Catalyst for preparing 1, 2-pentanediol from furfuryl alcohol as well as preparation method and application of catalyst

Abstract

The invention belongs to the field of furfuryl alcohol hydrogenation, and particularly relates to a catalyst for preparing 1, 2-pentanediol from furfuryl alcohol as well as a preparation method and application of the catalyst. The catalyst for preparing 1, 2-pentanediol from furfuryl alcohol comprises a composite oxide carrier and a metal catalyst attached to the composite oxide carrier, the composite oxide carrier comprises an oxide core and magnesium oxide attached to the oxide core; the oxide inner core is selected from one, two or three of TiO2, CeO2 and Al2O3; the metal catalyst is Pt or Pt and doped metal, and the doped metal is selected from at least one of Pd and Ru. A novel catalyst carrier design is adopted, the selectivity of the catalyst to 1, 2-pentanediol is further improved, the selectivity of the catalyst to 1, 2-pentanediol reaches 65% or above, and when a double-doped metal form is adopted, the selectivity of 1, 2-pentanediol reaches 80% or above.

Description

Technical Field

[0001] The invention belongs to the field of furfuryl alcohol hydrogenation, and specifically relates to a catalyst for preparing 1,2-pentanediol from furfuryl alcohol, and a preparation method and application thereof. Background Art

[0002] 1,2-Pentanediol is a key intermediate of the fungicide propiconazole. It can also be used as a cosmetic additive to moisturize, lubricate, and inhibit bacteria. 1,2-Pentanediol can also be used to produce surfactants, medicines, polyester fibers, and other products, so it is an important chemical raw material.

[0003] 1,2-Pentanediol can be synthesized from petroleum-based raw materials, for example, using n-pentanoic acid as the raw material, and preparing it through bromination, hydrolysis and reduction reactions; or using n-pentanol as the raw material, preparing it through the route of n-pentanol dehydration → 1-pentene → 1-epoxypentane → 1,2-pentanediol; or hydrolyzing 1,2-epoxypentane with formic acid solution to obtain 1,2-pentanediol. The disadvantage of petroleum-based raw materials is that petroleum resources are non-renewable, and the above reactions also have relatively harsh reaction conditions and problems such as the discharge of three wastes.

[0004] Biomass agricultural and forestry wastes are rich in xylose, arabinose and other resources, and have a natural excellent carbon skeleton for the preparation of pentanediol. Biomass-derived furan compounds are typically furfural, which can be obtained from hemicellulose after hydrolysis and dehydration. Furfural can be further hydrogenated to produce furfuryl alcohol. Using furfural / furfuryl alcohol as raw materials to prepare 1,2-pentanediol through hydrogenation can perfectly solve the shortcomings of using petroleum-based raw materials to prepare 1,2-pentanediol.

[0005] The Chinese invention patent with the authorization announcement number CN113318735B discloses the application of a composite oxide supported Pt catalyst in the preparation of pentanediol from furfural, which uses a sol-gel method to prepare the catalyst carrier MMgO x , M is any one or more of Ti, Fe, and Ce metals; the precursor solution of Pt is impregnated with MMgO x After drying, calcination and reduction, the final catalyst Pt / MMgO was obtained. x Further research found that the carrier MMgO prepared by the sol-gel method x The formation process is calcined at about 800°C, and the final substance is of intermetallic compound nature. It is based on the above characteristics that the catalyst shows improved stability, and the total yield of 1,2-pentanediol and 1,5-pentanediol reaches more than 90%. Under the premise of satisfying the raw material conversion rate, the selectivity of the catalyst for 1,2-pentanediol is about 63%, and 1,5-pentanediol is 33%. The selectivity of the corresponding catalyst for 1,2-pentanediol needs to be further improved. Summary of the invention

[0006] The purpose of the present invention is to provide a catalyst for preparing 1,2-pentanediol from furfuryl alcohol, so as to solve the problem that the selectivity of existing catalysts for 1,2-pentanediol needs to be further improved.

[0007] The second object of the present invention is to provide a method for preparing the catalyst for preparing 1,2-pentanediol from furfuryl alcohol, so as to prepare a catalyst with better selectivity for 1,2-pentanediol in the product.

[0008] The third object of the present invention is to provide the use of the above-mentioned catalyst for preparing 1,2-pentanediol from furfuryl alcohol, which can further reduce the use of catalyst.

