A method for preparing alcohol substances using aldehyde substances

Abstract

The present invention discloses a method for preparing 2,5-furan dimethanol by selective hydrogenation of C=O using 5-hydroxymethylfurfural, 5-hydroxymethylfurfural, rhodium / cerium oxide catalyst and tetrahydrofuran are added to the reactor in proportion of 0.08-0.2g:0.025-0.05g:10mL, hydrogen replaces air, and catalyzes the selective synthesis of 2,5-furan dimethanol from 5-hydroxymethylfurfural. The reaction conditions are: reaction temperature 100-150°C, hydrogen pressure 0.1-3MPa, stirring speed 400-800rpm, and reaction time 0.1h-5h. The present invention uses rhodium / cerium oxide containing oxygen vacancies as a catalyst, not only effectively activates and cracks hydrogen to realize hydrogen overflow, and has a strong adsorption capacity for 5-hydroxymethylfurfural, and has a weak adsorption capacity for 2,5-furan dimethanol, effectively improving the selective hydrogenation of 5-hydroxymethylfurfural to generate 2,5-furan dimethanol.

Description

Technical Field

[0001] The invention belongs to the technical field of 2,5-furan dimethanol preparation, and specifically relates to a method for preparing 2,5-furan dimethanol by selective hydrogenation of 5-hydroxymethylfurfural. Background Art

[0002] 2,5-bis(hydroxymethyl)furan (BHMF), as a hydrogenation product of 5-hydroxymethylfurfural, can be used to synthesize chemicals such as foams, resins, and pharmaceutical intermediates.

[0003] At present, the catalysts used for catalytic hydrogenation of 5-hydroxymethylfurfural to prepare 2,5-furan dimethanol mainly include supported catalysts and some single-atom catalysts. Compared with non-precious metals such as Co, Cu, Fe, etc., precious metals such as Pt, Pd, Ru, Ir, and Rh (The Journal of Physical Chemistry C, 125 (2021) 9657-9678; Applied Catalysis A: General, 578 (2019) 122-133; Chinese Journal of Catalysis, 43 (2022) 793-801; Applied Catalysis A: General, 643 (2022) 118762) have absolute advantages in activating and cracking hydrogen, and are therefore often used as active sites for hydrogen. At the same time, CeO 2 、TiO 2 、SiO 2 Metal oxides such as (AngewandteChemieInternational Edition 60.30(2021)16622–16627; Journal of Colloid and InterfaceScience 615(2022)19-29; ACS Sustainable Chemistry&Engineering 6.11(2018)14292–14301) have the characteristics of more surface oxygen vacancies promoting hydrogen overflow and strong adsorption capacity for 5-hydroxymethylfurfural and C=O of aldehydes, and therefore play an important role in the selective hydrogenation of 5-hydroxymethylfurfural. Summary of the invention

[0004] The purpose of the present invention is to realize the selective hydrogenation of C=O of 5-hydroxymethylfurfural to prepare 2,5-furan dimethanol. 2 On, Rh / CeO 2(110) It can not only efficiently hydrogenate C=O to convert 5-hydroxymethylfurfural into 2,5-furan dimethanol, but also promote hydrogen overflow to completely convert 5-hydroxymethylfurfural. The present invention achieves the selective hydrogenation of biomass-derived 5-hydroxymethylfurfural to prepare 2,5-furan dimethanol by regulating the catalyst crystal surface. The reaction conditions are mild, the selectivity is high, and the yield is high.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] The present invention provides a method for preparing a rhodium / cerium dioxide catalyst, which comprises the following steps:

[0007] S1: dissolve the cerium dioxide support in methanol solution by ultrasonication; add RhCl 3 ·xH 2 O into the solution, stir until the mixture is completely dry, and collect the solid powder;

[0008] S2 The solid powder is then calcined in a tube furnace at N 2 / H 2 Calcinate in an atmosphere, wait for the tube furnace to cool to room temperature, and collect the black solid, which is the rhodium / cerium dioxide catalyst;

[0009] Wherein, the preparation method of the cerium dioxide carrier is as follows:

[0010] a. Slowly add NaOH aqueous solution to Ce(NO 3 ) 2 The aqueous solution is added into a reaction kettle and reacted at 80-200°C;

[0011] b. After the reaction is complete, the product is collected after the reactor is cooled and washed with deionized water and ethanol;

[0012] c. Dry the remaining material in a vacuum drying oven;

[0013] d. The dried material is then placed in a muffle furnace and baked to obtain a cerium dioxide carrier.

