Composite carrier supported hydrogenation catalyst and application thereof

Abstract

The invention discloses a composite carrier supported hydrogenation catalyst and application thereof, the composition of the catalyst is Pd-M-Nb2O5-B, and the content of the active component palladium Pd is 0.2-1.5%; the auxiliary agent M is one or two of silver and bismuth, and the molar ratio of the content of the auxiliary agent M to the active component Pd is 1: (0.5-4); nb2O5-B is a composite carrier, and the composite carrier accounts for 97.0-99.5% of the total weight of the catalyst; in the composite carrier Nb2O5-B, the content of Nb2O5 is 8 to 15 percent; b is one or more of TiO2, SiO2 and Al2O3, and the weight ratio of TiO2 to SiO2 to Al2O3 is (1-3): (5-20): 100. The catalyst has excellent water resistance, the complex carrier has stronger acidity compared with common solid acid, the product yield is higher, and the stability of the acetyl n-propanol generated by the reaction of the catalyst can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst preparation, and in particular to a composite carrier-supported hydrogenation catalyst and application thereof. Background Art

[0002] 2-Methylfuran is one of the important biomass-based platform compounds, which has the potential to replace fuels. Acetyl propanol (5-hydroxy-2-pentanone) is an important synthetic part of antimalarial drugs and vitamin B, and is an important chemical intermediate. The current production of acetyl propanol is 2-methylfuran, hydrochloric acid and palladium carbon catalyst in an autoclave at room temperature, but the hydrochloric acid in the reaction environment is more harmful to the environment and equipment. In addition to the above-mentioned traditional processes, the existing technology is diol oxidation and alkyne hydration, but the above-mentioned catalyst has problems such as catalyst recovery difficulty, low substrate concentration, and expensive raw materials, which limits its application in industrial production.

[0003] Therefore, it is particularly important to develop a green and environmentally friendly metal acid dual-energy catalyst for the production of acetyl propanol from dimethylfuran. Summary of the invention

[0004] The purpose of the present invention is to provide a composite carrier-supported hydrogenation catalyst and its application. The catalyst has excellent water resistance, and the complex carrier has stronger acidity than general solid acid, higher product yield, can improve the stability of the catalyst reaction to generate acetyl propanol, and reduce the formation of condensation products.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A composite carrier-supported hydrogenation catalyst, the composition of the catalyst is Pd-M@Nb2O5-B, wherein:

[0007] The content of the active component palladium Pd is 0.2-1.5%;

[0008] The auxiliary agent M is one or both of silver and bismuth, and the molar ratio of the auxiliary agent M to the active component palladium Pd is between 1:0.5 and 4;

[0009] Nb2O5-B is a composite carrier, and the composite carrier accounts for 97.0-99.5% of the total weight of the catalyst;

[0010] In the composite carrier Nb2O5-B, the content of Nb2O5 is 8-15%;

[0011] B is TiO 2、 One or more of SiO2 and Al2O3, and the weight ratio of TiO2, SiO2 and Al2O3 is 1-3:5-20:100.

[0012] The invention discloses an application of a composite carrier-supported hydrogenation catalyst. The catalyst is applied to the process of preparing acetyl n-propanol from 2-methylfuran. The reaction is carried out in a stirred autoclave under the following conditions: a pressure of 1 to 4 MPa, a temperature of 50 to 120 DEG C, a reaction time of 1 to 5 hours, a concentration of the reaction substrate 2-methylfuran of 10 to 40 wt%, and an amount of the catalyst of 1 to 10 wt% of the mass of the 2-methylfuran.

[0013] The invention discloses an application of a composite carrier-supported hydrogenation catalyst, wherein the catalyst is applied to the process of preparing acetyl n-propanol from 2-methylfuran, and a fixed bed reactor is used, wherein the concentration of the reaction substrate 2-methylfuran is 10-25wt%, and the amount of the catalyst used is 1-8wt% of the mass of the 2-methylfuran; the liquid hourly space velocity is 1.0-3.0h -1 The reaction conditions are pressure 1-3 MPa and temperature 50-80°C.

