Catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde, preparation method and application thereof

Abstract

The present invention provides a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde, and a preparation method and application thereof. The catalyst comprises a hollow structure SiO2 carrier and nickel oxide and alkaline earth metal oxide loaded on the surface of the hollow structure SiO2 carrier, wherein the alkaline earth metal oxide is selected from any one or more of calcium oxide, magnesium oxide, and barium oxide. The preparation method of the present application is simple in process and low in cost, and the prepared catalyst has suitable catalytic activity and stability. By utilizing the characteristics of the hollow structure SiO2 carrier, such as small specific surface area, small pore volume, and acid resistance of the carrier, nickel oxide and alkaline earth metal oxide can only be loaded on the surface shell of silicon dioxide, which is conducive to improving the selectivity of the product, promoting the adsorption and diffusion of the reactants and the desorption of the product. In addition, nickel oxide is the main active component of the hydrogenation of nicotinonitrile and is inexpensive, so that the catalyst cost of the present application is low. And the above catalyst can be continuously produced on a fixed bed.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde, and a preparation method and application thereof. Background Art

[0002] Nicotinaldehyde, also known as 3-pyridinecarboxaldehyde, is an important chemical intermediate and a key intermediate in the synthesis of pymetrozine. Pymetrozine is a new heterocyclic insecticide developed by Novartis in Switzerland in 1988 for the control of aphids and whiteflies. It has the characteristics of high efficiency, low toxicity, high selectivity, and environmental friendliness. Nicotinaldehyde, as an intermediate of pymetrozine, is the key in the entire synthesis route and is also a hot spot and difficulty in research. Among the many synthetic routes, the use of nicotinonitrile as a raw material and the use of catalytic hydrogenation to synthesize nicotinaldehyde has always been the main research direction, because the reaction conditions of this method are mild, the catalyst is easy to obtain, and the yield is high, which is more suitable for industrial production. At present, the preparation method of nicotinonitrile hydrogenation often uses homogeneous catalyst batch reactor production, which is often accompanied by the production of by-products. Among them, how to control nicotinonitrile from being excessively reduced to amine is also a key point in the synthesis of this reaction.

[0003] A Chinese patent application with the patent application publication number CN 108863913 A discloses a method for improving the stability of nicotinaldehyde. The specific production process of nicotinaldehyde is as follows: 3-cyanopyridine is used as a raw material, and Raney nickel is used to catalyze hydrogenation in an acetic acid aqueous solution to obtain a nicotinaldehyde solution, wherein the amount of acetic acid added is 1 to 1.5 times the molar amount of 3-cyanopyridine, and the yield is 84%. European patent EP 613888 discloses a method for preparing nicotinaldehyde by catalytic hydrogenation using Raney nickel (content of 60%) in a stirred tank, and the yield is 84% ​​after 5 hours of reaction.

[0004] As can be seen from the above, the types of existing catalysts for the catalytic hydrogenation of nicotinonitrile are relatively single, mainly using Raney nickel, but there are the following problems: 1. Raney nickel is expensive and can only be used for batch kettle hydrogenation reactions, and does not have the conditions for continuous production; 2. The hydrogenation depth using Raney nickel as a catalyst is difficult to control, and the reaction yield is not high; 3. The reaction solvent is water and the generated product also has water. General carriers (such as alumina) are difficult to meet the requirements of long-term fixed bed production; 4. Commercially purchased silica has a large specific surface area and abundant internal pores, which is not conducive to the rapid adsorption and desorption of reaction products, and it is difficult to control the hydrogenation depth. Summary of the invention

[0005] The main purpose of the present invention is to provide a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde, and its preparation method and application, so as to solve the technical problems in the prior art such as the inability to continuously produce the catalyst, the difficulty in controlling the hydrogenation depth, the low reaction yield and product purity.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is provided, the catalyst comprising a hollow structure SiO2 carrier and nickel oxide and alkaline earth metal oxide loaded on the surface of the hollow structure SiO2 carrier, wherein the alkaline earth metal oxide is selected from any one or more of calcium oxide, magnesium oxide and barium oxide.

[0007] Furthermore, the specific surface area of ​​the catalyst is 61-75 m 2 / g; and / or, the total pore volume of the catalyst is 0.15~0.29cm 3 / g; and / or, the average pore size of the catalyst is 8.5~10nm.

[0008] Furthermore, the mass ratio of the hollow structure SiO2 carrier, nickel oxide and alkaline earth metal oxide is 100:19~25:1~2.

