CN110523416A - A mesoporous carbon-supported catalyst for catalyzing conversion of ethanol into n-butanol and preparation method thereof - Google Patents

Abstract

The invention discloses a mesoporous carbon-supported catalyst for catalyzing the conversion of ethanol into n-butanol and a preparation method thereof, belonging to the technical field of biomass catalytic conversion. The first is to prepare the mesoporous carbon support, and then impregnate the active components copper and cerium into the mesoporous carbon support step by step, wherein copper exists in the form of metal state, cerium exists in the form of oxidation state, and the loading amount of copper is 1wt%~ 20 wt%, and the atomic molar ratio of copper and cerium is (2-5):1. The preparation method of the present invention is simple, can be self-reduced to metallic copper during the preparation process, does not require additional reduction treatment during use, does not use any precious metal as the catalyst raw material, is cheap and easy to obtain, and has popularization. The catalyst has high catalytic activity under mild reaction conditions, and can effectively inhibit the sintering of metallic copper nanoparticles during the reaction process. The catalyst has good catalytic stability, is easy to recycle, and can be reused after simple treatment at a certain temperature.

Description

A mesoporous carbon-supported catalyst for catalyzing the conversion of ethanol into n-butanol and its Preparation

technical field

The invention belongs to the technical field of catalytic conversion of biomass, in particular to a mesoporous carbon-supported catalyst capable of self-reduction and effectively inhibiting the sintering of metallic copper nanoparticles in the reaction process and used for catalyzing the conversion of ethanol into n-butanol and its Preparation.

Background technique

The chemicals and fuels we use in production and life are mainly converted from fossil resources, and the excessive consumption of this non-renewable energy will inevitably bring about an energy crisis. Compared with traditional fossil resources, biomass energy has the advantages of renewable, clean, and abundant resources, so the development and utilization of biomass energy has attracted worldwide attention. As a biomass energy source, ethanol has attracted worldwide attention for its conversion into higher value-added chemicals.

N-butanol is usually used as a very important organic solvent and chemical raw material. It is mainly used in the manufacture of n-butyl plasticizers of phthalic acid, aliphatic dibasic acid and phosphoric acid. It is also widely used in various plastics and In rubber products, it is also the raw material for preparing butyraldehyde, butyric acid, butylamine and butyl lactate in organic synthesis. It is also an extractant for oils, drugs (such as antibiotics, vitamins) and spices, an additive for alkyd resin coatings, etc. It can also be used as a solvent for organic dyes and printing inks, and a dewaxing agent. At present, the development and utilization of n-butanol as a new type of automobile fuel has attracted worldwide attention. As a substitute for gasoline, n-butanol is a motor fuel with better performance than ethanol. The physical and chemical properties of n-butanol are closer to gasoline. It can be miscible with gasoline and has no corrosion on existing engines and pipelines. The energy density of n-butanol (29MJ·L ^-1 ) is close to that of gasoline (32MJ·L ^-1 ), while the energy density of widely used ethanol (19.6MJ·L ^-1 ) is only 61% of that of gasoline. In addition, the heat of vaporization (0.43MJ·L ^-1 ) of n-butanol is only half of that of ethanol (0.92MJ·L ^-1 ), which is close to that of gasoline (0.36MJ·L ^-1 ), so it has better engine low-temperature starting performance , and existing vehicles can use gasoline mixed with n-butanol as fuel without any modification. As a biofuel, n-butanol can reduce the emission of SO _X , NO _X , CO, hydrocarbons and greenhouse gases, and has good environmental benefits. It has great application prospects to replace ethanol with n-butanol as a renewable energy source, so it will be The conversion of ethanol to n-butanol has become an important direction of energy development.

