Process for the synthesis of a highly dispersed supported catalyst, and its use for the catalytic preparation of furfuryl alcohol from furfural

Abstract

The application relates to the technical field of catalyzing furaldehyde to catalyze furfuryl alcohol, and discloses synthesis of a supported catalyst and a method for preparing furfuryl alcohol from furaldehyde. x O y The carrier is a metal oxide, the active metal is copper, the nano material can catalyze furaldehyde to prepare furfuryl alcohol, the supported catalyst synthesized by the method provided by the application has regular morphology and better hydrothermal stability, the catalyst has higher catalytic activity and reusability in catalyzing furaldehyde to prepare furfuryl alcohol. x O y The catalyst has regular morphology and better hydrothermal stability, and has higher catalytic activity and reusability in catalyzing furaldehyde to prepare furfuryl alcohol.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass chemical preparation, and specifically relates to M / N x O y The invention relates to the synthesis of a supported catalyst and a method for catalyzing furfural to prepare furfuryl alcohol. Background Art

[0002] Currently, increasing energy demand and overuse of fossil fuels have led to a severe fossil energy crisis and environmental pollution. Oil fields are depleting, and carbon dioxide emissions from the combustion of fossil fuels are affecting the Earth's climate, posing a serious obstacle for developing countries. Consequently, numerous studies are underway to explore and develop new renewable energy sources. Biomass energy, as a new type of renewable energy, is inherently carbon neutral, and the CO2 generated is reconsumed by the biomass, resulting in minimal environmental pollution. It is considered an excellent alternative to fossil fuels and a new generation of primary energy sources. Furfural is an important biomass platform derivative that can be produced from agricultural by-products such as corn cobs, waste straw, oat and wheat bran, sawdust, and sugarcane bagasse. This raw material not only poses no environmental risks but also offers considerable benefits for improving the environment.

[0003] Furfural derivatives are diverse, primarily including furfuryl alcohol, tetrahydrofurfuryl alcohol, tetrahydrofuran, furan, 2-methylfuran, 2-methyltetrahydrofuran, and cyclopentanol. In furfural hydrogenation reactions, furfuryl alcohol is one of the most valuable furfural derivatives. It can be obtained by hydrogenating furfural with H2 in the gas or liquid phase over a transition metal catalyst. Furfuryl alcohol plays a major role in agriculture, healthcare, printing and dyeing, and the leather industry, serving as an important raw material for light industry and chemical products. It is particularly useful in the synthesis of furan resins, phenolic resins, and furfuryl alcohol-urea-formaldehyde resins, as a diluent for epoxy resins and a solvent for insoluble pigments such as phenolic resins. It can also be used in fine chemicals such as pharmaceuticals, pesticides, and coatings. The production process for producing furfuryl alcohol from furfural hydrogenation can be divided into two types: liquid-phase hydrogenation and gas-phase hydrogenation. The liquid-phase hydrogenation process was developed earlier, and the reaction is generally carried out at relatively high pressures (3-8 MPa) and temperatures (190-210°C). This places high demands on the reactor, and the degree of catalyst separation and selectivity determine the difficulty of product purification. Therefore, this method is generally not used to produce furfuryl alcohol. However, the vapor-phase hydrogenation reaction is carried out at room temperature or low pressure, making the catalyst easily recoverable and recyclable while also eliminating chromium pollution. Major furfural manufacturers both domestically and internationally use the vapor-phase method to produce furfuryl alcohol.

[0004] Typically, the hydrogenation of furfural to furfuryl alcohol occurs on the surface of a metal catalyst. Various monometallic and bimetallic catalysts are used for furfural hydrogenation, with commonly used catalysts primarily categorized as precious metals and non-precious metals. Precious metal catalysts, such as Pd, Ru, Pt, and Au, are often used. However, their high activity makes side reactions (decarbonization, hydrogenolysis, and ring hydrogenation) almost unavoidable. Furthermore, the high cost of precious metals makes them prohibitive for industrial production. Consequently, attention has shifted to non-precious metals such as Cu, Co, Ni, and Fe. Copper-based catalysts were the first to be used in industrial furfural hydrogenation. They have attracted widespread attention for their high selectivity for C=O bond hydrogenation, avoiding furan ring hydrogenation and significantly increasing the yield of furfuryl alcohol. However, their ability to decompose hydrogen is poor, making improving the hydrogenation activity of copper-based catalysts a key to enhancing the selective hydrogenation of furfural to furfuryl alcohol.

