阅读说明：本技术 一种5-羟甲基糠醛加氢制备2，5-二羟甲基四氢呋喃的方法 (Method for preparing 2, 5-dihydroxymethyl tetrahydrofuran by hydrogenation of 5-hydroxymethylfurfural ) 是由 林鹿 田野 曾宪海 陈炳霖 李闯 李铮 唐兴 杨述良 孙勇 于 2021-09-16 设计创作，主要内容包括：本发明公开了一种5-羟甲基糠醛(5-HMF)催化加氢制备2,5-二羟甲基四氢呋喃(BHMTHF)的方法及应用。其中采用负载型催化剂,其第一活性组分和第二组分分别来自相应的非贵金属盐溶液,选自Ni(NO-(3))-(2)·6H-(2)O和Co(NO-(3))-(2)·6H-(2)O。以典型的酸性氧化物气相SiO-(2)为载体,两种活性组分的负载量为(4/1～1/1),采用共沉淀法制备双金属催化剂。该催化剂制备方法简便,价格低廉且具有循环性,该催化反应体系绿色,反应底物具有可再生性,反应条件温和,投入成本低,具有广阔的工业化应用前景。(The invention discloses a method for preparing 2, 5-dihydroxymethyl tetrahydrofuran (BHMTHF) by catalytic hydrogenation of 5-hydroxymethylfurfural (5-HMF) and application thereof. Wherein a supported catalyst is adopted, and the first active component and the second component of the supported catalyst are respectively from corresponding non-noble metal salt solutions and are selected from Ni (NO) 3 ) 2 ·6H 2 O and Co (NO) 3 ) 2 ·6H 2 And O. With a typical acidic oxide gas phase SiO 2 The catalyst is a carrier, the loading amount of the two active components is (4/1-1/1), and a coprecipitation method is adopted to prepare the bimetallic catalyst. The catalyst has the advantages of simple preparation method, low price, recyclability, green catalytic reaction system, renewable reaction substrates, mild reaction conditions, low input cost and wide industrial application prospect.)

1. The preparation method of the non-noble bimetal supported catalyst is characterized in that a catalyst carrier is two metal oxides CeO₂、SiO₂One of (1); the first active component of the catalyst is Ni; the second active component is Co; the preparation steps are as follows: respectively adding metal salt aqueous solution containing active components into a catalyst carrier to form precursor mixed solution, and then adding Na₂CO₃And NaOH in deionized water to form a precipitate, and slowly adding the precursorStirring the mixed solution until the pH value is 8-12, washing the aged mixed solution to be neutral by using deionized water, drying the mixed solution in an oven, and roasting for 3-6 h; further preferably, the reduction is carried out in a hydrogen atmosphere before use.

2. The production method according to claim 1, wherein the catalyst support is fumed silica.

3. The method according to claim 1, wherein the metal salt of the active components of the first and second active components of the catalyst is Ni (NO)₃)₂·6H₂O，NiCl₂·6H₂O and Co (NO)₃)₂·6H₂O，CoCl₂·6H₂O; preferably Ni (NO)₃)₂·6H₂O and Co (NO)₃)₂·6H₂O。

4. The method according to claim 1, wherein the Na is₂CO₃And NaOH in a weight ratio of 1-6: 1.

5. the method of claim 1, wherein the medium-strong alkalinity is a pH of 9 to 11, and aging is continued for 10 hours.

6. The preparation method according to claim 1, wherein the drying in the oven is drying in an oven at 100 ℃ for 10-15 h; the roasting is carried out at 400-600 ℃ for 3-6 h.

7. The method according to claim 1, wherein the reduction in the hydrogen atmosphere is carried out in a tubular furnace at 400-600 ℃ and through which hydrogen is introduced for 3-6h, preferably in a tubular furnace at 500 ℃ and through which hydrogen is introduced for 4 h.

8. The non-noble bimetallic supported catalyst prepared by the process for preparing a non-noble bimetallic supported catalyst according to any one of claims 1 to 7.

