Nitrogen-modified activated carbon supported Ru-ni bimetallic catalyst, preparation method and application thereof

Abstract

The application discloses a nitrogen-modified activated carbon supported Ru-Ni bimetallic catalyst and a preparation method and application thereof. The catalyst uses a nitrogen-modified activated carbon carrier, and because nitrogen with moderate valence in a nitrogen precursor is doped, on one hand, high activity is maintained, and on the other hand, the interaction between the noble metal is enhanced, the selectivity of the product is obviously increased, and the activity and selectivity are double-optimized. The nitrogen-modified activated carbon supported Ru-Ni bimetallic catalyst is applied to the reaction of preparing tetramethylpiperidinol by hydrogenating triacetoneamine, and potassium hydroxide is added as a cocatalyst in the reaction, and the catalytic hydrogenation is carried out under relatively mild conditions, and excellent activity and high selectivity are exhibited, and the reaction time is shortened, and the yield of tetramethylpiperidinol is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a nitrogen-modified activated carbon supported Ru-Ni bimetallic catalyst, its preparation method, and its application in the preparation of tetramethylpiperidinol. Background Technology

[0002] 2,2,6,6-Tetramethyl-4-piperidinol (TMP) is an important intermediate in hindered amine light stabilizers (HALS). Hindered amine light stabilizers are a class of organic polymer additives with excellent light and heat stability, and are among the most widely used light stabilizers in the anti-photoaging process of polyolefin materials. Hindered amines include derivatives of piperidine, imidazolidinone, and azacycloalkane, with 2,2,6,6-tetramethylpiperidine and its substituted derivatives being the most prevalent. Tetramethylpiperidinol can also be used as a resin monomer polymerization inhibitor, bleaching agent, lubricant, polymerization inhibitor, and epoxy resin crosslinking agent; it also has special applications in the biopharmaceutical industry, serving as a free radical scavenger or antioxidant, and has high commercial economic value in both industrial and pharmaceutical fields.

[0003] Currently, piperidinol is typically prepared by the reduction of 2,2,6,6-tetramethyl-4-piperidinone (TAA), with main processes including catalytic hydrogenation, electrochemical reduction, and chemical reduction. Electrochemical reduction is easy to control, produces few byproducts, and the product is easy to separate, but its disadvantages include high energy consumption, large investment costs, and complex electrolytic cell structures. Chemical reduction uses aluminum isopropoxide or sodium borohydride as reducing agents, offering mild conditions and good selectivity, but the reducing agents are expensive and post-reaction processing is complex. Therefore, the current industrial preparation method for tetramethylpiperidinol is still the batch reactor catalytic method using Raney-Ni as the main catalyst. However, the Raney-Ni process is complex, with problems such as harsh reaction conditions, the need to improve catalyst lifespan and regeneration methods, high production costs, and difficulty in recovery. Furthermore, the high pressure places high demands on equipment, and explosions are possible during the preparation process, posing significant safety hazards. Additionally, the preparation of TMP from TAA often involves denitrification side reactions, generating byproducts that affect product quality.

[0004] This invention prepares a nitrogen-modified activated carbon-supported highly dispersed Ru-Ni bimetallic catalyst. This catalyst has high reactivity, high selectivity and stability for the product, and produces very few by-products during the reaction, which greatly improves the yield of tetramethylpiperidinol. Summary of the Invention

[0005] To address the aforementioned problems, this invention discloses a nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst, its preparation method, and its application in the preparation of tetramethylpiperidinol.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst, comprising the following specific steps:

[0008] (1) A certain mass of activated carbon is placed in hydrochloric acid solution for full immersion, then filtered and washed until neutral, and dried to obtain acidified activated carbon;

[0009] (2) Dissolve ruthenium trichloride trihydrate and nickel chloride hexahydrate in deionized water to obtain ruthenium trichloride solution and nickel chloride solution respectively;

[0010] (3) Take the acidified activated carbon obtained in step (1), add an appropriate amount of deionized water, dissolve a certain amount of urea in deionized water, add it dropwise, and stir at 60-70℃ for 12-16 hours; the acidified activated carbon and urea are fed according to the theoretical N doping amount of 3-7wt%, where the theoretical N doping amount = m N / (m N +m 酸化处理后的活性炭 )×100%, where m N This refers to the mass of nitrogen (N) contained in urea;

[0011] (4) The mixture obtained in step (3) is vacuum dried and then calcined in an inert atmosphere at a temperature of 600-800℃ for 2-4 hours to obtain nitrogen-modified activated carbon carrier.