[0009] According to another aspect of the present invention, there is provided a method for preparing the aforementioned catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde, the preparation method comprising: step S1, mixing raw materials comprising a first template, a silicate and an alkaline solvent, and sequentially performing hydrolysis, suction filtration and a first drying to obtain an intermediate product; step S2, mixing raw materials comprising the intermediate product, a second template, an alkaline agent and water, and sequentially performing etching, suction filtration, washing and a second drying to obtain a hollow structure SiO2 carrier, and performing a first calcination on the hollow structure SiO2 carrier to obtain a calcined product; step S3, mixing raw materials comprising the calcined product, an extrusion aid and nitric acid, and then extruding and molding to obtain a molded SiO2 carrier; step S4, in an inert atmosphere, mixing a molded SiO2 carrier, a third template, a nickel source, an alkaline earth metal and water, and sequentially performing aging, standing, filtering, a third drying and a second calcination to obtain a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde.

[0010] Furthermore, in the above step S4, the temperature of the third drying is 90-100°C, and the time of the third drying treatment is 12-24 hours; and / or the temperature of the second calcination is 350-450°C, and the time of the second calcination is 5-6 hours; and / or the aging time is 1-2 hours, and ultrasound is performed during the aging process, and the output power of the ultrasound is 60-70 W; and / or the standing time is 1-2 hours.

[0011] Furthermore, in the above step S4, the mass of the third template is 0.05~0.1% of the mass of the hollow structure SiO2 carrier, and / or the third template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide; and / or, the mass of the nickel source in the nickel source is 15%~20% of the mass of the hollow structure SiO2 carrier in terms of nickel atoms, and the nickel source is Ni(NO3)2·6H2O and / or NiCl2; and / or, the mass of the alkaline earth metal in the alkaline earth metal is 1%~2% of the mass of the hollow structure SiO2 carrier in terms of alkaline earth metal atoms, and the alkaline earth metal is selected from any one or more of Ca(NO3)2·4H2O, MgN2O6·6H2O and Ba(NO3)2.

[0012] Furthermore, in the above step S1, the hydrolysis temperature is 30-40°C, and the hydrolysis time is 3-5 h; and / or the first drying temperature is 60-80°C; and / or the alkaline solvent includes aqueous ammonia, ethanol and water, and / or the volume ratio of aqueous ammonia, ethanol and water is 1:6-9:35-40; the mass ratio of aqueous ammonia, silicate and the first template is 1:8-10:0.8-1, and / or the silicate is ethyl orthosilicate and / or tetrabutyl silicate; and / or the first template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide.

[0013] Furthermore, in the above step S2, the etching temperature is 40~60°C, the hydrolysis time is 5~8 h; and / or the second drying temperature is 60~80°C; and / or the first calcination temperature is 550°C~650°C; and / or the mass ratio of silicate, second template, alkaline reagent and water is 1:0.035~0.045:0.3~0.35:18~20, and / or the second template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide, and / or the alkaline reagent is selected from any one or more of Na2CO3, K2CO3 and NaOH.

[0014] Furthermore, in the above step S3, the mass ratio of the calcined product, the extrusion aid and the nitric acid is 1:0.02~0.03:0.03~0.05.

[0015] According to another aspect of the present invention, a method for synthesizing nicotinaldehyde by hydrogenating nicotinonitrile using a catalyst is provided, wherein the catalyst is the above-mentioned catalyst for synthesizing nicotinaldehyde by hydrogenating nicotinonitrile.

[0016] By applying the technical scheme of the present invention, the preparation method of the present application is simple in process and low in cost, and the prepared catalyst has suitable catalytic activity and stability. By utilizing the characteristics of the hollow structure SiO2 carrier with small specific surface area (not too rich in pore structure), small pore volume and acid resistance of the carrier, nickel oxide and alkaline earth metal oxide can only be loaded on the surface shell of silicon dioxide, which is conducive to improving the selectivity of the product, promoting the adsorption and diffusion of reactants and the desorption of products. By introducing alkaline earth metal oxide additives, the number of hydroxyl groups on the catalyst surface is changed, the surface acidity of the hollow structure SiO2 carrier and the surface dispersion of the active components are adjusted, and the metal dispersion of the main active component of nickel oxide is improved, which is conducive to the reduction of nicotinonitrile with hydrogen to imine and rapid desorption and hydrolysis from the catalyst surface to generate nicotinaldehyde, reducing the deep hydrogenation reduction of the intermediate imine to amine to generate impurities, which is conducive to improving the selectivity and purity of the nicotinonitrile reaction. And the alkaline earth metal oxide changes the interaction between nickel oxide and the carrier, thereby improving the service life. In addition, nickel oxide is the main active component of nicotinonitrile hydrogenation and is cheap, so that the catalyst cost of the present application is low. And the above catalyst can be continuously produced on a fixed bed. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0018] As analyzed in the background technology of this application, there are technical problems in the prior art such as the inability to produce catalysts continuously, difficulty in controlling the depth of hydrogenation, low reaction yield and product purity, etc. In order to solve the above problems, this application provides a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde, as well as a preparation method and application thereof.

