Preparation method of bimetallic supported catalyst and method for preparing hemiacetal from furfural and alcohol

Abstract

The application discloses a preparation method of a bimetallic supported catalyst and a method for preparing a hemiacetal from a furan aldehyde and an alcohol, and the preparation method of the bimetallic supported catalyst comprises the following steps: mixing a carrier Y and a precursor salt of an active metal M1, standing at room temperature and drying to obtain a solid A; calcining the solid A under an air atmosphere to obtain a solid B; mixing a precursor salt of an active metal M2, the solid B and deionized water, regulating the acid-base property of a mixed solution, adding a hydrogen donor reducing agent, loading the active metal M2 on the solid B by using a hydrogen donor reduction method, and filtering and drying a product to obtain the bimetallic supported catalyst. The catalyst loaded with two active metals is prepared by using the preparation method, the catalyst has high stability, the two active components play a synergistic role, the activity of the catalyst is improved, and the method has high conversion rate and high selectivity for the hemiacetal reaction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic catalytic conversion, in particular to a preparation method of a bimetallic supported catalyst and a method for preparing hemiacetal from furfural and alcohol. BACKGROUND

[0002] With the continuous development of traditional industry and the rapid growth of the earth's population, the contradiction between the decrease of non-renewable resource reserves and the increase of fuel demand, as well as the environmental pollution caused by the overuse and development of fossil resources, has become a great challenge for mankind. In order to get out of this dilemma, mankind will focus on the future development of renewable energy such as wind energy, solar energy, biomass energy and so on. As the only renewable organic carbon source in nature, biomass has the characteristics of environmental protection, abundant reserves and low cost, and can be used as raw material for producing high value-added chemicals and materials.

[0003] Furfural is a kind of widely used biomass platform compound, which is produced by hydrolysis of biomass raw materials such as cellulose. It contains aldehyde group and hydroxyl group in the molecule, which can be derived into many furan chemical products through catalytic hydrogenation, oxidative dehydrogenation, esterification, halogenation and other chemical reactions. At present, the research focus of biomass conversion is concentrated on the synthesis of furfural from monosaccharides or disaccharides produced by biomass hydrolysis, and the preparation of its derivatives is also mostly limited to oxidation reaction, while the hemiacetal reaction is rarely involved. The aldehyde group of furfural can react with chain monohydric saturated alcohol to produce hemiacetal, which can be used to produce a series of derivatives, and can be used as food flavor and fuel additive, or directly used as biofuel. It can be seen that the application value of hemiacetal reaction is very great, and has great application potential and market.

[0004] The existing catalyst has low selectivity for hemiacetalization reaction and poor stability, and the yield of hemiacetal product is not ideal. Although part of the noble metal catalyst can bring higher yield of hemiacetal product, due to its high price, the production cost of biomass conversion is greatly increased, which further limits the application and popularization of hemiacetal derivatives, and is not conducive to the expansion of production. SUMMARY

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present application is to develop a cheap and efficient catalyst to improve the conversion rate and selectivity of hemiacetalization reaction.

[0006] To solve the above technical problems, the present application provides a preparation method of a bimetallic supported catalyst, comprising the following steps:

[0007] S11, mixing a carrier Y and a precursor salt of an active metal M1, loading the active metal M1 on the carrier Y by an impregnation method, standing at room temperature, drying to obtain a solid A, the carrier Y being a metal oxide, the active metal M1 being a non-noble metal;

[0008] S12, calcining the solid A under an air atmosphere to obtain a solid B;

[0009] S13, mixing a precursor salt of an active metal M2, the solid B and deionized water, adjusting the acidity and alkalinity of the mixed solution, adding a hydrogen donor reducing agent, loading the active metal M2 on the solid B by a hydrogen donor reduction method, the active metal M2 being a noble metal, and obtaining a bimetallic supported catalyst after filtering and drying the product.

[0010] The catalyst loaded with two active metals prepared by the preparation method has two active components which play a synergistic role, improves the activity of the catalyst, is suitable for catalyzing furan aldehyde condensation to obtain a hemiacetal compound, has high conversion rate and high selectivity for hemiacetal reaction, is beneficial to reducing the use of noble metals and reducing the cost of the catalyst, and has high stability and can be recycled and reused.

[0011] Further, the step S13 specifically comprises: mixing the solid B and deionized water, heating and stirring for 1-2 h; adding a sodium hydroxide aqueous solution to adjust the pH to 8-9; adding the precursor salt of the active metal M2, stirring for 2-5 h; adding a reducing agent, continuing to stir for 4-6 h; filtering to obtain a product, washing, and drying to obtain a bimetallic supported catalyst. The loading of the active metal M2 is realized by the hydrogen donor reduction method, the process condition is mild, does not affect the active metal M1 loaded on the carrier, makes the two active metals uniformly distributed, and is beneficial to realizing the synergistic catalysis effect.

