Method for preparing 2, 5-tetrahydrofuran dimethyl carbinol

Abstract

The invention discloses a method for preparing 2, 5-tetrahydrofuran dimethyl carbinol. The method comprises the following steps: reacting 5-hydroxymethylfurfural in the presence of a catalyst by taking hydrogen as a hydrogen source to obtain 2, 5-tetrahydrofurandimethanol; the catalyst is a Ni-Silicalite-1 molecular sieve, and the total acid amount of the Ni-Silicalite-1 molecular sieve is 10 to 150 [mu] mol * g <-1 >. The method provided by the invention has the characteristics of efficient conversion of 5-hydroxymethylfurfural under mild reaction conditions, high selectivity of the product 2, 5-tetrahydrofuran dimethyl carbinol, prominent recycling stability of the catalyst and the like.

Description

Technical Field

[0001] The present invention relates to the field of catalytic chemistry, and in particular to a method for preparing 2,5-tetrahydrofuran dimethanol. Background Art

[0002] Biomass resources have huge potential for development. Rationally and efficiently converting biomass into high-value-added fine chemicals and fuels to alleviate the energy crisis and achieve the phased development of replacing fossil resources with new energy is the goal of scientists around the world today and is of great significance to the development of mankind. 5-Hydroxymethylfurfural (HMF) is a biomass-based platform compound. After quality improvement and upgrading, it can be used to prepare a variety of high-value-added chemicals and fuels. Among them, the hydrogenation product of HMF, 2,5-tetrahydrofuran dimethanol (THFDM), has both a tetrahydrofuran ring structure and a symmetrical diol functional group. It can be widely used in adhesives, coatings, resins, polyesters and other fields. It is expected to show unique advantages in barrier properties, dyeability, and degradability. Therefore, it has become a hot research topic in academia and industry.

[0003] 2,5-Tetrahydrofuran dimethanol (THFDM) is mainly prepared by hydrogenation of 5-hydroxymethyl furfural (HMF). When hydrogen is used as the hydrogen source, commonly used catalysts include supported precious metals such as ruthenium (Ru), platinum (Pt) and palladium (Pd), as well as transition metals such as nickel (Ni), copper (Cu), etc. CN 103228626B reported that 5% Ru / C was used as a catalyst and methanol was used as a reaction solvent. After reacting at 5MPa hydrogen and 75°C for 1.5 hours, and then at 9MPa hydrogen and 200°C for 14 hours, the THFDM yield was only 30%. The low reusability and high cost of precious metals seriously hinder their commercial application. Therefore, the use of non-precious metals has gradually attracted the attention of researchers. For example, the research group of Klaus Hellgardt (RSC Adv., 2017, 7, 31401) used Raney Cu and Ni double-layer catalysts to implement a two-stage hydrogenation method. Under the reaction conditions of a flow rate of 0.05 mL / min, 9 MPa hydrogen and 90 ° C, the initial selectivity of THFDM can reach up to 98%, but the Raney Ni catalyst used in the second stage gradually deactivated. In the presence of non-precious metal catalysts, the reaction pressure is usually high and the loss of active components is serious.

[0004] In summary, the existing technologies mainly have problems such as low THFDM selectivity, harsh reaction conditions or poor catalyst cycle stability, which bring great problems to practical industrial applications. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the 2,5-tetrahydrofuran dimethanol has low selectivity, harsh reaction conditions or poor catalyst cycle stability in the prior art, and provides a method for preparing 2,5-tetrahydrofuran dimethanol by catalytic conversion of 5-hydroxymethylfurfural. The method has the characteristics of efficient conversion of 5-hydroxymethylfurfural under mild reaction conditions and high selectivity of the product 2,5-tetrahydrofuran dimethanol, as well as outstanding stability of the catalyst cycle.

[0006] The first aspect of the present invention provides a method for preparing 2,5-tetrahydrofuran dimethanol, comprising: reacting 5-hydroxymethyl furfural with hydrogen as a hydrogen source in the presence of a catalyst to obtain 2,5-tetrahydrofuran dimethanol; the catalyst is Ni-Silicalite-1 molecular sieve, and the total acid content of the Ni-Silicalite-1 molecular sieve is 10 to 150 μmol·g -1 .

[0007] According to the present invention, preferably, 5-hydroxymethylfurfural is dissolved in an organic solvent. Further preferably, the organic solvent comprises one or more of methanol, ethanol, n-butanol, tetrahydrofuran, 1,4-dioxane, and methyl isobutyl ketone, preferably at least one of n-butanol and tetrahydrofuran.

[0008] According to the present invention, the mass ratio of 5-hydroxymethylfurfural to catalyst is 0.2-10:1, preferably 0.5-5.0:1.

[0009] According to the present invention, the mass ratio of the organic solvent to 5-hydroxymethylfurfural is 20 to 300:1, preferably 30 to 200:1.

[0010] According to the present invention, hydrogen is charged into the reaction system to adjust the reaction pressure, which is 0.2 to 5 MPa, preferably 0.5 to 3 MPa.

[0011] According to the present invention, the reaction conditions are as follows: the reaction temperature is 115 to 220° C., preferably 120 to 200° C.; and / or the reaction time is 1 to 24 hours, preferably 2 to 8 hours.

