A method for preparing 2,5-tetrahydrofurandiethanol

Abstract

This invention discloses a method for preparing 2,5-tetrahydrofurandiethanol. The method includes: reacting 5-hydroxymethylfurfural in the presence of a catalyst, using hydrogen as the hydrogen source, to obtain 2,5-tetrahydrofurandiethanol; the catalyst is Ni-Silicalite-1 molecular sieve, and the total acidity of the Ni-Silicalite-1 molecular sieve is 10–150 μmol·g. ‑1 The method of this invention features high efficiency in the conversion of 5-hydroxymethylfurfural under mild reaction conditions, high selectivity for the product 2,5-tetrahydrofurandiethanol, and outstanding stability of the catalyst during recycling.

Description

Technical Field

[0001] This invention relates to the field of catalytic chemistry, and more specifically, to a method for preparing 2,5-tetrahydrofurandiethanol. Background Technology

[0002] Biomass resources possess enormous development potential. The rational and efficient conversion of 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 sources is a goal pursued by scientists worldwide and is of great significance to the progress of humankind. 5-Hydroxymethylfurfural (HMF) is a biomass-based platform compound that, after upgrading, can be used to prepare a variety of high-value-added chemicals and fuels. Among them, the hydrogenation product of HMF, 2,5-tetrahydrofurandimethylethanol (THFDM), possesses both a tetrahydrofuran cyclic structure and symmetrical diol functional groups, and can be widely used in adhesives, coatings, resins, and polyesters. It is expected to exhibit unique advantages in barrier properties, dyeability, and degradability, thus becoming a research hotspot in both academia and industry.

[0003] 2,5-Tetrahydrofurandimethylethanol (THFDM) is mainly prepared by hydrogenation of 5-hydroxymethylfurfural (HMF). When hydrogen is used as the hydrogen source, commonly used catalysts include supported noble metals such as ruthenium (Ru), platinum (Pt), and palladium (Pd), as well as transition metals such as nickel (Ni) and copper (Cu). CN 103228626B reported that using 5% Ru / C as a catalyst and methanol as the reaction solvent, the reaction was carried out at 5 MPa hydrogen and 75 °C for 1.5 hours, followed by a reaction at 9 MPa hydrogen and 200 °C for 14 hours, but the THFDM yield was only 30%. The low reusability and high cost of noble metals seriously hinder their commercial application. Therefore, the use of non-precious metals has gradually gained attention from researchers. For example, Klaus Hellgardt's group (RSC Adv., 2017, 7, 31401) used Raney Cu and Ni bilayer catalysts to achieve a two-stage hydrogenation method. Under the reaction conditions of a flow rate of 0.05 mL / min, 9 MPa hydrogen gas, and 90 °C, the initial selectivity of THFDM reached up to 98%. However, the Raney Ni catalyst used in the second stage showed a gradual deactivation phenomenon. In the presence of non-precious metal catalysts, the reaction pressure is usually high, and the loss of active components is severe.

[0004] In summary, existing technologies mainly suffer from problems such as low selectivity of THFDM, harsh reaction conditions, or poor catalyst cycle stability, which pose significant challenges to practical industrial applications. Summary of the Invention

[0005] The technical problem this invention aims to solve is the low selectivity, harsh reaction conditions, or poor catalyst cycling stability of existing technologies for 2,5-tetrahydrofurandiethanol. This invention provides a method for the catalytic conversion of 5-hydroxymethylfurfural to 2,5-tetrahydrofurandiethanol. This method features high efficiency in the conversion of 5-hydroxymethylfurfural under mild reaction conditions, high selectivity for the product 2,5-tetrahydrofurandiethanol, and outstanding catalyst cycling stability.

[0006] The first aspect of this invention provides a method for preparing 2,5-tetrahydrofurandiethanol, comprising: reacting 5-hydroxymethylfurfural in the presence of a catalyst, using hydrogen as a hydrogen source, to obtain 2,5-tetrahydrofurandiethanol; wherein the catalyst is a Ni-Silicalite-1 molecular sieve, and the total acidity of the Ni-Silicalite-1 molecular sieve is 10–150 μmol·g. -1 .

[0007] According to the present invention, preferably, 5-hydroxymethylfurfural is dissolved in an organic solvent. More preferably, the organic solvent includes 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 to 10:1, preferably 0.5 to 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 gas is introduced into the reaction system to adjust the reaction pressure. The reaction pressure 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 115-220°C, preferably 120-200°C; and / or the reaction time is 1-24 h, preferably 2-8 h.