[0012] (5) Take nitrogen-modified activated carbon carrier and add deionized water and stir thoroughly. Then add the nickel chloride solution treated in step (2) so that the theoretical loading of Ni is 1-2wt%. Impregnate at 60-70℃ for 12-16h, then filter and dry.

[0013] (6) Mix the sample obtained in step (5) with deionized water, stir to form a uniform slurry, and then add the ruthenium trichloride solution obtained in step (2) to make the theoretical loading of Ru 2-8 wt%. At the same time, add a dispersant and stir to stabilize the mixture. Impregnate at 60-70℃ for 12-16 h. The dispersant is at least one of sodium citrate, polyvinylpyrrolidone, and oxaloacetic acid tetraacetic acid. The mass of the dispersant is 20-30% of the mass of the nitrogen-modified activated carbon carrier.

[0014] (7) After being fully impregnated in step (6), the pH of the resulting suspension is controlled to be 8-9 with alkaline solution. After standing for 1.5-2 hours, the metal precursor in the suspension is reduced by sodium borohydride. After the reduction is completed, the suspension is filtered, washed to neutral, and dried to obtain nitrogen-modified activated carbon supported Ru-Ni bimetallic catalyst.

[0015] The theoretical loading of Ni = m Ni / (m Ni +m Ru +m 氮改性活性炭载体 )×100%, Theoretical load of Ru = m Ru / (m Ni +m Ru +m 氮改性活性炭载体 )×100%, where m Ni m Ru These refer to the mass of nickel and ruthenium in the nickel chloride solution and ruthenium trichloride solution, respectively.

[0016] Preferably, in step (1), the concentration of hydrochloric acid is 5-10 wt%.

[0017] Preferably, the impregnation conditions in step (1) are: impregnation at room temperature for 24-26 hours under stirring conditions.

[0018] Preferably, in step (4), the vacuum drying conditions are: drying temperature of 100-110℃ and drying time of 8-10 hours.

[0019] Preferably, in step (4), the calcination temperature is 600°C.

[0020] Preferably, in step (4), the theoretical doping amount of N in the nitrogen-modified activated carbon carrier is 5 wt%.

[0021] Preferably, in step (6), the dispersant is polyvinylpyrrolidone.

[0022] Preferably, in step (7), the alkaline solution is 5-10% ammonia or 5-10% NaOH solution.

[0023] Preferably, in step (7), the molar amount of sodium borohydride is 5-15 times the molar amount of ruthenium, and the reduction conditions are a rotation speed of 400-500 r·min. -1 The reduction is carried out at a temperature of 60-70℃ for 1.5-2 hours.

[0024] Preferably, the theoretical loading of Ru is 3-8 wt%, more preferably 3-5 wt%, and most preferably 5 wt%.

[0025] In a second aspect, the present invention provides a nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst prepared according to the preparation method described in the first aspect.

[0026] Thirdly, the present invention provides the application of the nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst in the hydrogenation of triacetone amine to prepare tetramethylpiperidinol.

[0027] The application includes the following steps: Triacetone amine is dissolved in a solvent, namely a 20%-40% isopropanol aqueous solution, to obtain a feed solution. A nitrogen-modified activated carbon-supported highly dispersed noble metal catalyst is added to the feed solution, along with 20-30% (by mass) of potassium hydroxide as a co-catalyst. A continuous hydrogenation reaction is carried out at 70-90°C, 0.7-2.0 MPa hydrogen pressure, and under stirring conditions to produce tetramethylpiperidinol. The hydrogenation product is quantitatively analyzed using gas chromatography.

[0028] Preferably, the reaction temperature is 70-80℃, and most preferably 70℃.

[0029] Preferably, the hydrogen pressure is 1-1.5 MPa, and most preferably 1 MPa.