[0014] Preferably, in step S1, RhCl 3 ·xH 2 O and the ceria carrier are used in a mass ratio of 1:30 to 1:10, preferably RhCl 3 ·xH 2 The mass ratio of O and ceria carrier used was 1:20.

[0015] In step S2, the solid powder is calcined in a tube furnace, specifically at N 2 / H 2(10%) atmosphere, increase the temperature to 280-320°C at 1.8-2.2°C / min and keep it for 1-3h.

[0016] Preferably, in step a, the concentration of the NaOH aqueous solution is 0.025 mol / L-20.8 mol / L; Ce(NO 3 ) 2 Ce(NO 3 ) 2 6H 2 O, the concentration of its aqueous solution is 0.30mol / L-0.54mol / L; the ratio of the two is 0.05-70; in step b, react at 100-180℃ for 18-32h; wash with deionized water and ethanol alternately for 3-8 times; in step c, put the residual material into a vacuum drying oven and dry it at 60-90℃ for 6-24h; in step d, the specific operation of baking is to heat in a muffle furnace to 400-600℃ at 4-6℃ / min and keep it warm for 2-6h;

[0017] The invention provides a rhodium / cerium dioxide catalyst obtained by the preparation method.

[0018] The present invention further provides a method for preparing 2,5-furan dimethanol by selectively hydrogenating C=O with 5-hydroxymethylfurfural, which comprises the following steps: adding 5-hydroxymethylfurfural, the rhodium / cerium dioxide catalyst as claimed in claim 5 and tetrahydrofuran into a closed reactor, replacing air with hydrogen, and causing a catalytic reaction to generate 2,5-furan dimethanol.

[0019] Preferably, the conditions of the catalytic reaction are: reaction temperature 100-150°C, hydrogen pressure 0.1-4MPa, preferably 2-3MPa, stirring speed 400-1000rpm, preferably 700-900rpm, reaction time 0.5h-8h, preferably 5-7h.

[0020] More preferably, the conditions of the catalytic reaction are: reaction temperature 145° C., hydrogen pressure 3 MPa, stirring speed 800 rpm, and reaction time 5 h.

[0021] In a specific embodiment, the ratio of 5-hydroxymethylfurfural, rhodium / cerium dioxide catalyst and tetrahydrofuran is 0.08-0.2g:0.025-0.05g:10mL; preferably, the ratio of 5-hydroxymethylfurfural, rhodium / cerium dioxide catalyst and tetrahydrofuran is 0.126g:0.05g:10mL.

[0022] Preferably, the closed reactor is a stainless steel closed reactor.

[0023] The beneficial effect of the present invention is that the present invention realizes the directional conversion of 5-hydroxymethylfurfural to 2,5-furan dimethanol by constructing catalysts with different crystal faces under the action of hydrogen overflow. The rhodium / cerium dioxide is used as a catalyst, which can not only effectively activate and crack hydrogen to realize hydrogen overflow, but also has a strong adsorption capacity for 5-hydroxymethylfurfural and a weak adsorption capacity for 2,5-furan dimethanol, effectively improving the selective hydrogenation of 5-hydroxymethylfurfural and realizing the selective hydrogenation of 5-hydroxymethylfurfural to generate 2,5-furan dimethanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the gas chromatogram of 2,5-dimethylfuran prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described with reference to the following examples. Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