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

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

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

[0015] According to the present invention, preferably, the total acidity of the Ni-Silicalite-1 molecular sieve is 20–120 μmol·g. -1 More preferably 75–100 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 120–500 m². 2 / g, preferably 150-400m 2 / g; External specific surface area is 30-80m² 2 / g, preferably 40-70m 2 / g; total pore volume is 0.04~0.30cm³ 3 / g, preferably 0.05~0.25cm 3 / g.

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

[0019] According to the present invention, the preparation method of the catalyst includes the following steps: mixing a template agent, an additive, water, and a silicon source, then adding a nickel precursor dropwise, followed by aging, crystallization, calcination, and reduction to obtain the catalyst; preferably, the nickel precursor includes a complexing agent and a nickel source.

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

[0021] According to the present invention, in the method for preparing the catalyst, the molar ratio of the template agent, additive, water and silicon source (based on 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, more 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 silicon source (calculated as SiO2) is 0.02 to 0.20:1, preferably 0.03 to 0.15:1, and more preferably 0.09 to 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 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 agent, additive 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, tetrapropylchlorine hydroxide and tetrapropylbromine hydroxide, preferably tetrapropylammonium hydroxide.

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

[0027] According to the present invention, in the method for preparing the catalyst, one or more of silica, sodium silicate, silica sol and tetraethyl orthosilicate are used, 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 method for preparing the catalyst, the complexing agent includes one or more of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, 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-cobalt precursor solution is formed by dissolving a nickel source and a complexing agent in water.

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

[0034] According to the present invention, the reduction temperature is 450-1000°C, preferably 550-900°C, and more 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 this invention, 5-hydroxymethylfurfural undergoes hydrogenolysis in a solvent in the presence of the catalyst Ni-Silicalite-1 molecular sieve to obtain 2,5-tetrahydrofurandiethanol. It has the characteristics of high efficiency in the conversion of 5-hydroxymethylfurfural under mild reaction conditions, high selectivity of the product 2,5-tetrahydrofurandiethanol, and outstanding stability of the catalyst for recycling.

[0037] (2) In this invention, the catalyst is Ni-Silicalite-1 molecular sieve. By controlling the total acid content of the molecular sieve, and preferably controlling the molar ratio of Ni / NiO in the active component nickel, 5-hydroxymethylfurfural can be efficiently converted into 2,5-tetrahydrofurandiethanol under mild reaction conditions, with significantly improved substrate conversion and product selectivity. In addition, the prepared catalyst has good stability, and no significant change in catalyst performance was observed after four cycles of use. Attached Figure Description

[0038] Figure 1 The image shows the XRD pattern of the Ni-Silicalite-1 catalyst obtained in Example 1.

[0039] Figure 2 The NH3-TPD diagram of the Ni-Silicalite-1 catalyst obtained in Example 1 is shown.

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

[0041] Figure 4 The image shows the H2-TPR of the Ni-Silicalite-1 catalyst obtained in Example 1.

[0042] Figure 5 The HMF conversion and THFDM selectivity are given under the recycling conditions of the Ni-Silicalite-1 catalyst obtained in Example 1. Detailed Implementation

[0043] In this invention, the reaction product 2,5-tetrahydrofurandiethanol (THFDM) was qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the conversion rate of the substrate 5-hydroxymethylfurfural (HMF) and the yield of the reaction product THFDM were analyzed by gas chromatography (GC). The GC-MS system was an Agilent 7890A from Agilent Technologies, USA, with an HP-5 nonpolar capillary column (30m, 0.53mm). The gas chromatograph was an Agilent 7890B, with a flame ionization detector (FID) and an SE-54 capillary column (30m, 0.53mm).

[0044] In this invention, the XRD measurement method for molecular sieve products is as follows: the phase composition of the sample is analyzed using a Rigaku Ultima IV X-ray powder diffractometer (Japan), with a CuKα ray source. Nickel filter, 2θ scanning range 2°-50°, operating voltage 35kV, current 25mA, scanning rate 10° / min.

[0045] In this invention, an inductively coupled plasma atomic emission spectrometer (ICP) of model Varian 725-ES is used to dissolve the analytical sample in hydrofluoric acid to detect the content of metal elements.

