A trimetallic activated carbon supported catalyst and its use

Abstract

The application discloses a three-metal active carbon supported catalyst and application thereof, and the catalyst takes active carbon as a carrier, and a first metal element, a second metal element and an auxiliary metal element are loaded on the carrier, wherein the first metal element is selected from Rh, W and Ir, the second metal element is selected from Ga, Sn and Mg, and the auxiliary metal element is selected from La, Ce and Y. The application is applied to the catalytic hydrogenation of 4-heptanone into 4-heptanol, and when the conversion rate of 4-heptanone reaches 100%, the product selectivity of 4-heptanol can reach 100%, the burden of product separation and purification in the later stage can be greatly reduced, and the production cost is lowered; no solvent is used in the catalytic reaction process, the reaction temperature is relatively low, and the green production requirement is met; the catalyst has high activity, the reaction time is relatively short, and the production efficiency can be improved.

Description

Technical Field

[0001] This invention belongs to the field of industrial catalyst technology, specifically relating to a trimetallic activated carbon supported catalyst and its application. Background Technology

[0002] 4-Heptanol is an important chemical raw material, used as an upstream feedstock in fine organic synthesis, and is also an important pharmaceutical and material intermediate. 4-Heptanol can be prepared by hydrogenation of 4-heptanone; currently, no patents have been found for catalysts used in the hydrogenation of 4-heptanone to 4-heptanol.

[0003] Previous technologies have disclosed catalysts and processes for the hydrogenation of ketones to alcohols. CN1152744C, CN1114490C, and CN1347758A disclose methods for the hydrogenation of 2-octanone to 2-octanol, using a self-made catalyst system (containing copper and nickel catalysts) and a fixed-bed liquid-phase hydrogenation process at a reaction temperature of 100-250℃. The selectivity for 2-octanol is 96%-99.5%. CN1974514A discloses a method for the hydrogenation reduction of 2-octanone to 2-octanol, in which a ferromagnetic hydrogenation catalyst is added to a magnetically stabilized bed reactor, and the reaction is carried out under the following conditions: temperature 70-120℃, pressure 0.3-2.5MPa, liquid hourly space velocity 1-50h⁻¹, hydrogen to 2-octanone solution volume ratio 2-100:1, and magnetic field strength 10-50kA / m. The yield of 2-octanol can reach 70%. Patent CN1083415C uses a pressed CuO-ZnO mixture as a catalyst, achieving a conversion rate and selectivity of 99% for the gas-phase hydrogenation of acetone to isopropanol at a reaction temperature of 150-250℃. Japanese Patent Hei 2-279643 discloses a Ru / Al2O3-catalyzed acetone hydrogenation process that is demanding, requiring a reaction pressure of 9 MPa and significant equipment investment. Japanese Patent Hei-41038 and Soviet Patent SU1118632A introduce acetone hydrogenation methods using Cu-Cr catalysts. Russian Patent RU2047590 uses catalysts containing NiO and CuO, but these catalysts have low conversion rates and poor selectivity. Furthermore, the use of Cr2O3 as an auxiliary agent causes environmental pollution, failing to meet the requirements of green chemistry. CN103030525A discloses a method for preparing isopropanol by liquid-phase hydrogenation of acetone, but the reaction temperature is relatively high, at 100-200℃, with an acetone conversion rate of over 96% and an isopropanol selectivity greater than 95%. CN1962588 discloses a continuous gas-phase hydrogenation reaction of acetone using a nickel-cobalt bimetallic catalyst supported on activated carbon, with a reaction temperature of 100-150℃ and a pressure of 1.0-1.5 MPa, achieving high acetone conversion and isopropanol selectivity. CN103706365 discloses a nickel-copper bimetallic supported catalyst for atmospheric pressure gas-phase fixed-bed hydrogenation of acetone, with a reaction temperature of 100-150℃, achieving 100% isopropanol selectivity and an acetone conversion rate of over 85.5%. CN103706377A and CN103752327A disclose the liquid-phase hydrogenation of acetone to isopropanol using a metal catalyst with Pt, Fe, Sn, and Co as the main components, at a reaction temperature of 100-150℃ and a reaction time of 4 h. USP4,182,721 discloses a method for the catalytic hydrogenation of ketones using a molybdenum-modified skeletal nickel catalyst, although the reaction conditions are relatively mild (60℃, 2.1 MPa), the product selectivity is poor.USP4,459,419 discloses a method for hydrogenating organic ketones or aldehydes using a ruthenium catalyst supported on a molecular sieve, and cites its application in the hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol, but the reaction system requires a high pressure of 12.7 MPa.