[0012] According to the present invention, the Ni in the Ni-Silicalite-1 molecular sieve represents the active component nickel, and does not represent the form of the active component nickel in the catalyst. The active component nickel includes metallic nickel and nickel oxide, wherein the molar ratio of metallic nickel to nickel oxide is represented by Ni / NiO.

[0013] According to the present invention, the molar ratio of Ni / NiO in the Ni-Silicalite-1 molecular sieve is 1.3-2.0:1, preferably 1.5-1.8:1.

[0014] According to the present invention, in the catalyst, based on the mass of Silicalite-1 calculated as SiO2, the content of active component nickel calculated as Ni is 1wt% to 20wt%; preferably, in the catalyst, based on the mass of Silicalite-1 calculated as SiO2, the content of active component nickel calculated as Ni is 3wt% to 10wt%.

[0015] According to the present invention, preferably, the total acid content of the Ni-Silicalite-1 molecular sieve is 20 to 120 μmol·g -1 , more preferably 75 to 100 μmol·g -1 .

[0016] According to the present invention, the reduction degree of nickel in the Ni-Silicalite-1 molecular sieve is 50-80%, preferably 60-75%.

[0017] According to the present invention, the specific surface area of ​​the Ni-Silicalite-1 molecular sieve is 120 to 500 m 2 / g, preferably 150 to 400 m 2 / g; external specific surface area is 30~80m 2 / g, preferably 40 to 70 m 2 / g; total pore volume is 0.04~0.30cm 3 / g, preferably 0.05 to 0.25 cm 3 / g.

[0018] According to the present invention, the catalyst is prepared by an in-situ synthesis crystallization method.

[0019] According to the present invention, the preparation method of the catalyst comprises the following steps: after mixing the template, additives, water and silicon source, adding a nickel precursor dropwise, and then aging, crystallizing, calcining and reducing to obtain the catalyst; preferably, the nickel precursor comprises a complexing agent and a nickel source.

[0020] According to the present invention, the crystallization equipment is preferably a crystallization kettle.

[0021] According to the present invention, in the preparation method of the catalyst, the molar ratio of the template, additive, water and silicon source in terms of SiO2 is 0.05-0.5:0.05-0.90:5-50:1, preferably 0.1-0.4:0.05-0.80:10-40:1, further preferably 0.1-0.4:0.10-0.60:10-40:1, and even more preferably 0.1-0.4:0.10-0.15:10-40:1.

[0022] According to the present invention, in the method for preparing the catalyst, the mass ratio of nickel in the nickel precursor, calculated as Ni, to the silicon source, calculated as SiO2, is 0.02-0.20:1, preferably 0.03-0.15:1, and further preferably 0.09-0.15:1.

[0023] According to the present invention, in the method for preparing the catalyst, the molar ratio of nickel in the nickel precursor (calculated as Ni) to the complexing agent is 0.1 to 3.0:1, preferably 0.2 to 2.0:1.

[0024] According to the present invention, in the preparation method, the template, additives and water are first mixed and then mixed with the silicon source.

[0025] According to the present invention, in the method for preparing the catalyst, the template agent includes one or more of tetrapropylammonium hydroxide, tetrapropylchloride hydroxide and tetrapropylbromide hydroxide, preferably tetrapropylammonium hydroxide.

[0026] According to the present invention, in the method for preparing the catalyst, the additive comprises one or more of urea, cyanamide, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol and glycerol, preferably urea.

[0027] According to the present invention, in the method for preparing the catalyst, one or more of white carbon black, sodium silicate, silica sol and tetraethyl orthosilicate is preferably tetraethyl orthosilicate.

[0028] According to the present invention, in the method for preparing the catalyst, the nickel source includes one or more of nickel nitrate, nickel acetate, nickel chloride, nickel acetylacetonate, and nickel sulfate, preferably nickel nitrate.

[0029] According to the present invention, in the preparation method of the catalyst, the complexing agent includes one or more of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate, and ethylenediamine, preferably ethylenediamine.

[0030] According to the present invention, preferably, the nickel precursor exists in the form of a nickel precursor solution, that is, a nickel source and a complexing agent are dissolved in water to form a nickel-cobalt precursor solution.

[0031] According to the present invention, the aging temperature is 30 to 160° C., preferably 30 to 100° C.; the aging time is 2 to 48 hours, preferably 6 to 24 hours.

[0032] According to the present invention, the crystallization temperature is 140-210° C., preferably 160-180° C.; the crystallization time is 2-9 days, preferably 3-7 days.

[0033] According to the present invention, the calcination temperature is 300-650° C.; the calcination time is 1-12 hours; and the calcination atmosphere is oxygen-containing gas.