[0046] In this invention, the NH3 temperature-programmed desorption (NH3-TPD) experiment was conducted on a TPD / TPR Altamira AMI-3300 instrument, and the total acid content was calculated by fitting and peaking the obtained spectrum.

[0047] In this invention, the H2 temperature-programmed reduction (H2-TPR) experiment was conducted on a TPD / TPR Altamira AMI-3300 instrument, from which the hydrogen consumption was calculated. The formula for calculating the nickel reduction degree is:

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

[0049] In this invention, the physical adsorption instrument is a Micromeretic ASAP2020M. The test conditions are: measurement temperature -169℃, molecular sieve pre-treated in vacuum at 300℃ for 10 hours before measurement, and parameters such as pore volume and specific surface area are calculated using the BET method and t-plot method.

[0050] In this invention, the element binding energy on the catalyst surface was measured on a Thermo X-ray photoelectron spectrometer (ESCA LAB-250), and the measured element signal was corrected using C1s = 284.6 eV as an internal standard.

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

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

[0053] In this invention, the formula for calculating the selectivity of the product THFDM is as follows:

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

[0055] To facilitate understanding of the present invention, the following embodiments are provided. However, these embodiments are merely for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] Example 1

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

[0058] The specific synthesis steps are as follows: 29.3g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 1.44g of urea, and 43.2g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 2.24g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 1.47g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 90℃ for 12 hours. The resulting gel mixture was crystallized at 170℃ for 4 days. After crystallization, it was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 900℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0059] The specific surface area of ​​the sample was calculated to be 246 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​53m² 2 / g, total pore volume is 0.16cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) analysis showed that the relative Ni content (based on SiO2) was 8 wt% relative to Silicalite-1, and the catalyst was named 8Ni-Silicalite-1-A; the XRD pattern of the sample is shown below. Figure 1 As shown; the NH3-TPD of the sample is as follows Figure 2 As shown, the total acid content calculated from this is 92 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 As shown, a binding energy of 852.9 eV corresponds to the metallic 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, calculated using the ratio of two peak areas (Ni / NiO ratio), is 1.6. H2-TPR, as shown... Figure 4 As shown, the hydrogen consumption is 1160 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 68%.

[0060] Example 2

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

[0062] The specific synthesis steps are as follows: 19.5g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 1.44g of urea, and 43.2g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 2.24g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 0.92g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 100℃ for 12 hours. The resulting gel mixture was crystallized at 180℃ for 6 days. After crystallization, it was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 850℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0063] The specific surface area of ​​the sample was calculated to be 273 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​59m² 2 / g, total pore volume is 0.18cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) was used to determine the relative Ni content (based on SiO2) to Silicalite-1; the catalyst was named 8Ni-Silicalite-1-B. XRD analysis of the sample and... Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 82 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 Similarly, the molar ratio (Ni / NiO) of metallic Ni and oxidized NiO is 1.7, and H2-TPR and Figure 4 Similarly, the hydrogen consumption was 1072 μmol·g. -1 Therefore, the degree of restoration is calculated to be 63%.

[0064] Example 3

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

[0066] The specific synthesis steps are as follows: 29.3g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 2.88g of urea, and 32.4g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 3.36g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 2.76g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 100℃ for 10 hours. The resulting gel mixture was crystallized at 180℃ for 5 days. After crystallization, the mixture was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 900℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0067] The specific surface area of ​​the sample was calculated to be 271 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​63m² 2 / g, total pore volume is 0.16cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) analysis showed that the relative Ni content (based on SiO2) was 12wt% relative to Silicalite-1, and the catalyst was named 12Ni-Silicalite-1-A; the XRD of the sample and Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 83 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 Similarly, the molar ratio (Ni / NiO) of metallic Ni and oxidized NiO is 1.8, and H2-TPR and Figure 4 Similarly, the hydrogen consumption was 1120 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 66%.

[0068] Example 4

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

[0070] The specific synthesis steps are as follows: 29.3g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 4.32g of urea, and 32.4g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 2.02g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 1.32g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 100℃ for 24 hours. The resulting gel mixture was crystallized at 180℃ for 6 days. After crystallization, the mixture was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 850℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0071] The specific surface area of ​​the sample was calculated to be 307 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​61m² 2 / g, total pore volume is 0.16cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) analysis showed that the relative Ni content (based on SiO2) was 7 wt% relative to Silicalite-1, and the catalyst was named 7Ni-Silicalite-1; the XRD of the sample and Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 79 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3Similarly, the molar ratio (Ni / NiO) of metallic Ni and oxidized NiO is 1.7, and H2-TPR and Figure 4 Similarly, the hydrogen consumption was 1069 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 64%.

