Method for preparing furfuryl alcohol through furfural hydrogenation

Abstract

The invention relates to the technical field of furfuryl alcohol preparation, in particular to a method for preparing furfuryl alcohol through furfural hydrogenation. According to the method for preparing furfuryl alcohol through furfural hydrogenation, in a hydrogen atmosphere, under the catalytic action of a catalyst and in a reducing atmosphere, a reaction system is formed by taking furfural as a substrate, adding oxidized coenzyme NAD < + > and alcohol dehydrogenase ADH and taking a buffer solution as a reaction medium, and furfuryl alcohol is generated through furfural hydrogenation reaction. According to the method, hydrogenation reduction of furfural is catalyzed through a catalyst coupling cofactor regeneration (NADH) and an enzyme (alcohol dehydrogenase, ADH) reaction to prepare furfuryl alcohol, a high catalytic effect can be obtained under a very mild condition, and the method has a good market prospect.

Description

Technical Field

[0001] The invention relates to the technical field of furfuryl alcohol preparation, and in particular to a method for preparing furfuryl alcohol by hydrogenating furfural. Background Art

[0002] As a versatile chemical product, furfuryl alcohol is widely used in the manufacture of lubricants, dispersants, and materials such as lysine and vitamin C. In the process of upgrading and transforming biomass resources, the implementation of selective hydrogenation reduction reaction strategy is an important link in obtaining high value-added products.

[0003] Direct hydrogenation of furfural to prepare furfural alcohol with general catalysts produces byproducts, and the conditions are mostly high temperature and high pressure, which poses a safety hazard. For example, in the experiment of preparing furfural alcohol by hydrogenation reduction of furfural in Chinese patent CN202410103423.X, the catalyst prepared by it needs to be under the conditions of hydrogen pressure of 2MPa and temperature of 100℃ to achieve a good furfural conversion rate and furfural alcohol yield, which has the disadvantages of high reaction temperature and high hydrogen pressure. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing furfuryl alcohol by hydrogenating furfural in view of the above-mentioned deficiencies in the prior art.

[0005] The method for preparing furfuryl alcohol by hydrogenation of furfural comprises the following steps: in a hydrogen atmosphere, under the catalytic action of a catalyst, under a reducing atmosphere, using furfural as a substrate, adding an oxidized coenzyme NAD + , alcohol dehydrogenase ADH, and a buffer solution as the reaction medium to form a reaction system, and furfural is hydrogenated to produce furfural alcohol.

[0006] Further, the method specifically comprises the following steps: fully mixing furfural, platinum catalyst and pH 3-10 buffer solution and then adding oxidized coenzyme NAD + , alcohol dehydrogenase ADH, light, 0.1-2 MPa hydrogen, and stirring at 20-60 ℃ for 2-6 h to obtain furfuryl alcohol.

[0007] Furthermore, the platinum catalyst is Pt / TiO 2 、Pt / Al 2 O 3 or Pt / SAPO-11.

[0008] Furthermore, the platinum catalyst is Pt / TiO 2 The preparation method is to make TiO 2 With Pt(NH 3 ) 4 (NO 3 ) 2 After the hydrothermal reaction, the mixture was dried and kept at 450°C for a period of time to obtain platinum-based catalyst nanoparticles with an average particle size of less than 12 nm.

[0009] Furthermore, the buffer is a phosphate buffer with a pH of 9.

[0010] Furthermore, the mass volume ratio of furfural to buffer is 1-10 mg / ml.

[0011] Furthermore, the mass volume ratio of the catalyst to the buffer solution is 0.5-5 mg / ml.

[0012] Furthermore, the oxidized coenzyme NAD + The molar volume ratio to the buffer is 0.5-3 mM.

[0013] Furthermore, the mass volume ratio of the alcohol dehydrogenase ADH to the buffer solution is 1-5 mg / ml.

[0014] The present invention catalyzes the hydrogenation reduction of furfural to prepare furfuryl alcohol by the reaction of catalyst-coupled cofactor regeneration (NADH) and enzyme (alcohol dehydrogenase, ADH), and can obtain high catalytic effect under very mild conditions, which has good market prospects. In the enzymatic reaction cycle, oxidized coenzyme I (NADH + ) is reduced to generate NADH, which acts as a hydrogen donor and uses hydrogen ions to reduce furfural, which is then oxidized to generate NAD + The platinum catalyst decomposes hydrogen into hydrogen ions (the only byproduct of the reaction), and NAD + Then it is reduced to generate NADH, achieving a closed-loop cycle. The reaction process is as follows: Figure 1 .

