Catalyst for catalytic hydrogenation and its preparation method and application

Abstract

This invention discloses a catalyst for catalytic hydrogenation, its preparation method, and its application. The catalyst for catalytic hydrogenation is lanthanum cobalt oxide supported on copper and cobalt. This invention selects Cu / Co@LaCoO3, which exhibits higher conversion and selectivity with less hydrogen and lower reaction temperature compared to other catalysts. This catalyst is applied to the catalytic production of 1,2-pentanediol and 1,5-pentanediol from furfural, achieving a furfural conversion of up to 100%; a selectivity of 22.9% for 1,2-pentanediol; and a selectivity of 52% for 1,5-pentanediol.

Description

Technical Field

[0001] This invention relates to the field of inorganic material preparation, specifically to a catalyst for catalytic hydrogenation, its preparation method, and its application. Background Technology

[0002] Furfural (FA) is an aromatic compound, readily soluble in organic solvents such as alcohols and ethers. It is a widely discussed biomass derivative, derived from xylose through acid-catalyzed dehydration. Xylose, a key component of lignocellulose and hemicellulose, is abundant in nature, and its industrial preparation is well-established, enabling the production of large quantities of furfural to meet the needs of various industries. Catalytic hydrogenation of furfural can not only produce pentanediol (mainly 1,5-pentanediol and 1,2-pentanediol) as a raw material for polyester production, but also furfuryl alcohol (FFA), tetrahydrofurfural (THFA), and 2-methylfuran (2-MF). The production of these chemicals can be used in cosmetics, pharmaceuticals, and plasticizers.

[0003] In previous studies, researchers have mostly designed catalysts for the catalytic hydrogenation of furfural to pentanediol using precious metals as active components. However, the high cost of precious metals limits their application in industrial production. In recent years, non-precious metals such as Cu, Co, and Ni have attracted attention as active components. However, current non-precious metal catalysts do not show high selectivity for pentanediol, and most of them use 1,2-pentanediol as the main product. In terms of industrial raw material utilization, especially in the production of polyester products, the utilization value of 1,2-pentanediol is not as high as that of 1,5-pentanediol.

[0004] Therefore, there is an urgent need to provide a catalyst for catalytic hydrogenation that can exhibit high catalytic activity under relatively economical and safe conditions, and whose preparation method is easy and simple. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the present invention proposes a non-precious metal supported hydrogenation catalyst that can exhibit high catalytic activity under relatively economical and safe conditions, and the catalyst preparation method is economical and simple.

[0006] The first aspect of the present invention provides a catalyst for catalytic hydrogenation, wherein the catalyst is lanthanum cobalt oxide supported on copper and cobalt.

[0007] Preferably, the molar mass ratio of copper, cobalt, and lanthanum in the catalyst is (0.5-2):(2-3.5):(0.25-1.5).

[0008] A second aspect of the present invention provides a method for preparing the catalyst described above, comprising the following steps:

[0009] (1) Dissolve copper source, cobalt source and lanthanum source in water and stir to obtain a mixed salt solution;

[0010] (2) Add alkaline solution dropwise to the mixed salt solution to maintain the pH value above 11. After the addition is complete, stir for 20-40 minutes and let it age at room temperature. After aging, the solid and liquid are separated to obtain a solid, which is then washed, dried, and ground into powder.

[0011] (3) The powder is calcined in a tube furnace and then reduced in a mixed atmosphere of H2 and N2 to obtain the catalyst Cu / Co@CoLaO3.

[0012] Preferably, the copper source is at least one of copper nitrate trihydrate, copper chloride dihydrate, and copper sulfate pentahydrate; in some specific embodiments of the present invention, the copper source is copper nitrate trihydrate.

[0013] Preferably, the cobalt source is at least one of cobalt nitrate hexahydrate, cobalt chloride, cobalt acetate, and cobalt sulfate monohydrate; in some specific embodiments of the present invention, the cobalt source is cobalt nitrate hexahydrate.

[0014] Preferably, the lanthanum source is at least one of lanthanum nitrate hexahydrate and lanthanum chloride; in some specific embodiments of the present invention, the lanthanum source is lanthanum nitrate hexahydrate.

[0015] Preferably, in step (2), the alkaline solution is either sodium hydroxide or potassium hydroxide solution; the concentration of the alkaline solution is 1-2 mol / L.

[0016] Preferably, in step (2), the aging time is 12 to 24 hours.