[0004] Existing technologies for the catalytic hydrogenation of ketone compounds involve high operating temperatures, demanding equipment requirements, or difficulties in simultaneously achieving high conversion rates and product selectivity. Therefore, developing a heterogeneous catalyst that can react at lower operating temperatures, without solvents, and exhibits high activity and product selectivity would alleviate the burden on product separation and purification processes, reduce energy consumption, and significantly lower production costs. Low-energy and high-efficiency production aligns with the requirements of green chemistry. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a trimetallic activated carbon supported catalyst.

[0006] Another object of the present invention is to provide the application of the above-mentioned trimetallic activated carbon supported catalyst.

[0007] The technical solution of the present invention is as follows:

[0008] A trimetallic activated carbon supported catalyst is characterized in that: activated carbon is used as a support, on which a first metal element, a second metal element and an auxiliary metal element are loaded, wherein the first metal element is selected from Rh, W and Ir, the second metal element is selected from Ga, Sn and Mg, and the auxiliary metal element is selected from La, Ce and Y.

[0009] In a preferred embodiment of the present invention, the loading amount of the first metal element is 0.1-1.6 wt.%, the loading amount of the second metal element is 0.5-1.6 wt.%, and the loading amount of the auxiliary metal element is 0.1-1.5 wt.%.

[0010] The preparation process of the above-mentioned trimetallic activated carbon supported catalyst includes: firstly, loading the auxiliary metal element onto activated carbon, and then simultaneously loading the first metal element and the second metal element onto activated carbon. The specific loading method includes: mixing and stirring the activated carbon with the salt solution of the metal precursor, adding a surfactant and adjusting the pH, adding a chemical reducing agent for reduction, filtering and washing until neutral, and then vacuum drying at 75-85℃ for 10-12h.

[0011] The salts of the metal precursors used are selected from nitrates, acetylacetone salts, or chlorides.

[0012] The surfactant is selected from PVA (polyvinylpyrrolidone), PVP (polyvinylpyrrolidone), or CTAB (hexadecyltrimethylammonium bromide).

[0013] The pH of the salt solution of the metal precursor is adjusted to 0.5-5.5 or 8-13.

[0014] The chemical reducing agent is selected from hydrazine hydrate, sodium borohydride, and ascorbic acid.

[0015] The above-mentioned trimetallic activated carbon supported catalyst is used in the hydrogenation of 4-heptanone to 4-heptanol.

[0016] In a preferred embodiment of the present invention, the trimetallic activated carbon supported catalyst needs to be pretreated with a hydrogen-nitrogen mixed gas before feeding. The pretreatment process is as follows: the hydrogen-nitrogen mixed gas passes through the catalyst bed at a flow rate of 40-80 mL / min, the hydrogen content in the hydrogen-nitrogen mixed gas is 4-6%, the pretreatment temperature is 200-500℃, the heating rate is 2-10℃ / min, and the pretreatment time is 1-6 h.

[0017] The catalytic hydrogenation of 4-heptanone to 4-heptanol was carried out in a batch autoclave for liquid-phase hydrogenation without the use of solvent.

[0018] Preferably, in the intermittent high-pressure autoclave liquid-phase hydrogenation process, the hydrogen pressure is 0.5-5.5 MPa, the operating reaction temperature is 20-50℃, the catalyst feed rate / substrate is 0.001-0.01 g / mL, and the reaction time is 0.5-2 h.

[0019] Before being fed, the catalyst needs to be pretreated with a hydrogen-nitrogen mixture. The process is as follows: the hydrogen-nitrogen mixture passes through the catalyst bed at a flow rate of 40-80 mL / min, the hydrogen content in the mixture is 4-6%, the pretreatment temperature is 200-500℃, the heating rate is 2-10℃ / min, and the pretreatment time is 1-6 h.

[0020] In a preferred embodiment of the present invention, an intermittent high-pressure autoclave liquid-phase hydrogenation process is used, without the use of solvents.

[0021] More preferably, in the intermittent high-pressure autoclave liquid-phase hydrogenation process, the hydrogen pressure is 0.5-5.5 MPa, the reaction temperature is 20-50℃, the catalyst feed rate / substrate is 0.001-0.01 g / mL, and the reaction time is 0.5-2 h.