[0009] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0010] A catalyst for preparing 1,2-pentanediol from furfuryl alcohol, comprising a composite oxide carrier and a metal catalyst attached to the composite oxide carrier; the composite oxide carrier comprises an oxide core and magnesium oxide attached to the oxide core; the oxide core is selected from TiO 2 、CeO 2 、Al 2 O 3 One, two or three of the following: the metal catalyst is Pt or Pt and a doped metal, and the doped metal is selected from at least one of Pd and Ru.

[0011] The catalyst for preparing 1,2-pentanediol from furfuryl alcohol provided by the present invention adopts a new catalyst carrier design, the carrier has good stability and recycling performance, and can be recycled at least ten times. The selectivity of the catalyst for 1,2-pentanediol is further improved, and the selectivity for 1,2-pentanediol reaches more than 65%. When a dual-doped metal form is used, the selectivity for 1,2-pentanediol reaches more than 80%.

[0012] Preferably, the molar ratio of the oxide core to magnesium oxide is 1:1 to 3. Controlling the oxide core and magnesium oxide within the above range is conducive to obtaining a catalyst with higher 1,2-pentanediol selectivity.

[0013] In order to obtain a catalyst with higher furfuryl alcohol conversion rate and 1,2-pentanediol selectivity, preferably, the content of Pt in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 0.5-8wt%, and the content of the doped metal in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 0-0.8wt%.

[0014] In order to further improve the furfuryl alcohol conversion rate and 1,2-pentanediol selectivity, it is further preferred that the content of Pt in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 2-8wt%, and the content of the doped metal in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 0.2-0.8wt%. A Pt content of more than 2% can ensure a higher furfuryl alcohol conversion rate, for example, a conversion rate of more than 90%. When the doped metal content is further increased, such as increased to 0.4-0.8wt%, the selectivity of 1,2-pentanediol can be further improved.

[0015] Further preferably, the doping metal is Pd or Pd and Ru co-doping, and when Pd and Ru are co-doped, the molar ratio of Pd to Ru is 1:1 to 2. Pd doping or Pd and Ru co-doping can further improve the selectivity of 1,2-pentanediol relative to Ru doping. When Pd and Ru are co-doped, the two doping metals show a similar synergistic effect, and the selectivity of 1,2-pentanediol is increased to about 80%.

[0016] Further preferably, the particle size of the oxide core is 1 to 10 nm. The above particle size range can obtain a catalyst with stable quality and selective catalytic effect. The typical particle size can be in the form of 2 to 10 nm, 2 to 8 nm, 2 to 4 nm, etc. Within the above particle size range, it is conducive to obtaining a catalyst with high 1,2-pentanediol selectivity.

[0017] A method for preparing a catalyst for preparing 1,2-pentanediol from furfuryl alcohol comprises the following steps:

[0018] (1) mixing the dispersion of the oxide core and a soluble magnesium salt solution, performing a precipitation reaction and separation under alkaline conditions, and then performing a first calcination to obtain a carrier precursor powder;

[0019] (2) Mixing and impregnating the support precursor powder with a soluble substance solution of the metal catalyst, and then performing a second calcination and reduction treatment to obtain the catalyst.

[0020] The method for preparing a catalyst for preparing 1,2-pentanediol from furfuryl alcohol of the present invention has a simpler preparation process, high process repeatability and good stability, is suitable for industrial production, and the catalytic performance of the obtained catalyst is significantly improved compared with the prior art.

[0021] In order to make the precipitation reaction proceed uniformly and stably, preferably, in step (1), the soluble magnesium salt is selected from one or a combination of two or more of magnesium chloride, magnesium nitrate and magnesium acetate; and the alkaline condition is to add alkali until the pH of the system is 9 to 11.

[0022] In order to further improve the precipitation process, it is further preferred that the alkali is added in the form of a mixed alkali solution, wherein the mixed alkali solution contains a strong alkali and a weak alkali; the strong alkali is NaOH, and the weak alkali is Na 2 CO 3 ; NaOH, Na 2 CO 3 The molar ratio is (2~0.5):1.

[0023] The precipitation reaction can be efficiently promoted by heating. Generally speaking, the precipitation reaction temperature is controlled to be 40-100°C and the time is 3-4h, and the precipitation reaction can be completed quickly. More preferably, the precipitation reaction temperature can be controlled to be 40-80°C and the time is 3-4h. Preferably, in step (1), the first calcination temperature is 600-800°C and the time is 2-6h. Using the above calcination conditions, the composite oxide carrier can be quickly obtained.

[0024] The metal catalyst can be loaded on the composite oxide support by referring to the existing methods. For example, the mixed impregnation in step (2) adopts the equal volume impregnation method. Preferably, the mixed impregnation time is at least 2 hours. Further preferably, the mixed impregnation is carried out under the assistance of ultrasound.