[0017] Preferably, in step (2), the solid is washed with deionized water 4 to 6 times, the drying temperature is 75 to 85°C, and the drying time is 12 to 24 hours.

[0018] Preferably, in step (3), the calcination temperature is 450-700℃, the calcination time is 3.5-4.5h, and the heating rate is 4-6℃ / min; more preferably, the calcination temperature is 500-600℃.

[0019] Preferably, in step (3), the reduction temperature is 250℃~450℃, the reduction time is 6~8h, and the heating rate is 4~6℃ / min; more preferably, the reduction temperature is 400℃~450℃.

[0020] The third aspect of the present invention provides the application of the catalyst for catalytic hydrogenation in the catalytic hydrogenation reaction of aldehyde-containing compounds.

[0021] Preferably, the catalyst for catalytic hydrogenation is used in the catalytic hydrogenation reaction of furfural.

[0022] More preferably, the catalyst for catalytic hydrogenation is used in the catalytic preparation of 1,2-pentanediol and 1,5-pentanediol from furfural.

[0023] A fourth aspect of the present invention provides a method for catalytically preparing 1,2-pentanediol and 1,5-pentanediol from furfural, comprising the following steps:

[0024] Furfural, the catalyst, and the solvent are mixed and reacted under pressure with pure hydrogen. After cooling and filtration, 1,2-pentanediol and 1,5-pentanediol are obtained.

[0025] Preferably, the mass ratio of furfural to the catalyst is (1-2):1.

[0026] Preferably, the solvent is at least one selected from methanol, ethanol, isopropanol, and sec-butanol.

[0027] Preferably, the reaction pressure is 3 to 6 MPa.

[0028] Preferably, the reaction temperature is 120–200°C; and the reaction time is 6–12 h.

[0029] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0030] Since furfural contains aldehyde groups and a furan ring, the key to obtaining 1,2-pentanediol and 1,5-pentanediol lies in the hydrogenation of the aldehyde group and the carbon-oxygen bond of the furan ring. Therefore, selecting a suitable catalyst system is of great significance for improving the activity of FA conversion to 1,2-pentanediol and 1,5-pentanediol. This invention uses Cu / Co@CoLaO3, utilizing Cu / Co as the active component and CoLaO3 as the support to provide basic sites for the catalyst. Through a series of experiments, it was found that this catalyst can perform catalytic hydrogenation under more economical and safer conditions with high selectivity. Its catalyst structure and performance are stable; even after multiple cycles, the catalyst still exhibits high conversion and selectivity.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention selects Cu / Co@LaCoO3, a catalyst that achieves higher conversion and selectivity with less hydrogen and lower reaction temperature compared to other catalysts. When applied to the catalytic production of 1,2-pentanediol and 1,5-pentanediol from furfural, the catalyst achieves a furfural conversion of up to 100%; a selectivity of 22.9% for 1,2-pentanediol; and a selectivity of 52% for 1,5-pentanediol.

[0033] The catalyst provided by this invention has good stability and recyclability, and still maintains high conversion rate and selectivity after multiple cycles.

[0034] This invention uses a co-precipitation method to simply calcine and reduce catalyst precursors. The preparation method is simple, safe to operate, and highly efficient. Attached Figure Description

[0035] Figure 1 A comparison chart of the activity of different Cu:Co:La ratios;

[0036] Figure 2 XRD patterns of the catalysts prepared in Examples 1-4;

[0037] Figure 3 The XRD patterns of the catalysts prepared in Examples 2, 7-9 are shown.

[0038] Figure 4 The bar chart shows the furfural conversion and the selectivity of 1,2-pentanediol and 1,5-pentanediol in five cycles of furfural catalytic hydrogenation reaction using the catalyst prepared in Example 6. Detailed Implementation