[0019] In a typical embodiment of the present application, a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is provided, the catalyst comprising a hollow structure SiO2 carrier and nickel oxide and alkaline earth metal oxide loaded on the surface of the hollow structure SiO2 carrier, wherein the alkaline earth metal oxide is selected from any one or more of calcium oxide, magnesium oxide, and barium oxide.

[0020] The preparation method of the present application is simple in process and low in cost. The prepared catalyst has suitable catalytic activity and stability. By utilizing the characteristics of the hollow structure SiO2 carrier with small specific surface area (not too rich in pore structure), small pore volume and acid resistance of the carrier, nickel oxide and alkaline earth metal oxide can only be loaded on the surface shell of silicon dioxide, which is conducive to improving the selectivity of the product, promoting the adsorption and diffusion of reactants and the desorption of products. By introducing alkaline earth metal oxide additives, the number of hydroxyl groups on the catalyst surface is changed, the surface acidity of the hollow structure SiO2 carrier and the surface dispersion of the active components are adjusted, and the metal dispersion of the main active component of nickel oxide is improved, which is conducive to the reduction of nicotinic acid nitrile with hydrogen to imine and rapid desorption and hydrolysis from the catalyst surface to generate nicotinaldehyde, reducing the deep hydrogenation reduction of the intermediate imine to amine to generate impurities, which is conducive to improving the selectivity and purity of the nicotinic acid nitrile reaction. And the alkaline earth metal oxide changes the interaction between nickel oxide and the carrier, thereby improving the service life. In addition, nickel oxide is the main active component of nicotinic acid nitrile hydrogenation and is cheap, so that the catalyst cost of the present application is low. And the above catalyst can be continuously produced on a fixed bed.

[0021] In one embodiment of the present application, the specific surface area of ​​the catalyst is 61-75 m 2 / g; and / or, the total pore volume of the catalyst is 0.15~0.29cm 3 / g; and / or, the average pore size of the catalyst is 8.5~10nm.

[0022] The present application utilizes the low specific surface area and small pore size of the hollow structure SiO2 carrier, and the active components can only be loaded on the surface shell of the hollow structure SiO2 carrier, so that the specific surface area, total pore volume and average pore size of the catalyst are within the above range. On the one hand, it is beneficial to improve the adsorption and diffusion efficiency of the reactant molecules, thereby helping to improve the rate and selectivity of the catalytic reaction. On the other hand, it is beneficial to promote the maximization of the utilization of the effective active sites of the catalyst and reduce the occurrence of side reactions.

[0023] In one embodiment of the present application, the mass ratio of the hollow structure SiO2 carrier, nickel oxide and alkaline earth metal oxide is 100:19~25:1~2.

[0024] The hollow structure SiO2 carrier is conducive to the adsorption and diffusion of reactants, nickel oxide is the key active component of the hydrogenation reaction of nicotinonitrile, and alkaline earth metal oxide is conducive to adjusting the surface acidity and alkalinity of the carrier SiO2 and the surface dispersion of Ni atoms. Therefore, by controlling the mass ratio of the hollow structure SiO2 carrier, nickel oxide and alkaline earth metal oxide within the above range, it is conducive to changing the binding force and dispersion of the active components and the carrier, so that nicotinonitrile can be quickly separated and hydrolyzed after hydrogenation, reducing the probability of its deep hydrogenation to generate amines and generate impurity products, improving the activity and selectivity of the catalyst, and further improving the catalytic performance of the catalyst.

[0025] In another typical embodiment of the present application, a method for preparing a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is provided, the preparation method comprising: step S1, mixing raw materials including a first template, a silicate and an alkaline solvent, and sequentially performing hydrolysis, suction filtration and a first drying to obtain an intermediate product; step S2, mixing raw materials including the intermediate product, a second template, an alkaline agent and water, and sequentially performing etching, suction filtration, washing and a second drying to obtain a hollow structure SiO2 carrier, and performing a first calcination on the hollow structure SiO2 carrier to obtain a calcined product; step S3, mixing raw materials including the calcined product, an extrusion aid and nitric acid, and then extruding and molding to obtain a molded SiO2 carrier; step S4, in an inert atmosphere, mixing a molded SiO2 carrier, a third template, a nickel source, an alkaline earth metal and water, and sequentially performing aging, standing, filtering, a third drying and a second calcination to obtain a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde.