[0025] During calcination and reduction, the desired oxidation and reduction purposes can be achieved. In terms of reaction efficiency, preferably, in step (2), the temperature of the second calcination is 350-750°C, and the time is 2-6 hours; the temperature of the reduction treatment is 150-350°C, and the time is 2-6 hours.

[0026] Preferably, the reduction treatment is carried out in a hydrogen atmosphere or a mixed atmosphere containing hydrogen. In step (2), among the soluble substances of the metal catalyst, the soluble substance of Pt is selected from HPtCl 6 or NaPtCl 6 , the soluble substance of Pd is selected from PdCl 3 or NaPdCl 4 , the soluble substance of Ru is selected from RuCl 3 or ruthenium acetate.

[0027] The catalyst for preparing 1,2-pentanediol from furfuryl alcohol is used in preparing 1,2-pentanediol by hydrogenation of furfuryl alcohol.

[0028] The catalyst shows excellent industrial production advantages in the hydrogenation of furfuryl alcohol to prepare 1,2-pentanediol, making the stability and product value of the hydrogenation of furfuryl alcohol to prepare 1,2-pentanediol higher and the industrial adaptability significantly improved.

[0029] Preferably, the furfuryl alcohol hydrogenation is carried out in a high-pressure reactor, using the furfuryl alcohol aqueous solution as a raw material, and carrying out the hydrogenation reaction under the conditions of hydrogen and the catalyst. Further preferably, the mass ratio of the catalyst to the furfural mass is 0.1 to 1, the mass concentration of the furfural aqueous solution is 1 to 40%, the hydrogen pressure is 0.1 to 3 MPa, the reaction temperature is 120 to 180°C, and the reaction time is 6 to 24 hours.

[0030] Preferably, the furfuryl alcohol hydrogenation adopts a high-pressure fixed bed process, with furfuryl alcohol aqueous solution as liquid raw material and hydrogen as gas raw material, and the liquid raw material and gas raw material are reversely passed through the bed layer filled with the catalyst. Further preferably, at a temperature of 120-180°C, a hydrogen pressure of 1-5 MPa, and a mass space velocity of 0.1-5 h of the furfuryl alcohol aqueous solution, the catalyst is heated to 100 °C and the temperature is 200 °C. -1 , the volume space velocity of hydrogen is 300~5000h -1 The reaction produces 1,2-pentanediol. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the XRD diagram of the catalyst obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The reaction formula for preparing 1,2-pentanediol from furfuryl alcohol of the present invention is as follows:

[0033]

[0034] The implementation process of the present invention is described in detail below in conjunction with specific embodiments.

[0035] 1. The specific embodiments of the catalyst for preparing 1,2-pentanediol from furfuryl alcohol and the preparation method thereof of the present invention are as follows:

[0036] Example 1

[0037] The preparation method of the catalyst for preparing 1,2-pentanediol from furfuryl alcohol of the present embodiment comprises the following steps:

[0038] (1) 1g of TiO with a particle size of 8nm 2 Add 50 mL of water and disperse to form a suspension. Add 2 times the molar amount (relative to TiO 2 ) and stirred to dissolve, then the mixed alkaline solution was added dropwise to the solution until the pH of the system reached 9-11, and then heated to 50°C and maintained for 3 hours for precipitation reaction to obtain a mixed solution. The mixed alkaline solution in this example is NaOH and Na 2 CO 3 The aqueous solution, in which the molar amount of NaOH is 1 mol / L, Na 2 CO 3 The molar amount is 0.5 mol / L.

[0039] The mixed solution was filtered, and the filter cake was washed with water and dried (drying temperature was 60° C.), followed by a first calcination (first calcination temperature was 750° C., time was 3 h), to obtain a carrier precursor powder.

[0040] (2) Add the metal catalyst salt solution to the carrier precursor powder obtained in step (1) to allow the metal catalyst salt solution to fully infiltrate the carrier precursor powder, ultrasonicate for 2 hours, and then dry at 60° C. to obtain a dried powder. The metal catalyst salt solution in this example is HPtCl 6 An aqueous solution of HPtCl 6 The concentration is 0.2mol / L.

[0041] The dried powder was second calcined in a muffle furnace at 450° C. for 3 h, and then reduced at 300° C. for 3 h in a hydrogen atmosphere to obtain the catalyst product.