[0039] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0041] Example 1

[0042] Accurately weigh 2.42 g of copper nitrate trihydrate, 2.91 g of cobalt nitrate hexahydrate, and 2.17 g of lanthanum nitrate hexahydrate, and dissolve them in 50 ml of deionized water. Stir at 400 rpm for 30 minutes until fully dissolved to obtain a mixed salt solution. Separately, dissolve 3.2 g of sodium hydroxide in 40 ml of deionized water and stir at 400 rpm for 30 minutes until fully dissolved to obtain a 2 mol / L NaOH solution. 2 mol / L NaOH and a mixed salt solution were slowly added dropwise to a beaker while stirring at 400 rpm, maintaining the pH at 12. After the addition was complete, stirring continued at 400 rpm for 30 minutes. The mixture was then aged for 24 hours. The resulting solid-liquid mixture was separated using a Buchner funnel and washed with deionized water until neutral. It was then dried in an oven at 80°C for 12 hours. The resulting solid was ground into powder and calcined in a tube furnace under a N2 atmosphere at a temperature of 550°C and a heating rate of 5°C / min. Finally, it was reduced under a 5% H2 / N2 atmosphere at a temperature of 450°C and a heating rate of 5°C / min, with a Cu:Co:La ratio of 2 / 2 / 1, yielding catalyst 1.

[0043] The preparation of 1,2-pentanediol and 1,5-pentanediol from furfural using catalyst 1 includes the following steps:

[0044] 0.2g of reactant, 0.2g of catalyst, 0.2g of ethylene glycol, and 20ml of isopropanol (IPA) were added to a 100ml high-pressure reactor. The reactor was purged with hydrogen to remove dissolved O2 or air, and then 3.1MPa of hydrogen was introduced. The reactor was reacted at 160℃ and a mechanical stirring rate of 500rpm for 9 hours. After the reaction was completed, the reactor was rapidly cooled to room temperature. The reaction solution was filtered to obtain 1,2-pentanediol and 1,5-pentanediol products. The activity results were obtained by gas chromatography analysis.

[0045] The activity results of catalyst 1 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 17.34%, and selectivity for 1,5-pentanediol is 31.76%.

[0046] Example 2

[0047] Accurately weigh 1.21 g of copper nitrate trihydrate, 4.36 g of cobalt nitrate hexahydrate, and 2.17 g of lanthanum nitrate hexahydrate, and dissolve them in 50 ml of deionized water. Stir at 400 rpm for 30 minutes until fully dissolved to obtain a mixed salt solution. Separately, dissolve 3.2 g of sodium hydroxide in 40 ml of deionized water and stir at 400 rpm for 30 minutes until fully dissolved to obtain a 2 mol / L NaOH solution. A 2 mol / L NaOH and mixed salt solution were slowly added dropwise to a beaker while stirring at 400 rpm, maintaining the pH at 12. After the addition was complete, stirring continued at 400 rpm for 30 minutes. The mixture was then aged for 24 hours. The resulting solid-liquid mixture was separated using a Buchner funnel and washed with deionized water until neutral. It was then dried in an oven at 80°C for 12 hours. The resulting solid was ground into powder and calcined in a tube furnace under a N2 atmosphere at 550°C and a heating rate of 5°C / min. Finally, reduction was performed under a 5% H2 / N2 atmosphere at 450°C and a heating rate of 5°C / min. The Cu:Co:La ratio was 1 / 3 / 1, yielding catalyst 2.

[0048] The preparation of 1,2-pentanediol and 1,5-pentanediol from furfural using catalyst 2 includes the following steps:

[0049] 0.2g of reactant, 0.2g of catalyst, 0.2g of ethylene glycol, and 20ml of isopropanol (IPA) were added to a 100ml high-pressure reactor. The reactor was purged with hydrogen to remove dissolved O2 or air, and then passed through 3.1MPa hydrogen gas. The reactor was reacted at 160℃ and a mechanical stirring rate of 500rpm for 9 hours. After the reaction was completed, the reactor was rapidly cooled to room temperature. The reaction solution was filtered to obtain 1,2-pentanediol and 1,5-pentanediol products. The activity results were obtained by gas chromatography analysis.

[0050] The activity results of catalyst 2 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 22.9%, and selectivity for 1,5-pentanediol is 52.07%.

[0051] Example 3

[0052] Accurately weigh 1.82 g of copper nitrate trihydrate, 3.64 g of cobalt nitrate hexahydrate, and 2.17 g of lanthanum nitrate hexahydrate, and dissolve them in 50 ml of deionized water. Stir at 400 rpm for 30 minutes until fully dissolved to obtain a mixed salt solution. Separately, dissolve 3.2 g of sodium hydroxide in 40 ml of deionized water and stir at 400 rpm for 30 minutes until fully dissolved to obtain a 2 mol / L NaOH solution. Slowly add the 2 mol / L NaOH and the mixed salt solution dropwise to a beaker while stirring at 400 rpm, maintaining the pH at 12. After the addition is complete, continue stirring at 400 rpm for 30 minutes. Aging for 24 hours, the resulting solid-liquid mixture is analyzed using a Buchner funnel and filtered and washed with deionized water until neutral. It is then dried in an oven at 80°C for 12 hours at a heating rate of 5°C / min. Finally, reduction is carried out under a 5% H2 / N2 atmosphere at a reduction temperature of 450°C and a heating rate of 5°C / min. The ratio of Cu:Co:La = 1.5 / 2.5 / 1 yields catalyst 3.