[0026] Preparation Example of Rhodium / Cerium Oxide Catalyst

[0027] Step 1: Synthesize ceria with different morphologies (prepare Rh loaded on ceria with different crystal faces to form different catalysts), dissolve 25g NaOH in 30mL deionized water and stir thoroughly to form solution A; 2.17g Ce(NO 3 ) 2 6H 2 O was dissolved in 20mL of deionized water and stirred thoroughly to form solution B; then solution A was slowly added dropwise to solution B and stirred for 1h to form a mixed solution C; then the solution was poured into a 70mL polytetrafluoroethylene reactor and reacted at 100°C for 24h. After the reactor was cooled to room temperature, the product was collected and washed alternately with deionized water and ethanol for 6 times. The residual material was placed in a vacuum drying oven and dried at 80°C for 12h. The dried material was then placed in a muffle furnace, heated to 500°C at 5°C / min, and kept warm for 4h. The light yellow powder obtained is cerium dioxide nanorods. Since cerium dioxide nanorods are mainly surrounded by {110} crystal planes, they are named CeO 2 (110) carrier. The raw materials for the synthesis of cerium dioxide octahedrons are the same as those for nanorods, but the dosage and hydrothermal reaction temperature are different. Solution A contains 120 mL of deionized water and 24 g of Ce(NO 3 ) 2 6H 2 O; solution B contains 40 mL of deionized water and 0.04 g of NaOH. The hydrothermal reaction temperature is 180 °C, and the rest of the operations are consistent with the synthesis of nanorods. Since the surface of the cerium dioxide octahedron is mainly surrounded by {111} crystal planes, it is named CeO 2(111)Carrier.

[0028] Step 2: Weigh 0.2 g of cerium dioxide support and dissolve it in 20 mL of methanol solution by ultrasound. Then weigh 0.01 g of RhCl 3 ·xH 2 O was added to the mixed solution, and magnetic stirring was performed at 80°C until the mixed solution was completely dry, and the solid powder was collected. The solid powder was then calcined in a tube furnace under N 2 / H 2 The temperature was raised to 300°C at 2°C / min in a (10%) atmosphere and kept at this temperature for 2 hours. After the tube furnace was cooled to room temperature, the black solid was collected. The black solid was the catalyst and was named Rh / CeO 2 (110) and Rh / CeO 2 (111).

[0029] Comparative Example

[0030] 0.126 g 5-hydroxymethylfurfural and 0.050 g CeO 2 As a catalyst, 10 mL of tetrahydrofuran was added to a stainless steel sealed reactor and filled with 2 MPa H 2 , react at 145°C for 5h at a stirring speed of 600rpm. After the reaction is completed, cool to room temperature. Use a centrifuge for solid-liquid separation (8000r / min, 5min), and use a gas chromatograph (GC, Agilent 7890A) for quantitative analysis. According to gas chromatography analysis, the selectivity of 2,5-furan dimethanol is calculated to be greater than 86.4%, and the molar yield is 36.6%.

[0031] Example 1

[0032] Referring to the comparative example, 0.050 g Rh / CeO 2 (111) was used as the catalyst. The selectivity of 2,5-furan dimethanol was calculated to be greater than 66% and the molar yield was 60% by gas chromatography analysis.

[0033] Example 2

[0034] Referring to the comparative example, 0.050 g Rh / CeO 2 (110) as a catalyst. According to gas chromatography analysis, the selectivity of 2,5-furan dimethanol was calculated to be greater than 97% and the molar yield was 96%.

[0035] Example 3

[0036] Referring to Example 1, 1 MPa H 2 The selectivity of 2,5-furan dimethanol was calculated to be greater than 64% and the molar yield was 58% by gas chromatography analysis.

[0037] Example 4

[0038] Referring to Example 2, 1 MPa H 2 The selectivity of 2,5-furan dimethanol was calculated to be greater than 96% and the molar yield was 95% by gas chromatography analysis.

[0039] Example 5

[0040] Referring to Example 1, 3MPa H 2 The selectivity of 2,5-furan dimethanol was calculated to be greater than 68% and the molar yield was 63% by gas chromatography analysis.

[0041] Example 6

[0042] Referring to Example 2, 3MPa H 2 The selectivity of 2,5-furan dimethanol was calculated to be greater than 97% and the molar yield was 98% by gas chromatography analysis.

[0043] Example 7

[0044] Referring to Example 1, 0.025 g Rh / CeO 2 (111) was used as the catalyst. The selectivity of 2,5-furan dimethanol was calculated to be greater than 56% and the molar yield was 40% by gas chromatography analysis.

[0045] Example 8

[0046] Referring to Example 2, 0.025 g Rh / CeO 2 (110) as a catalyst. According to gas chromatography analysis, the selectivity of 2,5-furan dimethanol was calculated to be greater than 96% and the molar yield was 62%.

[0047] Example 9

[0048] Referring to Example 2, the reaction was carried out at 145° C. for 5 h at a stirring speed of 400 rpm. According to gas chromatography analysis, the selectivity of 2,5-furan dimethanol was calculated to be greater than 96%, and the molar yield was 90%.