At present, in the research on the catalytic conversion of n-butanol from ethanol, the approved reaction path is carried out according to the Guerbet route, that is, firstly the dehydrogenation of ethanol produces acetaldehyde, and then two molecules of acetaldehyde are dehydrated through aldol condensation to produce crotonaldehyde, Finally, crotonaldehyde is hydrogenated to give n-butanol. The homogeneous catalyst systems currently reported for this reaction are mainly noble metal catalysts based on ruthenium (Ru) and iridium (Ir). High, complex preparation methods and difficult separation and recovery, which largely limit the large-scale application and industrial production of the catalyst. At present, in the reaction of preparing n-butanol from ethanol, heterogeneous catalyst systems are studied more. The heterogeneous catalyst systems currently used in this reaction mainly include solid acid-base catalysts and supported catalysts, but most solid acid-base catalysts must Only under harsh conditions such as higher temperature can a certain catalytic activity be exhibited, which limits the practical application of this type of catalyst. Exhibits excellent catalytic activity, but the catalyst exhibits significant catalyst deactivation in a relatively short period of time. According to the Guerbet reaction path, the catalyst needs to have a certain amount of metal active centers and acid-base active centers for dehydrogenation, hydrogenation and aldol condensation. A series of supported catalysts have been developed for this feature, but currently reported supported catalysts Low catalytic activity is ubiquitous, and the supported metal nanoparticles are easy to sinter during the reaction, resulting in severe catalyst deactivation. In the paper published in Journal of Catalysis (2016) 344, 184-193, it was reported that a hydrotalcite precursor prepared a simultaneous The supported catalyst Ni/MgAlO with acid-base active center and metal active center has low catalytic activity, and the single-pass yield of n-butanol is only 10%. Published in the Chemical communications (2016) 52, 13749-13752 paper, it is reported that a commercial activated carbon is used as a catalyst for dispersing metal particles on a carrier. The single-pass yield of n-butanol of the catalyst is close to 20%, but the catalyst is It requires a certain concentration of hydrogen to be reduced at a certain temperature for a period of time, which is inconvenient to use, and the process is cumbersome and has certain safety hazards. After 12 hours of continuous reaction, the metal nanoparticles in the catalyst are sintered, the catalytic activity gradually decreases, and the stability is relatively low. Difference. Therefore, how to prepare efficient and stable supported catalysts through cheap, simple, green and safe means is a key technology to realize the industrial production of bioethanol into n-butanol.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide a mesoporous carbon-supported catalyst capable of efficiently and stably catalyzing the conversion of ethanol into n-butanol under mild conditions and a preparation method thereof, which can effectively solve the above problems.

A kind of mesoporous carbon-loaded catalyst that is used to catalyze ethanol conversion into n-butanol according to the present invention is characterized in that: the active components copper and cerium are impregnated on the mesoporous carbon carrier (MC) step by step, and the copper is The metal state exists, the cerium exists in the oxidized state, the loading amount of copper is 1wt%-20wt%, and the atomic molar ratio of copper and cerium is (2-5):1.

A kind of preparation method of the mesoporous carbon-supported catalyst that is used to catalyze ethanol conversion into n-butanol of the present invention, its steps are as follows:

1. Preparation of Mesoporous Carbon Support (MC)

Add aluminum nitrate, citric acid, and sucrose into distilled water in a certain proportion, and after fully dissolving, add a certain amount of phosphoric acid drop by drop, so that the molar ratio of citric acid, sucrose, aluminum nitrate, and phosphoric acid in the solution is 0.5: (0.5～ 2.5): 1.0: 1.0, after stirring for 0.5 to 1 hour, adjust the pH of the solution to 4.8 to 5.5 with ammonia water, continue to stir for 2 to 5 hours, and evaporate the solution to dryness in a water bath at 70 to 90 ° C to obtain a gel-like precursor; The precursor is treated at 280-350°C for 8-15 minutes, and then placed in an argon atmosphere at 700-900°C for 5-8 hours to obtain a composite product of aluminum phosphate and carbon; the composite product is prepared at a concentration of 3-6mol Treat L ^-1 nitric acid solution at 70-90°C for 5-8 hours, remove the aluminum phosphate hard template, filter the obtained product with water, and dry it at 80-100°C to obtain a mesoporous carbon carrier (MC);

2. Preparation of mesoporous carbon-supported catalyst

(1) Weigh the mesoporous carbon carrier and cerium precursor, add the cerium precursor into 30-50mL distilled water, the concentration of cerium salt is 1.0×10 ^-2 ～3.0×10 ^-2 mol/L, after fully dissolved, add 1~2g mesoporous carbon carrier;

(2) Stir the mixture obtained in step (1) for 3 to 6 hours, evaporate to dryness in a water bath at 80 to 100°C, and then dry at 80 to 100°C for 8 to 12 hours;

(3) Calcining the product obtained in step (2) at 400-600° C. for 2-6 hours in an argon atmosphere to obtain a mesoporous carbon carrier loaded with cerium;

(4) Weigh the copper precursor and add it to distilled water, and add the mesoporous carbon carrier loaded with cerium obtained in step (3) after fully dissolving; the molar dosage ratio of the copper precursor and the cerium precursor is (2～5) :1;

(5) Stir the mixture obtained in step (4) for 3 to 6 hours, evaporate to dryness in a water bath at 80 to 100°C, and then dry at 80 to 100°C for 8 to 12 hours;

(6) The product obtained in step (5) is roasted at 400-600° C. for 2-6 hours in an argon atmosphere, so as to obtain the cerium- and copper-loaded catalyst for catalytic ethanol conversion into n-butanol described in the present invention. Mesoporous carbon-supported catalysts.