9. Use of the non-noble bimetallic supported catalyst according to claim 8 in hydrogenation reactions with 5-hydroxymethylfurfural, 3-hydroxymethylcyclopentanol and 3-hydroxymethylcyclopentanone as substrates.

10. A method for preparing BHMTHF by catalytic hydrogenation of 5-HMF is characterized by comprising the following steps: the method comprises the following steps:

adding 5-HMF, a solvent and the non-noble bimetal supported catalyst according to claim 8 into a batch type closed high-pressure reaction kettle, and carrying out catalytic selective hydrogenation reaction under stirring; after the reaction is finished, the reaction product is cooled to room temperature, the pressure is released, further preferably, the product is subjected to centrifugal separation, and the non-noble bimetal supported catalyst is separated by a magnet;

preferably, the dosage of the non-noble bimetallic supported catalyst is 1/10-1/2, preferably 3/10 of 5-HMF, the initial pressure of hydrogen is 1-6 MPa, the reaction temperature is 90-130 ℃, preferably 100-120 ℃, and the reaction time is 1-6 hours, preferably 2-5 hours; the stirring speed is 300-500r/min, preferably 400 r/min;

the solvent is deionized water; the ratio of the 5-HMF to the solvent is 1g:10-100ml, preferably 1g: 50 ml.

Technical Field

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a preparation method of a non-noble bimetallic supported catalyst and a method for preparing 2, 5-dihydroxymethyl tetrahydrofuran by hydrogenation of 5-hydroxymethylfurfural.

Background

Currently, 5-hydroxymethylfurfural (5-HMF) is receiving much attention as an important multifunctional platform compound. It is usually obtained by dehydration of biomass-derived carbohydrates under the action of acid catalysis. The 5-HMF can be converted into 2, 5-dimethyloltetrahydrofuran (BHMTHF) which is a high value-added chemical through complete hydrogenation. BHMTH can be used as a degradable, low-toxicity and high-stability green solvent. In addition, the product can be further hydrogenated into high value-added linear polyol as a substrate. Such as 1, 5 pentanediol and 1, 6 hexanediol, etc. (Keiichi Tomishige, ACS Catal.2014,4, 2718-. This again indicates that the preparation of BHMTH by 5-HMF is of great importance.

Typically, BHMTH is prepared in a two-step process: firstly, under the action of a solid acid catalyst, biomass derivative saccharides and the like are dehydrated to synthesize 5-HMF (Yunchao Feng, Green Chemistry 2020,22(18), 5984-; 5-HMF is then converted to BHMTH over a heterogeneous metal catalyst (Keiichi Tomishige, Catalysis communications.12(2010) 154-156). Furthermore, first, the following stepsCu-catalyzed 5-HMF preparation of 2, 5-Dihydroxymethylfuran (DHMF), andn-catalyzed DHMF to produce BHMTH (Klaus Hellgardt, RSCAdv.,2017,7, 31401). Use twoThe BHMTH prepared by the step method not only has complex reaction process, but also increases the cost. Therefore, the direct conversion of 5-HMF to BHMTH has attracted considerable attention. However, the related studies in the aqueous phase and using non-noble metal catalysts are still in the initiative. It is therefore an urgent challenge to develop efficient, inexpensive, environmentally friendly non-noble metal catalysts for the catalytic conversion of HMF to BHMTHF.

Disclosure of Invention

In view of the above background, the present invention proposes the use of inexpensive non-noble bimetallic nickel and cobalt as active components, acidic oxide gas phase SiO₂As carrier, Na₂CO₃The double-metal catalyst is prepared by adopting a coprecipitation method as a precipitant and is used for synthesizing fine chemicals BHMTHF with high added value by carrying out water-phase catalytic hydrogenation on 5-HMF by a one-pot method. The catalytic system takes water as a solvent, is green and economical compared with an organic solvent system, takes non-noble metal as an active component, is easier for industrial production compared with a noble metal catalyst, and is simple in preparation method. The reaction process is schematically shown in figure 1. The method provides a simple, cheap, efficient and environment-friendly industrial production method for converting 5-HMF into BHMTHF.

