Method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural

Abstract

The present invention relates to a method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural. The method comprises the following steps: adding 5-hydroxymethylfurfural, a catalyst and an organic solvent into a reactor, sealing it under a nitrogen atmosphere, and reacting at 120°C to 160°C for 10 to 14 h with mechanical stirring to obtain the products 2,5-furandicarboxaldehyde and 2,5-furandimethanol; the catalyst is a supported metal catalyst, and the composition of the catalyst includes an active metal and a support, the active metals are Cu and Ce; the loading amount of metallic copper is 1% to 10%, and the loading amount of metallic cerium is 2% to 8%; the support is γ-Al2O3. The present invention realizes the safe and efficient utilization of hydrogen atoms, and the catalyst can be reused.

Description

Technical Field

[0001] The present invention belongs to the field of biomass conversion for preparing chemicals, and specifically relates to a method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol by intermolecular hydrogen transfer of 5-hydroxymethylfurfural. Background Art

[0002] The biomass derivative 5-hydroxymethylfurfural (HMF) is considered a versatile platform compound and an important intermediate connecting biomass resources and the fossil fuel industry. 5-Hydroxymethylfurfural contains a hydroxymethyl group, an aldehyde group, and a furan ring structure, which enables it to produce various valuable products through multiple reactions. 5-Hydroxymethylfurfural is hydrogenated through the aldehyde group to form 2,5-furandimethanol (DHMF). 2,5-Furandimethanol is a diol with high added value and has important applications in the preparation research of fine chemical synthesis, polyurethane, and multi-heterocyclic compounds of drugs. 5-Hydroxymethylfurfural can also be gradually oxidized to 2,5-furandicarboxaldehyde (DFF). 2,5-Furandicarboxaldehyde is a monomer of furan-based biopolymers and an intermediate for drugs, antibacterial agents, and ligands.

[0003] Currently, the catalytic processes for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural usually require external supply of oxidants (H2O2\O2) or hydrogen donors (H2\ethanol), and most reactions need to be carried out under high temperature and high pressure. This makes the redox reaction of HMF very dangerous and environmentally unfriendly, not meeting the standards of green chemistry. Yuan et al. prepared cesium-doped manganese dioxide (Cs / MnO x ) by a soft template method. In N,N-dimethylformamide, at 100 °C and 10 bar O2, the conversion rate of HMF was 98.4%, and the yield of DFF was 94.7%. (Catalysis Science & Technology, 2018, 8: 4430-4439). Aeling et al. used 1,4-butanediol as a hydrogen donor at a relatively high temperature (220 °C), with Cu / AlO xUsing [catalyst name] as the catalyst, the catalytic transfer hydrogenation of HMF to prepare DHMF was studied, and a DHMF yield of 93% was obtained (Catalysis Science & Technology, 2014, 4(8): 2326 - 2331). The Li team reported a method that uses HMF itself as an oxidant and a reductant, in an acetonitrile reaction system, with trimethylaluminum as the catalyst, and through the MPVO reaction, HMF is selectively converted (HMF conversion rate of 44.7%) to DFF and DHMF in a molar ratio of 1:1 (ChemSusChem. 2017, 10(3): 494 - 498). However, the trimethylaluminum catalyst is extremely reactive and prone to spontaneous combustion in air, catching fire instantly, which is too dangerous. As a homogeneous catalyst, the recycling of trimethylaluminum remains a problem in industrial applications. Therefore, developing an efficient, stable, and environmentally friendly heterogeneous catalyst to highly selectively convert HMF to DFF and DHMF under mild reaction conditions is an extremely attractive challenge. Summary of the Invention