[0072] Examples 5-8

[0073] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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 from Examples 1-4 above, along with 0.2 g of HMF and 20 g of THF, were added to a high-pressure reactor equipped with a stirrer, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 130 °C for 5 h. The HMF conversion and THFDM selectivity of the reaction liquid were calculated by gas phase analysis, as shown in Table 1.

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

[0075]

[0076] Example 9

[0077] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 120 and an HMF / catalyst mass ratio of 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 from Example 1, 0.16 g of HMF, and 19.2 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.2 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 130 °C for 4 h. Gas phase analysis of the reaction liquid showed complete HMF conversion (conversion rate > 99%) and a THFDM selectivity of 89.9%.

[0078] Example 10

[0079] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 150 and an HMF / catalyst mass ratio of 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 from Example 1, 0.2 g of HMF, and 30.0 g of THF were added to a high-pressure reactor equipped with a stirrer, and the reactor was charged with 2.5 MPa of hydrogen. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was then stirred magnetically. The reaction was carried out at 120 °C for 8 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 88.6%.

[0080] Example 11

[0081] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 80 and an HMF / catalyst mass ratio of 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 from Example 1, 0.26 g of HMF, and 20.8 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.2 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 160 °C for 3 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 90.1%.

[0082] Example 12

[0083] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 1:10 and an HMF / catalyst mass ratio of 2:0. The hydrogen pressure was 2.0 MPa, the reaction temperature was 150 °C, and the reaction time was 4 h. 0.2 g of the catalyst from Example 2, 0.40 g of HMF, and 44.0 g of THF were added to a high-pressure reactor equipped with a stirrer, and 2.0 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 150 °C for 4 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 90.5%.

[0084] Example 13

[0085] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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 from Example 2, 0.20 g of HMF, and 20.0 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.4 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 140 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 89.8%.

[0086] Example 14

[0087] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 80 and an HMF / catalyst mass ratio of 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 from Example 3, 0.30 g of HMF, and 24.0 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.7 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 89.7%.

[0088] Example 15

[0089] n-Butanol was used as the reaction solvent, with a n-butanol to HMF mass ratio of 120 and an HMF to catalyst mass ratio of 0.6. The hydrogen pressure was 1.5 MPa, the reaction temperature was 140 °C, and the reaction time was 5 h. 0.2 g of the catalyst from Example 3, 0.12 g of HMF, and 14.4 g of n-butanol were added to a high-pressure reactor equipped with a stirrer, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 140 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 90.3%.

[0090] Example 16

[0091] n-Butanol was used as the reaction solvent, with a n-butanol to HMF mass ratio of 150 and an HMF to catalyst mass ratio of 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 from Example 3, 0.40 g of HMF, and 60.0 g of n-butanol were added to a high-pressure reactor equipped with a stirrer, and 2.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 150 °C for 4 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 88.5%.

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

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

[0094]

[0095] Example 17

[0096] Tetrahydrofuran (THFDM) was used as the reaction solvent, with a THF / HMF mass ratio of 120 and an HMF / catalyst mass ratio of 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 from Example 1, 0.16 g of HMF, and 19.2 g of THFDM were added to a high-pressure reactor with a stirrer, and 1.2 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 130 °C for 4 h. The HMF conversion and THFDM selectivity were calculated using gas phase analysis of the reaction liquid. The used catalyst was washed, dried, and then used in the next reaction cycle, for a total of 4 cycles. The results are as follows. Figure 5 As shown in the figure. The results show that after four reactions, the HMF conversion was complete, and the THFDM selectivity remained at 87.6%, indicating that the catalyst of the present invention has good cycle stability.