[0049] Example 10

[0050] Referring to Example 2, the reaction was carried out at 145° C. for 5 h at a stirring speed of 800 rpm. According to gas chromatography analysis, the selectivity of 2,5-furan dimethanol was calculated to be greater than 97%, and the molar yield was 98%.

[0051] The specific embodiments of the present invention are only for illustrative purposes and do not limit the protection scope of the present invention in any way. Those skilled in the art may modify or change them according to the above description, and these improvements and changes should fall within the protection scope of the claims attached to the present invention.

Claims

1. A method for preparing 2,5-furan dimethanol by selectively hydrogenating C=O with 5-hydroxymethylfurfural, It is characterized in that The method comprises the following steps: adding 5-hydroxymethylfurfural, rhodium / cerium dioxide catalyst and tetrahydrofuran into a closed reactor, replacing air with hydrogen, and causing a catalytic reaction to generate 2,5-furan dimethanol; The rhodium / cerium dioxide catalyst is prepared as follows: S1: dissolve the cerium dioxide support in methanol solution by ultrasonication; add RhCl 3 ·xH 2 O into the solution, stir until the mixture is completely dry, and collect the solid powder; and RhCl 3 ·xH 2 The mass ratio of O and ceria carrier is 1:30 ~ 1:10; S2 The solid powder is then calcined in a tube furnace at N 2 / H 2 The temperature is raised to 280-320°C at 1.8-2.2°C / min in an atmosphere and kept at this temperature for 1-3 hours for calcination. After the tube furnace is cooled to room temperature, the black solid is collected, which is the rhodium / cerium dioxide catalyst; Wherein, the preparation method of the cerium dioxide carrier is as follows: a. Slowly add NaOH aqueous solution to Ce(NO 3 ) 2 The aqueous solution is added into a reaction kettle and reacted at 80-200°C; b. After the reaction is complete, the product is collected after the reactor is cooled and washed with deionized water and ethanol; c. Dry the remaining material in a vacuum drying oven; d. The dried material is then placed in a muffle furnace and baked to obtain a cerium dioxide carrier.

2. The method according to claim 1, It is characterized in that In step S1, RhCl 3 ·xH 2 The mass ratio of O and ceria carrier used was 1:

20.

3. The preparation method according to claim 1, It is characterized in that In step a, the concentration of NaOH aqueous solution is 0.025 mol / L-20.8 mol / L; Ce(NO 3 ) 2 Ce(NO 3 ) 2 6H 2 O, the concentration of its aqueous solution is 0.30mol / L-0.54mol / L; the ratio of the two is 0.05-70; In step b, react at 100-180° C. for 18-32 hours; wash with deionized water and ethanol alternately 3-8 times; In step c, the residual material is placed in a vacuum drying oven and dried at 60-90°C for 6-24h; In step d, the specific operation of baking is to heat the material to 400-600°C at 4-6°C / min in a muffle furnace and then keep the temperature for 2-6 hours.

4. The method according to any one of claims 1 to 3, It is characterized in that The conditions of the catalytic reaction are: reaction temperature 100-150° C., hydrogen pressure 0.1-4 MPa, stirring speed 400-1000 rpm, and reaction time 0.5 h-8 h.

5. The method according to claim 4, It is characterized in that The conditions of the catalytic reaction are: hydrogen pressure 2-3 MPa, stirring speed 700-900 rpm, and reaction time 5-7 h.

6. The method according to claim 5, It is characterized in that The conditions of the catalytic reaction are: reaction temperature 145° C., hydrogen pressure 3 MPa, stirring speed 800 rpm, and reaction time 5 h.

7. The method according to claim 4, It is characterized in that The ratio of the 5-hydroxymethylfurfural, rhodium / cerium dioxide catalyst and tetrahydrofuran is 0.08-0.2g: 0.025~0.05g: 10mL.

8. The method according to claim 7, It is characterized in that The ratio of the 5-hydroxymethylfurfural, rhodium / cerium dioxide catalyst and tetrahydrofuran is 0.126 g: 0.05 g: 10 mL.

9. The method according to claim 4, It is characterized in that The closed reactor is a stainless steel closed reactor.

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