[0005] Supported copper-based catalysts refer to catalysts in which the active components of the catalyst are evenly dispersed on a selected carrier. Many carriers contain acidic or basic sites, which have certain catalytic performance for furfural hydrogenation. Ren et al. studied the characteristics of Cu / CuAl-MMO-400 catalyst in furfural hydrogenation and pointed out that: Cu + Species are both dehydrogenation active sites and hydrogenation active sites; Cu 0 The sites promote the transfer of H atoms between adsorbed substrates. Liu et al. prepared the catalyst Cu / MgO by the separated nucleation aging method. The high efficiency was attributed to the surface synergy between the catalytically active metallic copper species and the Lewis base sites, which is the key to the hydrogenation reaction related to hydrogen dissociation and carbonyl activation. Therefore, in the reaction of catalyzing furfural to furfuryl alcohol, we need to design a catalyst with both L acid sites and hydrogenation active sites, but it is still unknown what kind of carrier to choose to make the supported catalyst more conducive to the catalytic synthesis of furfural into furfuryl alcohol. In this patent, we use Cu + L acid sites, Cu 0 The hydrogenation active sites were obtained by adjusting the Cu + / Cu 0 The ratio of the two active sites is effectively combined and the synergistic effect is maximized, so that the reaction proceeds smoothly. Therefore, a new type of supported catalyst M / N is studied and developed. x O y and preparation method, so that the catalyst can efficiently catalyze furfural and selectively prepare furfuryl alcohol has become a problem to be solved. Summary of the Invention

[0006] In view of this, the present invention provides a supported catalyst M / N x O yA synthesis method and a method for catalyzing furfural to prepare furfuryl alcohol using the same. The catalyst synthesized using the preparation method requires simple steps, is easy to operate, can be carried out at room temperature, consumes little energy, and the resulting supported catalyst metal is evenly dispersed, has strong hydrothermal stability, and can be recycled multiple times.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] S1. Mix the metal salt precursor with water, stir until the solid is dissolved, then add the oxide support, sonicate for a period of time, and stir to obtain the corresponding mixed solution;

[0009] S2, stop the above stirring, let it stand overnight, and then place it in an oven at a certain temperature for drying;

[0010] S3, the dried product is calcined and reduced under the action of H2 to obtain M / N x O y ;

[0011] S4, M / N x O y The catalytic reaction of furfural to furfuryl alcohol is carried out in a stainless steel autoclave. The air in the autoclave is replaced several times with N2, and then replaced several times with H2. The H2 pressure in the autoclave is maintained at a certain pressure, and the catalytic reaction is carried out with stable heating and stirring.

[0012] S5. After the reaction is completed, the catalyst M / N is recovered by centrifugation. x O y The catalyst phase can be directly recycled without post-treatment.

[0013] The S1 method is characterized in that the water is deionized water, the metal salt is selected from one of Cu(NO3)2·3H2O, Cu(CH3COO)2·H2O, and CuSO4·5H2O, the oxide carrier is selected from one of MgO, ZnO, CeO2, TiO2, Al2O3, and SiO2, and the metal loading is 5wt%. The equal volume impregnation method is adopted, the ultrasonic time is 5 to 30 minutes, and the stirring time is 10 to 12 hours.

[0014] The S2 method is characterized in that the standing time is 10 to 12 hours, the drying temperature is 60 to 80° C., and the drying time is 6 to 8 hours.

[0015] The S3 method is characterized in that the heating rate of the muffle furnace is controlled at 1 to 3°C / min, and the temperature is maintained at 400 to 600°C for 2 to 5 hours. The heating rate of the tubular furnace is controlled at 1 to 3°C / min, and the temperature is maintained at 300 to 600°C for 2 to 5 hours.

[0016] The S4 method is characterized in that nitrogen is used to replace the air in the kettle 5-8 times, nitrogen is used to replace the air in the kettle 3-5 times, and the H2 pressure is maintained at 2-5 MPa, M / N x O y The mass ratio of furfural to 1:(1-5), the reaction temperature is 100-140℃, and the reaction time is 1-3h.

[0017] The S5 method is characterized in that after the reaction is completed, the catalyst M / N is recovered by centrifugation. x O y The catalyst phase can be directly recycled without post-treatment to produce furfuryl alcohol.

