Preparation and Application of a Hydrogenolysis Catalyst for Furanmethanol Compounds

Abstract

The present invention discloses the preparation and application of a hydrogenolysis catalyst for furfuryl alcohol compounds, belonging to the field of fine organic chemicals. In the present invention, molybdenum disulfide is used as a raw material to prepare molybdenum disulfide materials with different structures by different methods such as hydrothermal method, chemical intercalation, etc., and then used as a precursor to obtain catalysts with different O-containing ends through hydrogen peroxide oxidation. The catalyst prepared by the present invention can be used for the one-step catalytic hydrogenolysis reaction of furfuryl alcohol compounds, with good catalytic activity and high selectivity, providing new ideas and methods for the efficient catalytic conversion of biomass.

Description

Technical Field

[0001] The present invention belongs to the field of fine organic chemicals, and particularly relates to the preparation and application of a hydrogenolysis catalyst for furfuryl alcohol compounds. Background Art

[0002] 5-Methylfurfural (MF) is a typical derivative of 5-hydroxymethylfurfural (HMF) and has received increasing attention in recent years in both industry and academia. For example, it serves as a precursor for certain anti-cancer natural products and drugs, as a substrate for organic synthesis research, as an intermediate in agrochemical production. In addition, MF is also a key intermediate in the production of candidate biofuels.

[0003] Generally, the conversion of biomass to MF requires multiple steps. There have been some reports at home and abroad on the preparation of 5-methylfurfural from 5-hydroxymethylfurfural: Chinese Patent with application number CN201410302966.0 reported the preparation and application of a bifunctional synergistic catalyst for catalytic biomass reforming to selectively prepare 5-methylfurfural. This catalyst is mainly composed of montmorillonite-supported metal nanoparticles. Using 5-hydroxymethylfurfural as the substrate and reacting at 130 °C for 16 h, the yield of 5-methylfurfural can reach 90.9%. Hirota et al. reacted 2-methylfuran, phosgene and N,N-dimethylformamide, and then hydrolyzed the reaction mixture to develop a process for preparing MF with high yield; however, this approach has a drawback that phosgene is a toxic substance that has an adverse impact on the environment. Sen et al. reported an effective method for directly synthesizing MF starting from fructose; using Pd / C as the catalyst and in the presence of HI, the MF yield of fructose is 69%.

[0004] As described above, there are still great challenges in synthesizing MF from hydroxymethylfurfural or sugars. Developing a new and green reaction pathway is very urgent. In addition, how to avoid the hydrogenation of highly active aldehyde groups and remove hydroxyl groups without adding remaining groups is a challenge. These challenges require the development of selective hydrogenation catalysts by regulating hydrogenation activity. Therefore, designing a new solid catalyst to enable the catalytic reaction to be completed directionally, selectively and efficiently generate 5-methylfurfural and maximize the separation and purification has very important research significance. Summary of the Invention

[0005] Aiming at the problems mentioned in the background art, the purpose of the present invention is to provide the preparation and application of a hydrogenolysis catalyst for furfuryl alcohol compounds. Molybdenum disulfide (MoS 2 ) as a hydrogenation catalyst widely used in the petroleum industry has broad application prospects due to its relatively low price; Yang Yunquan et al. conducted hydrogenation experimental studies on phenolic compounds using MoS 2 with different structures as catalysts. The results showed that: MoS 2The structure depends on the preparation process. In addition to having a great relationship with its structure, the activity of the catalyst is also affected by the reaction temperature. MoS 2 has characteristics such as a large specific surface area and high activity, providing a basic condition for catalysis, and has achieved good results in the applications in fields such as photocatalysis and catalytic hydrogenation. MoS 2 Applied to the catalytic oxygenation experiment of biomass oil, the refined oil obtained has a relatively high H / C value, increasing from 2.35 of the initial biomass crude oil to 3.38, and it is a type of hydrogenation catalyst worthy of development.

[0006] The present invention specifically adopts the following technical solutions:

[0007] The present invention provides a preparation method of a hydrogenolysis catalyst for furfuryl alcohol compounds, comprising the following steps:

[0008] 1) Using molybdenum disulfide as a raw material to prepare few-layer molybdenum disulfide, multi-layer molybdenum disulfide and nanoporous molybdenum disulfide;

[0009] Among them, few-layer molybdenum disulfide is prepared by a chemical intercalation method, and multi-layer molybdenum disulfide and nanoporous molybdenum disulfide are prepared by a hydrothermal method;

[0010] 2) Respectively using the different molybdenum disulfides prepared in step 1) as precursors, and preparing an O-terminated catalyst through hydrogen peroxide oxidation.