[0026] The present application first hydrolyzes silicate under alkaline conditions. Specifically, during the formation of SiO2, silicate is first hydrolyzed to produce monomers with 1 to 4 hydroxyl groups. These monomers condense to form SiO2 balls. The hydrolysis of silicate in the early stage is slow, so that there are more ethoxy groups in the solution system. These ethoxy groups make the internal SiO2 have a larger porosity, while the external SiO2 is formed by the condensation of silicic acid. This part of SiO2 is relatively denser. When etching the intermediate product, due to the different polymerization degrees of the inner and outer layers when condensing to generate SiO2 during the hydrolysis process, the stability of the inner and outer SiO2 of the intermediate product to the etchant is different, so that the etching process is carried out from the inside to the outside of the SiO2 ball, that is, the low-aggregation SiO2 inside the SiO2 ball can be etched away, thereby forming a hollow structure SiO2 carrier. Finally, a nickel source and an alkaline earth metal auxiliary agent are added, and the nickel active component is loaded on the shell layer by ultrasound. The introduction of alkaline earth metal can change the surface acidity of the carrier SiO2 and the surface dispersion of the nickel atoms. The nickel active component and the alkaline earth metal auxiliary agent are changed into metal oxides by roasting, and the surfactant is removed at the same time, so that the nickel atoms on the surface of the prepared shell layer are evenly distributed. The preparation method of the present application is simple in process and low in cost. The prepared catalyst has suitable catalytic activity and stability. The hollow structure SiO2 carrier has small specific surface area, small pore volume, and acid resistance of the carrier, which is conducive to improving the adsorption and diffusion of the reactants, as well as the desorption of the products, and avoiding deep hydrogenation to generate amines to generate impurity products, thereby improving the selectivity and purity of the products. And the catalyst can be continuously produced on a fixed bed by simple extrusion molding.

[0027] In one embodiment of the present application, in the above step S4, the temperature of the third drying is 90~100°C, and the time of the third drying treatment is 12~24h; and / or the temperature of the second calcination is 350°C~450°C, and the time of the second calcination is 5~6h; and / or the aging time is 1~2h, and ultrasound is performed during the aging process, and the output power of the ultrasound is 60~70 W; and / or the standing time is 1~2h.

[0028] By controlling the aging conditions within the above range, it is beneficial to quickly introduce the nickel source active component and the alkaline earth metal additive, thereby greatly improving the catalyst preparation efficiency. By controlling the drying conditions within the above range, it is beneficial to remove the template agent and reduce its damage to the catalyst pore structure. By controlling the calcination conditions within the above range, the mechanical strength of the catalyst at high temperature is improved, thereby improving the stability of the catalyst.

[0029] In one embodiment of the present application, the mass of the above-mentioned third template is 0.05~0.1% of the mass of the hollow structure SiO2 carrier, and / or the third template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide; and / or, the mass of the nickel source in the nickel source is 15%~20% of the mass of the hollow structure SiO2 carrier in terms of nickel atoms, and the nickel source is Ni(NO3)2·6H2O and / or NiCl2; and / or, the mass of the alkaline earth metal in the alkaline earth metal is 1%~2% of the mass of the hollow structure SiO2 carrier in terms of alkaline earth metal atoms, and the alkaline earth metal is selected from any one or more of Ca(NO3)2·4H2O, MgN2O6·6H2O and Ba(NO3)2.

[0030] The amount of the third template affects the pore structure of the catalyst, while the loading amount of the nickel source and the alkaline earth metal is directly related to the activity and stability of the catalyst. By controlling the content and composition of the nickel source and the alkaline earth metal, it is beneficial to improve the activity and selectivity of the catalyst, thereby improving the catalytic performance of the catalyst.

[0031] In one embodiment of the present application, in the above step S1, the hydrolysis temperature is 30~40°C, and the hydrolysis time is 3~5 h; and / or the first drying temperature is 60~80°C; and / or the alkaline solvent includes ammonia water, ethanol and water, and / or the volume ratio of ammonia water, ethanol and water is 1:6~9:35~40; the mass ratio of ammonia water, silicate and the first template is 1:8~10:0.8~1, and / or the silicate is ethyl orthosilicate and / or tetrabutyl silicate; and / or the first template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide.

[0032] It is preferred to control the range of the above conditions, which is beneficial to adjust the pore size distribution and specific surface area of ​​the hollow structure SiO2 carrier within a more optimal range, thereby improving the uniformity and stability of its pore structure and providing an ideal carrier substrate for subsequent metal loading.

[0033] In one embodiment of the present application, in the above step S2, the etching temperature is 40~60°C, the hydrolysis time is 5~8 h; and / or the second drying temperature is 60~80°C; and / or the first calcination temperature is 550°C~650°C; and / or the mass ratio of silicate, second template, alkaline reagent and water is 1:0.035~0.045:0.3~0.35:18~20, and / or the second template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide, and / or the alkaline reagent is selected from any one or more of Na2CO3, K2CO3 and NaOH.

[0034] The etching conditions and the first calcination temperature affect the formation and stability of the hollow structure SiO2 carrier, and the raw material ratio determines the pore structure and chemical properties of the carrier. By controlling the range of the above reaction conditions, it is beneficial to reasonably control the pore volume and stability of the hollow structure SiO2 carrier.

[0035] In one embodiment of the present application, in the above step S3, the mass ratio of the calcined product, the extrusion aid and the nitric acid is 1:0.02~0.03:0.03~0.05.