The non-noble bimetal supported catalyst comprises the following specific steps: firstly, respectively adding metal salt aqueous solution containing active components into a carrier to form precursor mixed liquor, and then adding prepared Na₂CO₃And the NaOH solution is added into the precursor mixed solution dropwise and kept stirring until the precursor mixed solution is medium-strong alkaline (such as pH 8-12, preferably 10), and the aging is continued for 10 h. And washing the aged mixed solution to be neutral by using deionized water. Then the mixture is dried in an oven at 100 ℃ for 12 hours. Then roasting at 400-600 ℃, preferably 500 ℃ for 3-5h, and reducing in a hydrogen atmosphere before use.

The invention also provides application of the non-noble bimetallic supported catalyst in hydrogenation reaction with 5-hydroxymethylfurfural, 3-hydroxymethylcyclopentanol and 3-hydroxymethylcyclopentanone as substrates.

The invention also provides a method for preparing BHMTHF by catalytic hydrogenation of 5-HMF, which comprises the following steps: adding 5-HMF, a solvent and a non-noble bimetal supported catalyst into an intermittent closed high-pressure reaction kettle, and carrying out catalytic selective hydrogenation reaction under stirring, wherein preferably, the dosage of the non-noble bimetal supported catalyst is 1/10-1/2, preferably 3/10 of the mass of the 5-HMF, the initial pressure of hydrogen is 1-6 MPa, the reaction temperature is 90-120 ℃, and the reaction time is 1-5 h.

The 5-HMF water phase hydrogenation comprises the following specific steps: 0.2g of 5-HMF, 10mL of water and 0.06g of catalyst were weighed into a 40mL reactor. Replacing the air in the kettle with nitrogen for three to four times, filling hydrogen until the initial pressure is 3MPa, starting a stirring device at about 400r/min, heating to 110 ℃, reacting for 4 hours, cooling, separating the product by a centrifuge, and carrying out quantitative analysis by adopting high performance liquid chromatography (HPLC, Thermo Scientific).

The non-noble bimetallic catalyst provided by the invention is used for preparing BHMTHF by the aqueous phase hydrogenation of 5-HMF, and the deionized water is used as a solvent, so that the production cost can be reduced, and the environment protection can be facilitated. The method has the advantages of low requirement on equipment, simple operation, renewable raw material 5-HMF, high product selectivity and wide market application prospect. Compared with a noble metal catalyst, the catalyst adopted by the invention has the advantages of low price and the like. The catalyst can be recycled only after being dried without regeneration, and the yield is basically kept unchanged, so that the method has obvious advantages.

Drawings

FIG. 1 non-noble bimetallic catalyst Ni₁/Co₃-SiO₂Reaction scheme for preparing BHMTHF by catalyzing 5-HMF aqueous phase hydrogenation.

FIG. 2 is a graph showing the effect of separating the metal catalyst of the present invention by a magnet after the reaction is completed.

FIG. 3 is a liquid phase spectrogram of a BHMTHF product prepared by aqueous phase hydrogenation of 5-HMF at a reaction temperature of 110 ℃, a reaction pressure of 3MPa, a reaction material-liquid ratio of 0.2g/10ml, a reaction time of 4h and a stirring speed of 400 r/min.

Detailed Description

The invention is further illustrated by reference to the examples. Unless otherwise specified, reagents and equipment used in the following examples are commercially available products. The specific implementation case is as follows:

example 1

Preparation of the catalyst: weighing 0.003mol of Ni (NO)₃)₂·6H₂O and 0.009mol of Co (NO)₃)₂·6H₂O in 150ml deionized water, 1g of CeO₂To obtain a precursor. Then 3g of Na is weighed₂CO₃And 1g NaOH in 10ml deionized water. Dropwise adding the mixture into the precursor mixed solution and keeping stirring. Stirring until the pH value is 10, and continuing aging for 10 h. And washing the aged mixed solution to be neutral by using deionized water. Then the mixture is dried in an oven at 100 ℃ for 12 hours. And roasting at 500 ℃ for 4h, and reducing in a hydrogen atmosphere before use to obtain the bimetallic catalyst.