[0011] Preferably, the hydrogen peroxide oxidation in step 2) is carried out at 30 °C.

[0012] Preferably, the molar ratio of hydrogen peroxide to molybdenum disulfide in step 2) is 3:1.

[0013] The present invention also provides the application of the catalyst obtained by the above preparation method in the one-step catalytic hydrogenolysis reaction of furfuryl alcohol compounds.

[0014] Preferably, the furfuryl alcohol compounds include 5-hydroxymethylfurfural, 2,5-dihydroxymethylfuran, furfuryl alcohol, 5-methylfurfuryl alcohol, 3-hydroxymethylfuran, 1-benzofuran-2-methanol, 2-thiophenemethanol, 5-nitrofurfuryl alcohol, 5-hydroxymethyl-2-furoic acid, 4-hydroxymethylpyridine.

[0015] Preferably, the one-step catalytic hydrogenolysis reaction of furfuryl alcohol compounds is: using furfuryl alcohol compounds as reactants, isopropanol (IPA) as a reaction medium, mixing the reactants, the reaction medium and the catalyst, and carrying out a catalytic reaction under a hydrogen atmosphere at 70 °C.

[0016] Preferably, the catalyst is an O-terminated few-layer molybdenum disulfide catalyst synthesized by a chemical intercalation method.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The present invention provides a preparation method of a hydrogenolysis hydroxyl catalyst for furfuryl alcohol compounds. The preparation method is easy to operate, and the obtained catalyst has high catalytic activity and selectivity and can be recycled multiple times.

[0019] 2. The catalyst prepared by the process of the present invention can efficiently catalyze the hydrogenolysis conversion of furfuryl alcohol compounds into fine chemicals. It is synthesized based on biomass platform compounds, reducing the problem of excessive dependence on petroleum. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 In the figure, A is the synthesis process of the F-MoS 2 -O catalyst of the present invention, B is the X-ray diffraction pattern of the F-MoS 2 -O catalyst, C is the atomic force microscope image of the F-MoS 2 -O catalyst, D and E are the transmission electron microscope images of the F-MoS 2 -O catalyst, F is the Raman spectrum of the F-MoS 2 -O catalyst, and G is the X-ray photoelectron spectrum of the Mo element of the F-MoS 2 -O catalyst. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can all be obtained as conventional products through commercial purchase.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] Example 1 Preparation of few-layer molybdenum disulfide (F-MoS 2 ) catalytic material

[0024] Synthesize F-MoS 2 by chemical intercalation method: Under a nitrogen atmosphere, soak 0.5 g of molybdenum disulfide crystalline powder in 4 mL of 1.6 M n-butyllithium / hexane for 48 h. After the MoS 2 is intercalated with lithium to generate Li xMoS 2 Wash with 50 mL of n - hexane by vacuum filtration to remove excess n - butyllithium and organic substances, and then dry under N 2 . Immerse the obtained dry powder in 250 mL of water, and sonicate the resulting suspension to assist in the completion of the exfoliation process. The inserted lithium reacts with water to form hydrogen between the two layers. The generation of H 2 tends to assist in the separation of MoS 2 layers. The obtained dispersion is centrifuged at 5000 revolutions per minute for 15 min to remove the unexfoliated precursors. Finally, the exfoliated molybdenum disulfide layers are completely suspended in the aqueous solution; the precipitate is washed and centrifuged several times for collection, and the final product is dried under vacuum for 12 hours. Subsequently, it is oxidized by H 2 O 2 (H 2 O 2 : MoS 2 molar ratio = 3:1) to prepare F - MoS 2 - O.

[0025] Example 2 Preparation of catalytic materials of multi - layer molybdenum disulfide (M - MoS 2 ) and nanoporous molybdenum disulfide (NP - MoS 2 )

[0026] Synthesize M - MoS 2 , NP - MoS 2 by hydrothermal method:

[0027] Dissolve ammonium molybdate tetrahydrate (NH 4 ) 6 Mo 7 O 24 ·4H 2 O (2 mmol) and thiourea (60 mmol) in deionized water (70 mL) under magnetic stirring to obtain a homogeneous solution. Then transfer the solution to a 100 mL Teflon - lined stainless - steel autoclave for hydrothermal treatment and maintain it at 200 °C for 24 h. After natural cooling, wash it three times with distilled water and absolute ethanol, and then dry it in a vacuum oven at 60 °C for 12 h to obtain multi - layer molybdenum disulfide (M - MoS 2 ).

