An aminolysis reaction catalyst, a preparation method and application thereof
By introducing zirconium metal into molecular sieves and optimizing the processing technology, a highly active and selective ammonolysis catalyst was prepared, which solved the problem of low conversion rate and selectivity of existing phosphate catalysts and realized the efficient ammonolysis reaction for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA TIANCHEN ENGINEERING CORPORATION LTD
- Filing Date
- 2026-01-30
- Publication Date
- 2026-06-12
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Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of catalyst synthesis technology, and in particular to an ammonolysis reaction catalyst, its preparation method, and its application. Background Technology
[0002] Ammonolysis is the process by which organic compounds containing various functional groups react with ammonia to form amines or nitrile compounds. It has wide applications in the chemical industry.
[0003] Ammonolysis, as an important method for constructing carbon-nitrogen bonds in organic synthesis, has always had its technological development closely linked to the needs of the chemical industry. From the rise of the dye industry in the 19th century to the development of the modern pharmaceutical industry, ammonolysis technology has undergone an evolution from simple to complex, and from inefficient to efficient.
[0004] In its early stages of development, ammonolysis reactions primarily employed harsh conditions of high temperature and high pressure. In the late 19th century, German chemists discovered that aromatic halides could react with ammonia in the presence of a copper catalyst to produce aromatic amines. This discovery laid the foundation for the industrial production of aniline dyes. In the early 20th century, with the rise of petrochemicals, gas-phase ammonolysis technology developed, enabling the industrialization of the reaction of lower alcohols with ammonia to prepare lower amine compounds.
[0005] Modern ammonolysis technology has seen several development directions. Optimization of the catalytic system is a key breakthrough; the application of transition metal catalysts such as palladium and nickel complexes has significantly improved reaction efficiency and selectivity. The introduction of phase-transfer catalysis has solved the mass transfer problem in heterogeneous reaction systems, enabling efficient ammonolysis in aqueous-organic two-phase systems. The application of microwave-assisted synthesis technology has greatly shortened reaction time and improved energy utilization efficiency.
[0006] In the pharmaceutical and pesticide fields, ammonolysis technology faces new challenges and requirements. The increasing complexity of drug molecular structures has spurred the development of more mild and efficient ammonolysis methods, such as room-temperature ammonolysis reactions promoted by organic bases. The promotion of green chemistry concepts has also driven the development of environmentally friendly technologies such as aqueous phase ammonolysis and solvent-free ammonolysis.
[0007] Ammonolysis reactions have numerous industrial applications, among which the most representative is the ammonolysis of caprolactam to aminohexanonitrile. Aminohexanonitrile can be hydrogenated to synthesize hexamethylenediamine, a key raw material for the synthesis of nylon-66 and for the production of nylon 66 fibers and engineering plastics, possessing extremely high commercial and strategic value.
[0008] The internationally accepted industrial methods for producing hexamethylenediamine mainly include the adiponitrile process, the acrylonitrile process, the adipic acid process, and the caprolactam process. The caprolactam process primarily involves the reaction of caprolactam and ammonia in the presence of a catalyst, utilizing a gas-phase principle to produce 6-aminohexanonitrile. The 6-aminohexanonitrile is then hydrogenated to yield hexamethylenediamine. The chemical reaction is as follows: In the preparation of 6-aminohexanonitrile, the reaction temperature needs to be maintained above 350℃, and the yield can reach almost 95% or more. The subsequent hydrogenation process is the same as that of adiponitrile hydrogenation, and the overall reaction principle is basically the same. Compared with the butadiene method and the adipic acid method, the caprolactam method has the advantages of shorter process, lower raw material toxicity, lower equipment cost, and higher product yield.
[0009] With the promotion and maturation of caprolactam technology, the domestic caprolactam market is nearing saturation. The caprolactam method can provide ideal downstream products for caprolactam, which is of great significance to the development of the domestic caprolactam industry.
[0010] Existing methods for producing aminohexanonitrile via caprolactam ammonolysis often use metal phosphates as catalysts. However, phosphate-based catalysts have low single-pass conversion rates and low selectivity, resulting in high energy consumption and raw material losses during production. Summary of the Invention
[0011] The purpose of this invention is to solve at least one of the above-mentioned technical problems by providing an ammonolysis reaction catalyst, its preparation method, and the ammonolysis reaction.
[0012] A method for preparing an ammonolysis catalyst includes the following steps: (1) Prepare acid solution-a, then add the catalyst support to acid solution-a, heat and stir the acid solution to acid treat the catalyst support; after the treatment is completed, wash the catalyst support until neutral, and then dry it; (2) The catalyst support obtained in step (1) is mixed with metal salt-a and metal salt-b, and the mixture is placed in a planetary ball mill for ball milling to obtain the catalyst precursor; (3) Place the catalyst precursor obtained in step (2) in an electric furnace and calcine the catalyst precursor in a flowing atmosphere to obtain a supported catalyst; (4) Prepare acid solution-b, place the supported catalyst obtained in step (3) in acid solution-b, heat and stir the mixed acid solution-b to treat the supported catalyst obtained in step (3) with acid; after the treatment is completed, wash the supported catalyst obtained in step (3) until neutral, and then dry it to obtain the ammonolysis reaction catalyst.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes a method for preparing an ammoniation reaction catalyst. The prepared catalyst can effectively catalyze the ammonolysis reaction of chemical substances containing one of the functional groups: hydroxyl, carboxylic acid, lactam, or epoxy groups. Compared with commonly used phosphate-based catalysts, the catalyst prepared by this invention has advantages such as high feed conversion rate, high product selectivity, and long catalyst lifetime, making it suitable for large-scale industrial production.