[0030] Preferably, the mechanical stirring rate is controlled at 700-800 r·min. -1 .

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

[0032] (1) Compared with general activated carbon supported noble metal catalysts, the catalyst of the present invention uses nitrogen modified activated carbon support. Due to the doping of nitrogen in the nitrogen precursor with a moderate oxidation state, it maintains high activity on the one hand, and enhances the interaction with noble metal on the other hand, resulting in a significant increase in the selectivity of the product, thus achieving dual optimization of activity and selectivity.

[0033] (2) The catalyst used in this invention is easy to prepare.

[0034] (3) In this invention, a nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst is applied to the hydrogenation of triacetone amine to prepare tetramethylpiperidinol. At the same time, potassium hydroxide is added as a co-catalyst in the reaction. Catalytic hydrogenation is carried out under milder conditions, which shows excellent activity and high selectivity, and shortens the reaction time, greatly improving the yield of tetramethylpiperidinol. Attached Figure Description

[0035] Figure 1 The image shows the XRD characterization of the catalyst prepared in Example 1.

[0036] Figure 2 The image shows the TEM characterization of the catalyst prepared in Example 1. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The specific embodiments described below are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0038] Example 1

[0039] 1. Preparation method of nitrogen-modified carbon-supported noble metal catalyst:

[0040] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0041] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0042] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0043] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The theoretical doping amount of N was calculated to be 5 wt%, and the actual nitrogen content was 3.8 wt% as determined by elemental analysis.

[0044] (5) Take 2 grams of nitrogen-modified activated carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven and dry at 110°C and 0.9 MPa for 8 h.

[0045] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0046] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0047] 2. Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0048] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0049] Example 2

[0050] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0051] (2) Take 0.1126 g of ruthenium trichloride trihydrate and 0.1722 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution.

[0052] (3) Take 2 grams of the acidified activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0053] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.8 wt% by elemental analysis.

[0054] (5) Take 2 grams of nitrogen-modified activated carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven and dry at 110°C and 0.9 MPa for 8 h.

[0055] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0056] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.15g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0057] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0058] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0059] Example 3

[0060] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0061] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0062] (2) Take 0.2906 g of ruthenium trichloride trihydrate and 0.1777 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0063] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0064] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.7 wt% by elemental analysis.

[0065] (5) Take 2 grams of nitrogen-modified activated carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with a polyethylene film to prevent splashing during stirring, and immerse at 60°C for 14 hours. Subsequently, filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 hours.

[0066] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0067] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.39g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0068] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0069] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0070] Example 4

[0071] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0072] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0073] (2) Take 0.4805 g of ruthenium trichloride trihydrate and 0.1837 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0074] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0075] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.8 wt% by elemental analysis.

[0076] (5) Take 2 grams of nitrogen-modified activated carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven and dry at 110°C and 0.9 MPa for 8 h.

[0077] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0078] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.65g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0079] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0080] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0081] Example 5

[0082] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0083] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0084] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0085] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.1326 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0086] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 1.9 wt% by elemental analysis.

[0087] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0088] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0089] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0090] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0091] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0092] Example 6

[0093] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0094] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0095] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.1786 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0096] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 2.8 wt% by elemental analysis.

[0097] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0098] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0099] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0100] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0101] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0102] Example 7

[0103] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0104] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0105] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2737 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0106] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 4.7 wt% by elemental analysis.

[0107] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0108] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0109] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0110] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0111] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0112] Example 8

[0113] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0114] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0115] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.3227 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0116] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 5.6 wt% by elemental analysis.

[0117] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0118] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0119] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0120] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0121] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0122] Example 9

[0123] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0124] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0125] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution.

[0126] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0127] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 800°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.5 wt% by elemental analysis.

[0128] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0129] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0130] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0131] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0132] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0133] Example 10

[0134] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0135] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0136] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0137] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0138] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.8 wt% by elemental analysis.

[0139] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0140] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant sodium citrate and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with polyethylene film and fully impregnate at 60°C.

[0141] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.24g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0142] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0143] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0144] Example 11

[0145] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0146] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0147] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0148] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0149] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.7 wt% by elemental analysis.