[0028] Dissolve 400 mg of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O and 1600 mg of SiO 2 (30 wt.% SiO 2Dissolved in ethylene glycol) was dispersed in 20 mL of deionized water, stirred and air-dried at room temperature, and then vacuum-dried at 80 °C. The dried product was sealed in a 40 mL stainless steel autoclave with 10 mL of CS 2 under argon protection at 400 °C for 4 h. The final product was treated with HF solution at room temperature for more than 8 h to remove SiO 2 , and then washed several times with water and absolute ethanol, and vacuum-dried at 80 °C to obtain nanoporous molybdenum disulfide (NP-MoS 2 ).

[0029] Subsequently, it was oxidized by H 2 O 2 at 30 °C (the molar ratio of H 2 O 2 :MoS 2 = 3:1) to prepare M-MoS 2 -O and NP-MoS 2 -O.

[0030] Example 3 used F-MoS 2 -O catalytic material to catalyze the preparation of 5-methylfurfural from 5-hydroxymethylfurfural

[0031] Weighed 0.03 g of 5-hydroxymethylfurfural and 10 mL of IPA and added them to a 20 mL reaction kettle. Then added 0.05 g of F-MoS 2 -O, and replaced the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heated to 70 °C and maintained for 12 h; waited for the reaction to end, quickly cooled to room temperature, and collected the sample.

[0032] Example 4 used M-MoS 2 -O catalytic material to catalyze the preparation of 5-methylfurfural from 5-hydroxymethylfurfural

[0033] Weighed 0.03 g of 5-hydroxymethylfurfural and 10 mL of IPA and added them to a 20 mL reaction kettle. Then added 0.05 g of M-MoS 2 -O, and replaced the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heated to 70 °C and maintained for 12 h; waited for the reaction to end, quickly cooled to room temperature, and collected the sample.

[0034] Example 5 used NP-MoS 2 -O catalytic material to catalyze the preparation of 5-methylfurfural from 5-hydroxymethylfurfural

[0035] Weighed 0.03 g of 5-hydroxymethylfurfural and 10 mL of IPA and added them to a 20 mL reaction kettle. Then added 0.05 g of NP-MoS 2-O, displace the air in the autoclave with hydrogen five to six times to reduce the air content in the autoclave. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0036] Example 6 uses F-MoS 2 -O catalytic material to catalyze the preparation of 2,5-dimethylfuran from 2,5-dihydroxymethylfuran

[0037] Weigh 0.03 g of 2,5-dihydroxymethylfuran and 10 mL of IPA and add them to a 20 mL autoclave. Then add 0.05 g of F-MoS 2 -O, displace the air in the autoclave with hydrogen five to six times to reduce the air content in the autoclave. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0038] Example 7 uses F-MoS 2 -O catalytic material to catalyze the preparation of 2-methylfuran from furfuryl alcohol

[0039] Weigh 0.03 g of furfuryl alcohol and 10 mL of IPA and add them to a 20 mL autoclave. Then add 0.05 g of F-MoS 2 -O, displace the air in the autoclave with hydrogen five to six times to reduce the air content in the autoclave. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0040] Example 8 uses F-MoS 2 -O catalytic material to catalyze the preparation of 2,5-dimethylfuran from 5-methylfurfuryl alcohol

[0041] Weigh 0.03 g of 5-methylfurfuryl alcohol and 10 mL of IPA and add them to a 20 mL autoclave. Then add 0.05 g of F-MoS 2 -O, displace the air in the autoclave with hydrogen five to six times to reduce the air content in the autoclave. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0042] Example 9 uses F-MoS 2 -O catalytic material to catalyze the preparation of 3-methylfuran from 3-hydroxymethylfuran

[0043] Weigh 0.03 g of 3-hydroxymethylfuran and 10 mL of IPA and add them to a 20 mL autoclave. Then add 0.05 g of F-MoS 2 -O, displace the air in the autoclave with hydrogen five to six times to reduce the air content in the autoclave. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0044] Example 10 uses F-MoS 2Preparation of 2-methylbenzofuran by catalytic oxidation of 1-benzofuran-2-methanol with -O catalytic material