[0042] The catalyst for preparing 1,2-pentanediol from furfuryl alcohol obtained in this embodiment includes a composite oxide support and a monometallic catalyst attached to the composite oxide support. The composite oxide support includes a titanium dioxide core and magnesium oxide attached to the titanium dioxide core, and the molar ratio of the oxide core to the magnesium oxide is 1:2. The monometallic catalyst is metal Pt, wherein the proportion of Pt in the entire catalyst is 2wt%.

[0043] Embodiments 2 to 17

[0044] Referring to the method of Example 1, a catalyst with the following structural composition was prepared, as shown in Table 1.

[0045] Table 1 Preparation parameters of each embodiment and composition of the prepared catalyst

[0046]

[0047]

[0048] 2. Specific Examples of Application of the Catalyst for 1,2-Pentanediol in the Preparation of 1,2-Pentanediol by Hydrogenation of Furfuryl Alcohol

[0049] Embodiment 18

[0050] The application of the catalyst for 1,2-pentanediol in the preparation of 1,2-pentanediol by hydrogenation of furfuryl alcohol in this embodiment is described by taking a high-pressure reactor process as an example, comprising the following steps: 120 mL of furfuryl alcohol, 280 mL of water, and 15 g of the catalyst (Example 1) are added to a high-pressure reactor (1 L), the air in the reactor is replaced with normal-pressure nitrogen, and then 1 MPa of hydrogen is introduced after the nitrogen is replaced with normal-pressure hydrogen, and the reaction is heated to 160° C. for 15 hours. After the reaction is completed, the catalyst is recovered by filtration.

[0051] The obtained reaction liquid was sampled, and the components in the reaction liquid were qualitatively and quantitatively analyzed by gas chromatography to obtain the conversion rate of the raw material furfuryl alcohol and the selectivity of the target product 1,2-pentanediol. The remaining reaction liquid was purified by distillation to obtain pure 1,2-pentanediol, pure 1,5-pentanediol and tetrahydrofurfuryl alcohol.

[0052] Embodiment 19

[0053] The application of the catalyst for 1,2-pentanediol in the preparation of 1,2-pentanediol by hydrogenation of furfuryl alcohol in this embodiment is described by taking a high-pressure fixed bed process as an example, and comprises the following steps:

[0054] (1) The catalyst of Example 1 is directly tableted, crushed, and sieved to obtain catalyst particles.

[0055] (2) The catalyst particles obtained in step (1) are added to the catalyst particles to form a catalyst bed, nitrogen is introduced for leak detection, and then a 50% mass concentration furfuryl alcohol aqueous solution is pumped into the catalyst bed using a constant flow pump. The furfuryl alcohol aqueous solution flows through the catalyst bed from top to bottom, and hydrogen flows through the catalyst bed from bottom to top. The reaction temperature is 180° C. and the hydrogen pressure is 3 MPa; the mass space velocity of the furfuryl alcohol aqueous solution is 2 h -1 , the volume space velocity of hydrogen is 500h -1 The obtained reaction solution is purified by distillation to obtain pure 1,2-pentanediol, pure 1,5-pentanediol and tetrahydrofurfuryl alcohol respectively.

[0056] 3. Comparative Proportion

[0057] Comparative Example The catalyst 0.8Pt / MgTiO was prepared according to the method of Example 2 in the authorization announcement number CN113318735B. x The catalyst is the catalyst with the best selectivity for 1,2-pentanediol in CN113318735B.

[0058] IV. Experimental Examples

[0059] Experimental Example 1 XRD Analysis

[0060] In this experimental example, the catalyst obtained in Example 1 was subjected to XRD analysis. The results are as follows Figure 1 shown.

[0061] Depend on Figure 1 It can be seen that the components of the catalyst obtained in Example 1 are MgO and TiO 2 As a comparison, the composite oxide carrier used in the comparative example is MgTiO x , in the form of intermetallic compounds.

[0062] Experimental Example 2

[0063] This experimental example investigates the performance of the catalysts of Examples 1-17 and the comparative example in catalyzing furfuryl alcohol to prepare 1,2-pentanediol. All conditions are carried out in the manner of Example 18. Except for the catalyst, other conditions are the same. The results are shown in Table 2 below.

[0064] Table 2 Results of preparing 1,2-pentanediol by furfuryl alcohol using different catalysts

[0065]

[0066]

[0067] It can be seen from Examples 1 to 5 that when the core particle size is 8 nm and the Pt content is 2%, TiO 2 、Al 2 O 3 、CeO 3 The effects are basically the same, and the selectivity of 1,2-pentanediol is much better than the comparative example. It can be seen from Examples 2 and 6 to 8 that when the Pt loading is 0.5-8% and the Ru doping amount is 0.2%, the selectivity of 1,2-pentanediol is much better than the comparative example. Further considering the furfuryl alcohol conversion rate, the Pt loading is better when it is more than 2%.