[0012] Further, the hydrogen donor reducing agent is at least one selected from formic acid, hydrazine hydrate, ammonia borane, ammonium formate, sodium formate, cyclohexene, decalin and tetralin.

[0013] Further, the carrier Y is at least one selected from MoO2, Al2O3, In2O3, SiO2, CeO2 and ZnO.

[0014] Further, the active metal M1 is at least one selected from Co, Ni, Cu, Sc, Ti, Cr, Mn, Fe and Zn.

[0015] Further, the active metal M2 is at least one selected from Ru, Pt, Pd, Au, Ag, Ir, Rh and Os.

[0016] Further, the mass ratio of the active metal M1 in the bimetallic supported catalyst is 1% to 4%.

[0017] Further, the mass ratio of the active metal M2 is 0.01% to 0.1%.

[0018] The catalyst is loaded with two active metals, which can play a synergistic role to improve the catalytic effect, so the required amount of each active component is less, which is conducive to reducing the cost of the catalyst.

[0019] The second aspect of the application provides a method for preparing a hemiacetal from a furfural and an alcohol, comprising the following steps:

[0020] S21, the bimetallic supported catalyst prepared by the above preparation method, furfural and alcohol organic solvent are added into a reaction device to form a mixed solution;

[0021] S22, hydrogen is introduced into the reaction device to carry out condensation reaction to obtain a hemiacetal compound.

[0022] The bimetallic supported catalyst is used for catalyzing the hemiacetalization reaction, and the above preparation method has the advantages of simple process, high furfural conversion rate, high selectivity of hemiacetal, high product purity and the like.

[0023] Further, in the step S22, the reaction temperature is 80℃ to 140℃, the pressure is 0.5MPa to 4MPa, and the time is 0.5h to 8h. The reaction conditions of the method for preparing a hemiacetal from a furfural and an alcohol are relatively mild, the reaction period is short, and it is conducive to realizing industrial application.

[0024] Further, in the step S21, the molar ratio of the furfural to the bimetallic supported catalyst is 3500 to 40000:1. The bimetallic supported catalyst has high reaction activity, and the required amount for catalyzing the hemiacetalization reaction is small, which is conducive to reducing the cost of preparing a hemiacetal compound.

[0025] Further, in the step S21, the molar concentration of the furfural in the mixed solution is 0.1M to 1M. The molar concentration of the furfural is controlled to ensure sufficient reaction and high conversion rate.

[0026] Further, the furfural is selected from at least one of furfural, 5-methylfurfural, 5-hydroxymethylfurfural, 2,5-diformylfuran, 2-furyl ethanol, 5-chloromethylfuran, 4-hydroxymethylfurfural, and 2,5-furandicarboxaldehyde.

[0027] Further, the alcohol organic solvent is selected from at least one of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, isobutyl alcohol, n-pentanol, isopentyl alcohol, n-hexanol, and isohexyl alcohol.

[0028] The bimetallic supported catalyst of the present application has good catalytic effect on various furfural and alcohol, and can catalyze the condensation of furfural to obtain hemiacetal compounds with high conversion rate and selectivity.

[0029] In summary, compared with the prior art, the present application has the following beneficial effects:

[0030] 1) The catalyst loaded with two active metals is prepared by a specific process in the present application, and has high stability and can be reused. The two active metals play a synergistic role, so that the catalyst has high activity, and can catalyze the condensation of furfural and alcohol to prepare hemiacetal compounds under mild reaction conditions and in a short reaction time.

[0031] 2) The bimetallic supported catalyst of the present application has less noble metal components and low preparation cost, which is conducive to the application and popularization of hemiacetal derivatives, and the future expansion of production.

[0032] 3) The bimetallic supported catalyst of the present application has high conversion rate and selectivity for the hemiacetalization reaction of furfural, and the maximum conversion rate can reach 70%, and the highest selectivity can reach 100%.

[0033] 4) The bimetallic supported catalyst of the present application has less noble metal components and low preparation cost, which is conducive to the application and popularization of hemiacetal derivatives, and the future expansion of production. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The route map for the preparation of hemiacetal by the condensation of HMF with alcohol under hydrogen atmosphere in Example 1 of the present application. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0036] It should be understood that the terms described in the present application are only for describing the specific embodiments, and are not used to limit the present application. In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range and any other stated value or intermediate value in the stated range is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0037] Many modifications and variations to the illustrative embodiments described herein will be apparent to those skilled in the art from consideration of the specification and practice of the subject technology. Additional embodiments of the present technology will be apparent to those skilled in the art from consideration of the specification and practice of the subject technology. The specification and examples provided should be considered exemplary only.