[0034] According to the present invention, the reduction temperature is 450-1000°C, preferably 550-900°C, and further preferably 650-900°C; the reduction time is 2-10 hours, preferably 3-6 hours; the reduction atmosphere is hydrogen or a hydrogen-argon mixture, wherein the volume fraction of hydrogen in the hydrogen-argon mixture is not less than 10%, preferably 10%-50%.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) In the present invention, 5-hydroxymethylfurfural is subjected to hydrogenolysis reaction in a solvent in the presence of a catalyst Ni-Silicalite-1 molecular sieve to obtain 2,5-tetrahydrofuran dimethanol, which has the characteristics of efficient conversion of 5-hydroxymethylfurfural under mild reaction conditions and high selectivity of the product 2,5-tetrahydrofuran dimethanol, as well as outstanding stability in catalyst recycling.

[0037] (2) In the present invention, the catalyst is Ni-Silicalite-1 molecular sieve. By controlling the total acid content of the molecular sieve, preferably controlling the molar ratio of Ni / NiO in the active component nickel, 5-hydroxymethylfurfural can be efficiently converted into 2,5-tetrahydrofuran dimethanol under mild reaction conditions, and the substrate conversion rate and product selectivity are significantly improved. In addition, the prepared catalyst has good stability, and no significant change in catalyst performance is observed after four cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is the XRD pattern of the Ni-Silicalite-1 catalyst obtained in Example 1;

[0039] Figure 2 NH3-TPD diagram of the Ni-Silicalite-1 catalyst obtained in Example 1;

[0040] Figure 3 This is the XPS graph of the Ni-Silicalite-1 catalyst obtained in Example 1;

[0041] Figure 4 is the H2-TPR diagram of the Ni-Silicalite-1 catalyst obtained in Example 1;

[0042] Figure 5 The HMF conversion rate and THFDM selectivity under the recycling conditions of the Ni-Silicalite-1 catalyst obtained in Example 1. DETAILED DESCRIPTION

[0043] In the present invention, the reaction product 2,5-tetrahydrofuran dimethanol (THFDM) is qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the conversion rate of substrate 5-hydroxymethylfurfural (HMF) and the yield of reaction product THFDM are analyzed by gas chromatography (GC). The gas chromatography-mass spectrometer is Agilent 7890A of Agilent Corporation of the United States, the chromatographic column is HP-5 non-polar capillary column (30m, 0.53mm), the gas chromatograph is Agilent 7890B, the detector is hydrogen flame ionization detector (FID), and the chromatographic column is SE-54 capillary column (30m, 0.53mm).

[0044] In the present invention, the XRD measurement method of the molecular sieve product is: using Japanese Rigaku Ultima IV X-ray powder diffractometer to analyze the physical phase of the sample, CuKα ray source Nickel filter, 2θ scanning range 2°-50°, operating voltage 35 kV, current 25 mA, scanning rate 10° / min.

[0045] In the present invention, the inductively coupled plasma atomic emission spectrometer (ICP) model is Varian 725-ES, and the analysis sample is dissolved with hydrofluoric acid to detect the content of the metal element.

[0046] In the present invention, the NH3 temperature-programmed desorption (NH3-TPD) experiment is carried out on a TPD / TPR Altamira AMI-3300 instrument, and the total acid content is calculated by fitting and peak separation of the obtained spectrum.

[0047] In the present invention, the H2-TPR experiment was carried out on a TPD / TPR Altamira AMI-3300 instrument, and the hydrogen consumption was calculated. The nickel reduction degree calculation formula is:

[0048] Reduction degree of nickel metal % = (hydrogen consumption μmol·g -1 )×58.69×10 -6 / (wt% nickel content in molecular sieve)×100%.

[0049] In the present invention, the physical adsorption instrument model is Micromeretic ASAP2020M, and the test conditions are: the measurement temperature is -169°C, the molecular sieve is vacuum pretreated at 300°C for 10 hours before the measurement, and the pore volume, specific surface area and other parameters are calculated by using the BET method and t-plot method.

[0050] In the present invention, the determination of the element binding energy on the catalyst surface is carried out on an X-ray photoelectron spectrometer (ESCA LAB-250) produced by Thermo Company, using C1s=284.6eV as an internal standard to calibrate the measured element signal.

[0051] In the present invention, the 5-hydroxymethylfurfural conversion formula is:

[0052] HMF conversion rate % = (molar amount of HMF participating in the reaction) / (molar amount of HMF as the reaction substrate) × 100%.

[0053] In the present invention, the product THFDM selectivity calculation formula is:

[0054] The selectivity of the product THFDM (%) = (the molar amount of THFDM produced by the reaction) / (the molar amount of HMF reacted) × 100%.

[0055] In order to facilitate the understanding of the present invention, the present invention lists the following embodiments, but the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] Example 1

[0057] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.3:0.20:20:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.10:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.5.