Preparation of BHMTHF: 0.2g of 5-HMF, 10mL of water and 0.06g of catalyst (Ni)_x-Co_y/CeO₂Where x is 1, y is 3, CeO₂As a carrier) was charged into a 40mL reaction kettle. Replacing the air in the kettle with nitrogen for three to four times, filling hydrogen until the initial pressure is 3MPa, starting a stirring device at about 400r/min, heating to 110 ℃, reacting for 4 hours, cooling, separating the catalyst and the product by a magnet, and recovering the catalyst, wherein the separation effect diagram is shown in figure 2. The liquid product (HPLC, Thermo Scientific) was qualitatively and quantitatively analyzed by high performance liquid chromatography. The result is: the conversion of 5-HMF was 99.7% and the yield of BHMTHF was 14.7%.

Example 2

The catalyst was prepared in the same manner as in example 1, except that CeO was used as the catalyst₂Replacement by gas-phase SiO₂And the reacted catalyst is recovered by a magnet and is used for repeated circulation experiments.

The preparation method of BHMTHF was performed according to the method in example 1. The product was qualitatively and quantitatively analyzed by High Performance Liquid Chromatography (HPLC), and a liquid chromatogram under such conditions is shown in FIG. 3. The peak at 22-24min is indicative of BHMTHF. The result is: the conversion of 5-HMF was 100% and the yield of BHMTHF was 82.9%.

Examples 3 to 5

The corresponding bimetallic catalyst was prepared as in example 2, with the Co/Ni atoms of example 3The ratio is 1/1 (i.e. 0.003mol of Ni (NO) is weighed out₃)₂·6H₂O and 0.003mol of Co (NO)₃)₂·6H₂O); the Co/Ni atomic ratio in example 4 was 2/1 (i.e., 0.003mol of Ni (NO) was weighed in₃)₂·6H₂O and 0.006mol of Co (NO)₃)₂·6H₂O); the Co/Ni atomic ratio in example 5 was 4/1 (i.e., 0.003mol of Ni (NO)₃)₂·6H₂O and 0.012mol of Co (NO)₃)₂·6H₂O)。

The catalyst prepared as described above was tested in the same manner as in example 2, and the conversion and selectivity of the product obtained by the reaction were measured, and are shown in Table 1.

TABLE 1 preparation of different types of catalysts and their effect on the conversion and selectivity of the aqueous hydrogenation of 5-HMF to BHMTHF

From the general examples 1 to 5, it is clear that SiO is present in the carrier gas phase₂Compared with CeO₂The method is more suitable for preparing BHMTHF by the aqueous phase catalytic hydrogenation of 5-HMF, the yield of the BHMTHF is obviously and gradually increased along with the continuous increase of the Co content, and the BHMTHF reaches the maximum yield in the case of Co/Ni (3/1). The BHMTHF yield is reduced by continuing to increase the Co/Ni (4/1) content, so Co/Ni (3:1) is the optimum ratio for catalyst preparation.

Examples 6 to 18

The corresponding bimetallic catalysts prepared by the method of example 2 according to the reaction parameters in the following table were used for the hydrogenation preparation of BHMTHF to study the influence on the conversion and selectivity. The results of the reaction product measurements for each example are shown in Table 2.

TABLE 2 influence of the reaction parameters on the conversion and selectivity of the aqueous hydrogenation of 5-HMF to BHMTHF^[a]

Wherein the content of the first and second substances,^[a]the catalyst dosage to substrate ratio was 30/100,^[b]the ratio of the catalyst amount to the substrate is 10/100;^[c]the ratio of the catalyst amount to the substrate is 20/100;^[d]the ratio of the catalyst amount to the substrate is 40/100;^[e]the catalyst loading to substrate ratio was 5/10.