[0045] Weigh 0.03 g of 1-benzofuran-2-methanol and 10 mL of IPA, add them to a 20 mL reaction kettle, and then add 0.05 g of F-MoS 2 -O. Replace the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0046] Example 11 uses F-MoS 2 -O catalytic material to catalyze the preparation of 2-methylthiophene from 2-thiophenemethanol

[0047] Weigh 0.03 g of 2-thiophenemethanol and 10 mL of IPA, add them to a 20 mL reaction kettle, and then add 0.05 g of F-MoS 2 -O. Replace the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0048] Example 12 uses F-MoS 2 -O catalytic material to catalyze the preparation of 5-nitro-2-methylfuran from 5-nitrofurfuryl alcohol

[0049] Weigh 0.03 g of 5-nitrofurfuryl alcohol and 10 mL of IPA, add them to a 20 mL reaction kettle, and then add 0.05 g of F-MoS 2 -O. Replace the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0050] Example 13 uses F-MoS 2 -O catalytic material to catalyze the preparation of 5-methyl-2-furoic acid from 5-hydroxymethyl-2-furoic acid

[0051] Weigh 0.03 g of 5-hydroxymethyl-2-furoic acid and 10 mL of IPA, add them to a 20 mL reaction kettle, and then add 0.05 g of F-MoS 2 -O. Replace the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heat to 70 °C and maintain for 12 h; wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0052] Example 14 uses F-MoS 2 -O catalytic material to catalyze the preparation of 4-methylpyridine from 4-hydroxymethylpyridine

[0053] Weigh 0.03 g of 4-hydroxymethylpyridine and 10 mL of IPA and add them to a 20 mL reaction kettle. Then add 0.05 g of F-MoS 2 -O. Replace the air in the kettle with hydrogen five to six times to reduce the air content in the kettle. Then heat to 70 °C and maintain for 12 h. Wait for the reaction to end, quickly cool to room temperature, and collect the sample.

[0054] The reaction conditions and sample properties of Examples 3-14 are shown in Table 1.

[0055] Table 1

[0056]

[0057]

[0058] As can be seen from Table 1, the catalyst of the present invention can achieve efficient one-step catalytic hydrogenolysis of hydroxyl groups in furan compounds. Among them, in the case of Example 3, the selectivity of hydrogenolysis and hydrogenation of 5-hydroxymethylfurfural to synthesize 5-methylfurfural is as high as 99.5%; and it is universal for the reactions of other furans (such as 2,5-hydroxymethylfuran, furfuryl alcohol, 5-methylfurfuryl alcohol, 3-hydroxymethylfuran, etc.).

[0059] The embodiments described above only represent several preferred embodiments of the present invention. The description is relatively specific and detailed, but it does not limit the present invention. It should be noted that for those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the concept and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. Application of a hydrogenolysis catalyst for furfuryl alcohol compounds in the one-step catalytic hydrogenolysis reaction of furfuryl alcohol compounds; The preparation method of the hydrogenolysis catalyst for furfuryl alcohol compounds comprises the following steps: 1) Prepare few-layer molybdenum disulfide, multi-layer molybdenum disulfide and nanoporous molybdenum disulfide using molybdenum disulfide as a raw material; Among them, Prepare few-layer molybdenum disulfide by chemical intercalation method, and prepare multi-layer molybdenum disulfide and nanoporous molybdenum disulfide by hydrothermal method; 2) Respectively use the different molybdenum disulfides prepared in step 1) as precursors, and prepare an O-terminated catalyst by hydrogen peroxide oxidation at 30 °C; Among them, the molar ratio of hydrogen peroxide to molybdenum disulfide is 3:

1.

2. The application according to claim 1, characterized in that the furfuryl alcohol compounds include 5-hydroxymethylfurfural, 2,5-dihydroxymethylfuran, furfuryl alcohol, 5-methylfurfuryl alcohol, 3-hydroxymethylfuran, 1-benzofuran-2-methanol, 5-nitrofurfuryl alcohol, 5-hydroxymethyl-2-furoic acid.

3. The application according to claim 1, characterized in that the one-step catalytic hydrogenolysis reaction of furfuryl alcohol compounds is: using furfuryl alcohol compounds as reactants, isopropanol as a reaction medium, mixing the reactants, the reaction medium and the catalyst, and carrying out a catalytic reaction in a hydrogen atmosphere at 70 °C.

4. The application according to claim 3, characterized in that the catalyst is an O-terminated few-layer molybdenum disulfide catalyst synthesized by chemical intercalation method.

Images