[0004] The object of the present invention is to address the problems in the method for producing 2,5 - furandicarboxaldehyde and 2,5 - furandimethanol from 5 - hydroxymethylfurfural, such as the inflammability and explosiveness of hydrogen and oxygen, many by - products, low atom utilization rate, and difficulty in recycling the catalyst. The present invention provides a method for preparing 2,5 - furandicarboxaldehyde and 2,5 - furandimethanol from 5 - hydroxymethylfurfural. The present invention uses a heterogeneous copper - cerium bimetallic catalyst (1% Cu - 5% Ce / γ - Al2O3) to simultaneously prepare 2,5 - furandicarboxaldehyde and 2,5 - furandimethanol from 5 - hydroxymethylfurfural through intermolecular hydrogen transfer without external redox reagents. The catalytic intermolecular hydrogen transfer reaction of 5 - hydroxymethylfurfural realizes the safe and efficient utilization of hydrogen atoms, especially the catalyst can be reused.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for preparing 2,5 - furandicarboxaldehyde and 2,5 - furandimethanol from 5 - hydroxymethylfurfural, the method comprising the following steps:

[0007] Add 5 - hydroxymethylfurfural, the catalyst, and an organic solvent into a reactor, seal it, under a nitrogen atmosphere, stir mechanically, and react at 120°C to 160°C for 10 to 14 h to obtain the products 2,5 - furandicarboxaldehyde and 2,5 - furandimethanol;

[0008] Among them, the molar ratio of the materials is: for every 8 mmol of 5 - hydroxymethylfurfural, add 15 - 25 mL of solvent and 0.5 g - 1 g of the catalyst;

[0009] The catalyst described is a supported metal catalyst, and the composition of the catalyst includes an active metal and a support;

[0010] The active metals of the catalyst are Cu and Ce; the loading amount of the metal copper is 1% to 10%, the loading amount of the metal cerium is 2% to 8%, and the carrier is gamma-Al2O3.

[0011] The organic solvent is tetrahydrofuran, acetonitrile, benzene or 1,4-dioxane.

[0012] The reactor is a high-pressure reactor.

[0013] The material ratio is preferably as follows: 20 mL of solvent is added for every 8 mmol of 5-hydroxymethylfurfural; and 0.5 g of metal catalyst is added for every 8 mmol of 5-hydroxymethylfurfural.

[0014] The preferred reaction temperature is 140°C.

[0015] The preferred reaction time is 12h.

[0016] The essential features of the present invention are:

[0017] The current technology for simultaneously preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural uses a homogeneous catalyst, trimethylaluminum, for the catalytic reaction. However, since the trimethylaluminum catalyst is a colorless, transparent liquid with extremely high reactivity, it is prone to spontaneous combustion in the air and can catch fire instantly, which is too dangerous. In addition, as a homogeneous catalyst, the recycling of trimethylaluminum remains a problem in industrial applications.

[0018] In the liquid-phase catalytic transfer hydrogenation reaction, a metal catalyst is used to dehydrogenate a molecule of 5-hydroxymethylfurfural to produce 2,5-furandicarboxaldehyde in the absence of an external redox reagent, generating hydrogen as a hydrogen donor. Another molecule of 5-hydroxymethylfurfural is hydrogenated as a hydrogen acceptor to produce 2,5-furan dimethanol. This method does not have the presence of hydrogen and oxygen, which can overcome the shortcomings of traditional catalytic oxidation and catalytic hydrogenation methods such as flammability and explosion. The metal catalyst has good catalytic performance and can be recycled, with better safety and greenness. The inventor took into account that 5-hydroxymethylfurfural contains a hydroxymethyl group and an aldehyde group. The hydroxymethyl group can theoretically be dehydrogenated to convert to an aldehyde group, and the aldehyde group can theoretically be hydrogenated to convert to a hydroxymethyl group. Therefore, in the absence of an external redox reagent, 5-hydroxymethylfurfural is used to simultaneously prepare 2,5-furandicarboxaldehyde and 2,5-furan dimethanol through intermolecular hydrogen transfer. The reaction process is as follows:

[0019]

[0020] The present invention uses the method of "intermolecular hydrogen transfer" to replace the traditional redox method. A supported metal copper-cerium catalyst is added to the reactor to catalyze 5-hydroxymethylfurfural to simultaneously prepare 2,5-furandicarboxaldehyde and 2,5-furandimethanol through intermolecular hydrogen transfer.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) This method realizes for the first time the preparation of 2,5-furandicarboxaldehyde and 2,5-furandimethanol by catalyzing 5-hydroxymethylfurfural with a recyclable metal copper-cerium catalyst. The metal catalyst has good performance. The conversion rate of 5-hydroxymethylfurfural can reach up to 45.5%, the yield of 2,5-furandicarboxaldehyde can reach 20.3%, and the highest yield of 2,5-furandimethanol can reach 20.0%.