[0058] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 1.44g of urea and 43.2g of deionized water, mix them evenly, slowly drop 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 2.24g of nickel nitrate and dissolve it in 10g of deionized water, add 1.47g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 90°C for 12 hours. The gel mixture obtained above is crystallized at 170°C for 4 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 900°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0059] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 246 m 2 / g, external specific surface area is 53m 2 / g, and the total pore volume is 0.16cm 3 / g. Using inductively coupled plasma atomic emission spectroscopy (ICP) testing, the relative content of Ni is 8wt% relative to Silicalite-1 (in terms of SiO2), and the catalyst is named 8Ni-Silicalite-1-A; the XRD of the sample is as follows Figure 1 As shown; the NH3-TPD of the sample is as follows Figure 2 As shown, the total acid content calculated is 92 μmol·g -1 The XPS of the sample is as follows Figure 3 As shown, the binding energy at 852.9 eV corresponds to the metal element Ni (2p 3 / 2 The peak with a binding energy of 855.4 eV corresponds to divalent nickel (2 + ), the molar ratio of metallic Ni to oxidized NiO was calculated by the ratio of the two peak areas (Ni / NiO ratio) to be 1.6. Figure 4 As shown, the hydrogen consumption is 1160 μmol·g -1 , from which the nickel reduction degree was calculated to be 68%.

[0060] Example 2

[0061] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.2:0.20:20:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.10:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.8.

[0062] The specific synthesis steps are as follows: weigh 19.5g of 25% tetrapropylammonium hydroxide aqueous solution, 1.44g of urea and 43.2g of deionized water, mix them evenly, slowly drop 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 2.24g of nickel nitrate and dissolve it in 10g of deionized water, add 0.92g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 100°C for 12 hours. The gel mixture obtained above is crystallized at 180°C for 6 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 850°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0063] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 273 m 2 / g, external specific surface area is 59m 2 / g, with a total pore volume of 0.18 cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 8wt% relative to Silicalite-1 (in terms of SiO2). The catalyst was named 8Ni-Silicalite-1-B. The XRD and Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 82 μmol·g -1 The XPS of the sample is as follows Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.7, and H2-TPR is Figure 4 Similarly, the hydrogen consumption is 1072 μmol·g -1 , the reduction degree was calculated to be 63%.

[0064] Example 3

[0065] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.3:0.40:15:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.15:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.4.

[0066] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 2.88g of urea and 32.4g of deionized water, mix them evenly, slowly drop 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 3.36g of nickel nitrate and dissolve it in 10g of deionized water, add 2.76g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 100°C for 10 hours. The gel mixture obtained above is crystallized at 180°C for 5 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 900°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0067] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 271 m 2 / g, external specific surface area is 63m 2 / g, and the total pore volume is 0.16cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 12wt% relative to Silicalite-1 (in terms of SiO2). The catalyst was named 12Ni-Silicalite-1-A. The XRD and Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 83 μmol·g -1 The XPS of the sample is as follows Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.8, and H2-TPR is Figure 4 Similarly, the hydrogen consumption is 1120 μmol·g -1 , from which the nickel reduction degree was calculated to be 66%.

[0068] Example 4

[0069] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.3:0.60:15:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.09:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.5.

[0070] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 4.32g of urea and 32.4g of deionized water, mix them evenly, slowly drop 25g of ethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 2.02g of nickel nitrate and dissolve it in 10g of deionized water, add 1.32g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A and age it at 100°C for 24 hours. The gel mixture obtained above is crystallized at 180°C for 6 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 850°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0071] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 307 m 2 / g, external specific surface area is 61m 2 / g, and the total pore volume is 0.16cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 7wt% relative to Silicalite-1 (in terms of SiO2), and the catalyst was named 7Ni-Silicalite-1; XRD and Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 79 μmol·g -1 The XPS of the sample is as follows Figure 3Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.7, and H2-TPR is Figure 4 Similarly, the hydrogen consumption is 1069 μmol·g -1 , from which the nickel reduction degree was calculated to be 64%.

[0072] Embodiment 5-8

[0073] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 100, the mass ratio of HMF to catalyst was 1, the hydrogen pressure was 1.5 MPa, the reaction temperature was 130°C, and the reaction time was 5 h. 0.2 g of the catalyst in the above-mentioned Examples 1-4, 0.2 g of HMF and 20 g of tetrahydrofuran were added to a stirred autoclave, and 1.5 MPa of hydrogen was filled. The heating jacket was heated to a preset temperature using a programmed temperature increase, and then stirred using a magnetic stirrer. The reaction was carried out at 130°C for 5 h, and the HMF conversion rate and the product THFDM selectivity were calculated by gas phase analysis of the reaction liquid, as shown in Table 1.

[0074] Table 1 Catalytic evaluation results of catalysts of Examples 1-4

[0075]

[0076] Example 9

[0077] Tetrahydrofuran is used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF is 120, the mass ratio of HMF to catalyst is 0.8, the hydrogen pressure is 1.2MPa, the reaction temperature is 130°C, and the reaction time is 4h. 0.2g of the catalyst in the above-mentioned Example 1, 0.16g of HMF and 19.2g of tetrahydrofuran are added to a stirred autoclave, and 1.2MPa of hydrogen is filled. The programmed temperature heating jacket is raised to the preset temperature, and magnetic stirring is used and then stirred. The reaction is carried out at 130°C for 4h, and the HMF conversion is completely calculated by gas phase analysis of the reaction liquid (conversion rate>99%), and the product THFDM selectivity is 89.9%.