[0015] In the method of the present invention, NADH can be regenerated, which greatly reduces the cost. The reaction conditions of the present invention are low temperature and low pressure, the environment is milder and safer, and the highest furfuryl alcohol selectivity, that is, higher TOF, can be achieved after 4 hours of reaction. It can also effectively reduce H 2 The usage amount can be reduced by using the cheaper oxidized coenzyme I to further reduce the reaction cost.

[0016] The present invention uses an activator hydrothermal method to induce metal oxides to generate highly dispersed, small particles, and a multiphase catalyst Pt / TiO with a smaller band gap. 2 , based on Pt / TiO 2 The photocatalyst uses furfural as a substrate, and the reaction system is constructed by reducing oxidative coenzyme I to generate NADH, a coenzyme factor for hydrogenation reduction of furfural to furfuryl alcohol. The invention has the advantages of mild reaction conditions, low reaction cost, high yield, good recyclability, and easy catalyst separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of the reaction process of the present invention; Figure 2 The X-ray diffraction pattern (XRD) of the catalyst synthesized in Example 1 of the present invention; Figure 3 This is a high-resolution transmission electron microscopy (HRTEM) image of the catalyst synthesized in Example 1 of the present invention. DETAILED DESCRIPTION

[0018] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0019] Example 1 Take TiO 2 Carrier 50 mg, 20 mg Pt(NH 3 ) 4 (NO 3 ) 2 , placed in a polytetrafluoroethylene liner, and 10-15 ml of deionized water was added dropwise and stirred to mix evenly; then transferred to a stainless steel reactor and hydrothermaled at 180 °C in an oven for 5 h; the hydrothermal sample was dried at 80 °C overnight, then heated to 450 °C at a heating rate of 5 °C / min, kept constant for 150 min, cooled naturally, and finally ground and sealed the obtained sample to obtain a Pt / TiO with an active metal content of 5 wt%. 2 Catalyst, denoted as PT-1.

[0020] like Figure 2 , Figure 3 As shown in the XRD and HRTEM images of the catalyst synthesized in Example 1, it can be seen that the catalyst particles prepared in Example 1 are uniformly distributed and highly dispersed, and the particles are smaller than 12 nm.

[0021] The particles of the catalyst prepared by the present invention are smaller than 12 nm, and the particles are evenly dispersed, small in size, highly dispersed, and have the characteristics of high activity, stability, and selectivity of target products.

[0022] Example 2 Take TiO 2 Carrier 50 mg, 20 mg H 2 PtCl 6 , the rest is the same as in Example 1, to obtain Pt / TiO 2 Catalyst, denoted as PT-2.

[0023] Example 3 Take TiO 2 Carrier 50 mg, 20 mg Cl 4 K 2Pt, and the rest are the same as in Example 1 to prepare Pt / TiO 2 Catalyst, denoted as PT-3.

[0024] Example 4 Take TiO 2 Carrier 50 mg, 20 mg Pt(NH 3 ) 4 (NO 3 ) 2 , placed in a polytetrafluoroethylene liner, and 10-15 ml of deionized water was added dropwise and stirred to mix evenly; then transferred to a stainless steel reactor and hydrothermaled at 160 °C in an oven for 7 h; the hydrothermal sample was dried at 80 °C overnight, then heated to 500 °C at a heating rate of 10 °C / min, kept constant for 150 min, cooled naturally, and finally ground and sealed the obtained sample to obtain Pt / TiO with an active metal content of 5 wt%. 2 Catalyst, denoted as PT-4.

[0025] Example 5 Take 50 mg of SAPO-11 molecular sieve and 20 mg of Pt(NH 3 ) 4 (NO 3 ) 2 , the rest were the same as in Example 1 to obtain a Pt / SAPO-11 catalyst, denoted as PS-1.

[0026] Example 6 Take 50 mg of ZIF-8 molecular sieve and 20 mg of Pt(NH 3 ) 4 (NO 3 ) 2 , the rest were the same as in Example 1 to obtain a Pt / ZIF-8 catalyst, denoted as PZ-1.

[0027] Example 7 A method for preparing furfuryl alcohol from furfural comprises the following steps: (1) Mix furfural and phosphate buffer in proportion; (2) adding the platinum catalyst prepared in Example 1 to the mixed solution of step (1); (3) adding oxidized coenzyme NAD+ and alcohol dehydrogenase ADH to the mixed solution of step (1); (4) Irradiation, 0.9 MPa hydrogen, 35°C, stirring and reacting for 2-10 h.