[0097] Example 18

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

[0099] The specific synthesis steps are as follows: 19.5g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 1.44g of urea, and 43.2g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 4.48g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 0.59g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 100℃ for 12 hours. The resulting gel mixture was crystallized at 180℃ for 6 days. After crystallization, the mixture was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 850℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0100] The specific surface area of ​​the sample was calculated to be 252 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​38m² 2 / g, total pore volume is 0.20cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) analysis showed that the relative Ni content (based on SiO2) was 17 wt% relative to Silicalite-1, and the catalyst was named 17Ni-Silicalite-1; the XRD of the sample and Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 122 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 Similarly, the molar ratio (Ni / NiO) of metallic Ni to oxidized NiO is 1.4. H2-TPR and Figure 4 Similarly, the hydrogen consumption was 938 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 55%.

[0101] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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, 0.2 g of HMF, and 20 g of THF were added to a stirred high-pressure reactor, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was magnetically stirred and then stirred. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 87.4%. The used catalyst was washed, dried, and then used in the next reaction cycle, for a total of 4 cycles. The results showed that after 4 reactions, the HMF conversion was complete, and the THFDM selectivity remained at 85.3%.

[0102] Example 19

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

[0104] The specific synthesis steps are as follows: 29.3g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 2.88g of urea, and 32.4g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 3.36g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 7.36g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 130℃ for 10 hours. The resulting gel mixture was crystallized at 180℃ for 5 days. After crystallization, the mixture was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 600℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0105] The specific surface area of ​​the sample was calculated to be 271 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​63m² 2 / g, total pore volume is 0.15cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) was used to determine the relative Ni content (based on SiO2) of Silicalite-1; the catalyst was named 12Ni-Silicalite-1-B. XRD analysis of the sample and... Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 147 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 Similarly, the molar ratio (Ni / NiO) of metallic Ni to oxidized NiO is 1.3. H2-TPR and Figure 4 Similarly, the hydrogen consumption was 892 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 52%.

[0106] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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, 0.2 g of HMF, and 20 g of THF were added to a stirred high-pressure reactor, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was magnetically stirred and then stirred. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 86.7%. The used catalyst was washed, dried, and then used in the next reaction cycle, for a total of 4 cycles. The results showed that after 4 reactions, HMF was completely converted, and the THFDM selectivity remained at 84.5%.

[0107] Example 20

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

[0109] The specific synthesis steps are as follows: 29.3 g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 1.49 g of ethylene glycol, and 43.2 g of deionized water were weighed and mixed evenly, and 25 g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50 °C to obtain solution A. 2.24 g of nickel nitrate was weighed and dissolved in 10 g of deionized water, and 7.17 g of ethylenediaminetetraacetic acid was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 90 °C for 12 hours. The resulting gel mixture was crystallized at 170 °C for 4 days. After crystallization, the mixture was washed, centrifuged, and dried, then calcined at 550 °C for 6 hours, and reduced at 900 °C for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0110] The specific surface area of ​​the sample was calculated to be 174 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​45m² 2 / g, total pore volume is 0.15cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) was used to determine the relative Ni content (based on SiO2) to Silicalite-1; the catalyst was named 8Ni-Silicalite-1-C. XRD analysis of the sample and... Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 82 μmol·g. -1 The XPS values ​​of the sample are... Figure 3 Similarly, a binding energy of 852.9 eV corresponds to the metallic element Ni (2p0). 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, calculated using the ratio of two peak areas (Ni / NiO ratio), is 1.4. H2-TPR and Figure 4 Similarly, the hydrogen consumption was 778 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 57%.

[0111] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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 from the above examples, 0.2 g of HMF, and 20 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was then stirred magnetically. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 86.9%. The used catalyst was washed, dried, and then used in the next reaction cycle, for a total of 4 cycles. The results showed that after 4 reactions, HMF was completely converted, and the THFDM selectivity remained at 84.8%.

[0112] Example 21

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

[0114] The specific synthesis steps are as follows: 29.3g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 1.08g of urea, and 32.4g of deionized water were weighed and mixed evenly, and 25g of tetraethyl orthosilicate was slowly added dropwise. The mixture was stirred evenly at 50℃ to obtain solution A. 2.91g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 2.39g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 80℃ for 10 hours. The resulting gel mixture was crystallized at 180℃ for 5 days. After crystallization, it was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 800℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0115] The specific surface area of ​​the sample was calculated to be 225 m² using the BET and t-plot methods. 2 / g, total pore volume is 0.16cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) was used for analysis. The relative Ni content (based on SiO2) relative to Silicalite-1 was 10wt%, and the catalyst was named 10Ni-Silicalite-1. The sample exhibited a thin, elongated morphology with a crystal length of 8μm, an aspect ratio of 6.0, and an average thickness of 510nm. The XRD pattern of the sample and... Figure 1Similar. The NH3-TPD of the sample is similar to... Figure 2 Similarly, the total acidity calculated from this is 87 μmol·g. -1 The XPS values ​​of the sample are... Figure 3 Similarly, the molar ratio (Ni / NiO) of metallic Ni to oxidized NiO is 1.6. H2-TPR and Figure 4 Similarly, the hydrogen consumption was 1070 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 62.7%.