[0068] From the comparison of Example 2, Example 9 and Example 10, it can be seen that when the molar ratio of the oxide core to magnesium oxide is in the range of 1:(1-3), the furfuryl alcohol conversion rate and 1,2-pentanediol selectivity are basically the same.

[0069] From the comparison between Example 2 and Examples 11 to 13, it can be seen that when the doping amount of Ru is further increased to 0.4 to 0.8%, the selectivity for 1,2-pentanediol is further improved, but the conversion rate of furfuryl alcohol decreases to a certain extent.

[0070] From the comparison between Example 2 and Example 14, it can be seen that when the doping metal is changed from Ru to Pd, the selectivity for 1,2-pentanediol is further improved. From the comparison between Example 2 and Examples 14 to 16, it can be seen that when the doping metal is Pd and the doping amount is 0.4 to 0.8%, the selectivity for 1,2-pentanediol reaches more than 80%, and the furfuryl alcohol conversion rate is also maintained at more than 90%.

[0071] It can be seen from Example 17 that when Pd and Ru are co-doped as the doping metal, the furfuryl alcohol conversion rate and the selectivity for 1,2-pentanediol are maintained at a high level.

[0072] Experimental Example 3

[0073] In this experimental example, the catalyst of Example 2 was used to conduct catalyst stability and cycle performance experiments in the manner of Example 18. After the catalyst was recovered, 1,2-pentanediol was prepared in the manner of Example 18. The experimental results are shown in Table 3 below.

[0074] Table 3 Cyclic test results of the catalyst in the embodiment

[0075]

[0076]

[0077] In the actual preparation of 1,2-pentanediol, as the number of cycles increases, the overall mass of the catalyst decreases during the catalyst recovery process, the furfuryl alcohol conversion rate shows a certain downward trend, and the 1,2-pentanediol selectivity fluctuates to a certain extent. This is a normal phenomenon, and the overall performance of 1,2-pentanediol selectivity is still far better than the control example.

Claims

1. A catalyst for preparing 1,2-pentanediol from furfuryl alcohol, characterized in that: It includes a composite oxide support and a metal catalyst attached to the composite oxide support; the composite oxide support includes an oxide core and magnesium oxide attached to the oxide core; the oxide core is selected from one, two or three of TiO2, CeO2, and Al2O3; the metal catalyst is Pt or Pt and a doped metal, and the doped metal is selected from at least one of Pd and Ru.

2. The catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in claim 1, characterized in that: The molar ratio of the oxide core to magnesium oxide is 1:1-3.

3. The catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in claim 1, characterized in that: The content of Pt in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 0.5-8wt%, and the content of the doped metal in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 0-0.8wt%.

4. The catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in claim 3, characterized in that: The content of Pt in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 2-8 wt %, and the content of the doped metal in the catalyst for preparing 1,2-pentanediol from furfuryl alcohol is 0.2-0.8 wt %.

5. The catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in claim 4, characterized in that: The doping metal is Pd or Pd and Ru co-doped. When Pd and Ru are co-doped, the molar ratio of Pd to Ru is 1:1-2.

6. The catalyst for preparing 1,2-pentanediol from furfuryl alcohol according to any one of claims 1 to 5, characterized in that: The particle size of the oxide core is 1 to 10 nm.

7. A method for preparing a catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: (1) mixing the dispersion of the oxide core and a soluble magnesium salt solution, performing a precipitation reaction and separation under alkaline conditions, and then performing a first calcination to obtain a carrier precursor powder; (2) Mixing and impregnating the support precursor powder with a soluble substance solution of the metal catalyst, and then performing a second calcination and reduction treatment to obtain the catalyst.

8. The method for preparing a catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in claim 7, characterized in that: In step (1), the first calcination temperature is 600-800° C. and the time is 2-6 hours.

9. The method for preparing a catalyst for preparing 1,2-pentanediol from furfuryl alcohol according to claim 7 or 8, characterized in that: In step (2), the temperature of the second calcination is 350-750° C., and the time is 2-6 hours; the temperature of the reduction treatment is 150-350° C., and the time is 2-6 hours.

10. Use of the catalyst for preparing 1,2-pentanediol from furfuryl alcohol as claimed in any one of claims 1 to 6 in preparing 1,2-pentanediol by hydrogenation of furfuryl alcohol.

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