[0018] The supported catalyst prepared by the present invention M / N x O y , the active metal is copper, and the carrier is a nanostructure of metal oxide. Compared with the existing technology, by adjusting the reduction temperature, the Cu + and Cu 0 ratio, to achieve a highly dispersed supported catalyst with an optimal ratio of active metals. 0 As hydrogenation active sites, Cu + As the L acid active site, the two active sites are effectively combined to maximize the synergistic effect, that is, Cu + Selective adsorption of terminal carbonyl groups, Cu 0 Decompose H2 into hydrogen protons and transfer to Cu + The catalyst selectively hydrogenates the C=O double bond to produce furfuryl alcohol, significantly enhancing the reaction activity. After the catalytic reaction, centrifugation allows for simple and efficient separation of the catalyst and product. The catalyst phase requires no post-treatment and can be reused directly. After five reuses, no significant decrease in catalytic performance was observed, demonstrating excellent recycling effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The multi-step method for synthesizing supported catalyst M / N provided by the present invention x O y Schematic diagram of the synthesis mechanism of -X.

[0020] Figure 2 The supported catalyst M / N provided by the present invention x O y -X SEM and TEM images; (a1) unreduced Cu /

[0021] Lattice spacing of MgO-350, (a2)Cu / MgO-350, (b1)Cu / MgO-350, (b2)Cu, (c1)-(c2)MgO.

[0022] Figure 3M / N x O y XRD patterns of the -X catalysts. DETAILED DESCRIPTION

[0023] The present invention discloses a method for synthesizing a supported catalyst and a method for catalyzing the production of furfural from furfuryl alcohol. Those skilled in the art can refer to the contents of this invention and appropriately improve the process parameters to achieve the desired results. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content and scope of the present invention to implement and apply the technology of the present invention.

[0024] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with specific embodiments.

[0025] Example 1

[0026] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0027] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0028] S3, the dried product was calcined in a muffle furnace, the calcination temperature was increased to 500° C. at a rate of 1° C. / min, and the calcination time was 3 h. The obtained solid product was placed in a tube furnace for reduction, the reduction temperature was increased to 350° C. at a rate of 2° C. / min, and the calcination time was 3 h to obtain the product Cu / MgO-350(S);

[0029] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO-350(S), 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0030] S5. After the reaction is completed, the mixture is allowed to cool to room temperature. The catalyst Cu / MgO-350(S) is recovered by centrifugation and can be directly recycled without post-treatment.

[0031] The yield of furfuryl alcohol is 99.9%, and the calculation formula of furfural yield is as follows:

[0032]

[0033] Y=S*X

[0034] Wherein, Y is the yield of furfuryl alcohol; X is the conversion rate of furfural; S is the selectivity of furfuryl alcohol; n initial is the molar amount of furfural added; n final is the remaining molar amount of furfuryl alcohol; m product is the molar mass of the product furfuryl alcohol.

[0035] Example 2

[0036] S1. Mix 0.32 g of Cu(NO3)2·5H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0037] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0038] S3, the dried product was calcined in a muffle furnace, the calcination temperature was increased to 500 ° C. at a rate of 1 ° C. / min, and the calcination time was 3 h. The obtained solid product was placed in a tube furnace for reduction, the reduction temperature was increased to 350 ° C. at a rate of 2 ° C. / min, and the calcination time was 3 h to obtain the product Cu / MgO-350 (N);

[0039] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO-350(N), 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110° C. for 80 min.

[0040] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / MgO-350(N) catalyst is recovered by centrifugation and directly recycled without post-treatment. The yield of furfuryl alcohol is 11.5%.

[0041] Example 3

[0042] S1. Mix 0.34 g of Cu(CH3COO)2·H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0043] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0044] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min for 3 h, and reducing the solid product in a tube furnace, raising the reduction temperature to 350° C. at a rate of 2° C. / min for 3 h to obtain product Cu / MgO-350 (A);

[0045] S4, 0.05 mL of furfural, 0.05 g of Cu / MgO-350(A), 5 mL of isopropanol and a high-temperature magnet were placed in a 50 mL high-temperature, high-pressure stainless steel reactor, the air in the reactor was replaced with nitrogen 5 times and with hydrogen 3 times, the pressure in the high-pressure reactor was maintained at 2 MPa, and heated with stirring at 110°C for 80 min;

[0046] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The catalyst Cu / MgO-350(A) is recovered by centrifugation and directly recycled without post-treatment. The yield of furfuryl alcohol is 16.8%.