As can be seen from examples 6 to 9, the selectivity of BHMTHF (increased from 20.7% to 82.9% and then decreased to 57.0%) was increased continuously at a constant substrate concentration, hydrogen pressure and reaction time (0.2 g/10ml,3MPa,4 hours, respectively) (increased from 90 ℃ to 110 ℃), and the yield of BHMTHF reached a maximum of 82.9% at 110 ℃. Therefore, 110 ℃ is the optimum reaction temperature.

As can be seen from examples 10 to 13, the selectivity of BHMTHF, which increased from 2.4% to 82.9% and then decreased to 72.4%, was similar to that at an increasing temperature (from 90 ℃ to 110 ℃), with increasing reaction pressure (from 1MPa to 4MPa), under constant substrate concentration, reaction temperature and reaction time (0.2 g/10ml,110 ℃ C., 4h, respectively). The BHMTHF yield reached a maximum of 82.9% at 3 MPa. Therefore, 3MPa is the optimum hydrogen pressure.

As can be seen from examples 14 to 18, the selectivity of BHMTHF was gradually changed (from 57.9% to 82.9% and further to 80.6%) with increasing reaction time (from 2h to 6h) under the conditions of constant substrate concentration, hydrogen pressure and reaction temperature (0.2 g/10ml,3MPa,110 ℃ respectively), and the yield of BHMTHF reached a maximum of 82.9% at 4 h. Therefore, 4h is the optimum reaction time.

As can be seen from examples 19 to 23, the selectivity of BHMTHF tends to change (from 3.2% to 82.9% and then to 52.8%) with increasing amounts of catalyst (from 10/100 to 50/100) under the conditions of constant substrate concentration, hydrogen pressure, reaction time and reaction temperature (0.2 g/10ml,3MPa,4h,110 ℃ respectively), and the maximum MTBHHF yield reaches 82.9% at a catalyst to substrate ratio of 30/100. Thus, the optimum ratio of catalyst amount to substrate was 30/100.

Example 24

The catalyst recovered in example 2 was washed with deionized water several times and placed in a dry box overnight before being used for the second conversion reaction. The aqueous phase hydrogenation process and test methods were the same as in example 2. The result is: the conversion of 5-HMF was 100% and the yield of BHMTHF was 79.5%.

After the reaction is further completed, the catalyst is recovered, washed with deionized water for multiple times, placed in a drying oven overnight and then used for the third conversion reaction. The aqueous phase hydrogenation process and test methods were the same as in example 2. The result is: the conversion of 5-HMF was 100% and the yield of BHMTHF was 77.6%.

From the comprehensive examples 1 to 24, the present inventors have developed Ni₁-Co₃/SiO₂The bimetallic catalytic system is used for preparing fine chemicals BHMTHF with high added value by the aqueous phase hydrogenation of 5-HMF. When the reaction temperature is 110 ℃, the reaction time is 4h, the hydrogen pressure is 3MPa, the dosage of the catalyst is 30 percent of the substrate, and the stirring speed is 400r/min, the loading capacity of two active components (Co/Ni) is 3/1, the conversion rate of 5-HMF is 100 percent, the selectivity of BHMTHF is 82.9 percent, and the yield of BHMTHF is basically kept unchanged after twice circulation.

The specific examples of the present invention are for illustrative purposes only, and the catalyst is applicable to hydrogenation reactions in which 5-hydroxymethylfurfural, 3-hydroxymethylcyclopentanol and 3-hydroxymethylcyclopentanone are used as substrates. It is not intended to limit the scope of the invention in any way, and modifications and variations will occur to those skilled in the art in light of the foregoing description, and all such modifications and variations are considered to fall within the scope of the invention as defined by the appended claims.