[0038] The specific embodiments of the present application provide a bimetallic supported catalyst, which is suitable for catalyzing the semi-acetalization reaction of furan aldehyde and alcohol. The bimetallic supported catalyst comprises a carrier Y and active metals M1 and M2 supported thereon, the carrier Y is a metal oxide such as MoO2, Al2O3, In2O3, SiO2, CeO2, ZnO, etc., the active metal M1 is a non-noble metal such as Co, Ni, Cu, Sc, Ti, Cr, Mn, Fe, Zn, etc., and the active metal M2 is a noble metal such as Ru, Pt, Pd, Au, Ag, Ir, Rh, Os, etc. The two active components play a synergistic role, thereby improving the activity of the catalyst.

[0039] In specific embodiments, the mass percentage of the active metal M1 in the bimetallic supported catalyst is 1% to 4%, and the mass percentage of the active metal M2 is 0.01% to 0.1%. Typical mass fractions of the active metal M1 include 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, etc., and typical mass fractions of the active metal M2 include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, etc.

[0040] The preparation method of the above-mentioned supported metal catalyst comprises the following steps:

[0041] S11, mix the carrier Y with the precursor salt of the active metal M1, load the active metal M1 onto the carrier Y by impregnation, stand at room temperature, and dry to obtain a solid A.

[0042] S12, calcine the solid A obtained in step S11 to obtain a solid B. The calcination step causes the precursor salt of the active metal M1 to become a metal oxide, while controlling the growth of metal particles.

[0043] In specific embodiments, the calcination temperature is 200°C to 900°C, and the time is 2h to 15h. Typical calcination temperatures include 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, etc.

[0044] S13, mixing the solid B with deionized water, heating and stirring for 1-2h; adding sodium hydroxide solution to adjust the pH to 8-9; adding the precursor salt of the active metal M2, stirring for 2-5h; adding a hydrogen donor reducing agent, continuing to stir for 4-6h; filtering to obtain the product, washing, and drying to obtain a bimetallic supported catalyst.

[0045] In specific embodiments, the precursors of the active metal M1 and the active metal M2 are independently selected from corresponding nitrate salts, chloride salts, acetate salts, acetylacetone salts, etc.

[0046] In specific embodiments, the hydrogen donor reducing agent is selected from formic acid, hydrazine hydrate, ammonia borane, ammonium formate, sodium formate, cyclohexene, decalin, tetralin, etc.

[0047] The above preparation method combines impregnation method and hydrogen donor reduction method, so that two active metals are loaded on the carrier, the catalyst has high stability, the two active metals can have a synergistic catalytic effect, the catalyst has high activity, and has high selectivity for hemiacetal.

[0048] The specific embodiments of the present application also provide a method for preparing hemiacetal from furfural and alcohol, which specifically comprises the following steps:

[0049] S21, adding the bimetallic supported catalyst prepared in the present application, furfural, and an alcohol organic solvent into a reaction device to form a mixed solution.

[0050] In specific embodiments, the furfural can be selected from furfural, 5-methylfurfural, 5-hydroxymethylfurfural, 2,5-diformylfuran, 2-furyl ethanol, 5-chloromethylfuran, 4-hydroxymethylfurfural, 2,5-furandicarboxaldehyde, etc.; and the alcohol organic solvent can be selected from methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, isobutyl alcohol, n-pentanol, isopentyl alcohol, n-hexanol, isohexyl alcohol, etc.

[0051] Preferably, the molar ratio of furfural to bimetallic supported catalyst is 3500-40000:1, and typical molar ratios include 3500:1, 4000:1, 4500:1, 5000:1, 5500:1, 6000:1, 6500:1, 7000:1, 7500:1, 8000:1, 8500:1, 9000:1, 9500:1, 10000:1, 15000:1, 20000:1, 25000:1, 30000:1, 35000:1, 40000:1, etc.

[0052] The molar concentration of furfural in the mixed solution is 0.1M-1M, and typical molar concentrations include 0.1M, 0.2M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, etc.

[0053] S22, hydrogen is introduced into the reaction device to perform condensation reaction to obtain a hemiacetal compound.

[0054] In specific embodiments, the reaction conditions are as follows: the temperature is 80-140°C, the pressure is 0.5-4 MPa, and the time is 0.5-8 h. Typical reaction temperatures include 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, etc.; typical reaction times include 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, etc.; and typical reaction pressures include 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, etc.