[0014] It can be seen from the technical solution provided by the present invention that the catalyst has excellent water resistance, the carrier complexity has stronger acidity than general solid acid, the product yield is higher, the stability of the catalyst reaction to generate acetyl propanol can be improved, and the formation of condensation products can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0016] Figure 1 This is a gas chromatogram of the preparation of 3-acetyl-n-propanol (3-AP) from 2-methylfuran (2-MF) described in Example 3 of the present invention;

[0017] Figure 2 This is the gas chromatogram of preparing 3-AP from 2-MF described in Example 5 of the present invention;

[0018] Figure 3 This is a schematic diagram of the stability of the catalyst used in the embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The embodiment of the present invention provides a composite carrier-supported hydrogenation catalyst, wherein the catalyst is composed of Pd-M@Nb2O5-B, wherein:

[0021] The content of the active component palladium Pd is 0.2-1.5%;

[0022] The auxiliary agent M is one or both of silver and bismuth, and the molar ratio of the auxiliary agent M to the active component palladium Pd is between 1:0.5 and 4;

[0023] Nb2O5-B is a composite carrier, and the composite carrier accounts for 97.0-99.5% of the total weight of the catalyst;

[0024] In the composite carrier Nb2O5-B, the content of Nb2O5 is 8-15%;

[0025] B is TiO 2、 One or more of SiO2 and Al2O3, and the weight ratio of TiO2, SiO2 and Al2O3 is 1-3:5-20:100.

[0026] In a specific implementation, the catalyst is in the form of microspheres, and the diameter of the catalyst is 0.05 to 1 mm;

[0027] The diameter of the composite carrier Nb2O5-B is 0.02-2 mm.

[0028] In addition, the catalyst is prepared by the following process:

[0029] First, NbCl5 and composite carrier microspheres B are immersed in the solution, heated to the target temperature, condensed and refluxed for 2 hours, 1 mol / L tetrabutylammonium hydroxide precipitant is added, the pH is controlled to 8-11, and the mixture is refluxed and stirred for 24-48 hours. After the temperature of the mixed solution drops to room temperature, it is washed with distilled water until the pH is 7;

[0030] The carrier precursor is dried overnight at 80°C, and the carrier precursor is air-baked for 4 to 8 hours to remove the organic template. The calcination temperature is between 400 and 800°C to obtain the composite carrier Nb2O5-B.

[0031] Then, the active component palladium Pd and the additive M were loaded on the composite carrier Nb2O5-B by the equal volume impregnation method, and the catalyst Pd-M@Nb2O5-B was obtained after drying overnight.

[0032] Based on the catalyst prepared above, the present invention also provides an application of a composite carrier-supported hydrogenation catalyst, specifically:

[0033] The above catalyst is applied to the process of preparing acetyl propanol from 2-methylfuran, the reaction is carried out in a stirred autoclave, the reaction conditions are pressure 1-4MPa, temperature 50-120°C, reaction time 1-5h, the concentration of the reaction substrate 2-methylfuran is 10-40wt%, and the amount of the catalyst used is 1-10wt% of the mass of 2-methylfuran.

[0034] In a specific implementation, the reaction liquid is distilled under reduced pressure to obtain a light yellow liquid, and the product yield is analyzed by gas chromatography, or the product purity is titrated by the hydroxylamine hydrochloride method.

[0035] Based on the catalyst prepared above, the present invention also provides another application of a composite carrier-supported hydrogenation catalyst, specifically:

[0036] The above catalyst is applied to the process of preparing acetyl propanol from 2-methylfuran, using a fixed bed reactor, wherein the concentration of the reaction substrate 2-methylfuran is 10-25wt%, the amount of the catalyst used is 1-8wt% of the mass of 2-methylfuran, and the liquid hourly space velocity (LHSV) is 1.0-3.0h -1 The reaction conditions are pressure 1-3 MPa and temperature 50-80°C.

[0037] Among them, liquid hourly space velocity (LHSV) is a form of space velocity, which is used to measure the processing capacity of the catalyst and is applicable to the case where the reactants are in liquid phase. The liquid hourly space velocity is calculated by the ratio of the volume of liquid passing through the catalyst per unit time to the volume of the catalyst.

[0038] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to professional and technical personnel in the field.