[0047] Example 4

[0048] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0049] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0050] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min, and calcining for 3 h, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 300° C. at a rate of 2° C. / min, and calcining for 3 h to obtain the product Cu / MgO-300;

[0051] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO-300, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0052] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / MgO-300 catalyst is recovered by centrifugation and directly recycled without post-treatment. The yield of furfuryl alcohol is 34.8%.

[0053] Example 5

[0054] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0055] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0056] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min, and calcining for 3 h, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 400° C. at a rate of 2° C. / min, and calcining for 3 h to obtain the product Cu / MgO-400;

[0057] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO-400, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0058] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / MgO-400 catalyst is recovered by centrifugation and directly recycled without post-treatment. The yield of furfuryl alcohol is 55.7%.

[0059] Example 6

[0060] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0061] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0062] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min for 3 h, and reducing the solid product in a tube furnace, raising the reduction temperature to 450° C. at a rate of 2° C. / min for 3 h to obtain the product Cu / MgO-450;

[0063] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO-300, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0064] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / MgO-450 catalyst is recovered by centrifugation and recycled without further treatment. The yield of furfuryl alcohol is 40.8%.

[0065] Example 7

[0066] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of MgO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0067] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0068] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min, and calcining for 3 h, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 500° C. at a rate of 2° C. / min, and calcining for 3 h to obtain the product Cu / MgO-500;

[0069] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO-500, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0070] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / MgO-500 catalyst is recovered by centrifugation and directly recycled without post-treatment. The yield of furfuryl alcohol is 29.5%.

[0071] Example 8

[0072] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, add the oxide support, and then add 1.50 g of ZnO support. Ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution.

[0073] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0074] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min, and calcining for 3 h, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 350° C. at a rate of 2° C. / min, and calcining for 3 h to obtain the product Cu / ZnO;

[0075] S4. Place 0.05 mL of furfural, 0.05 g of Cu / ZnO, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen 5 times and with hydrogen 3 times. Maintain the pressure in the high-pressure reactor at 2 MPa and heat with stirring at 110°C for 80 min.

[0076] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / ZnO catalyst is recovered by centrifugation and recycled without further treatment. The yield of furfuryl alcohol is 10.3%.

[0077] Example 9

[0078] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, then add the oxide support, then add 1.50 g of CeO2 support, ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution;

[0079] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0080] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min, and calcining for 3 h, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 350° C. at a rate of 2° C. / min, and calcining for 3 h to obtain product CeO2;

[0081] S4, 0.05 mL of furfural, 0.05 g of Cu / CeO2, 5 mL of isopropanol and a high-temperature magnet were placed in a 50 mL high-temperature and high-pressure stainless steel reactor, the air in the reactor was replaced with nitrogen 5 times and hydrogen 3 times, the pressure in the high-pressure reactor was maintained at 2 MPa, and heated and stirred at 110 ° C for 80 min;

[0082] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / CeO2 catalyst is recovered by centrifugation and recycled without further treatment. The yield of furfuryl alcohol is 42.6%.

[0083] Example 10

[0084] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, then add the oxide support, then add 1.50 g of Al2O3 support, ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution;

[0085] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0086] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500°C at a rate of 1°C / min for 3 hours, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 350°C at a rate of 2°C / min for 3 hours to obtain the product Cu / Al2O3;

[0087] S4. Place 0.05 mL of furfural, 0.05 g of Cu / Al2O3, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0088] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / Al2O3 catalyst is recovered by centrifugation and directly recycled without post-treatment. The yield of furfuryl alcohol is 68.7%.

[0089] Example 11

[0090] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, then add the oxide support, then add 1.50 g of TiO2 support, ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution;

[0091] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0092] S3, calcining the dried product in a muffle furnace, raising the calcination temperature to 500° C. at a rate of 1° C. / min, and calcining for 3 h, and reducing the obtained solid product in a tube furnace, raising the reduction temperature to 350° C. at a rate of 2° C. / min, and calcining for 3 h to obtain product Cu / TiO2;

[0093] S4. Place 0.05 mL of furfural, 0.05 g of Cu / MgO, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0094] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / TiO2 catalyst is recovered by centrifugation and can be directly recycled without post-treatment. The yield of furfuryl alcohol is 11.5%.