[0055] The above method uses a bimetallic supported catalyst for hemiacetalization of furfural and alcohol, and can prepare a hemiacetal product with high purity under mild reaction conditions and in a short reaction time, and the hemiacetalization reaction has high conversion rate and selectivity.

[0056] The technical effects of the present application are described below in conjunction with specific embodiments. Unless otherwise specified, the raw materials in the examples of the present application are purchased through commercial channels. The conversion rate and selectivity in the examples are calculated as follows:

[0057] HMF conversion rate = (initial HMF concentration - post-reaction HMF concentration) / initial HMF concentration x 100%;

[0058] Hemiacetal yield = post-reaction hemiacetal concentration / initial hemiacetal concentration x 100%;

[0059] Hemiacetal selectivity = hemiacetal yield / HMF conversion rate x 100%.

[0060] Example 1

[0061] (1) A bimetallic supported catalyst was prepared, and the specific steps were as follows:

[0062] (1.1) A 0.6 M copper nitrate hexahydrate aqueous solution and molybdenum dioxide powder were mixed at a ratio of 1:1, and stirred thoroughly until uniform; after drying the surface moisture at 80°C, it was left to stand at room temperature for 12 h; then it was ground into powder and calcined at 800°C for 5 h to obtain a solid CuO / MoO2 with Cu supported on MoO2.

[0063] (1.2) CuO / MoO2 obtained in step (1.1) is added into deionized water, heated and stirred for 2 h; a 1M NaOH aqueous solution is added to adjust the pH to 8; a H2PtCl6 solution is added, with the mass concentration of Pt being 1 mg / mL, and stirred for 2 h; then a reducing agent formic acid solution is added, and stirring is continued for 4 h; deionized water is used for filtration and washing until the pH is neutral, and the filter cake is dried at 90°C for 10 h; then the filter cake is ground into powder to obtain a bimetallic supported catalyst with Cu and Pt supported on MoO2, which is denoted as Cu-Pt / MoO2-FA.

[0064] (2) Catalytic activity test, the Cu-Pt / MoO2-FA catalyst is applied to catalyze the condensation reaction of 5-hydroxymethylfurfural to prepare hemiacetal, and the specific operation process is as follows:

[0065] 5-hydroxymethylfurfural is dissolved in an ethanol solvent, and the Cu-Pt / MoO2-FA bimetallic supported catalyst is added, so that the concentration of 5-hydroxymethylfurfural is 0.1M, and the molar ratio of 5-hydroxymethylfurfural to the catalyst is 10000:1; the hydrogen pressure is kept at 1 MPa, and the reaction is carried out at 100°C for 3 h; 5-hydroxymethylfurfural and ethanol undergo hemiacetalization reaction in a hydrogen environment, and the reaction principle is as shown in Figure 1 ; after the reaction is completed, cooling is carried out; the catalyst is separated from the reaction solution by filtration, and the catalyst is repeatedly washed and dried for recycling; the reaction solution is filtered and subjected to quantitative analysis by high-performance gas chromatography.

[0066] It is measured that the conversion rate of 5-hydroxymethylfurfural is 71%, the yield of hemiacetal is 70%, and the selectivity of hemiacetal is 98.6%, and the results show that the bimetallic supported catalyst prepared in this embodiment has excellent performance.

[0067] (3) Catalyst stability test, and the specific operation process is as follows:

[0068] The Cu-Pt / MoO2-FA recovered in step (2) is used again to catalyze the condensation reaction of 5-hydroxymethylfurfural to prepare hemiacetal, and the catalytic activity is tested, and the test steps and conditions are the same as those in step (2). This method is repeated for four times, and the yield of hemiacetal is 69.5%, 68.3%, 67.6% and 65.8% respectively each time

[0069] The results of the catalytic performance evaluation show that the activity loss of the catalyst is low and the stability is good during the recycling process.

[0070] Example 2

[0071] The same preparation steps as in Example 1 are adopted, MoO2 is used as the carrier, Cu is used as the active metal M1, Pd is used as the active metal M2, and formic acid is used as the hydrogen donor to prepare a bimetallic supported catalyst Cu-Pd / MoO2-FA.

[0072] The catalytic activity test method of Example 1 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 67.2%, the yield of the acetal as 65.1%, and the selectivity of the acetal as 96.9%.

[0073] Example 3

[0074] The same preparation procedure of Example 1 was used to prepare a bimetallic supported catalyst Cu-Ru / MoO2-FA, with MoO2as the carrier, Cu as the active metal M1, Ru as the active metal M2, and formic acid as the hydrogen donor.

[0075] The catalytic activity test method of Example 1 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 66.5%, the yield of the acetal as 64.2%, and the selectivity of the acetal as 96.5%.