[0028] Among them, the amount of phosphate buffer added is 30 mL, the amount of catalyst added is 1 mg / ml, the amount of furfural acid added is 0.5 mM, the amount of NAD+ added is 1 mM, the amount of alcohol dehydrogenase ADH added is 2 mg / ml, and the buffer pH is 8; it is numbered A1.

[0029] During the reaction, the concentration of furfuryl alcohol in the reaction solution was detected every 2 hours.

[0030] Example 8 A method for preparing furfuryl alcohol from furfural comprises the following steps: (1) Mix furfural and phosphate buffer in proportion; (2) adding the platinum catalysts prepared in Examples 2-6 to the mixed solution of step (1); (3) adding oxidized coenzyme NAD+ and alcohol dehydrogenase ADH to the mixed solution of step (1); (4) Irradiation, 0.9 MPa hydrogen, 35°C, stirring and reacting for 2-6 h.

[0031] Among them, the amount of phosphate buffer added is 30 mL, the amount of catalyst added is 1 mg / ml, the amount of furfural acid added is 0.5 mM, the amount of NAD+ added is 1 mM, the amount of alcohol dehydrogenase ADH added is 2 mg / ml, and the buffer pH is 8.

[0032] Example 9 The pH of the buffer solution in Example 7 was changed to 5.8, 6.4, 7, 7.6, and 9 to obtain reaction products numbered A2-A6.

[0033] Example 10 The temperature in Example 7 was changed to 25°C, 30°C, 40°C, and 45°C to obtain reaction products numbered A7-A10.

[0034] Embodiment 11 The hydrogen pressure in Example 7 was changed to 0.4 MPa, 0.6 MPa, 0.8 MPa, and 1 MPa to obtain reaction products numbered A11-A14.

[0035] The evaluation results of the hydrogenation reduction reaction of Examples 1-8 are shown in Table 1

[0036] The selectivity here is the amount of NADH obtained by the reactants divided by the NAD input before the reaction. + Quantity can be obtained.

[0037] It can be seen from Table 1 that under the low temperature and low pressure environment of pH 8, temperature 35°C, and hydrogen pressure 0.9 MPa, the reaction time of 4 hours makes the NADH yield reach the maximum, which is 94.4%. Under the above conditions, the selectivity of furfural reduction to prepare furfuryl alcohol is 94.4.

[0038] For matters not mentioned above, the prior art applies.

[0039] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art to which the present invention belongs may make various modifications or supplements to the specific embodiments described or replace them in a similar manner, but they will not deviate from the direction of the present invention or exceed the scope defined by the attached claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing furfuryl alcohol by hydrogenating furfural, characterized in that: In a hydrogen atmosphere, under the catalytic action of the catalyst, furfural is used as the substrate and the oxidized coenzyme NAD is added. + , alcohol dehydrogenase ADH, and a buffer solution as the reaction medium to form a reaction system, and furfural is hydrogenated to produce furfural alcohol.

2. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 1, characterized in that: The specific steps include: fully mixing furfural, platinum catalyst, and pH 3-10 buffer, and then adding oxidized coenzyme NAD + , alcohol dehydrogenase ADH, light, 0.1-2 MPa hydrogen, and stirring at 20-60 ℃ for 2-6 h to obtain furfuryl alcohol.

3. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 2, characterized in that: The platinum-based catalyst is Pt / TiO2, Pt / Al2O3 or Pt / SAPO-11.

4. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 3, characterized in that: The platinum catalyst is Pt / TiO2, and the preparation method is to hydrothermally react TiO2 with Pt(NH3)4(NO3)2, dry it, and keep it at 450°C for a period of time to obtain platinum catalyst nanoparticles with an average particle size of less than 12 nm.

5. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 2, characterized in that: The buffer is a phosphate buffer with a pH of 9.

6. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 1 or 2, characterized in that: The mass volume ratio of furfural to buffer is 1-10 mg / ml.

7. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 1 or 2, characterized in that: The mass volume ratio of the catalyst to the buffer solution is 0.5-5 mg / ml.

8. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 1 or 2, characterized in that: The oxidized coenzyme NAD + The molar volume ratio to the buffer is 0.5-3 mM.

9. A method for preparing furfuryl alcohol by hydrogenating furfural as claimed in claim 1 or 2, characterized in that: The mass volume ratio of the alcohol dehydrogenase ADH to the buffer solution is 1-5 mg / ml.

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