[0095] Example 12

[0096] S1. Mix 0.32 g of CuSO4·3H2O and 10.00 mL of deionized water in a 10.00 mL beaker, stir until the solid is dissolved, then add the oxide support, then add 1.50 g of SiO2 support, ultrasonicate for 30 min, stir at room temperature, and maintain for 12 h to obtain the corresponding mixed solution;

[0097] S2, stop the above stirring, let it stand overnight for 12 hours, and then place it in an oven at 80°C to dry for 6 hours;

[0098] S3, the dried product was calcined in a muffle furnace, the calcination temperature was increased to 500 ° C at a rate of 1 ° C / min, the calcination time was 3 h, the obtained solid product was placed in a tube furnace for reduction, the reduction temperature was increased to 350 ° C at a rate of 2 ° C / min, the calcination time was 3 h, and the product Cu / SiO2 was obtained;

[0099] S4. Place 0.05 mL of furfural, 0.05 g of Cu / SiO2, 5 mL of isopropanol, and a high-temperature magnet in a 50 mL high-temperature, high-pressure stainless steel reactor. Replace the air in the reactor with nitrogen five times and with hydrogen three times. Maintain the pressure in the high-pressure reactor at 2 MPa. Heat and stir at 110°C for 80 min.

[0100] S5. After the reaction is complete, the mixture is allowed to cool to room temperature. The Cu / SiO2 catalyst is recovered by centrifugation and recycled without further treatment. The yield of furfuryl alcohol is 17.7%.

[0101] Example 13

[0102] The experimental conditions and steps were the same as those in Example 1, except that the catalyst was replaced with the catalyst recovered in Example 1. The experiment was repeated five times, and the yield of furfuryl alcohol after five times of repeated use was 94.7%.

[0103] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. M / N x O y The method for preparing furfuryl alcohol by using furfural catalyzed by a supported catalyst is characterized in that: The following steps are involved: S1. Mix the metal salt precursor with water, stir until the solid is dissolved, then add the oxide support, sonicate for a period of time, and stir to obtain the corresponding mixed solution; S2, stop the above stirring, let it stand overnight, and then put it in an oven to dry at a certain temperature; S3, the dried product is calcined and reduced under the action of H2 to obtain M / N x O y ; S4, M / N x O y The catalytic reaction of furfural to furfuryl alcohol is carried out in a stainless steel autoclave. The air in the autoclave is replaced several times with N2 and then replaced several times with H2. The H2 pressure in the autoclave is maintained at a certain level, and the catalytic reaction is carried out with stable heating and stirring. S5. After the reaction is completed, the catalyst M / N is recovered by centrifugation. x O y The catalyst phase can be directly recycled without post-treatment; The metal salt precursor is selected from CuSO4·3H2O, the oxide carrier is MgO, and the reduction temperature is 350°C.

2. The method according to claim 1, wherein The water is deionized water, the metal loading amount is 5 wt%, an equal volume impregnation method is adopted, the ultrasonic time is 5 to 30 minutes, and the stirring time is 10 to 12 hours.

3. The method according to claim 1, wherein The standing time is 10 to 12 hours, the drying temperature is 60 to 80°C, and the drying time is 6 to 8 hours.

4. The method according to claim 1, wherein The calcination is carried out in a muffle furnace, the heating rate of the muffle furnace should be controlled at 1-3°C / min, and the temperature should be maintained for 2-5 hours after reaching 400-600°C. The reduction is carried out in a tubular furnace, the heating rate of the tubular furnace should be controlled at 1-3°C / min, and the temperature should be maintained for 2-5 hours after heating.

5. The method according to claim 1, wherein Use nitrogen to replace the air in the kettle 5 times, use hydrogen to replace it 3 times, and the H2 pressure should be maintained at 2-5MPa, M / N x O y The mass ratio of furfural to 1:(1-5), the reaction temperature is 100-140℃, and the reaction time is 1-3h.

6. The method according to claim 1, wherein After the reaction is completed, the catalyst M / N is recovered by centrifugation. x O y The catalyst phase can be directly recycled without post-treatment to produce furfuryl alcohol.

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