[0076] Example 4

[0077] The same preparation procedure of Example 1 was used to prepare a bimetallic supported catalyst Cu-Au / MoO2-FA, with MoO2as the carrier, Cu as the active metal M1, Au as the active metal M2, and formic acid as the hydrogen donor.

[0078] The catalytic activity test method of Example 1 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 59.6%, the yield of the acetal as 55.5%, and the selectivity of the acetal as 93.1%.

[0079] Example 5

[0080] The same preparation procedure of Example 1 was used to prepare a bimetallic supported catalyst Cu-Ir / MoO2-FA, with MoO2as the carrier, Cu as the active metal M1, Ir as the active metal M2, and formic acid as the hydrogen donor.

[0081] The catalytic activity test method of Example 1 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 52.2%, the yield of the acetal as 50%, and the selectivity of the acetal as 95.8%.

[0082] Example 6

[0083] The same preparation procedure of Example 1 was used to prepare a bimetallic supported catalyst Cu-Pt / Al2O3-FA, with Al2O3as the carrier, Cu as the active metal M1, Pt as the active metal M2, and formic acid as the hydrogen donor.

[0084] The catalytic activity test method of Example 1 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 63.2%, the yield of the acetal as 54.3%, and the selectivity of the acetal as 85.9%.

[0085] Example 7

[0086] The same preparation procedure of Example 1 was adopted to prepare a bimetallic supported catalyst Cu-Pt / In2O3-FA, with In2O3 as the carrier, Cu as the active metal M1, Pt as the active metal M2, and formic acid as the hydrogen donor.

[0087] The catalytic activity test method of Example 1 was adopted, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 58.5%, the yield of the hemiacetal was 55.2%, and the selectivity of the hemiacetal was 94.4%.

[0088] Example 8

[0089] The same preparation procedure of Example 1 was adopted to prepare a bimetallic supported catalyst Cu-Pt / SiO2-FA, with SiO2 as the carrier, Cu as the active metal M1, Pt as the active metal M2, and formic acid as the hydrogen donor.

[0090] The catalytic activity test method of Example 1 was adopted, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 58.4%, the yield of the hemiacetal was 47.1%, and the selectivity of the hemiacetal was 80.6%.

[0091] Example 9

[0092] The same preparation procedure of Example 1 was adopted to prepare a bimetallic supported catalyst Cu-Pt / CeO2-FA, with CeO2 as the carrier, Cu as the active metal M1, Pt as the active metal M2, and formic acid as the hydrogen donor.

[0093] The catalytic activity test method of Example 1 was adopted, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 53%, the yield of the hemiacetal was 44.3%, and the selectivity of the hemiacetal was 83.6%.

[0094] Example 10

[0095] The same preparation procedure of Example 1 was adopted to prepare a bimetallic supported catalyst Co-Pt / MoO2-FA, with MoO2 as the carrier, Co as the active metal M1, Pt as the active metal M2, and formic acid as the hydrogen donor.

[0096] The catalytic activity test method of Example 1 was adopted, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 46.2%, the yield of the hemiacetal was 32.2%, and the selectivity of the hemiacetal was 69.7%.

[0097] Example 11

[0098] The same preparation procedure of Example 1 was adopted to prepare a bimetallic supported catalyst Ni-Pt / MoO2-FA, with MoO2 as the carrier, Ni as the active metal M1, Pt as the active metal M2, and formic acid as the hydrogen donor.

[0099] The conversion of 5-hydroxymethylfurfural was 40%, the yield of the hemiacetal was 30.8%, and the selectivity of the hemiacetal was 77% in the reaction, which were measured by using the catalytic activity test method of Example 1.

[0100] Example 12

[0101] A bimetallic supported catalyst Cu-Pt / MoO2-NH was prepared by using the same preparation procedure of Example 1, with MoO2 as the carrier, Cu as the active metal M1, Pt as the active metal M2, and hydrazine hydrate as the hydrogen donor.

[0102] The conversion of 5-hydroxymethylfurfural was 68.8%, the yield of the hemiacetal was 66%, and the selectivity of the hemiacetal was 95.9% in the reaction, which were measured by using the catalytic activity test method of Example 1.

[0103] Example 13

[0104] A bimetallic supported catalyst Cu-Pt / MoO2-NH was prepared by using the same preparation procedure of Example 1, with MoO2 as the carrier, Cu as the active metal M1, Pt as the active metal M2, and hydrazine hydrate as the hydrogen donor.

[0105] The conversion of 5-hydroxymethylfurfural was 68.8%, the yield of the hemiacetal was 66%, and the selectivity of the hemiacetal was 95.9% in the reaction, which were measured by using the catalytic activity test method of Example 1.