Further, in steps (1) and (4), the cerium precursor and the copper precursor are nitrate or acetate;

In step (3) and step (6), the roasting temperature is 400-550°C;

The catalyst of the present invention uses a mesoporous carbon carrier with a high specific surface area as a carrier, and cerium and copper are impregnated onto the carrier step by step. Compared with the prior art, the present invention has the following advantages:

(1) The preparation method of the mesoporous carbon-supported catalyst of the present invention is simple, the catalyst raw material does not use any precious metals, the raw material is cheap and easy to obtain, and has generalizability.

(2) The mesoporous carbon-supported catalyst of the present invention can be self-reduced to metallic state copper (metallic state refers to that metal exists in the form of simple substance, and valence is zero valence. Copper is to exist in the form of metallic state, Cerium exists in the form of oxidation state), does not require additional reduction treatment when used, and has industrial application prospects.

(3) The mesoporous carbon-supported catalyst of the present invention can have higher catalytic activity under mild reaction conditions, can effectively inhibit the sintering of metallic copper nanoparticles during the reaction process, and the catalyst has better catalytic stability.

(4) The mesoporous carbon-supported catalyst of the present invention is easy to recover, and can be reused after simple treatment at a certain temperature.

Description of drawings

Fig. 1 is the nitrogen adsorption-desorption isotherm and pore size distribution curve of the mesoporous carbon carrier provided by the present invention;

The nitrogen adsorption-desorption isotherm shows that the carbon support is a mesoporous structure, and mesoporous carbon (MC) mainly has mesoporous pores in the size range of 7.6nm and 3.9nm.

Fig. 2 is the sample X-ray powder diffraction figure provided by the present invention;

This figure corresponds to Example 3. This figure only has the diffraction peak of metallic copper, and no diffraction peak of cerium oxide is found, indicating that copper has been reduced to metallic copper during the preparation of the catalyst, and cerium oxide is highly dispersed on the surface of the carbon support.

Fig. 3 is sample catalytic activity and stability curve provided by the present invention;

Fig. 3 shows that along with the carrying out of reaction time, the conversion rate of reactant, the change situation of the selectivity of target product and the yield of target product. This figure corresponds to Example 3, which shows that the catalyst has better catalytic activity and stability.

Detailed ways

In order to set forth the present invention more clearly, enumerate the following examples and comparative examples to facilitate understanding of the specific technical solutions of the present invention, but it has no limitation to the protection scope of the present invention.

Example 1

First prepare the mesoporous carbon support:

Add 48g of aluminum nitrate, 13.5g of citric acid and 21.9g of sucrose into 200mL of distilled water in a certain proportion. After fully dissolving, add 8.7mL of concentrated phosphoric acid with a mass fraction of 87% dropwise. After stirring for 0.5h, adjust the solution with ammonia water When the pH reached 5.1, the stirring was continued for 3 h, and the solution was evaporated to dryness in a water bath at 80° C. to obtain a gel-like precursor. The obtained precursor was treated in a muffle furnace at 300°C for 10 minutes, and then placed in an argon atmosphere at 800°C for 6 hours to obtain a composite product of aluminum phosphate and carbon. The composite product was treated in a nitric acid solution with a concentration of 4 mol L ^-1 at 80°C for 6 hours to remove the aluminum phosphate hard template, and the obtained product was suction-filtered, washed with water until the pH was 7.0, and oven-dried at 100°C to obtain about 12 g of mesoporous Carbon carrier (MC).

Preparation of mesoporous carbon-supported catalyst:

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4g of mesoporous carbon carrier treated with 4M nitric acid at 80°C for 6h, add it to the solution obtained in step A, stir for 4h, place it in a water bath at 80°C, and evaporate the water to dryness, then place the obtained sample in Dry in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.0532g of Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The catalytic products of ethanol were quantitatively analyzed by gas chromatography, and the evaluation results of catalyst activity are shown in Table 1.