[0023] (2) After the reaction is completed, the reaction solution can be centrifuged. The metal catalyst sinks to the bottom and can be recycled. The metal copper-cerium catalyst has good stability after running 5 times and has good application prospects.

[0024] (3) Compared with the traditional preparation of 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural by the redox method, using a supported metal catalyst to catalyze the intermolecular hydrogen transfer reaction overcomes the disadvantages of traditional catalytic oxidation and catalytic hydrogenation methods such as being flammable and explosive. Moreover, this reaction has fewer by-products, high atom utilization rate, a simple reaction system, mild reaction conditions, and the catalytic hydrogen transfer reaction can be realized at 140 °C. Specific embodiments

[0025] The essential features and remarkable effects of the present invention can be reflected in the following embodiments, but they do not limit the present invention in any way. Those skilled in the art can make some non-essential improvements and adjustments based on the content of the present invention. The present invention is further described below through specific embodiments.

[0026] The catalyst used in the present invention is a supported metal catalyst, which is a well-known substance. Using γ-Al2O3 as the carrier and metal copper and metal cerium as the active components, a supported metal catalyst is prepared by the impregnation method. The loading amount of metal copper is 0% - 10%, and the loading amount of metal cerium is 0% - 8%.

[0027] The preparation process of the CuCe / γ-Al2O3 catalyst is as follows:

[0028] The first step is to measure the saturated water absorption of the carrier: accurately weigh 1.0 g of the carrier on a watch glass, and gradually add deionized water dropwise until the carrier is completely wet and slightly flowing. Record the volume of pure water used, which is the saturated water absorption of the carrier.

[0029] Step 2: Preparation of supported metal catalyst by impregnation method: Accurately weigh 2.0 g of the support in a crucible. Weigh a certain amount of Cu(NO3)2·3H2O and Ce(NO3)2·6H2O in a beaker according to the loading requirement, add the saturated water absorption of the support measured in the first step, and dissolve completely. Dropwise add the copper-cerium solution onto the support until the support is completely wet and slightly flowing. After standing for 24 h, dry the obtained mixture in a vacuum drying oven at 80 °C for 12 h. Subsequently, grind the obtained solid into powder and calcine it in a muffle furnace at 450 °C for 5 h.

[0030] Step 3: Reduction of the catalyst: Before use, reduce the catalyst using a tubular resistance furnace under the conditions of 450 °C and H2 for 5 h to obtain the catalyst x%Cuy%Ce / γ-Al2O3 (where x represents the mass percentage content of Cu metal salt and y represents the mass percentage content of Ce metal salt).

[0031] Example 1

[0032] Add 5-hydroxymethylfurfural (8 mmol), tetrahydrofuran (20 mL), and the unreduced 1%Cu-5%Ce / γ-Al2O3 catalyst (0.5 g) to a high-pressure reaction kettle, introduce N2 to evacuate the air in the reaction kettle, and stop the reaction after mechanical stirring at 140 °C for 12 h. Cool the reaction to room temperature, centrifuge to separate the supernatant, the catalyst sinks to the bottom, take the supernatant, filter it, and analyze it on a gas chromatograph. The catalyst that sinks to the bottom is recovered, filtered, washed, dried in a vacuum drying oven at 80 °C, and reused in the next reaction.

[0033] Among them, the detection method of the product: After the reaction is completed, centrifuge the reaction solution. The upper layer is a colored clear liquid, and the lower layer is the metal catalyst. Filter the upper clear liquid and perform gas chromatographic analysis. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 45.5%, the yield of 2,5-furandicarboxaldehyde is 20.3%, and the yield of 2,5-furandimethanol is 20.0%.