[0053] The preparation of 1,2-pentanediol and 1,5-pentanediol from furfural using catalyst 3 includes the following steps:

[0054] Add 0.2g of reactant, 0.2g of catalyst, 0.2g of ethylene glycol, and 20ml of isopropanol (IPA) to a 100ml high-pressure reactor. Purge with hydrogen to remove dissolved O2 or air, then purge with 3.1MPa hydrogen gas. React at 160℃ and a mechanical stirring rate of 500rpm for 4 hours. After the reaction is complete, rapidly cool to room temperature. Filter the reaction solution to obtain 1,2-pentanediol and 1,5-pentanediol products. The activity results were obtained by gas chromatography analysis.

[0055] The activity results of catalyst 3 are as follows: furfural conversion rate is 100%, 1,2-pentanediol selectivity is 25.08%, and 1,5-pentanediol selectivity is 46.37%.

[0056] Example 4

[0057] Catalyst 4 was prepared according to Example 1, with Cu:Co:La = 0.5 / 3.5 / 1 controlled, and other parameters being the same as in Example 1.

[0058] The activity results of catalyst 4 were as follows: furfural conversion was 100%, selectivity for 1,2-pentanediol was 17.81%, and selectivity for 1,5-pentanediol was 49.05%.

[0059] Example 5

[0060] Accurately weigh 3.61g of copper nitrate trihydrate, 1.45g of copper nitrate hexahydrate, and 2.17g of lanthanum nitrate hexahydrate, and dissolve them in 50ml of deionized water. Stir at 400rpm for 30 minutes until fully dissolved to obtain a mixed salt solution. Separately, dissolve 3.2g of sodium hydroxide in 40ml of deionized water and stir at 400rpm for 30 minutes until fully dissolved to obtain a 2mol / L NaOH solution. 2 mol / L NaOH and a mixed salt solution were slowly added dropwise to a beaker while stirring at 400 rpm for 30 minutes. After aging for 24 hours, the resulting solid-liquid mixture was separated using a Buchner funnel and filtered and washed with deionized water until neutral. The mixture was then dried in an oven at 80°C for 12 hours. The resulting solid was ground into powder and calcined in a tube furnace under a N2 atmosphere at a temperature of 550°C and a heating rate of 5°C / min. Finally, reduction was carried out under a 5% H2 / N2 atmosphere at a temperature of 450°C and a heating rate of 5°C / min, with a Cu:Co:La ratio of 3 / 1 / 1, yielding catalyst 5.

[0061] The preparation of 1,2-pentanediol and 1,5-pentanediol from furfural using catalyst 5 includes the following steps:

[0062] 0.2g of reactant, 0.2g of catalyst, 0.2g of ethylene glycol, and 20ml of isopropanol (IPA) were added to a 100ml high-pressure reactor. The reactor was purged with hydrogen to remove dissolved O2 or air, and then 3.1MPa of hydrogen was introduced. The reactor was reacted at 160℃ and a mechanical stirring rate of 500rpm for 9 hours. After the reaction was completed, the reactor was rapidly cooled to room temperature. The reaction solution was filtered to obtain 1,2-pentanediol and 1,5-pentanediol products. The activity results were obtained by gas chromatography analysis.

[0063] The activity results of catalyst 5 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 19.9%, and selectivity for 1,5-pentanediol is 30.3%.