Example 2

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a 90°C water bath to evaporate Dry the water, and then place the obtained sample in an oven at 80°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.2663g of Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 3

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O, add to 40mL distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 4

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ 6H ₂ O, add to 40mL distilled water, and stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.7989g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 5

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 1.0652g of Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 6

Step A: Accurately weigh 0.4785g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a 90°C water bath to evaporate Dry the water, and then place the obtained sample in an oven at 90°C for 10 hours to obtain a powdery solid;

Step C: putting the powdered solid obtained in Step B into an argon atmosphere and calcining at 500° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdered solid obtained in Step E is placed in an argon atmosphere and calcined at 500° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 7

Step A: Accurately weigh 0.2392g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.5326g of Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 8

Step A: Accurately weigh 0.1748g Ce(CH ₃ COO) ₃ ·xH ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain a mesoporous carbon carrier loaded with cerium;

Step D: Accurately weigh 0.4401g of Cu(CH ₃ COO) ₂ ·H ₂ O into 40mL of distilled water, and stir until completely dissolved;

Step E: Add the cerium-loaded mesoporous carbon carrier obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Dry for 10h to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Example 9

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: The powdery solid obtained in step B is calcined at 450° C. for 4 hours in an argon atmosphere to obtain a finished catalyst.

Step D: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor with a reaction temperature of 250° C., a reaction pressure of 2 MPa, and an ethanol flow rate of 3.6 mL/h. The ethanol conversion product was quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1;

Example 10

Step A: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4 g of the mesoporous carbon carrier (prepared as described in Example 1) that has been treated with 4M nitric acid at 80°C for 6 hours, add it to the solution obtained in Step A, stir for 4 hours, and place it in a water bath at 80°C to evaporate Dry the water, and then place the obtained sample in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: put the powdery solid obtained in Step B into an argon atmosphere and roast at 450°C for 4 hours to obtain a finished catalyst;

Step D: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor with a reaction temperature of 250° C., a reaction pressure of 2 MPa, and an ethanol flow rate of 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Comparative example 1

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4g of silica carrier (purchased) and add it to the solution obtained in step A, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C Drying in medium for 10h, to obtain a powdery solid;

Step C: The powdered solid obtained in step B is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain cerium-loaded silica;

Step D: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, stir until completely dissolved;

Step E: Add the cerium-loaded silica obtained in step C to the solution in step D, stir for 4 hours, place in an 80°C water bath to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C to dry 10h, obtain powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Comparative example 2

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4g of titanium dioxide carrier (purchased) and add it to the solution obtained in step A, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C to dry for 10 hours , to obtain a powdery solid;

Step C: putting the powdery solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain titanium dioxide loaded with cerium;

Step D: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, stir until completely dissolved;

Step E: Add the cerium-loaded titanium dioxide obtained in Step C to the solution in Step D, stir for 4 hours, place in an 80°C water bath to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C to dry for 10 hours. Obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Comparative example 3

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4g of aluminum oxide carrier and add it to the solution obtained in step A, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C to dry for 10 hours , to obtain a powdery solid;

Step C: putting the powdered solid obtained in step B into an argon atmosphere and calcining at 450° C. for 4 hours to obtain cerium-loaded aluminum oxide;

Step D: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, stir until completely dissolved;

Step E: Add the cerium-loaded aluminum oxide (obtained from purchase) obtained in step C to the solution in step D, stir for 4 hours and then place it in a water bath at 80°C to evaporate the water to dryness, then place the obtained sample in a 100 ℃ drying in an oven for 10 hours to obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Comparative example 4

Step A: Accurately weigh 0.3191g Ce(NO ₃ ) ₃ ·6H ₂ O into 40mL distilled water, stir until completely dissolved;

Step B: Accurately weigh 1.4g of activated carbon carrier (purchased) that has been treated with 4M nitric acid at 80°C for 6h, add it to the solution obtained in step A, stir for 4h, place it in a water bath at 80°C, and evaporate the water to dryness, and then the obtained sample Dry in an oven at 100°C for 10 hours to obtain a powdery solid;

Step C: putting the powdered solid obtained in step B into an argon atmosphere and roasting at 450° C. for 4 hours to obtain activated carbon loaded with cerium;

Step D: Accurately weigh 0.5326g Cu(NO ₃ ) ₂ ·3H ₂ O into 40mL of distilled water, stir until completely dissolved;

Step E: Add the cerium-loaded activated carbon obtained in step C to the solution in step D, stir for 4 hours, place in a water bath at 80°C to evaporate the water to dryness, and then place the obtained sample in an oven at 100°C to dry for 10 hours. Obtain a powdery solid;

Step F: The powdery solid obtained in Step E is placed in an argon atmosphere and calcined at 450° C. for 4 hours to obtain a finished catalyst;

Step G: Weigh 1.0 g of the finished catalyst and fill it into the constant temperature zone of a continuous-flow miniature fixed-bed reactor. The reaction temperature is 250° C., the reaction pressure is 2 MPa, and the ethanol flow rate is 3.6 mL/h. The ethanol conversion products were quantitatively analyzed by gas chromatography, and the catalyst activity evaluation results are shown in Table 1.