[0022] The beneficial effects of this invention are:

[0023] 1. The trimetallic activated carbon supported catalyst of this invention operates at a low temperature and consumes less energy when applied to the liquid-phase hydrogenation process of 4-heptanone. The operating pressure is moderate, and the equipment investment is not large.

[0024] 2. The catalytic reaction process of this invention does not use solvents, making the process environmentally friendly. The catalyst exhibits high activity, and the reaction time is short, which can improve production efficiency.

[0025] 3. This invention achieves 100% conversion of 4-heptanone while maintaining 100% product selectivity for 4-heptanol, which greatly reduces the burden of product separation and purification and lowers production costs.

[0026] 4. The preparation and production method of the trimetallic activated carbon supported catalyst of the present invention is relatively simple and easy to implement, and is suitable for mass production. Detailed Implementation

[0027] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0028] Example 1

[0029] Weigh 0.022 g of cerium nitrate hexahydrate and 0.5 g of PVP, add them to 50 mL of deionized water, stir for 20 min, adjust the pH to 10 with NaOH, add 0.6 g of activated carbon and 3 mL of hydrazine hydrate, and continue stirring for 3 h. Filter and wash until neutral, then vacuum dry at 80 °C for 12 h. Heat to 500 °C at 5 °C / min with an argon flow rate of 20 mL / min, hold at this temperature for 3 h, and then cool to room temperature to obtain Ce / C.

[0030] Weigh 0.013 g of chloroiridic acid and 0.022 g of gallium nitrate hydrate and add them to 50 mL of deionized water, stirring for 30 min. Add the Ce / C obtained in the previous step to the above solution, adjust the pH to 10 with NaOH, and add 5 mL of hydrazine hydrate. The hydrazine hydrate is added at a dropping rate of 10 drops / min, and the mixture is stirred continuously for 2 h. After filtration and washing until neutral, the mixture is dried under vacuum at 80 °C for 12 h, followed by pretreatment: the temperature is raised to 200 °C at 2 °C / min under a hydrogen-nitrogen mixed gas atmosphere (containing 5% hydrogen), held at that temperature for 2 h, and then cooled to room temperature at a gas flow rate of 80 mL / min to obtain the trimetallic activated carbon supported catalyst.

[0031] The trimetallic activated carbon-supported catalyst prepared in this example was used for the hydrogenation of 4-heptanone to 4-heptanol: the catalyst feed / substrate ratio was 0.01 g / mL, the reaction was carried out in a batch high-pressure reactor at a reaction temperature of 30 °C for 1.5 h, a hydrogen pressure of 5.0 MPa, and a stirring rate of 500 rpm. The conversion rate of 4-heptanone hydrogenation was measured to be 53.3%, and the selectivity for 4-heptanol was 100%.

[0032] Example 2

[0033] The pretreatment conditions of the catalyst synthesized in Example 1 were changed. The temperature was increased to 400°C at 5°C / min under a hydrogen-nitrogen mixed gas atmosphere (containing 5% hydrogen), held at the temperature for 3 hours, and then cooled to room temperature. The gas flow rate was 50 mL / min. The rest of the conditions were the same as in Example 1, and the trimetallic activated carbon supported catalyst was obtained.

[0034] The trimetallic activated carbon-supported catalyst prepared in this example was used for the hydrogenation of 4-heptanone to 4-heptanol: the catalyst feed / substrate ratio was 0.01 g / mL, the reaction was carried out in a batch high-pressure reactor at a reaction temperature of 30 °C for 1.5 h, a hydrogen pressure of 5.0 MPa, and a stirring rate of 500 rpm. The conversion rate of 4-heptanone hydrogenation was measured to be 86.7%, and the selectivity for 4-heptanol was 100%.

[0035] Example 3

[0036] Weigh 0.025 g of yttrium nitrate hexahydrate and 0.2 g of CTAB, add them to 50 mL of deionized water, stir for 20 min, adjust the pH to 10 with NaOH, add 0.6 g of activated carbon and 3 mL of hydrazine hydrate, and continue stirring for 3 h. Filter and wash until neutral, then vacuum dry at 80 °C for 12 h. Heat to 500 °C at 5 °C / min with an argon flow rate of 20 mL / min, hold at this temperature for 3 h, and then cool to room temperature to obtain Y / C.