[0116] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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 from the above examples, along with 0.2 g of HMF and 20 g of THF, were added to a high-pressure reactor equipped with a stirrer, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was then stirred magnetically. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed complete HMF conversion and a THFDM selectivity of 92.3%. The used catalyst was washed, dried, and then used in the next reaction cycle, for a total of 4 cycles. The results showed that after 4 reactions, HMF was completely converted, and the THFDM selectivity remained at 90.4%.

[0117] Comparative Example 1

[0118] Using silica sol as the silicon source, tetrapropylammonium hydroxide (TPAOH) as the template agent, nickel nitrate as the nickel source, and ethylenediamine as the complexing agent, the molar ratio of template agent, water, and tetraethyl orthosilicate (calculated as SiO2) was 0.3:20:1, the mass ratio of nickel nitrate (calculated as Ni mass) to silica sol (calculated as SiO2 mass) was 0.10:1, and the molar ratio of nickel nitrate (calculated as Ni moles) to ethylenediamine was 0.5.

[0119] The specific synthesis steps are as follows: 29.3g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution was weighed and mixed evenly with 43.2g of deionized water, and 25g of tetraethyl orthosilicate was slowly added. The mixture was stirred evenly at 50℃ to obtain solution A. 2.24g of nickel nitrate was weighed and dissolved in 10g of deionized water, and 1.47g of ethylenediamine was added and stirred evenly to obtain solution B. Solution B was slowly added dropwise to solution A, and the mixture was aged at 90℃ for 12 hours. The resulting gel mixture was crystallized at 180℃ for 4 days. After crystallization, the mixture was washed, centrifuged, and dried, then calcined at 550℃ for 6 hours, and reduced at 900℃ for 4 hours under a hydrogen atmosphere to obtain the Ni-Silicalite-1 catalyst.

[0120] The specific surface area of ​​the sample was calculated to be 302 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​85m² 2 / g, total pore volume is 0.26cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) analysis revealed a Ni content of 8 wt% relative to SiO2 (based on SiO2) in Silicalite-1; this catalyst was named D-8Ni-Silicalite-1. XRD analysis of the sample and... Figure 1 Similar; the NH3-TPD of the sample is similar to Figure 2 Similarly, the total acidity calculated from this is 162 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 Similarly, the molar ratio (Ni / NiO) of metallic Ni to oxidized NiO is 1.0. H2-TPR and Figure 4 Similarly, the hydrogen consumption was 810 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 47%.

[0121] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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 from the comparative example above, 0.2 g of HMF, and 20 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was then stirred magnetically. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed that the HMF conversion rate was 95%, and the THFDM selectivity was 57.5%.

[0122] Comparative Example 2

[0123] First, Silicalite-1 molecular sieve was synthesized. The specific synthesis steps were as follows: 29.3 g of a 25% (w / w) tetrapropylammonium hydroxide aqueous solution, 1.44 g of urea, 1.47 g of ethylenediamine, and 43.2 g of deionized water were weighed and mixed evenly. 25 g of tetraethyl orthosilicate was slowly added dropwise, and the mixture was stirred evenly at 50 °C to obtain a homogeneous solution. The solution was then aged at 90 °C for 12 hours. The resulting gel mixture was crystallized at 170 °C for one day. After crystallization, the mixture was washed, centrifuged, and dried. Finally, it was calcined at 550 °C for 6 hours to obtain the Silicalite-1 molecular sieve.

[0124] The specific synthesis steps are as follows: 1.79g of nickel nitrate was dissolved in 10g of deionized water, and 7.2g of Silicalite-1 molecular sieve was added to the above solution. The mixture was stirred thoroughly until the solid reached a slightly wet state. The solid was placed in a 50℃ oven, dried, and then calcined at 550℃ for 6 hours. After reduction at 900℃ under a hydrogen atmosphere for 4 hours, the Ni / Silicalite-1 catalyst was obtained.