Table 1: Catalytic activity results data of different catalysts in the conversion of ethanol to n-butanol

From the catalytic activity results of different catalysts in Table 1 in the reaction of catalytic ethanol conversion into n-butanol, it can be seen that in this reaction, the catalyst needs to have different types of active sites, and there is a synergistic effect between the active sites and the support. In the catalyst, the active sites The difference in the amount of the catalyst and the type of the support has an important influence on the activity and stability of the catalyst.

What has been described above is only a preferred embodiment of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be considered protection scope of the present invention.

Claims (5)

1. a kind of preparation method for the mesoporous carbon loaded catalyst for being converted into n-butanol for catalysis ethanol, its step are as follows:

A. the preparation of mesoporous high-area carbon

Aluminum nitrate, citric acid, sucrose are added in distilled water by a certain percentage, it is a certain amount of to be added dropwise after completely dissolution Phosphoric acid makes dosage molar ratio 0.5:(0.5~2.5 of citric acid in solution, sucrose, aluminum nitrate, phosphoric acid): 1.0:1.0, stirring With ammonium hydroxide adjusting pH value of solution to 4.8~5.5 after 0.5~1h, continues 2~5h of stirring, solution is evaporated under 70~90 DEG C of water-baths, Obtain gel presoma；Obtained presoma is handled into 8~15min at 280~350 DEG C, is then placed in argon atmosphere again In, 5~8h of processing obtains the combination product of aluminum phosphate and charcoal at 700~900 DEG C；By the combination product concentration be 3~ 6mol·L^-1Nitric acid solution in 5~8h is handled at 70~90 DEG C, remove aluminum phosphate hard template, obtained product filtered, water It is washed till neutrality, it is dry under the conditions of 80~100 DEG C, obtain mesoporous high-area carbon；

B. the preparation of mesoporous carbon loaded catalyst

(1) mesoporous high-area carbon and cerium precursor are weighed, cerium precursor is added in 30~50mL distilled water, cerium salt concentration is 1.0×10^-2~3.0 × 10^-2Mol/L, to which the mesoporous high-area carbon of 1~2g is added after completely dissolution；

(2) mixture obtained step (1) stirs after 3~6h the water bath method at 80~100 DEG C, then at 80~100 DEG C 8~12h of lower drying；

(3) product for obtaining step (2) roasts 2~6h in argon atmosphere at 400~600 DEG C, obtains being loaded with the mesoporous of cerium High-area carbon；

(4) it weighs copper presoma to be added in distilled water, the mesoporous carbon for being loaded with cerium obtained to which step (3) is added after completely dissolution Carrier；The mole dosage ratio of copper presoma and cerium precursor is (2~5): 1；

(5) in 80~100 DEG C of water bath methods after the 3~6h of mixture stirring obtained step (4), then at 80~100 DEG C Dry 8~12h；

(6) product for obtaining step (5) roasts 2~6h in argon atmosphere at 400~600 DEG C, to be loaded with simultaneously The mesoporous carbon loaded catalyst that n-butanol is converted into for catalysis ethanol of cerium and copper.

2. a kind of preparation for the mesoporous carbon loaded catalyst for being converted into n-butanol for catalysis ethanol as described in claim 1 Method, it is characterised in that: in step (1) and (4), cerium precursor and copper presoma are nitrate or acetate.

3. a kind of preparation for the mesoporous carbon loaded catalyst for being converted into n-butanol for catalysis ethanol as described in claim 1 Method, it is characterised in that: in step (3) and step (6), maturing temperature is 400~550 DEG C.

4. a kind of mesoporous carbon loaded catalyst for being converted into n-butanol for catalysis ethanol, it is characterised in that: by claim 1 Method described in~3 any one is prepared.

5. a kind of mesoporous carbon loaded catalyst for being converted into n-butanol for catalysis ethanol as claimed in claim 4, special Sign is: copper exists in the form of metallic state, and cerium exists in the form of oxidation state, and the load capacity of copper is 1wt%~20wt%, copper Atomic molar ratio with cerium is (2~5): 1.