[0036] The extrusion aid helps to shape the catalyst. By controlling the mass ratio of the calcined product, the extrusion aid and the nitric acid within the above range, it helps to improve the structural integrity and mechanical strength, thereby reducing breakage during its use.

[0037] In another typical embodiment of the present application, a method for synthesizing nicotinaldehyde by hydrogenating nicotinonitrile using a catalyst is provided, and the catalyst is the above-mentioned catalyst for hydrogenating nicotinonitrile to synthesize nicotinaldehyde.

[0038] Since the catalyst used in the reaction of catalytic hydrogenation of nicotinonitrile to synthesize nicotinaldehyde in the present application is the above-mentioned catalyst, the catalyst is beneficial to promoting the effective adsorption and hydrogenation reaction of nicotinonitrile molecules, improving the production efficiency of nicotinaldehyde, reducing the formation of by-products, and providing an efficient, economical and environmentally friendly solution for the industrial continuous production of nicotinaldehyde.

[0039] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0040] Example 1

[0041] (1) Weigh 14 g of ammonia water, 126 g of ethanol, 560 g of purified water, and 14 g of CTAB (hexadecyltrimethylammonium bromide) respectively and add them into a beaker. Add 140 g of ethyl orthosilicate dropwise while stirring. Continue stirring for 0.5 h after the addition is complete, and hydrolyze at 30 °C for 3 h. After filtering, wash the filtrate alternately with purified water and ethanol until the pH is 7. Dry the filter cake at 60 °C to obtain a crude silica carrier.

[0042] (2) The crude silica carrier was dispersed in 2800 mL of purified water, 6.3 g of CTAB and 42 g of Na2CO3 were added, the mixture was stirred evenly, and then etched at 60°C for 5 h. After filtration, the mixture was washed twice with purified water and ethanol alternately, and then placed in an oven. The temperature was adjusted to 70°C and dried overnight to obtain a hollow structure SiO2 carrier. The hollow structure SiO2 carrier was calcined at 550°C to obtain a calcined hollow structure SiO2 carrier, wherein the mass ratio of tetraethyl orthosilicate, CTAB, Na2CO3 and water was 1:0.045:0.30:20.

[0043] (3) The calcined hollow structure SiO2 carrier, sesbania powder and nitric acid are mixed in a ratio of 1:0.03:0.05 and then extruded to obtain a strip-shaped silica carrier.

[0044] (4) Add 0.1% of the mass of the hollow structure SiO2 carrier to the beaker, 15% of the mass of Ni(NO3)2·6H2O in terms of nickel atoms, 1% of the mass of the hollow structure SiO2 carrier in terms of alkaline earth metal atoms, and 100g of purified water to disperse and dissolve the strip silica carrier in the beaker; age for 1h under ultrasound and then let stand for 2h, wherein the ultrasonic output power is 60W; filter the mixed solution, dry it at 100℃ for 12h, and calcine the dried solid at 350℃, wherein the heating rate is 5℃ / min and the calcination time is 5h, and finally obtain a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde.

[0045] Example 2

[0046] (1) Weigh 14 g of ammonia water, 126 g of ethanol, 490 g of purified water, and 14 g of cetylpyridinium bromide (CPB) respectively and add them into a beaker. Add 140 g of ethyl orthosilicate dropwise while stirring. Continue stirring for 0.5 h after the addition is complete, and hydrolyze at 40 °C for 5 h. After filtering, wash the filtrate alternately with purified water and ethanol until the pH is 7. Dry the filter cake at 75 °C to obtain a crude silica carrier.

[0047] (2) The crude silica carrier was dispersed in 2520 mL of purified water, 6.3 g of CPB and 49 g of K2CO3 were added, the mixture was stirred evenly and etched at 40°C for 8 h. After filtration, the mixture was washed twice with purified water and ethanol alternately and placed in an oven. The temperature was adjusted to 80°C and dried overnight to obtain a hollow structure SiO2 carrier. The hollow structure SiO2 carrier was calcined at 650°C to obtain a calcined hollow structure SiO2 carrier, wherein the mass ratio of tetraethyl orthosilicate, CPB, K2CO3 and water was 1:0.045:0.35:20.

[0048] (3) The calcined hollow structure SiO2 carrier, sesbania powder and nitric acid are mixed in a ratio of 1:0.02:0.05 and then extruded to obtain a strip-shaped silica carrier.

[0049] (4) Add CPB in a beaker at a mass of 0.1% of the mass of the hollow structure SiO2 carrier; Ni(NO3)2·6H2O in terms of nickel atoms at a mass of 20% of the mass of the hollow structure SiO2 carrier; MgN2O6.6H2O in terms of alkaline earth metal atoms at a mass of 1% of the mass of the hollow structure SiO2 carrier and 100 g of purified water to disperse and dissolve them, and then add the strip silica carrier into the beaker; age under ultrasound for 2 h, and then let it stand for 1 h, wherein the ultrasonic output power is 70 W; filter the mixed solution, dry it at 90 ° C for 24 h, and calcine the dried solid at 300 ° C, wherein the heating rate is 15 ° C / min, and the calcination time is 6 h, and finally obtain a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde.