[0078] Example 10

[0079] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 150, the mass ratio of HMF to catalyst was 1.0, the hydrogen pressure was 2.5 MPa, the reaction temperature was 120°C, and the reaction time was 8 h. 0.2 g of the catalyst in Example 1, 0.2 g of HMF and 30.0 g of tetrahydrofuran were added to a stirred autoclave, and 2.5 MPa of hydrogen was added. The temperature was raised to a preset temperature using a programmed heating jacket, and then stirred using magnetic stirring. The reaction was carried out at 120°C for 8 h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 88.6%.

[0080] Embodiment 11

[0081] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 80, the mass ratio of HMF to catalyst was 1.3, the hydrogen pressure was 1.2 MPa, the reaction temperature was 160°C, and the reaction time was 3 h. 0.2 g of the catalyst in Example 1, 0.26 g of HMF and 20.8 g of tetrahydrofuran were added to a stirred autoclave, and 1.2 MPa of hydrogen was filled. The temperature was raised to a preset temperature using a programmed heating jacket, and then stirred using magnetic stirring. The reaction was carried out at 160°C for 3 h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 90.1%.

[0082] Example 12

[0083] Tetrahydrofuran is used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF is 110, the mass ratio of HMF to catalyst is 2.0, the hydrogen pressure is 2.0MPa, the reaction temperature is 150°C, and the reaction time is 4h. 0.2g of the catalyst in Example 2 above, 0.40g of HMF and 44.0g of tetrahydrofuran are added to a stirred autoclave, and 2.0MPa of hydrogen is filled. The programmed temperature heating jacket is raised to a preset temperature, and magnetic stirring is used and then stirred. The reaction is carried out at 150°C for 4h, and the HMF conversion is completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity is 90.5%.

[0084] Embodiment 13

[0085] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 100, the mass ratio of HMF to catalyst was 1.0, the hydrogen pressure was 1.4 MPa, the reaction temperature was 140°C, and the reaction time was 4 h. 0.2 g of the catalyst in Example 2, 0.20 g of HMF and 20.0 g of tetrahydrofuran were added to a stirred autoclave, and 1.4 MPa of hydrogen was added. The programmed temperature heating jacket was raised to a preset temperature, and magnetic stirring was used and then stirred. The reaction was carried out at 140°C for 5 h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 89.8%.

[0086] Embodiment 14

[0087] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 80, the mass ratio of HMF to catalyst was 1.5, the hydrogen pressure was 1.7 MPa, the reaction temperature was 130°C, and the reaction time was 5 h. 0.2 g of the catalyst in Example 3, 0.30 g of HMF and 24.0 g of tetrahydrofuran were added to a stirred autoclave, and 1.7 MPa of hydrogen was added. The temperature was raised to a preset temperature using a programmed heating jacket, and then stirred using magnetic stirring. The reaction was carried out at 130°C for 5 h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 89.7%.

[0088] Embodiment 15

[0089] n-Butanol was used as the reaction solvent, the mass ratio of n-butanol to HMF was 120, the mass ratio of HMF to catalyst was 0.6, the hydrogen pressure was 1.5MPa, the reaction temperature was 140°C, and the reaction time was 5h. 0.2g of the catalyst in Example 3, 0.12g of HMF and 14.4g of n-butanol were added to a stirred autoclave, and 1.5MPa of hydrogen was added. The programmed temperature heating jacket was raised to a preset temperature, and magnetic stirring was used and then stirred. The reaction was carried out at 140°C for 5h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 90.3%.

[0090] Example 16

[0091] n-Butanol was used as the reaction solvent, the mass ratio of n-butanol to HMF was 150, the mass ratio of HMF to catalyst was 2.0, the hydrogen pressure was 2.5 MPa, the reaction temperature was 150°C, and the reaction time was 4 h. 0.2 g of the catalyst in Example 3, 0.40 g of HMF and 60.0 g of n-butanol were added to a stirred autoclave, and 2.5 MPa of hydrogen was added. The temperature was raised to a preset temperature using a programmed heating jacket, and then stirred using magnetic stirring. The reaction was carried out at 150°C for 4 h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 88.5%.

[0092] In order to more intuitively describe the reaction conditions and results of the above Examples 9-16, various parameters and results are listed in Table 2.

[0093] Table 2 Catalytic performance results of Examples 9-16

[0094]

[0095] Embodiment 17

[0096] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 120, the mass ratio of HMF to catalyst was 0.8, the hydrogen pressure was 1.2 MPa, the reaction temperature was 130°C, and the reaction time was 4 h. 0.2 g of the catalyst in Example 1 above, 0.16 g of HMF and 19.2 g of tetrahydrofuran were added to a stirred high-pressure reactor, and 1.2 MPa of hydrogen was filled in. The temperature was raised to the preset temperature using a programmed heating jacket, and then stirred using a magnetic stirrer. The reaction was carried out at 130°C for 4 hours, and the HMF conversion rate and product THFDM selectivity were calculated by gas phase analysis of the reaction liquid. The used catalyst was washed and dried and then put into the next reaction. A total of 4 reactions were repeated, and the results are as follows Figure 5 The results show that after 4 reactions, the HMF conversion rate is complete and the THFDM selectivity is maintained at 87.6%, indicating that the catalyst of the present invention has good cycle stability.

[0097] Embodiment 18

[0098] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.2:0.20:20:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.20:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 2.5.