[0034] Example 2

[0035] Other steps are the same as in Example 1, except that the added catalyst is the unreduced 1%Cu / γ-Al2O3. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 65%, the yield of 2,5-furandicarboxaldehyde is 35%, and the yield of 2,5-furandimethanol is 10%.

[0036] Example 3

[0037] Other steps are the same as those in Example 1, except that the added catalyst is 1% Cu / γ-Al2O3 reduced by H2. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 24.6%, the yield of 2,5-furandicarboxaldehyde is 5.5%, and the yield of 2,5-furandimethanol is 8.3%.

[0038] Example 4

[0039] Other steps are the same as those in Example 1, except that the added catalyst is 1% Cu-5% Ce / γ-Al2O3 reduced by H2. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 34.5%, the yield of 2,5-furandicarboxaldehyde is 6.8%, and the yield of 2,5-furandimethanol is 1.9%.

[0040] Example 5

[0041] Other steps are the same as those in Example 1, except that the added solvent is benzene. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 51.1%, the yield of 2,5-furandicarboxaldehyde is 35%, and the yield of 2,5-furandimethanol is 5.9%.

[0042] Example 6

[0043] Other steps are the same as those in Example 1, except that the added solvent is acetonitrile. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 30.8%, the yield of 2,5-furandicarboxaldehyde is 7.0%, and the yield of 2,5-furandimethanol is 6.8%.

[0044] Example 7

[0045] Other steps are the same as those in Example 1, except that the added solvent is 1,4-dioxane. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 26.2%, the yield of 2,5-furandicarboxaldehyde is 10%, and the yield of 2,5-furandimethanol is 9.6%.

[0046] Example 8

[0047] Other steps are the same as those in Example 1, except that the reaction temperature is 120 °C. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 21.1%, the yield of 2,5-furandicarboxaldehyde is 4.3%, and the yield of 2,5-furandimethanol is 1.4%.

[0048] Example 9

[0049] Other steps are the same as those in Example 1, except that the reaction temperature is 130 °C. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 30.5%, the yield of 2,5-furandicarboxaldehyde is 12.5%, and the yield of 2,5-furandimethanol is 9.3%.

[0050] Example 10

[0051] Other steps are the same as those in Example 1, except that the reaction temperature is 160 °C. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 50%, the yield of 2,5-furandicarboxaldehyde is 32.1%, and the yield of 2,5-furandimethanol is 2.9%.

[0052] Example 11

[0053] Other steps are the same as those in Example 1, except that the reaction time is 10 h. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 24.2%, the yield of 2,5-furandicarboxaldehyde is 3.4%, and the yield of 2,5-furandimethanol is 1.8%.

[0054] Example 12

[0055] Other steps are the same as those in Example 1, except that the reaction time is 14 h. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 31.6%, the yield of 2,5-furandicarboxaldehyde is 27.3%, and the yield of 2,5-furandimethanol is 3.0%.

[0056] Example 13

[0057] Other steps are the same as those in Example 1, except that the amount of 1% Cu-5% Ce / γ-Al2O3 added is 0 g. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 1.2%, the yield of 2,5-furandicarboxaldehyde is 0%, and the yield of 2,5-furandimethanol is 0%.

[0058] Example 14

[0059] Other steps are the same as those in Example 1, except that the amount of 1% Cu-5% Ce / γ-Al2O3 added is 1 g. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 58.3%, the yield of 2,5-furandicarboxaldehyde is 13.9%, and the yield of 2,5-furandimethanol is 2.7%.

[0060] Example 15

[0061] Other steps are the same as those in Example 1, except that the copper loading of the added CuCe / γ-Al2O3 is 0 wt% and the cerium loading is 0 wt%. The reaction results show that the conversion rate of 5-hydroxymethylfurfural is 3.5%, the yield of 2,5-furandicarboxaldehyde is 1.7%, and the yield of 2,5-furandimethanol is 0%.