[0106] The performance evaluation results of the bimetallic supported catalysts prepared in Examples 1-13 are shown in Table 1 below.

[0107] Table 1 Performance test results of the catalysts of Examples 1-5 in the HMF hemiacetal reaction

[0108]

[0109]

[0110] Comparative Example 1

[0111] (1) Preparation of the catalyst, the specific steps are as follows:

[0112] A copper nitrate hexahydrate aqueous solution with a concentration of 0.6 M and molybdenum dioxide powder were mixed at a ratio of 1:1, and stirred thoroughly until mixed uniformly; after drying the surface moisture at 80°C, it was left to stand at room temperature for 12 h; then it was ground into powder and calcined at 800°C for 5 h; and then reduced at 700°C under a normal pressure hydrogen atmosphere for 5 h, to obtain a catalyst Cu / MoO2-H2 with Cu supported on MoO2.

[0113] (2) The catalytic activity test was carried out in the same manner as in Example 1, and the conversion of 5-hydroxymethylfurfural was 50%, the yield of the hemiacetal was 9%, and the selectivity of the hemiacetal was 18%.

[0114] Comparative Example 2

[0115] A catalyst Co / MoO2-H2 was prepared in the same manner as in Comparative Example 1, using MoO2 as the carrier, Co as the active ingredient, and hydrogen as the reducing agent.

[0116] The catalytic activity test was carried out in the same manner as in Comparative Example 1, and the conversion of 5-hydroxymethylfurfural was 42%, the yield of the hemiacetal was 5.2%, and the selectivity of the hemiacetal was 12.4%.

[0117] Comparative Example 3

[0118] A catalyst Ni / MoO2-H2 was prepared in the same manner as in Comparative Example 1, using MoO2 as the carrier, Ni as the active ingredient, and hydrogen as the reducing agent.

[0119] The catalytic activity test was carried out in the same manner as in Comparative Example 1, and the conversion of 5-hydroxymethylfurfural was 24.2%, the yield of the hemiacetal was 4.5%, and the selectivity of the hemiacetal was 18.6%.

[0120] Comparative Example 4

[0121] A catalyst Cu / SiO2-H2 was prepared in the same manner as in Comparative Example 1, using SiO2 as the carrier, Cu as the active ingredient, and hydrogen as the reducing agent.

[0122] The catalytic activity test was carried out in the same manner as in Comparative Example 1, and the conversion of 5-hydroxymethylfurfural was 16.9%, the yield of the hemiacetal was 0.8%, and the selectivity of the hemiacetal was 4.7%.

[0123] Comparative Example 5

[0124] A catalyst Cu / CeO2-H2 was prepared in the same manner as in Comparative Example 1, using CeO2 as the carrier, Cu as the active ingredient, and hydrogen as the reducing agent.

[0125] The catalytic activity test was carried out in the same manner as in Comparative Example 1, and the conversion of 5-hydroxymethylfurfural was 10.4%, the yield of the hemiacetal was 1.2%, and the selectivity of the hemiacetal was 11.5%.

[0126] Comparative Example 6

[0127] The same preparation procedure as Comparative Example 1 was adopted, with Al2O3 as the carrier, Cu as the active component, and hydrogen as the reducing agent, to prepare a catalyst with Cu supported on Al2O3, Cu / Al2O3-H2.

[0128] The catalytic activity test method of Comparative Example 1 was adopted, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 25.8%, the yield of hemiacetal was 5%, and the selectivity of hemiacetal was 19.4%.

[0129] Comparative Example 7

[0130] The same preparation procedure as Comparative Example 1 was adopted, with In2O3 as the carrier, Cu as the active component, and hydrogen as the reducing agent, to prepare a catalyst with Cu supported on In2O3, Cu / In2O3-H2.

[0131] The catalytic activity test method of Comparative Example 1 was adopted, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 5.6%, the yield of hemiacetal was 0.4%, and the selectivity of hemiacetal was 7.1%.

[0132] The performance evaluation results of the catalysts prepared in Comparative Examples 1-7 are shown in Table 2 below.