[0037] Weigh 0.012 g of ammonium metatungstate hydrate and 0.015 g of stannous chloride hydrate and dissolve them in 50 mL of deionized water. Add 0.8 g of PVA and stir until completely dissolved. Adjust the pH to 10 with NaOH. Add 10 mL of ethanol and 0.65 g of sodium borohydride and stir for 1 h. Then add 0.6 g of Y / C and continue stirring for 3 h. Filter and wash until neutral. Dry under vacuum at 80 °C for 12 h. Then perform pretreatment: raise the temperature to 300 °C at 2 °C / min under a hydrogen-nitrogen mixed gas atmosphere (containing 5% hydrogen) and hold for 3 h. Then lower the temperature to room temperature. The gas flow rate is 80 mL / min. The trimetallic activated carbon supported catalyst is obtained.

[0038] The trimetallic activated carbon-supported catalyst prepared in this example was used for the hydrogenation of 4-heptanone to 4-heptanol: the catalyst feed / substrate ratio was 0.01 g / mL, the reaction was carried out in a batch high-pressure reactor at a reaction temperature of 50°C for 2 h, a hydrogen pressure of 5.0 MPa, and a stirring rate of 500 rpm. The conversion rate of 4-heptanone hydrogenation was measured to be 31.5%, and the selectivity for 4-heptanol was 98.5%.

[0039] Example 4

[0040] The pretreatment conditions of the catalyst synthesized in Example 3 were changed. The temperature was increased to 500°C at 5°C / min under a hydrogen-nitrogen mixed gas atmosphere (containing 5% hydrogen), held at the temperature for 3 hours, and then cooled to room temperature. The gas flow rate was 50 mL / min. The rest of the conditions were the same as in Example 3, and the trimetallic activated carbon supported catalyst was obtained.

[0041] The trimetallic activated carbon-supported catalyst prepared in this example was used for the hydrogenation of 4-heptanone to 4-heptanol: the catalyst feed / substrate ratio was 0.01 g / mL, the reaction was carried out in a batch high-pressure reactor at a reaction temperature of 50 °C for 2 h, a hydrogen pressure of 5.0 MPa, and a stirring rate of 500 rpm. The conversion rate of 4-heptanone hydrogenation was measured to be 56.3%, and the selectivity for 4-heptanol was 100%.

[0042] Example 5

[0043] Weigh 0.025 g of lanthanum nitrate hexahydrate and 0.2 g of CTAB, add them to 50 mL of deionized water, stir for 20 min, adjust the pH to 10 with NaOH, add 0.6 g of activated carbon and 3 mL of hydrazine hydrate, and continue stirring for 3 h. Filter and wash until neutral, then vacuum dry at 80 °C for 12 h. Heat to 500 °C at 5 °C / min with an argon flow rate of 20 mL / min, hold at this temperature for 3 h, and then cool to room temperature to obtain La / C.

[0044] Weigh 0.012 g of rhodium chloride hydrate and 0.06 g of magnesium nitrate hexahydrate and dissolve them in 50 mL of deionized water. Add 0.8 g of PVA and stir until completely dissolved. Adjust the pH to 10 with NaOH. Add 10 mL of 5 mol / L ascorbic acid aqueous solution and stir for 1 h. Then add 0.6 g of La / C and continue stirring for 3 h. Filter and wash until neutral. Dry under vacuum at 80 °C for 12 h. Then perform pretreatment: raise the temperature to 500 °C at 5 °C / min under a hydrogen-nitrogen mixed gas atmosphere (containing 5% hydrogen), hold the temperature for 2 h, and then lower it to room temperature. The gas flow rate is 50 mL / min. The trimetallic activated carbon supported catalyst is obtained.

[0045] The trimetallic activated carbon-supported catalyst prepared in this example was used for the hydrogenation of 4-heptanone to 4-heptanol: the catalyst feed / substrate ratio was 0.01 g / mL, the reaction was carried out in a batch high-pressure reactor at a reaction temperature of 30 °C for 1.5 h, a hydrogen pressure of 5.0 MPa, and a stirring rate of 500 rpm. The conversion rate of 4-heptanone hydrogenation was measured to be 91.2%, and the selectivity for 4-heptanol was 100%.

[0046] Example 6

[0047] The pretreatment conditions of the catalyst synthesized in Example 5 were changed. The temperature was increased to 300°C at 2°C / min under a hydrogen-nitrogen mixed gas atmosphere (containing 5% hydrogen), held at the temperature for 3 hours, and then cooled to room temperature. The gas flow rate was 80 mL / min. The rest of the conditions were the same as in Example 5, and the trimetallic activated carbon supported catalyst was obtained.