[0050] Example 3

[0051] (1) Weigh 14 g of ammonia water, 85 g of ethanol, 560 g of purified water, and 14 g of CTAB respectively into a beaker, and add 140 g of ethyl orthosilicate dropwise while stirring. After the addition is complete, continue stirring for 0.5 h, and hydrolyze at 35 °C for 4 h. After filtering, wash the filtrate alternately with purified water and ethanol until the pH is 7, and dry the filter cake at 80 °C to obtain a crude silica carrier.

[0052] (2) The crude silica carrier was dispersed in 2800 mL of purified water, 4.9 g of CTAB and 45 g of NaOH were added, the mixture was stirred evenly, and then etched at 50°C for 8 h. After filtration, the mixture was washed twice with purified water and ethanol alternately, and then placed in an oven. The temperature was adjusted to 70°C and dried overnight to obtain a hollow structure SiO2 carrier. The hollow structure SiO2 carrier was calcined at 600°C to obtain a calcined hollow structure SiO2 carrier, wherein the mass ratio of tetraethyl orthosilicate, CTAB, NaOH and water was 1:0.035:0.32:20.

[0053] (3) The calcined hollow structure SiO2 carrier, sesbania powder and nitric acid are mixed in a ratio of 1:0.025:0.03 and extruded to obtain a strip-shaped silica carrier.

[0054] (4) Add CTAB in a beaker at a mass of 0.1% of the mass of the hollow structure SiO2 carrier; NiCl2 in terms of nickel atoms at a mass of 20% of the mass of the hollow structure SiO2 carrier; Ba(NO3)2 in terms of alkaline earth metal atoms at a mass of 2% of the mass of the hollow structure SiO2 carrier and 100 g of purified water to disperse and dissolve them, and then add the strip silica carrier into the beaker; age under ultrasound for 1.5 h, and then let it stand for 1.5 h, wherein the ultrasonic output power is 65 W; filter the mixed solution, dry it at 90 ° C for 15 h, and calcine the dried solid at 350 ° C, wherein the heating rate is 7 ° C / min, and the calcination time is 6 h, and finally obtain a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde.

[0055] Example 4

[0056] The difference from Example 1 is that, in terms of nickel atoms, Ni(NO3) 2• The mass of 6H2O is 18% of the mass of the hollow structure SiO2 carrier, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0057] Example 5

[0058] The difference from Example 1 is that, in terms of nickel atoms, Ni(NO3) 2• The mass of 6H2O is 16% of the mass of the hollow structure SiO2 carrier, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0059] Example 6

[0060] The difference from Example 1 is that, in terms of nickel atoms, Ni(NO3) 2• The mass of 6H2O is 14% of the mass of the hollow structure SiO2 carrier, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0061] Example 7

[0062] The difference from Example 1 is that, calculated on the basis of alkaline earth metal atoms, the mass of Ca(NO3)2·4H2O is 1.2% of the mass of the hollow structure SiO2 carrier, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0063] Example 8

[0064] The difference from Example 1 is that, calculated on the basis of alkaline earth metal atoms, the mass of Ca(NO3)2·4H2O is 1.8% of the mass of the hollow structure SiO2 carrier, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0065] Example 9

[0066] The difference from Example 1 is that, calculated on the basis of alkaline earth metal atoms, the mass of Ca(NO3)2·4H2O is 0.8% of the mass of the hollow structure SiO2 carrier, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0067] Example 10

[0068] The difference from Example 1 is that in step (1), the volume ratio of ammonia water, ethanol and water is 1:8:38, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0069] Embodiment 11

[0070] The difference from Example 1 is that in step (1), the volume ratio of ammonia water, ethanol and water is 1:6:35, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0071] Example 12

[0072] The difference from Example 1 is that in step (1), the volume ratio of ammonia water, ethanol and water is 1:6:33, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0073] Embodiment 13

[0074] The difference from Example 1 is that in step (2), the mass ratio of tetraethyl orthosilicate, CTAB, Na2CO3 and water is 1:0.035:0.32:20, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0075] Embodiment 14

[0076] The difference from Example 1 is that in step (2), the mass ratio of tetraethyl orthosilicate, CTAB, Na2CO3 and water is 1:0.04:0.35:18, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0077] Embodiment 15

[0078] The difference from Example 1 is that in step (2), the mass ratio of tetraethyl orthosilicate, CTAB, Na2CO3 and water is 1:0.028:0.30:18, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0079] Example 16

[0080] The difference from Example 1 is that in step (4), the temperature of the second calcination is 450° C., the time of the second calcination is 6 h, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0081] Embodiment 17

[0082] The difference from Example 1 is that in step (4), the temperature of the second calcination is 400° C., the time of the second calcination is 5.5 h, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0083] Embodiment 18

[0084] The difference from Example 1 is that in step (4), the temperature of the second calcination is 470° C., the time of the second calcination is 7 h, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde is obtained.