[0039] The preparation and application of the catalyst described in the embodiments of the present invention are illustrated by using specific examples below:

[0040] Example 1: Take 1.225g Pd(NO3)2·nH2O and impregnate 20g Al2O3 balls (i.e. composite carrier microspheres B) with equal volume, ultrasonicate for 4h, dry, and calcine in air at 500℃ for 6h to obtain catalyst 1% Pd-Al2O3;

[0041] Before using the catalyst, 20 g of the above catalyst was reduced in a tube furnace, heated to 180°C at a heating rate of 5°C / min in a H2 / N2 atmosphere, and kept warm for 6 h;

[0042] Batch reaction: Add 400g 2-methylfuran, 1kg water, and 15g reduced 1% Pd-Al2O3 catalyst into a 2L autoclave; replace with N2 three times, temperature 110℃, pressure 3MPa, and react for 12h. The yield is 40.71%. After distillation at 50℃ for 6h, the purity is 79.35% after titration by hydroxylamine hydrochloride method.

[0043] Example 2: After 64.7 g NbCl5 was dissolved in 500 g anhydrous ethanol, 50 g of 1 mm Al2O3 microspheres (i.e. composite carrier microspheres B) were added, stirred at 80°C for 2 h, tetrabutylammonium hydroxide was added dropwise, pH was adjusted to 11, stirring was continued for 24 h, and then the mixture was allowed to stand for 12 h. The catalyst was washed with deionized water until neutral, and dried at 80°C overnight. Subsequently, the mixture was air-baked at 500°C for 6 h to obtain a catalyst carrier 20Nb-Al2O3, in which the residual Ba was about 4.56 wt%.

[0044] An equal volume of 1.225 g Pd(NO3)2·nH2O solution was used to impregnate 20 g of the above catalyst carrier microspheres for 4 h, dried at 80°C, and calcined in air at 500°C for 6 h to obtain a catalyst 1% Pd-20Nb-Al2O3.

[0045] Reduce 20 g of the above catalyst in a tubular furnace, heat to 180°C at a heating rate of 5°C / min in a H2 / N2 atmosphere, and keep warm for 6 hours.

[0046] Batch reaction: 400g 2-methylfuran, 1kg water, and 15g reduced 1% Pd-20Nb-Al2O3 catalyst were added to a 2L autoclave. N2 was replaced three times, the temperature was 110°C, the pressure was 3MPa, and the reaction was carried out for 12h. The yield was 84.77%. After reduced pressure distillation at 80°C and vacuum degree -100KPa for 1h, the purity was 86.11% after titration by hydroxylamine hydrochloride method.

[0047] Example 3: After dissolving 64.7g NbCl5 in 500g anhydrous ethanol, add 50g of 1mm composite carrier B microspheres, stir at 80℃ for 2h, add tetrabutylammonium hydroxide dropwise, adjust pH≈11, continue stirring for 24h, let stand for 12h, wash the catalyst with deionized water until neutral, and dry at 80℃. The mass ratio of Al2O3-SiO2-TiO2 of the above microspheres is 50:5:1. Then, air calcined at 500℃ for 6h to obtain the catalyst carrier 20Nb-B, in which the residual Ba is about 5.95wt%.

[0048] An equal volume of 1.225 g Pd(NO3)2·nH2O was used to impregnate 20 g of the above catalyst support pellets for 4 hours. After drying, the pellets were calcined in air at 500°C for 6 hours to obtain a catalyst 1% Pd-@20Nb-B.

[0049] Reduce 20 g of the above catalyst in a tubular furnace, heat to 180°C at a heating rate of 5°C / min in a H2 / N2 atmosphere, and keep warm for 6 hours.

[0050] Batch reaction: 400g 2-methylfuran, 1kg water, and 15g reduced 1% Pd-20Nb-Al2O3-SiO2-TiO2 catalyst were added to a 2L autoclave. N2 and H2 were replaced three times in sequence, the temperature was 110℃, the pressure was 3MPa, and the reaction was carried out for 12h. The yield was 90.45%. After distillation at 50℃ for 6h, the purity was 94.68% after titration by hydroxylamine hydrochloride method.

[0051] Example 4: After dissolving 64.7g NbCl5 in 500g anhydrous ethanol, add 50g of 1mm composite carrier B microspheres, stir at 80℃ for 2h, add tetrabutylammonium hydroxide dropwise, adjust pH≈11, continue stirring for 24h, let stand for 12h, wash the catalyst with deionized water until neutral, and dry at 80℃. The mass ratio of Al2O3-SiO2-TiO2 of the above microspheres is 50:5:1. Then, air roast at 500℃ for 6h to obtain the catalyst carrier 20Nb-B, in which the residual Ba is about 5.95wt%.