[0133] Table 2 Performance test results of the catalysts of Comparative Examples 1-7 in the HMF hemiacetal reaction

[0134] Comparative Example Catalyst HMF conversion (%) Hemi-acetal yield (%) HMF conversion (%) Hemi-acetal yield (%) 1 [Cu / MoO2-H2] 50 9 2 Co / MoO2-H2 42 5.2 3 [Ni / MoO2-H2] 24.2 4.5 4 [Cu / SiO2-H2] 16.9 0.8 5 [Cu / CeO2-H2] 10.3 1.2 6 [Cu / Al203-H2] 25.8 5 7 [Cu / In2O3-H2] 5.6 0.4

[0135] It can be found from the performance test results of the catalysts of Comparative Examples 1-7 and the comparative example that when no noble metal component is added, the catalytic performance of the catalyst for the 5-hydroxymethylfurfural hemiacetal reaction is poor, the conversion rate of 5-hydroxymethylfurfural is low, and the yield and selectivity of hemiacetal are lower. After adding the second component noble metal, the performance of the catalyst is obviously improved.

[0136] Comparative Example 8

[0137] (1) Preparation of the catalyst, the specific steps are as follows:

[0138] A certain amount of Pt precursor solution and molybdenum dioxide powder were mixed and stirred uniformly; after drying the surface moisture at 80°C, it was left standing at room temperature for 12h; then it was ground into powder and calcined at 800°C for 5h; it was reduced at 700°C under normal pressure hydrogen atmosphere for 5h, to obtain a catalyst with Pt supported on MoO2, Pt / MoO2-H2.

[0139] (2) Catalytic activity test, the specific operation process was the same as that of Example 1, and the conversion rate of 5-hydroxymethylfurfural in the reaction was measured to be 18%, the yield of hemiacetal was 4.7%, and the selectivity of hemiacetal was 26%.

[0140] Comparative Example 9

[0141] A catalyst Pd / MoO2-H2 was prepared by the same preparation procedure as Comparative Example 8, using MoO2 as the support, Pd as the active ingredient, and hydrogen as the reducing agent.

[0142] The catalytic activity test method of Comparative Example 8 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 20%, the yield of the hemiacetal as 3.7%, and the selectivity of the hemiacetal as 18.6%.

[0143] Comparative Example 10

[0144] A catalyst Ru / MoO2-H2 was prepared by the same preparation procedure as Comparative Example 8, using MoO2 as the support, Ru as the active ingredient, and hydrogen as the reducing agent.

[0145] The catalytic activity test method of Comparative Example 8 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 13.6%, the yield of the hemiacetal as 3%, and the selectivity of the hemiacetal as 22.4%.

[0146] Comparative Example 11

[0147] A catalyst Au / MoO2-H2 was prepared by the same preparation procedure as Comparative Example 8, using MoO2 as the support, Au as the active ingredient, and hydrogen as the reducing agent.

[0148] The catalytic activity test method of Comparative Example 8 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 12.1%, the yield of the hemiacetal as 1.7%, and the selectivity of the hemiacetal as 14.1%.

[0149] Comparative Example 12

[0150] A catalyst Ir / MoO2-H2 was prepared by the same preparation procedure as Comparative Example 8, using MoO2 as the support, Ir as the active ingredient, and hydrogen as the reducing agent.

[0151] The catalytic activity test method of Comparative Example 8 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 5.5%, the yield of the hemiacetal as 1%, and the selectivity of the hemiacetal as 18.3%.

[0152] Comparative Example 13

[0153] A catalyst Pt / Al2O3-H2 was prepared by the same preparation procedure as Comparative Example 8, using Al2O3 as the support, Pt as the active ingredient, and hydrogen as the reducing agent.

[0154] The catalytic activity test method of Comparative Example 8 was used to measure the conversion rate of 5-hydroxymethylfurfural of the reaction as 15%, the yield of the hemiacetal as 3.5%, and the selectivity of the hemiacetal as 23.6%.

[0155] Comparative Example 14

[0156] The same preparation procedure as Comparative Example 8 was used to prepare a catalyst with Pt supported on In2O3, using In2O3 as the support, Pt as the active component, and hydrogen as the reducing agent (Pt / In2O3-H2).

[0157] The catalytic activity test method of Comparative Example 8 was used to measure the conversion of 5-hydroxymethylfurfural, the yield of the hemiacetal, and the selectivity of the hemiacetal, which were 11.8%, 1.7%, and 14.2%, respectively.

[0158] Comparative Example 15

[0159] The same preparation procedure as Comparative Example 8 was used to prepare a catalyst with Pt supported on SiO2, using SiO2 as the support, Pt as the active component, and hydrogen as the reducing agent (Pt / SiO2-H2).

[0160] The catalytic activity test method of Comparative Example 8 was used to measure the conversion of 5-hydroxymethylfurfural, the yield of the hemiacetal, and the selectivity of the hemiacetal, which were 4%, 0.6%, and 15%, respectively.

[0161] Comparative Example 16

[0162] The same preparation procedure as Comparative Example 8 was used to prepare a catalyst with Pt supported on CeO2, using CeO2 as the support, Pt as the active component, and hydrogen as the reducing agent (Pt / CeO2-H2).