[0150] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0151] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant oxalic acid tetraacetic acid and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with polyethylene film and fully impregnate at 60°C.

[0152] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0153] Example 12

[0154] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 40% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to the method in Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0155] Example 13

[0156] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to the method in Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 80 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0157] Example 14

[0158] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to the method in Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 90 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0159] Example 15

[0160] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to the method in Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 0.7 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0161] Example 16

[0162] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to the method in Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1.5 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0163] Example 17

[0164] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to the method in Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 2 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0165] Comparative Example 1

[0166] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0167] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0168] (2) Take 0.0557 g of ruthenium trichloride trihydrate and 0.1704 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0169] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0170] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.8 wt% by elemental analysis.

[0171] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0172] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0173] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.08g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0174] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0175] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0176] Table 1. Effect of Ru content on catalyst

[0177]

[0178] Comparative Example 2

[0179] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0180] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0181] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0182] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.0433 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0183] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 0.8 wt% by elemental analysis.

[0184] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven and dry at 110°C and 0.9 MPa for 8 h.

[0185] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0186] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0187] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0188] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 720 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0189] Comparative Example 3

[0190] Preparation method of carbon-supported noble metal catalysts:

[0191] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0192] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0193] (3) Take 2 grams of acidified activated carbon and calcine it under nitrogen at a temperature of 600℃ for 4 hours to obtain activated carbon carrier.

[0194] (4) Take 2 grams of activated carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven and dry at 110°C and 0.9 MPa for 8 h.

[0195] (5) Place the sample obtained in step (4) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0196] (6) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a highly dispersed noble metal catalyst supported on activated carbon.

[0197] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0198] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / C catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 720 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0199] Table 2 shows the effect of N doping amount on the catalyst.

[0200]

[0201] Comparative Example 4

[0202] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0203] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0204] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0205] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0206] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 400°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.9 wt% by elemental analysis.

[0207] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, impregnate at 60°C with equal volume, then filter and separate, place in a vacuum drying oven and dry at 110°C and 0.9 MPa for 8 hours.

[0208] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0209] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0210] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0211] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 730 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0212] Comparative Example 5

[0213] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0214] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0215] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0216] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0217] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours to obtain a nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 2.8 wt% by elemental analysis.

[0218] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0219] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant polyvinylpyrrolidone and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with a polyethylene film and fully impregnate at 60°C.

[0220] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0221] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0222] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 740 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0223] Table 3 Effect of support calcination on catalyst

[0224]

[0225]

[0226] Comparative Example 6

[0227] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0228] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0229] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0230] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0231] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.7 wt% by elemental analysis.

[0232] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0233] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2) and add 0.4 g of dispersant oxalic acid and stir to stabilize. The mass of the dispersant added is 20% of the mass of the nitrogen-modified activated carbon carrier. Then seal with polyethylene film and fully impregnate at 60°C.

[0234] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0235] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0236] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0237] Comparative Example 7

[0238] Preparation method of nitrogen-modified carbon-supported noble metal catalysts:

[0239] (1) Place 5 grams of activated carbon (SAC-02B from Fujian Xinsen Carbon Industry Co., Ltd.) in a 5 wt% hydrochloric acid solution at a rotation speed of 400 r·min. -1 Under the conditions of stirring at room temperature for 24 hours, the activated carbon was then filtered and washed with deionized water until neutral, dried and set aside to obtain acidified activated carbon.

[0240] (2) Take 0.1707 g of ruthenium trichloride trihydrate and 0.1740 g of nickel chloride hexahydrate and place them in beakers respectively. Add 20 mL of deionized water to dissolve them completely to obtain ruthenium trichloride solution and nickel chloride solution;

[0241] (3) Take 2 grams of activated carbon obtained in step (1), add 100 mL of deionized water, dissolve 0.2257 grams of urea in 20 mL of deionized water, add it drop by drop, and stir thoroughly at 60°C for 14 hours to make it evenly mixed.

[0242] (4) The mixture obtained in step (3) was placed in a vacuum drying oven at 110°C and 0.9 MPa for 8 hours and then calcined under nitrogen at 600°C for 4 hours to obtain nitrogen-modified activated carbon carrier. The actual nitrogen content was found to be 3.6 wt% by elemental analysis.