[0099] The specific synthesis steps are as follows: weigh 19.5g of 25% tetrapropylammonium hydroxide aqueous solution, 1.44g of urea and 43.2g of deionized water, mix them evenly, slowly drop 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 4.48g of nickel nitrate and dissolve it in 10g of deionized water, add 0.59g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 100°C for 12 hours. The gel mixture obtained above is crystallized at 180°C for 6 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 850°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0100] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 252 m 2 / g, external specific surface area is 38m 2 / g, with a total pore volume of 0.20 cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 17wt% relative to Silicalite-1 (in terms of SiO2). The catalyst was named 17Ni-Silicalite-1. The XRD and Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 122 μmol·g -1 The XPS of the sample is as follows Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.4. Figure 4 Similarly, the hydrogen consumption is 938 μmol·g -1 , from which the nickel reduction degree was calculated to be 55%.

[0101] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 100, the mass ratio of HMF to catalyst was 1, the hydrogen pressure was 1.5MPa, the reaction temperature was 130°C, and the reaction time was 5h. 0.2g of the above catalyst, 0.2g of HMF and 20g of tetrahydrofuran were added to a stirred high-pressure reactor, and 1.5MPa of hydrogen was filled. The programmed temperature heating jacket was raised to the preset temperature, and magnetic stirring was used and then stirred. The reaction was carried out at 130°C for 5h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 87.4%. The used catalyst was washed and dried and then put into the next reaction, and the reaction was repeated 4 times. The results showed that the HMF conversion rate was complete after 4 reactions, and the THFDM selectivity remained at 85.3%.

[0102] Embodiment 19

[0103] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.3:0.40:15:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.15:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.15.

[0104] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 2.88g of urea and 32.4g of deionized water, mix them evenly, slowly drop 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 3.36g of nickel nitrate and dissolve it in 10g of deionized water, add 7.36g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 130°C for 10 hours. The gel mixture obtained above is crystallized at 180°C for 5 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 600°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0105] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 271 m 2 / g, external specific surface area is 63m 2 / g, with a total pore volume of 0.15 cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 12wt% relative to Silicalite-1 (in terms of SiO2). The catalyst was named 12Ni-Silicalite-1-B. The XRD and Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 147 μmol·g -1 The XPS of the sample is as follows Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.3. Figure 4 Similarly, the hydrogen consumption is 892 μmol·g -1 , from which the nickel reduction degree was calculated to be 52%.

[0106] Tetrahydrofuran was used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF was 100, the mass ratio of HMF to catalyst was 1, the hydrogen pressure was 1.5MPa, the reaction temperature was 130°C, and the reaction time was 5h. 0.2g of the above catalyst, 0.2g of HMF and 20g of tetrahydrofuran were added to a stirred high-pressure reactor, and 1.5MPa of hydrogen was filled. The programmed temperature heating jacket was raised to the preset temperature, and magnetic stirring was used and then stirred. The reaction was carried out at 130°C for 5h, and the HMF conversion was completely calculated by gas phase analysis of the reaction liquid, and the product THFDM selectivity was 86.7%. The used catalyst was washed and dried and then put into the next reaction, and the reaction was repeated 4 times. The results showed that after 4 reactions, HMF was completely converted and the THFDM selectivity was maintained at 84.5%.

[0107] Embodiment 20

[0108] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, ethylene glycol is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediaminetetraacetic acid. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.3:0.20:20:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.10:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediaminetetraacetic acid is 0.5.

[0109] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 1.49g of ethylene glycol and 43.2g of deionized water, mix them evenly, slowly drop 25g of ethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 2.24g of nickel nitrate and dissolve it in 10g of deionized water, add 7.17g of ethylenediaminetetraacetic acid and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 90°C for 12 hours. The gel mixture obtained above is crystallized at 170°C for 4 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 900°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0110] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 174 m 2 / g, external specific surface area is 45m 2 / g, with a total pore volume of 0.15 cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 8wt% relative to Silicalite-1 (in terms of SiO2). The catalyst was named 8Ni-Silicalite-1-C. The XRD and Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 82 μmol·g -1 The XPS and Figure 3 Similarly, the binding energy at 852.9 eV corresponds to the metal element Ni (2p 3 / 2 The peak with a binding energy of 855.4 eV corresponds to divalent nickel (2 + ), the molar ratio of metallic Ni to oxidized NiO was calculated by the ratio of the two peak areas (Ni / NiO ratio) to be 1.4. Figure 4 Similarly, the hydrogen consumption is 778 μmol·g -1 , from which the nickel reduction degree was calculated to be 57%.

[0111] Tetrahydrofuran is used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF is 100, the mass ratio of HMF to catalyst is 1, the hydrogen pressure is 1.5MPa, the reaction temperature is 130°C, and the reaction time is 5h. 0.2g of the catalyst in the above embodiment, 0.2gHMF and 20g of tetrahydrofuran are added to a stirred autoclave, and 1.5MPa of hydrogen is filled. The program temperature heating jacket is raised to a preset temperature, and magnetic stirring is used and then stirred. React at 130°C for 5h, and the reaction liquid gas phase analysis calculates that HMF is completely converted, and the product THFDM selectivity is 86.9%. The used catalyst is washed and dried and then put into the next reaction, and the reaction is circulated 4 times. The results show that after 4 reactions, HMF is completely converted and the THFDM selectivity remains at 84.8%.