[0085] Comparative Example 1

[0086] (1) Weigh 14 g of ammonia water, 126 g of ethanol, 560 g of purified water, and 14 g of CTAB respectively into a beaker, add 140 g of ethyl orthosilicate dropwise while stirring, continue stirring for 0.5 h after the addition is complete, and hydrolyze at 35 °C for 4 h. After filtering, wash the filtrate alternately with purified water and ethanol to pH = 7, dry the filter cake at 80 °C to obtain a crude silica carrier, and calcine the crude silica carrier at 600 °C to obtain a calcined crude silica carrier.

[0087] (2) The calcined silica carrier crude product, sesbania powder and nitric acid are mixed in a ratio of 1:0.03:0.05 and extruded to obtain a strip-shaped silica carrier.

[0088] (3) The mass of CTAB added to the beaker is 0.1% of the mass of the hollow structure SiO2 carrier; the mass of NiCl2 added to the beaker is 20% of the mass of the hollow structure SiO2 carrier in terms of nickel atoms; the mass of MgN2O added to the beaker is 20% of the mass of the hollow structure SiO2 carrier in terms of alkaline earth metal atoms. 6• The mass of 6H2O is 1% of the mass of the hollow structure SiO2 carrier and 100g of purified water is dispersed and dissolved, and then the strip silica carrier is added to a beaker; it is aged for 1.5 hours under ultrasound, and then allowed to stand for 1.5 hours, wherein the ultrasonic output power is 65W; after filtering the mixed solution, it is dried at 90°C for 15 hours, and the dried solid is calcined at 350°C, wherein the heating rate is 7°C / min, and the calcination time is 6 hours, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0089] Comparative Example 2

[0090] (1) Commercial silica, sesbania powder, and nitric acid were mixed in a ratio of 1:0.03:0.05 and extruded to obtain a strip-shaped silica carrier.

[0091] (2) The mass of CTAB added to the beaker is 0.1% of the mass of the hollow structure SiO2 carrier; the mass of NiCl2 added to the beaker is 20% of the mass of the hollow structure SiO2 carrier in terms of nickel atoms; the mass of MgN2O added to the beaker is 20% of the mass of the hollow structure SiO2 carrier in terms of alkaline earth metal atoms.6• The mass of 6H2O is 1% of the mass of the hollow structure SiO2 carrier and 100g of purified water is dispersed and dissolved, and then the strip silica carrier is added to a beaker; it is aged for 1.5 hours under ultrasound, and then allowed to stand for 1.5 hours, wherein the ultrasonic output power is 65W; after filtering the mixed solution, it is dried at 90°C for 15 hours, and the dried solid is calcined at 350°C, wherein the heating rate is 7°C / min, and the calcination time is 6 hours, and finally a catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde is obtained.

[0092] Performance Testing:

[0093] After extrusion, 40g of the catalyst was added into a fixed bed. In a hydrogen atmosphere, the temperature was raised to 300°C at a heating rate of 5°C / min, reduced for 3h, and then cooled to a reaction temperature of 30°C. A 1g / min solution of nicotinonitrile (water: nicotinonitrile = 1:10, mass ratio) and acetic acid feed of 1.2g acetic acid / g nicotinonitrile were used. A hydrogen feed of 50-60mL / min was used to test the reaction in a gas phase.

[0094] The BET data results of the catalysts prepared in the above examples and comparative examples are shown in Table 1.

[0095] Table 1

[0096]

[0097] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0098] The preparation method of the present application is simple in process and low in cost. The prepared catalyst has suitable catalytic activity and stability. By utilizing the characteristics of the hollow structure SiO2 carrier with small specific surface area (not too rich in pore structure), small pore volume and acid resistance of the carrier, nickel oxide and alkaline earth metal oxide can only be loaded on the surface shell of silicon dioxide, which is conducive to improving the selectivity of the product, promoting the adsorption and diffusion of reactants and the desorption of products. By introducing alkaline earth metal oxide additives, the number of hydroxyl groups on the catalyst surface is changed, the surface acidity of the hollow structure SiO2 carrier and the surface dispersion of the active components are adjusted, and the metal dispersion of the main active component of nickel oxide is improved, which is conducive to the reduction of nicotinic acid nitrile with hydrogen to imine and rapid desorption and hydrolysis from the catalyst surface to generate nicotinaldehyde, reducing the deep hydrogenation reduction of the intermediate imine to amine to generate impurities, which is conducive to improving the selectivity and purity of the nicotinic acid nitrile reaction. And the alkaline earth metal oxide changes the interaction between nickel oxide and the carrier, thereby improving the service life. In addition, nickel oxide is the main active component of nicotinic acid nitrile hydrogenation and is cheap, so that the catalyst cost of the present application is low. And the above catalyst can be continuously produced on a fixed bed.