[0064] Example 6

[0065] Accurately weigh 3.02 g of copper nitrate trihydrate, 2.18 g of cobalt nitrate hexahydrate, and 2.17 g of lanthanum nitrate hexahydrate, and dissolve them in 50 ml of deionized water. Stir at 400 rpm for 30 minutes until fully dissolved to obtain a mixed salt solution. Separately, dissolve 3.2 g of sodium hydroxide in 40 ml of deionized water and stir at 400 rpm for 30 minutes until fully dissolved to obtain a 2 mol / L NaOH solution. A 2 mol / L NaOH and mixed salt solution were slowly added dropwise to a beaker while stirring at 400 rpm, maintaining the pH at 12. After the addition was complete, stirring continued at 400 rpm for 30 minutes. The mixture was then aged for 24 hours. The resulting solid-liquid mixture was separated using a Buchner funnel and washed with deionized water until neutral. It was then dried in an oven at 80°C for 12 hours. The resulting solid was ground into powder and calcined in a tube furnace under a N2 atmosphere at 550°C and a heating rate of 5°C / min. Finally, reduction was performed under a 5% H2 / N2 atmosphere at 450°C and a heating rate of 5°C / min. The Cu:Co:La ratio was 2.5 / 1.5 / 1, yielding catalyst 6.

[0066] The preparation of 1,2-pentanediol and 1,5-pentanediol from furfural using catalyst 6 includes the following steps:

[0067] Add 0.2g of reactant, 0.2g of catalyst, 0.2g of ethylene glycol, and 20ml of isopropanol (IPA) to a 100ml high-pressure reactor. Purge with hydrogen to remove dissolved O2 or air, then purge with 3.1MPa hydrogen gas. React at 160℃ and a mechanical stirring rate of 500rpm for 4 hours. After the reaction is complete, rapidly cool to room temperature. Filter the reaction solution to obtain 1,2-pentanediol and 1,5-pentanediol products. The activity results were obtained by gas chromatography analysis.

[0068] The activity results of catalyst 6 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 24.62%, and selectivity for 1,5-pentanediol is 33.27%.

[0069] Example 7

[0070] Catalyst 7 was prepared according to Example 1, with Cu:Co:La = 1 / 3 / 0.25 controlled and other parameters the same as in Example 1.

[0071] The activity results of catalyst 7 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 16.06%, and selectivity for 1,5-pentanediol is 45.1%.

[0072] Example 8

[0073] Catalyst 8 was prepared according to Example 1, with Cu:Co:La = 1 / 3 / 0.5 controlled and other parameters the same as in Example 1.

[0074] The activity results of catalyst 8 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 16.45%, and selectivity for 1,5-pentanediol is 48.03%.

[0075] Example 9

[0076] Catalyst 9 was prepared according to Example 1, with Cu:Co:La = 1 / 3 / 1.5 controlled, and other parameters being the same as in Example 1.

[0077] The activity results of catalyst 9 are as follows: furfural conversion rate is 100%, selectivity for 1,2-pentanediol is 17.17%, and selectivity for 1,5-pentanediol is 48.51%.

[0078] The above examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any substitutions, alterations or extensions made by those skilled in the art within the technical scope presented in the present invention, based on the technical solution and inventive concept of the present invention, are all within the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst for catalyzing the production of 1,2-pentanediol and 1,5-pentanediol from furfural, characterized by, The catalyst is lanthanum cobalt oxide supported on copper and cobalt; the molar ratio of copper, cobalt, and lanthanum in the catalyst is (0.5~2):(2~3.5):(0.25~1.5). The method for preparing the catalyst includes the following steps: (1) Dissolve copper source, cobalt source and lanthanum source in water and stir to obtain a mixed salt solution; (2) Add alkaline solution dropwise to the mixed salt solution, maintain the pH value above 11, stir for 20-40 min after the addition is complete, let it age at room temperature, and after aging, the solid and liquid are separated to obtain a solid, which is washed, dried and ground to obtain a powder. (3) The powder is calcined in a tube furnace under N2 atmosphere and then reduced in a mixed H2 and N2 atmosphere to obtain the catalyst Cu / Co@CoLaO3.

2. The preparation method according to claim 1, characterized in that, In step (2), the aging time is 12~24h.

3. The preparation method according to claim 1, characterized in that, In step (3), the calcination temperature is 450~700℃, the calcination time is 3.5~4.5h, and the heating rate is 4~6℃ / min.

4. The preparation method according to claim 1, characterized in that, In step (3), the reduction temperature is 250℃~450℃, the reduction time is 6~8h, and the heating rate is 4~6℃ / min.

5. A method for catalytically preparing 1,2-pentanediol and 1,5-pentanediol from furfural, characterized in that, Includes the following steps: Furfural, the catalyst prepared by any one of claims 1-4, and the solvent are mixed, reacted under pressure of pure hydrogen, cooled, and filtered to obtain the 1,2-pentanediol and 1,5-pentanediol.

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