[0112] Embodiment 21

[0113] Tetraethyl orthosilicate (TEOS) is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, urea is used as additive, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, additive, water to tetraethyl orthosilicate (calculated as SiO2) is 0.3:0.15:15:1, the mass ratio of nickel nitrate (calculated as Ni mass) to tetraethyl orthosilicate (calculated as SiO2 mass) is 0.13:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.4.

[0114] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 1.08g of urea and 32.4g of deionized water, mix them evenly, slowly drop 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 2.91g of nickel nitrate and dissolve it in 10g of deionized water, add 2.39g of ethylenediamine and stir evenly to obtain solution B; slowly drop solution B into solution A, and continue aging at 80°C for 10 hours. The gel mixture obtained above is crystallized at 180°C for 5 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 800°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0115] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 225 m 2 / g, and the total pore volume is 0.16cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 10wt% relative to Silicalite-1 (in terms of SiO2), and the catalyst was named 10Ni-Silicalite-1; the sample had a thin strip-like morphology, with a crystal length of 8μm, an aspect ratio of 6.0, and an average thickness of 510nm; the XRD and Figure 1The NH3-TPD of the sample is similar to Figure 2 Similarly, the total acid content calculated is 87 μmol·g -1 The XPS and Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.6. Figure 4 Similarly, the hydrogen consumption is 1070 μmol·g -1 , from which the nickel reduction degree was calculated to be 62.7%.

[0116] Tetrahydrofuran is used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF is 100, the mass ratio of HMF to catalyst is 1, the hydrogen pressure is 1.5MPa, the reaction temperature is 130°C, and the reaction time is 5h. 0.2g of the catalyst in the above embodiment, 0.2gHMF and 20g of tetrahydrofuran are added to a stirred autoclave, and 1.5MPa of hydrogen is filled. The program temperature heating jacket is raised to the preset temperature, and magnetic stirring is used and then stirred. React at 130°C for 5h, and the reaction liquid gas phase analysis calculates that HMF is completely converted, and the product THFDM selectivity is 92.3%. The used catalyst is washed and dried and then put into the next reaction, and the reaction is circulated 4 times. The results show that after 4 reactions, HMF is completely converted and the THFDM selectivity remains at 90.4%.

[0117] Comparative Example 1

[0118] Silica sol is used as silicon source, tetrapropylammonium hydroxide (TPAOH) is used as template, nickel source is nickel nitrate, and complexing agent is ethylenediamine. The molar ratio of template, water and ethyl orthosilicate (calculated as SiO2) is 0.3:20:1, the mass ratio of nickel nitrate (calculated as Ni mass) to silica sol (calculated as SiO2 mass) is 0.10:1. The molar ratio of nickel nitrate (calculated as Ni mole) to ethylenediamine is 0.5.

[0119] The specific synthesis steps are as follows: weigh 29.3g of 25% tetrapropylammonium hydroxide aqueous solution and mix it evenly with 43.2g of deionized water, slowly add 25g of tetraethyl orthosilicate, and stir evenly at 50°C to obtain solution A; weigh 2.24g of nickel nitrate and dissolve it in 10g of deionized water, add 1.47g of ethylenediamine and stir evenly to obtain solution B; slowly add solution B dropwise to solution A, and continue aging at 90°C for 12 hours. The gel mixture obtained above is crystallized at 180°C for 4 days, washed, centrifuged and dried after crystallization, calcined at 550°C for 6 hours, and reduced at 900°C in a hydrogen atmosphere for 4 hours to obtain Ni-Silicalite-1 catalyst.

[0120] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 302 m 2 / g, external specific surface area is 85m 2 / g, with a total pore volume of 0.26 cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 8wt% relative to Silicalite-1 (in terms of SiO2). The catalyst was named D-8Ni-Silicalite-1. Figure 1 Similar; the NH3-TPD of the sample is Figure 2 Similarly, the total acid content calculated is 162 μmol·g -1 The XPS of the sample is as follows Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO) is 1.0. Figure 4 Similarly, the hydrogen consumption is 810 μmol·g -1 , from which the nickel reduction degree was calculated to be 47%.

[0121] Tetrahydrofuran is used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF is 100, the mass ratio of HMF to catalyst is 1, the hydrogen pressure is 1.5MPa, the reaction temperature is 130°C, and the reaction time is 5h. 0.2g of the catalyst in the above comparative example, 0.2g of HMF and 20g of tetrahydrofuran are added to a stirred autoclave, and 1.5MPa of hydrogen is filled. The programmed temperature heating jacket is raised to the preset temperature, and magnetic stirring is used and then stirred. The reaction is carried out at 130°C for 5h, and the reaction liquid is analyzed and calculated. The results show that the HMF conversion rate is 95% and the product THFDM selectivity is 57.5%.