[0052] Take 1.225g Pd(NO3)2·nH2O and 0.19g Bi(NO3)3 and mix them. Then put in 20g of the above catalyst carrier beads in equal volume and immerse for 4 hours. After drying, calcine in air at 500℃ for 6 hours to obtain the catalyst 1% Pd-0.5% Bi@20Nb-B.

[0053] Reduce 20 g of the above catalyst in a tubular furnace, heat to 180°C at a heating rate of 5°C / min in a H2 / N2 atmosphere, and keep warm for 6 hours.

[0054] Batch reaction: Add 400g 2-methylfuran, 1kg water, and 15g reduced 1% Pd-0.5% Bi@20Nb-Al2O3 catalyst into a 2L autoclave. Replace with N2 three times, temperature 110℃, pressure 3MPa, and react for 12h. Yield 92.11%. After gradually heating from room temperature to 850℃ and constant -99KPa under reduced pressure distillation for 1h, titrate with hydroxylamine hydrochloride method, and take 78-85 degree fraction sample with a purity of 96.97%.

[0055] Continuous reaction: In a fixed bed reactor, the 2-methylfuran substrate is 20wt%, the amount of catalyst used is 3wt% of the mass of 2-methylfuran, and the liquid hourly space velocity is 2.0h -1 The reaction conditions were 3 MPa pressure and 75°C temperature. The yield was 90.89%. After distillation at 50°C for 6 h, the purity was 95.24% by titration with hydroxylamine hydrochloride method.

[0056] Example 5: After dissolving 64.7g NbCl5 in 500g anhydrous ethanol, add 50g of 3mm composite carrier B microspheres, stir at 80℃ for 2h, add tetrabutylammonium hydroxide dropwise, adjust pH≈11, continue stirring for 24h, let stand for 12h, wash the catalyst with deionized water until neutral, and dry at 80℃. The mass ratio of Al2O3-SiO2-TiO2 of the above microspheres is 50:5:1. Air roast at 500℃ for 6h to obtain catalyst carrier 20Nb-B.

[0057] Take 0.98g Pd(NO3)2·nH2O and mix it with 110ml 17g / LAgNO3 standard solution, put in 20g of the above catalyst carrier, stir and immerse for 4h, take out and dry, and calcine in air at 500℃ for 6h to obtain the catalyst 1% Pd-0.5% Ag@20Nb-B.

[0058] Reduce 20 g of the above catalyst in a tubular furnace, heat to 180°C at a heating rate of 5°C / min in a H2 / N2 atmosphere, and keep warm for 6 hours.

[0059] Batch reaction: 400g 2-methylfuran, 1kg water, and 15g reduced 1% Pd-0.5% Ag@20Nb-B catalyst microspheres were added to a 2L autoclave. N2 and H2 were replaced three times in sequence, the temperature was 110℃, the pressure was 3MPa, and the reaction was carried out for 12h. The yield was 93.89%. After distillation at 50℃ for 6h, the purity was 97.23% after titration by hydroxylamine hydrochloride method.

[0060] Continuous reaction: In a fixed bed reactor, the 2-methylfuran substrate is 15wt%, the amount of catalyst used is 2wt% of the mass of 2-methylfuran, and the liquid hourly space velocity is 2.0h -1 The reaction conditions were 3 MPa pressure and 60°C temperature. The yield was 91.79%. After distillation at 50°C for 6 hours, the purity was 96.04% by titration with hydroxylamine hydrochloride method.

[0061] In summary, the catalyst described in the embodiments of the present invention has the following advantages:

[0062] 1. The catalyst described in the embodiment of the present invention has excellent water resistance, and the complex carrier has stronger acidity than general solid acid, and the product yield is higher;

[0063] 2. The catalyst preparation process of the present invention is simple, the process flow is short, the catalyst microspheres are easy to recover, and the cost is low;

[0064] 3. Compared with the existing process technology, the catalyst of the present invention does not need to add liquid acid, is green and environmentally friendly, has a high substrate concentration, and can be used in industry;

[0065] 4. Acetyl propanol has the characteristics of two condensation products, which affects the yield. The additives silver Ag and bismuth Bi introduced into the catalyst of the present invention can improve the stability of the catalyst reaction to generate acetyl propanol and reduce the formation of condensation products.