[0062] Example 16

[0063] Other steps were the same as those in Example 1, except that the copper loading of the added CuCe / γ-Al2O3 was 5 wt%, and the cerium loading was 0 wt%. The reaction results showed that the conversion rate of 5-hydroxymethylfurfural was 62.2%, the yield of 2,5-furandicarboxaldehyde was 15.9%, and the yield of 2,5-furandimethanol was 2.0%.

[0064] Example 17

[0065] Other steps were the same as those in Example 1, except that the copper loading of the added CuCe / γ-Al2O3 was 1 wt%, and the cerium loading was 2 wt%. The reaction results showed that the conversion rate of 5-hydroxymethylfurfural was 33.8%, the yield of 2,5-furandicarboxaldehyde was 12.4%, and the yield of 2,5-furandimethanol was 6.2%.

[0066] Example 18

[0067] Other steps were the same as those in Example 1, except that the copper loading of the added CuCe / γ-Al2O3 was 1 wt%, and the cerium loading was 8 wt%. The reaction results showed that the conversion rate of 5-hydroxymethylfurfural was 24.6%, the yield of 2,5-furandicarboxaldehyde was 7.2%, and the yield of 2,5-furandimethanol was 4.7%.

[0068] Example 19

[0069] Other steps were the same as those in Example 1, except that the number of times the catalyst was reused was 5 times. The reaction results showed that the conversion rate of 5-hydroxymethylfurfural was 36.0%, the yield of 2,5-furandicarboxaldehyde was 16.8%, and the yield of 2,5-furandimethanol was 16.0%.

[0070] According to the above examples, in the case of no external redox reagent, the method for simultaneously preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural by intermolecular hydrogen transfer has good reaction performance, and the conversion rate and yield are relatively high under the experimental conditions of 5-hydroxymethylfurfural (8 mmol), tetrahydrofuran (20 mL), and 1% Cu-5% Ce / γ-Al2O3 (0.5 g). In this reaction, there is no need to use hydrogen and oxygen, which solves the risks of explosion and fire existing in traditional catalytic oxidation methods and catalytic hydrogenation methods, has inherent safety, and the catalytic system of the present invention is simple to operate. The supported metal catalyst has high catalytic activity and still has high catalytic activity after recovery and recycling, indicating that the metal catalyst can be recycled. It has important industrial application value.

[0071] Matters not covered in this invention are well-known technologies.

Claims

1. A method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural, characterized in that the method comprises the following steps: Add 5-hydroxymethylfurfural, a catalyst and an organic solvent into a reactor, seal it, under a nitrogen atmosphere, and react at 120°C to 160°C for 10 to 14 hours with mechanical stirring to obtain the products 2,5-furandicarboxaldehyde and 2,5-furandimethanol; Among them, the molar ratio of the materials is: for every 8 mmol of 5-hydroxymethylfurfural, 15 to 25 mL of solvent and 0.5 g to 1 g of catalyst are added; The catalyst is a supported metal catalyst, and the composition of the catalyst includes an active metal and a carrier; The active metal of the catalyst is Cu and Ce; the loading amount of metallic copper is 1% to 10%, the loading amount of metallic cerium is 2% to 8%, and the carrier is γ-Al2O3.

2. The method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural according to claim 1, characterized in that the organic solvent is tetrahydrofuran, acetonitrile, benzene or 1,4-dioxane.

3. The method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural according to claim 1, characterized in that the reactor is a high-pressure reactor.

4. The method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural according to claim 1, characterized in that the amount of the material ratio is 20 mL of solvent added for every 8 mmol of 5-hydroxymethylfurfural; 0.5 g of metal catalyst is added for every 8 mmol of 5-hydroxymethylfurfural.

5. The method for preparing 2,5-furandicarboxaldehyde and 2,5-furandimethanol from 5-hydroxymethylfurfural according to claim 1, characterized in that the reaction temperature is 140°C and the reaction time is 12 hours.

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