[0163] The catalytic activity test method of Comparative Example 8 was used to measure the conversion of 5-hydroxymethylfurfural, the yield of the hemiacetal, and the selectivity of the hemiacetal, which were 9.6%, 1.7%, and 17.7%, respectively.

[0164] The performance evaluation results of the catalysts prepared in Comparative Examples 9-16 are shown in Table 3 below.

[0165] Table 3 Performance test results of the catalysts of Comparative Examples 8-16 in the HMF hemiacetal reaction

[0166]

[0167]

[0168] The performance test results of the catalysts of Comparative Examples 8-16 show that when no non-noble metal component is added, the catalyst has poor catalytic performance in the 5-hydroxymethylfurfural hemiacetal reaction, the conversion of 5-hydroxymethylfurfural is low, and the yield and selectivity of the hemiacetal are even lower. After adding the second component of the non-noble metal, the performance of the catalyst is significantly improved.

[0169] Although the present disclosure has been disclosed with reference to the above embodiments, the scope of protection of the present disclosure is not limited to the above. Those skilled in the art, without departing from the spirit and scope of the present disclosure, can make various changes and modifications, and these changes and modifications will fall within the scope of protection of the present disclosure.

Claims

1. A method for preparing a bimetallic supported catalyst, characterized in that, The method comprises the following steps: S11, mixing a carrier Y with a precursor salt of an active metal M1, loading the active metal M1 on the carrier Y by impregnation, standing at room temperature, drying to obtain a solid A, wherein the carrier Y is a metal oxide, the active metal M1 is a non-noble metal, the carrier Y is selected from at least one of MoO2, Al2O3, In2O3, SiO2, and CeO2, the active metal M1 is selected from at least one of Co, Ni, Cu, Mn, Fe, and Zn, and the active metal M2 is selected from at least one of Ru, Pt, Pd, Au, Ag, Ir, Rh, and Os; S12, calcining the solid A in an air atmosphere to obtain a solid B; S13, mixing the solid B with deionized water, heating and stirring for 1-2 hours, adding a sodium hydroxide aqueous solution to adjust the pH to 8-9, and adding a precursor salt of the active metal M2 and stirring for 2-5 hours; adding a hydrogen donor reducing agent and continuing to stir for 4-6 hours; filtering to obtain a product, washing, and drying to obtain a bimetallic supported catalyst, wherein the bimetallic supported catalyst is used for preparing a hemiacetal from a furfural and an alcohol.

2. The method for preparing a bimetallic supported catalyst according to claim 1, characterized in that, The hydrogen donor reducing agent is selected from at least one of formic acid, hydrazine hydrate, ammonia borane, ammonium formate, and sodium formate.

3. The method of claim 1, wherein the bimetallic supported catalyst is prepared by the steps of: The mass percentage of the active metal M1 in the bimetallic supported catalyst is 1% to 4%, and the mass percentage of the active metal M2 is 0.01% to 0.1%.

4. A method of preparing a hemiacetal from a furfural and an alcohol, characterized in that, The method comprises the following steps: S21, adding a bimetallic supported catalyst prepared by the preparation method of any one of claims 1-3, a furfural, and an alcohol organic solvent into a reaction device to form a mixed solution; S22, introducing hydrogen into the reaction device to perform a condensation reaction to obtain a hemiacetal compound.

5. The method of preparing a hemiacetal from a furfural and an alcohol according to claim 4, wherein, In the step S22, the reaction temperature is 80°C to 140°C, the pressure is 0.5 MPa to 4 MPa, and the time is 0.5 hours to 8 hours.

6. The method of preparing a hemiacetal from a furfural and an alcohol according to claim 4, wherein, In the step S21, the molar ratio of the furfural to the bimetallic supported catalyst is 3500 to 40000:

1.

7. The method of preparing a hemiacetal from a furfural and an alcohol according to claim 6, wherein, In the step S21, the molar concentration of the furfural in the mixed solution is 0.1 M to 1 M.

8. The process for the preparation of a hemiacetal from a furfuraldehyde and an alcohol according to any one of claims 4 to 7, characterized in that, The furfural is selected from at least one of furfural, 5-methylfurfural, 5-hydroxymethylfurfural, 2,5-diformylfuran, 2-furyl ethanol, 5-chloromethylfuran, 4-hydroxymethylfurfural, and 2,5-furandicarboxaldehyde, and the alcohol organic solvent is selected from at least one of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, isobutyl alcohol, n-pentanol, isopentyl alcohol, n-hexanol, and isohexyl alcohol.

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