[0048] The trimetallic activated carbon-supported catalyst prepared in this example was used for the hydrogenation of 4-heptanone to 4-heptanol: the catalyst feed / substrate ratio was 0.01 g / mL, the reaction was carried out in a batch high-pressure reactor at a reaction temperature of 30°C for 1.5 h, a hydrogen pressure of 5.0 MPa, and a stirring rate of 500 rpm. The conversion rate of 4-heptanone hydrogenation was 100%, and the selectivity for 4-heptanol was 100%.

[0049] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. The application of a trimetallic activated carbon supported catalyst in the hydrogenation of 4-heptanone to 4-heptanol, characterized in that: A batch autoclave liquid-phase hydrogenation process is adopted without the use of solvents. During the batch autoclave liquid-phase hydrogenation process, the hydrogen pressure is 0.5-5.5 MPa, the reaction temperature is 20-50℃, the catalyst feed rate / substrate is 0.001-0.01 g / mL, and the reaction time is 0.5-2 h. This trimetallic activated carbon supported catalyst uses activated carbon as a support, on which a first metal element, a second metal element, and a promoter metal element are loaded. The first metal element is selected from Rh, W, and Ir; the second metal element is selected from Ga, Sn, and Mg; and the promoter metal element is selected from La, Ce, and Y. The loading amounts of the first metal element are 0.1-1.6 wt.%, the second metal element is 0.5-1.6 wt.%, and the promoter metal element is 0.1-1.5 wt.%. The preparation process of this trimetallic activated carbon supported catalyst includes: first, loading the auxiliary metal element onto activated carbon, and then simultaneously loading the first metal element and the second metal element onto activated carbon. The specific loading method includes: mixing and stirring the activated carbon with a salt solution of the metal precursor, adding a surfactant and adjusting the pH to 0.5-5.5 or 8-13, adding a chemical reducing agent for reduction, filtering and washing until neutral, and then vacuum drying at 75-85 ℃ for 10-12 h. The trimetallic activated carbon supported catalyst needs to be pretreated with a hydrogen-nitrogen mixed gas before feeding. The pretreatment is as follows: the hydrogen-nitrogen mixed gas passes through the catalyst bed at a flow rate of 40-80 mL / min, the hydrogen content in the hydrogen-nitrogen mixed gas is 4-6%, the pretreatment temperature is 200-500 ℃, the heating rate is 2-10 ℃ / min, and the pretreatment time is 1-6 h.

2. A method for hydrogenating 4-heptanone to 4-heptanol, characterized in that: A trimetallic activated carbon supported catalyst is used. Before feeding, the trimetallic activated carbon supported catalyst needs to be pretreated with a hydrogen-nitrogen mixed gas. The pretreatment is as follows: the hydrogen-nitrogen mixed gas passes through the catalyst bed at a flow rate of 40-80 mL / min, the hydrogen content in the hydrogen-nitrogen mixed gas is 4-6%, the pretreatment temperature is 200-500 ℃, the heating rate is 2-10 ℃ / min, and the pretreatment time is 1-6 h. This trimetallic activated carbon supported catalyst uses activated carbon as a support, on which a first metal element, a second metal element, and a promoter metal element are loaded. The first metal element is selected from Rh, W, and Ir; the second metal element is selected from Ga, Sn, and Mg; and the promoter metal element is selected from La, Ce, and Y. The loading amounts of the first metal element are 0.1-1.6 wt.%, the second metal element is 0.5-1.6 wt.%, and the promoter metal element is 0.1-1.5 wt.%. The preparation process of this trimetallic activated carbon supported catalyst includes: first, loading the auxiliary metal element onto activated carbon, and then simultaneously loading the first metal element and the second metal element onto activated carbon. The specific loading method includes: mixing and stirring the activated carbon with a salt solution of the metal precursor, adding a surfactant and adjusting the pH to 0.5-5.5 or 8-13, adding a chemical reducing agent for reduction, filtering and washing until neutral, and then vacuum drying at 75-85 ℃ for 10-12 h.

3. The method as described in claim 2, characterized in that: The process employs an intermittent high-pressure autoclave liquid-phase hydrogenation process without the use of solvents.

4. The method as described in claim 3, characterized in that: In the intermittent high-pressure autoclave liquid-phase hydrogenation process, the hydrogen pressure is 0.5-5.5 MPa, the reaction temperature is 20-50℃, the catalyst feed rate / substrate is 0.001-0.01 g / mL, and the reaction time is 0.5-2 h.