[0066] like Figure 1 The gas chromatogram of preparing 3-acetyl-n-propanol (3-AP) from 2-methylfuran (2-MF) described in Example 3 of the present invention is shown. Figure 2 The gas chromatogram of preparing 3-AP from 2-MF described in Example 5 of the present invention is shown. Figure 3 The figure shows the stability diagram of the catalyst used in the embodiment of the present invention. The complex carrier of the present invention can improve the reaction yield compared with the uncomplex carrier, and the product purity is high after vacuum distillation. The results are shown in Table 1 below:

[0067] Table 1: Intermittent reaction data of catalysts of Examples 1-5 of the present invention

[0068] Catalyst Yield (%) purity(%) <![CDATA[1%Pd-Al2O3]]> 40.71 79.35 <![CDATA[1%Pd-20Nb-Al2O3]]> 84.77 86.11 <![CDATA[1%Pd-20Nb-Al2O3-SiO2-TiO2]]> 90.45 94.68 <![CDATA[1%Pd-0.5%Bi@20Nb-Al2O3-SiO2-TiO2]]> 92.11 96.97 <![CDATA[1%Pd-0.5%Ag@20Nb-Al2O3-SiO2-TiO2]]> 93.89 97.23

[0069] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A composite carrier-supported hydrogenation catalyst, characterized in that: The composition of the catalyst is Pd-M@Nb2O5-B, wherein: The content of the active component palladium Pd is 0.2-1.5%; The auxiliary agent M is one or both of silver and bismuth, and the molar ratio of the auxiliary agent M to the active component palladium Pd is between 1:0.5 and 4; Nb2O5-B is a composite carrier, and the composite carrier accounts for 97.0-99.5% of the total weight of the catalyst; In the composite carrier Nb2O5-B, the content of Nb2O5 is 8-15%; B is TiO 2、 One or more of SiO2 and Al2O3, and the weight ratio of TiO2, SiO2 and Al2O3 is 1-3:5-20:

100.

2. The composite carrier-supported hydrogenation catalyst according to claim 1, characterized in that: The catalyst is in the form of microspheres, and the diameter of the catalyst is 0.05 to 1 mm; The diameter of the composite carrier Nb2O5-B is 0.02-2 mm.

3. The composite carrier-supported hydrogenation catalyst according to claim 1, characterized in that: The catalyst is prepared by the following process: First, NbCl5 and composite carrier microspheres B are immersed in the solution, heated to the target temperature, condensed and refluxed for 2 hours, 1 mol / L tetrabutylammonium hydroxide precipitant is added, the pH is controlled to 8-11, and the mixture is refluxed and stirred for 24-48 hours. After the temperature of the mixed solution drops to room temperature, it is washed with distilled water until the pH is 7; The carrier precursor is dried overnight at 80°C, and the carrier precursor is air-baked for 4 to 8 hours to remove the organic template. The calcination temperature is between 400 and 800°C to obtain the composite carrier Nb2O5-B. Then, the active component palladium Pd and the additive M were loaded on the composite carrier Nb2O5-B by the equal volume impregnation method, and the catalyst Pd-M@Nb2O5-B was obtained after drying overnight.

4. An application of a composite carrier-supported hydrogenation catalyst, characterized in that: The process of using any catalyst of claim 1-3 to prepare acetyl propanol from 2-methylfuran, the reaction is carried out in a stirred autoclave, the reaction conditions are pressure 1-4MPa, temperature 50-120°C, reaction time 1-5h, the concentration of the reaction substrate 2-methylfuran is 10-40wt%, and the amount of the catalyst used is 1-10wt% of the mass of 2-methylfuran.

5. An application of a composite carrier-supported hydrogenation catalyst, characterized in that: The process of applying any catalyst of claim 1 to claim 3 to prepare acetyl propanol from 2-methylfuran, using a fixed bed reactor, wherein the concentration of the reaction substrate 2-methylfuran is 10-25wt%, the amount of the catalyst used is 1-8wt% of the mass of 2-methylfuran; the liquid hourly space velocity is 1.0-3.0h -1 The reaction conditions are pressure 1-3 MPa and temperature 50-80°C.

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