[0243] (5) Take 2 grams of nitrogen-modified carbon carrier and add 100 mL of deionized water and stir thoroughly. Then add the nickel chloride solution prepared in step (2), seal with polyethylene film to prevent splashing during stirring, soak at 60°C for 14 h, then filter and separate, place in a vacuum drying oven, and dry at 110°C and 0.9 MPa for 8 h.

[0244] (6) Place the sample obtained in step (5) in a beaker, add 100 mL of deionized water and stir. After a uniform slurry is formed, add the ruthenium trichloride solution obtained in step (2), then seal it with a polyethylene film and fully impregnate it at 60°C.

[0245] (7) After soaking for 16 hours, control the pH to 8-9 with a 5% ammonia solution, let stand for 2 hours, then add 0.23g of sodium borohydride, and rotate at 400 r·min. -1 The catalyst was reduced at 60℃ for 1.5 h, cooled, filtered, washed until neutral, and dried at 110℃ for 8 h to obtain a nitrogen-modified activated carbon supported highly dispersed noble metal catalyst.

[0246] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0247] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of Ru-Ni / CN catalyst and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0248] Table 4. Effect of dispersant type on catalyst

[0249]

[0250] Comparative Example 8

[0251] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0252] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of deionized water, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 740 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0253] Comparative Example 9

[0254] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0255] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 10% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0256] Comparative Example 10

[0257] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0258] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of isopropanol, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0259] Comparative Example 11

[0260] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0261] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of anhydrous ethanol, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 730 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0262] Comparative Example 12

[0263] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0264] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 75% ethanol aqueous solution, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0265] Comparative Example 13

[0266] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0267] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% ethanol aqueous solution, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0268] Comparative Example 14

[0269] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0270] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of methanol, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0271] Table 3 Effect of solvent on reaction

[0272]

[0273] Comparative Example 15

[0274] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0275] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 60 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0276] Comparative Example 16

[0277] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0278] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 100 °C. The pressure was controlled at 1 MPa, and the mechanical stirring rate was controlled at 750 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0279] Table 4 Effect of temperature on the reaction

[0280]

[0281] Comparative Example 17

[0282] Application of catalysts in the selective catalytic hydrogenation of triacetone amine:

[0283] 15 g of triacetone amine (TAA) was placed in a 0.6 L high-pressure reactor, followed by 200 mL of 20% isopropanol aqueous solution, then 0.75 g of the catalyst prepared according to Example 1 and 0.2 g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 80 °C. The pressure was controlled at 0.5 MPa, and the mechanical stirring rate was controlled at 720 r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. After the reaction is complete, cool the reactor to room temperature, release the pressure inside the reactor, filter the reaction solution, and perform gas chromatography analysis.

[0284] Table 4 Effect of pressure on the reaction

[0285]

[0286] Example 18

[0287] The stability of the 2% Ru-Ni / CN prepared in Example 2 and the 3% Ru-Ni / CN prepared in Example 1 were evaluated.

[0288] 15g of triacetone amine (TAA) was placed in a 0.6L high-pressure reactor, followed by 200mL of 20% isopropanol aqueous solution, then 0.75g of catalyst and 0.2g of potassium hydroxide. The air inside the reactor was replaced three times with H2, and the airtightness of the reactor was checked. The stirrer was turned on, and the temperature was raised to the reaction temperature of 70℃. The pressure was controlled at 1MPa, and the mechanical stirring rate was controlled at 750r·min. -1 Observe the pressure changes inside the reactor. When the pressure drops, promptly replenish it with H2 to the original pressure. Repeat this operation until the pressure inside the reactor shows no significant change within half an hour, which is the reaction endpoint. Filter out the catalyst for reuse. The catalyst is reused four times consecutively. After five uses, the reaction is as follows:

[0289] Table 5

[0290]