[0122] Comparative Example 2

[0123] First, the Silicalite-1 molecular sieve is synthesized, and the specific synthesis steps are as follows: 29.3g of 25% tetrapropylammonium hydroxide aqueous solution, 1.44g of urea, 1.47g of ethylenediamine and 43.2g of deionized water are weighed and mixed evenly, and 25g of ethyl orthosilicate is slowly added dropwise, stirred evenly at 50°C to obtain a mixed solution, and then aged at 90°C for 12 hours. The obtained gel mixture is crystallized at 170°C for 1 day, and after the crystallization is completed, it is washed, centrifuged and dried, and then calcined at 550°C for 6 hours to obtain the Silicalite-1 molecular sieve.

[0124] The specific synthesis steps are as follows: 1.79 g of nickel nitrate is weighed and dissolved in 10 g of deionized water, 7.2 g of Silicalite-1 molecular sieve is added to the above solution, stirred thoroughly until the solid reaches an initial wet state, placed in a 50°C oven, dried, and then calcined at 550°C for 6 hours, and reduced in a hydrogen atmosphere at 900°C for 4 hours to obtain a Ni / Silicalite-1 catalyst.

[0125] The specific surface area of ​​the sample was calculated by BET method and t-plot method to be 340 m 2 / g, external specific surface area is 17m 2 / g, with a total pore volume of 0.23 cm 3 / g. Inductively coupled plasma atomic emission spectroscopy (ICP) was used to test that the relative content of Ni was 8wt% relative to Silicalite-1 (in terms of SiO2). The total acid content calculated from the NH3-TPD diagram of the sample was 54μmol·g -1 The XPS of the sample is as follows Figure 3 Similarly, the molar ratio of metallic Ni to oxidized NiO (Ni / NiO ratio) calculated from XPS of the sample was 2.4. Figure 4 Similarly, the hydrogen consumption is 1330 μmol·g -1 , from which the nickel reduction degree was calculated to be 77%.

[0126] Tetrahydrofuran is used as the reaction solvent, the mass ratio of tetrahydrofuran to HMF is 100, the mass ratio of HMF to catalyst is 1, the hydrogen pressure is 1.5MPa, the reaction temperature is 130°C, and the reaction time is 5h. 0.2g of the catalyst in the above comparative example, 0.2g of HMF and 20g of tetrahydrofuran are added to a stirred autoclave, and 1.5MPa of hydrogen is filled. The programmed temperature heating jacket is raised to the preset temperature, and magnetic stirring is used and then stirred. The reaction is carried out at 130°C for 5h, and the reaction liquid is analyzed and calculated. The results show that the HMF conversion rate is 78% and the product THFDM selectivity is 63.5%.

[0127] The above describes the specific implementation of the present invention in detail, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the various technical features being combined in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing 2,5-tetrahydrofuran dimethanol, comprising: 5-Hydroxymethylfurfural reacts with hydrogen as a hydrogen source in the presence of a catalyst to obtain 2,5-tetrahydrofuran dimethanol; The catalyst is Ni-Silicalite-1 molecular sieve, and the total acid content of the Ni-Silicalite-1 molecular sieve is 10 to 150 μmol·g -1 .

2. The method according to claim 1, characterized in that 5-Hydroxymethylfurfural is dissolved in an organic solvent, wherein the organic solvent comprises one or more of methanol, ethanol, n-butanol, tetrahydrofuran, 1,4-dioxane, and methyl isobutyl ketone, preferably at least one of n-butanol and tetrahydrofuran.

3. The method according to claim 1, characterized in that: The mass ratio of the 5-hydroxymethylfurfural to the catalyst is 0.2 to 10:1, preferably 0.5 to 5.0:

1.

4. The method according to claim 2, characterized in that: The mass ratio of the organic solvent to 5-hydroxymethylfurfural is 20 to 300:1, preferably 30 to 200:

1.

5. The method according to claim 1, characterized in that The reaction pressure is 0.2 to 5 MPa, preferably 0.5 to 3 MPa.

6. The method according to claim 1, characterized in that The reaction temperature is 115 to 220° C., preferably 120 to 200° C.; and / or the reaction time is 1 to 24 hours, preferably 2 to 8 hours.

7. The method according to claim 1, characterized in that The molar ratio of Ni / NiO in the Ni-Silicalite-1 molecular sieve is 1.3-2.0:1, preferably 1.5-1.8:

1.

8. The method according to claim 1, characterized in that The total acid content of the Ni-Silicalite-1 molecular sieve is 20 to 120 μmol·g -1 , preferably 75 to 100 μmol·g -1 .

9. The method according to claim 1, characterized in that: In the catalyst, based on the mass of Silicalite-1 calculated as SiO2, the content of active component nickel calculated as Ni is 1wt% to 20wt%, preferably 3wt% to 10wt%.

10. The method according to claim 1, characterized in that The specific surface area of ​​the Ni-Silicalite-1 molecular sieve is 120 to 500 m 2 / g, external specific surface area is 30~80m 2 / g, total pore volume is 0.04~0.30cm 3 / g; Preferably, the specific surface area of ​​the Ni-Silicalite-1 molecular sieve is 150 to 400 m 2 / g, external specific surface area is 40~70m 2 / g, total pore volume is 0.05~0.25cm 3 / g.

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