, characterized in that, the loading of ruthenium is 2wt%-3wt%, and the loading ratio of ruthenium and silver is 1:1.5-1:2. 3. according to the described ruthenium-silver/carbon catalyst of claim 1, it is characterized in that, described gac obtains by following method: biomass roasting process obtains biochar, then described biochar activation roasting process obtains described gac; Preferably, the biomass includes any one of fermented residue, plant biomass and animal biomass; More preferably, the fermented slag is mainly produced by joint anaerobic fermentation of kitchen waste and anaerobic sludge; More preferably, said animal biomass is selected from skin meal; More preferably, the plant biomass is selected from birch flour. 4. a preparation method according to any one of claim 1-3 ruthenium-silver/carbon catalyst, is characterized in that, comprises: gac is mixed with ruthenium salt solution and silver salt solution, adopts reducing agent to make solution then The ruthenium ions and silver ions in the catalyst are reduced to ruthenium-silver alloy nanoparticles and loaded on the activated carbon to obtain the ruthenium-silver/carbon catalyst. 5. preparation method according to claim 4, is characterized in that, comprises the following steps: The biomass is roasted and activated to obtain activated carbon, and then the obtained activated carbon is mixed with ruthenium salt, silver salt and deionized water in proportion, and the activated carbon is ultrasonically adsorbed to the metal ion at room temperature. liquid; Under ultrasonic conditions, adding a reducing agent to carry out the reduction reaction, after the reaction is completed, centrifuge washing and drying to obtain the ruthenium-silver/carbon catalyst. 6. The preparation method according to claim 5, wherein the ruthenium salt comprises at least one of ruthenium chloride, ruthenium nitrate, ruthenium chloride and potassium ruthenate chloride, and the silver salt is silver nitrate. 7. The preparation method according to claim 5, wherein the reducing agent comprises at least one selected from NaBH ₄ , formaldehyde, glycine, and ethylene glycol solution; Preferably, the reducing agent is selected from sodium borohydride, and the molar ratio of the total amount of metals in the sodium borohydride to the ruthenium salt and the silver salt is 3:1. 8. the application of the ruthenium-silver/carbon catalyst described in claim 1 or 2 in the preparation of cyclohexanol by catalytic hydrogenation of phenol. 9. The application according to claim 8, wherein the catalytic hydrogenation comprises: reacting phenol in a water system under the action of a hydrogen atmosphere and the ruthenium-silver/carbon catalyst to obtain cyclohexanol. 10. The application according to claim 9, characterized in that, in the catalytic hydrogenation, the mass molar ratio of the ruthenium-silver/carbon catalyst to the phenol is 25-150 mg: 1 mmol; The dosage ratio of said water is 2.5mmol: 25mL; Preferably, the hydrogen pressure is 0.5-4MPa, more preferably 1-2MPa; Preferably, the reaction temperature is 30-90°C, more preferably 50-70°C; the reaction time is 0.5-4h, more preferably 1-2h.