Claims

1. A method for preparing a nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst, characterized in that: The preparation method includes the following specific steps: (1) A certain mass of activated carbon is placed in hydrochloric acid solution for full immersion, then filtered and washed until neutral, and dried to obtain acidified activated carbon; (2) Dissolve ruthenium trichloride trihydrate and nickel chloride hexahydrate in deionized water to obtain ruthenium trichloride solution and nickel chloride solution respectively; (3) Take the acidified activated carbon obtained in step (1), add an appropriate amount of deionized water, dissolve a certain amount of urea in deionized water, and add it drop by drop. Stirring at 60-70℃ for 12-16 h; the acidified activated carbon and urea are fed in at a theoretical N doping amount of 3-7 wt%, where the theoretical N doping amount = m N / (m N +m 酸化处理后的活性炭 )×100%, where m N This refers to the mass of nitrogen (N) contained in urea; (4) After vacuum drying the mixture obtained in step (3), it is calcined in an inert atmosphere at a temperature of 600-800℃ for 2-4 h to obtain nitrogen-modified activated carbon carrier. (5) Take nitrogen-modified activated carbon carrier and add deionized water and stir thoroughly. Then add the nickel chloride solution treated in step (2) so that the theoretical loading of Ni is 1-2wt%. Impregnate at 60-70 °C for 12-16 h, then filter and dry. (6) Mix the sample obtained in step (5) with deionized water, stir to form a uniform slurry, and then add the ruthenium trichloride solution obtained in step (2) to make the theoretical loading of Ru 2-8 wt%. At the same time, add a dispersant and stir to stabilize. Impregnate at 60-70℃ for 12-16 h. The dispersant is one or two of sodium citrate and polyvinylpyrrolidone, and the mass of the dispersant is 20-30% of the mass of the nitrogen-modified activated carbon carrier. (7) After being fully impregnated in step (6), the pH of the resulting suspension is controlled by alkaline solution to 8-9. After standing for 1.5-2 h, the metal precursor in the suspension is reduced by sodium borohydride. After the reduction is completed, the suspension is filtered, washed to neutral, and dried to obtain nitrogen-modified activated carbon supported Ru-Ni bimetallic catalyst. The theoretical loading of Ni = m Ni / (m Ni +m Ru +m 氮改性活性炭载体 )×100%, Theoretical load of Ru = m Ru / (m Ni +m Ru +m 氮改性活性炭载体 )×100%, where m Ni m Ru These refer to the mass of nickel and ruthenium in the nickel chloride solution and ruthenium trichloride solution, respectively.

2. The preparation method according to claim 1, characterized in that: The immersion conditions in step (1) are: immersion at room temperature for 24-26 h under stirring conditions.

3. The preparation method according to claim 1, characterized in that: In step (4), the roasting temperature is 600℃.

4. The preparation method according to claim 1, characterized in that: In step (4), the theoretical doping amount of N in the nitrogen-modified activated carbon support is 5 wt%.

5. The preparation method according to claim 1, characterized in that: The theoretical loading of Ru is 3-8 wt%.

6. The preparation method according to claim 5, characterized in that: The theoretical loading of Ru is 3-5 wt%.

7. The preparation method according to claim 6, characterized in that: The theoretical loading of Ru is 5 wt%.

8. The application of the nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst prepared by any one of claims 1-7 in the hydrogenation of triacetone amine to prepare tetramethylpiperidinol.

9. The application as described in claim 8, characterized in that: The application includes the following steps: dissolving triacetone amine in a solvent to obtain a raw material solution, wherein the solvent is a 20%-40% isopropanol aqueous solution; adding a nitrogen-modified activated carbon-supported Ru-Ni bimetallic catalyst to the raw material solution; and adding potassium hydroxide at a mass of 20-30% of the catalyst mass as a co-catalyst; and carrying out a continuous hydrogenation reaction under conditions of 70-90℃, 0.7-2.0MPa hydrogen pressure, and stirring to generate tetramethylpiperidinol.

10. The application as described in claim 9, characterized in that: The reaction temperature is 70-80 ℃.

11. The application as described in claim 10, characterized in that: The reaction temperature is 70℃.

12. The application as described in claim 9, characterized in that: The hydrogen pressure is 1-1.5 MPa.

13. The application as described in claim 12, characterized in that: The hydrogen pressure is 1 MPa.

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