[0099] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde, characterized in that: The catalyst comprises a hollow structure SiO2 carrier and nickel oxide and alkaline earth metal oxide loaded on the surface of the hollow structure SiO2 carrier, wherein the alkaline earth metal oxide is selected from any one or more of calcium oxide, magnesium oxide and barium oxide; The mass ratio of the hollow structure SiO2 carrier, the nickel oxide and the alkaline earth metal oxide is 100:19-25:1-2; The specific surface area of ​​the catalyst is 61~75m 2 / g; the total pore volume of the catalyst is 0.15~0.29cm 3 / g; the average pore size of the catalyst is 8.5~10nm.

2. A method for preparing the catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde according to claim 1, characterized in that: The preparation method comprises: Step S1, mixing raw materials including a first template, a silicate and an alkaline solvent, and then sequentially performing hydrolysis, suction filtration and a first drying to obtain an intermediate product; Step S2, mixing the raw materials including the intermediate product, the second template, the alkaline reagent and water, and then sequentially etching, filtering, washing and second drying to obtain a hollow structure SiO2 carrier, and first calcining the hollow structure SiO2 carrier to obtain a calcined product; Step S3, mixing the raw materials including the calcined product, the extrusion aid, and the nitric acid, and then extruding and molding them to obtain a molded SiO2 carrier; Step S4, in an inert atmosphere, mixing the shaped SiO2 carrier, the third template, the nickel source, the alkaline earth metal and water, and then aging, standing, filtering, third drying and second calcining in sequence to obtain the catalyst for catalyzing the hydrogenation of nicotinonitrile to nicotinaldehyde; The mass of the third template is 0.05-0.1% of the mass of the hollow structure SiO2 carrier; The mass of the nickel source, calculated as nickel atoms, is 15% to 20% of the mass of the hollow structure SiO2 carrier; The mass of the alkaline earth metal in the alkaline earth metal is 1% to 2% of the mass of the hollow structure SiO2 carrier, calculated as alkaline earth metal atoms; The etching temperature is 40-60°C, and the etching time is 5-8 h; The mass ratio of the silicate, the second template, the alkaline reagent and the water is 1:0.035-0.045:0.3-0.35:18-20; Ultrasound was performed during the aging process, and the output power of the ultrasound was 60~70 W.

3. The preparation method according to claim 2, characterized in that: In step S4, the temperature of the third drying is 90-100° C., and the time of the third drying treatment is 12-24 hours; and / or the temperature of the second calcination is 350° C. to 450° C., and the time of the second calcination is 5 to 6 hours; And / or the aging time is 1-2 hours, ultrasound is performed during the aging process, and the output power of the ultrasound is 60-70 W; And / or the standing time is 1 to 2 hours.

4. The preparation method according to claim 2, characterized in that: In step S4, the third template agent is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide; And / or, the nickel source is Ni(NO3)2·6H2O and / or NiCl2; And / or, the alkaline earth metal is selected from any one or more of Ca(NO3)2·4H2O, MgN2O6·6H2O and Ba(NO3)2.

5. The preparation method according to claim 2, characterized in that: In the step S1, the hydrolysis temperature is 30-40°C, and the hydrolysis time is 3-5 h; and / or the first drying temperature is 60-80°C; and / or the alkaline solvent comprises aqueous ammonia, ethanol and water, and / or the volume ratio of the aqueous ammonia, the ethanol and the water is 1:6-9:35-40; The mass ratio of the ammonia water, the silicate and the first template is 1:8~10:0.8~1, and / or the silicate is ethyl orthosilicate and / or tetrabutyl silicate; and / or the first template is hexadecyltrimethylammonium bromide and / or hexadecylpyridinium bromide.

6. The preparation method according to claim 2, characterized in that: In the step S2, the temperature of the second drying is 60-80°C; and / or the temperature of the first calcination is 550-650°C; And / or the second template is cetyltrimethylammonium bromide and / or cetylpyridinium bromide, and / or the alkaline reagent is selected from any one or more of Na2CO3, K2CO3 and NaOH.

7. The preparation method according to claim 2, characterized in that: In the step S3, the mass ratio of the calcined product, the extrusion aid and the nitric acid is 1:0.02-0.03:0.03-0.

05.

8. A method for synthesizing nicotinaldehyde by hydrogenating nicotinonitrile using a catalyst, characterized in that: The catalyst is the catalyst for catalyzing the hydrogenation of nicotinonitrile to synthesize nicotinaldehyde as claimed in claim 1.

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