[0125] The specific surface area of ​​the sample was calculated to be 340 m² using the BET and t-plot methods. 2 / g, with an external specific surface area of ​​17m² 2 / g, total pore volume is 0.23cm³ 3 / g. Inductively coupled plasma atomic emission spectrometry (ICP) analysis showed that the relative Ni content (based on SiO2) was 8 wt% relative to Silicalite-1. The total acid content calculated from the NH3-TPD diagram of the sample was 54 μmol·g. -1 The XPS values ​​of the sample are as follows: Figure 3 Similarly, XPS calculations of the sample showed that the molar ratio of metallic Ni to oxidized NiO (Ni / NiO ratio) was 2.4. H2-TPR and Figure 4 Similarly, the hydrogen consumption was 1330 μmol·g. -1 Therefore, the nickel reduction degree is calculated to be 77%.

[0126] Tetrahydrofuran (THF) was used as the reaction solvent, with a THF / HMF mass ratio of 100 and an HMF / catalyst mass ratio of 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 from the comparative example above, 0.2 g of HMF, and 20 g of THF were added to a high-pressure reactor equipped with a stirrer, and 1.5 MPa of hydrogen gas was introduced. The temperature was raised to the preset temperature using a programmed heating mantle, and the reactor was then stirred magnetically. The reaction was carried out at 130 °C for 5 h. Gas phase analysis of the reaction liquid showed that the HMF conversion rate was 78%, and the THFDM selectivity was 63.5%.

[0127] The specific embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing 2,5-tetrahydrofurandiethanol, comprising: 5-Hydroxymethylfurfural reacts with hydrogen as the hydrogen source in the presence of a catalyst to yield 2,5-tetrahydrofurandiethanol; The catalyst is a Ni-Silicalite-1 molecular sieve, and the total acidity of the Ni-Silicalite-1 molecular sieve is 10~150 µmol•g. -1 The molar ratio of Ni / NiO in the Ni-Silicalite-1 molecular sieve is 1.3~2.0:1; the reaction pressure is 0.5~2.5MPa.

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

3. The method according to claim 2, characterized in that, The organic solvent is at least one of n-butanol and tetrahydrofuran.

4. The method according to claim 1, characterized in that, The mass ratio of 5-hydroxymethylfurfural to the catalyst is 0.2~10:

1.

5. The method according to claim 4, characterized in that, The mass ratio of 5-hydroxymethylfurfural to the catalyst is 0.5~5.0:

1.

6. The method according to claim 2, characterized in that, The mass ratio of the organic solvent to 5-hydroxymethylfurfural is 20~300:

1.

7. The method according to claim 5, characterized in that, The mass ratio of the organic solvent to 5-hydroxymethylfurfural is 30~200:

1.

8. The method according to claim 1, characterized in that, The reaction temperature is 115~220℃; and / or the reaction time is 1~24h.

9. The method according to claim 1, characterized in that, The reaction temperature is 120~200℃; and / or the reaction time is 2~8h.

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

1.

11. The method according to claim 1, characterized in that, The total acidity of the Ni-Silicalite-1 molecular sieve is 20~120 µmol•g. -1 .

12. The method according to claim 11, characterized in that, The total acidity of the Ni-Silicalite-1 molecular sieve is 75~100 µmol•g. -1 .

13. The method according to claim 1, characterized in that, In the catalyst, based on the mass of Silicalite-1 (SiO2), the content of the active component nickel (Ni) is 1wt%~20wt%.

14. The method according to claim 13, characterized in that, In the catalyst, based on the mass of Silicalite-1 (SiO2), the content of the active component nickel (Ni) is 3wt%~10wt%.

15. The method according to claim 1, characterized in that, The specific surface area of ​​the Ni-Silicalite-1 molecular sieve is 120~500 m². 2 / g, with an external specific surface area of ​​30~80 m² 2 / g, total pore volume is 0.04~0.30 cm³ 3 / g.

16. The method according to claim 15, characterized in that, The specific surface area of ​​the Ni-Silicalite-1 molecular sieve is 150~400 m². 2 / g, with an external specific surface area of ​​40~70 m² 2 / g, total pore volume is 0.05~0.25 cm³ 3 / g.

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