[0014] The catalyst prepared by this invention uses zirconium as the catalytically active component, exhibits high raw material conversion rate and product selectivity, and has a long catalyst life, making it suitable for large-scale industrial production.
[0015] Because zirconium oxide has a high density and dense structure, it is difficult to use as a highly active catalyst. Therefore, in the above technical solution, zirconium metal is introduced into the cage-like structure of the molecular sieve, and the fully dispersed zirconium is used as the active component of the catalyst. First, strong acid treatment creates vacancy defects in the cage-like structure of the molecular sieve, providing a support for the loading of the active phase. Then, the metal salt and molecular sieve are mixed by ball milling, which breaks down and disperses the metal salt, ensuring close contact with the molecular sieve. Further, the mixture is heated, causing the metal salt to volatilize and diffuse into the microspaces of the molecular sieve, where it decomposes. The metal ions exchange ions with H ions in the cage-like structure of the molecular sieve, causing the metal to deposit on the vacancy of the molecular sieve, resulting in a molecular sieve catalyst with an active phase. Finally, acid washing is used to corrode away the free metal oxide, yielding the catalyst. The metal ion active phase is not simply supported but becomes part of the cage-like structure of the molecular sieve. The molecular sieve structure has an electron-donating effect, which can significantly improve the adsorption of the metal active phase on the reactants, thereby improving the activity of the catalyst. Meanwhile, molecular sieves are highly acidic at high temperatures, which can easily cause coking of reactants and reduce catalyst life. Therefore, this invention introduces another metal that does not participate in ammonolysis but can adjust the acidity of molecular sieves, reduce the active sites of strong L acid, inhibit the occurrence of carbon deposition, protect the active sites from contamination, and further extend the catalyst life.
[0016] Zirconium metal supported molecular sieve catalysts can also be prepared by impregnation. However, the common impregnation method will form a large amount of crystals during the drying process, which cannot guarantee the close contact between the metal salt and the molecular sieve cage structure. As a result, the active metal phase cannot be selectively deposited in the vacancy of the molecular sieve cage structure. Instead, a large amount of free metal oxides will be produced, resulting in poor catalytic activity and easy carbon deposition.
[0017] Preferably, the acid solution-a is optimized. The acid solution-a is prepared by dissolving an acid in water, and the mass ratio of the acid solution-a to the supported catalyst is 3-5; wherein the acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, and benzenesulfonic acid, and the mass concentration of the acid solution-a is 10-30%.
[0018] Preferably, the catalyst support in step (1) has been optimized. The catalyst support is a molecular sieve, and the selected molecular sieve is one of S-1 type molecular sieve, β type molecular sieve, mordenite molecular sieve, Y type molecular sieve, or ZSM-5 type molecular sieve.
[0019] Preferably, the acid treatment conditions in step (1) have been optimized. In step (1), the mass ratio of acid solution-a to catalyst support (i.e., catalyst support that has not undergone acid treatment) is 2~10, the acid treatment temperature is 50~100℃, and the acid treatment time is 4~24h.
[0020] Preferably, the type and amount of metal salt in step (2) have been optimized. In step (2), metal salt-a is one of ZrCl4, Zr(SO4)2, Zr(C5H8O2)4, ZrO(NO3)2, ZrOCl2, and Zr(CH3COO)4, and the cation of metal salt-b is Fe. 3+ Cu 2+ Zn 2+ Sn 4+ Mn 4+ Ni 2+ One of them, the anion of metal salt-b is the same as the anion of metal salt-a, the mass ratio of metal salt-a to the catalyst support obtained in step (1) is 1~5, and the mass ratio of metal salt-b to the catalyst support obtained in step (1) is 0.05~0.3%.
[0021] Preferably, the ball milling conditions in step (2) were optimized. In step (2), the ball-to-material ratio was 0.2 to 1, the ball milling speed was 50 to 400 rpm, and the ball milling time was 10 to 30 min.
[0022] Preferably, the calcination conditions in step (3) have been optimized. In step (3), the calcination atmosphere is a nitrogen atmosphere. The calcination temperature is 400~600℃, and the calcination time is 3~10h.
[0023] Preferably, the acid solution-b in step (4) has been optimized. In step (4), the acid solution-b is prepared by dissolving an acid in water, wherein the acid is one of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, citric acid, and benzenesulfonic acid, and the mass concentration of the acid solution-b is 3~15%.
[0024] Preferably, the acid treatment conditions in step (4) have been optimized. In step (4), the mass ratio of the acid solution-b to the supported catalyst is 2~10, the acid treatment temperature is 50~100℃, and the acid treatment time is 4~24h.
[0025] The present invention also provides an ammonolysis reaction catalyst prepared by the above-described ammonolysis reaction preparation method.
[0026] An ammonolysis reaction in which the reactants are chemical substances containing one of the functional groups of hydroxyl, carboxylic acid, lactam, or epoxy groups, react with ammonia in the presence of the catalyst described above to produce nitriles.
[0027] Preferably, the reaction temperature of the ammonolysis reaction is 300-400°C, the molar ratio of ammonia to the chemical substance is 10-50:1, and the mass hourly space velocity of the chemical substance is 0.2-4 h⁻¹. -1 .
[0028] An ammonolysis reaction, wherein the reactants are chemical substances containing a functional group selected from hydroxyl, carboxylic acid, lactam, or epoxy groups, and the reactants react with ammonia in the presence of the ammonolysis catalyst described above to produce nitrile substances. Detailed Implementation
[0029] The present invention will now be described in detail with reference to the embodiments.
[0030] Example 1 Step (1): Prepare a 10% hydrochloric acid solution as acid solution-a. Place the β-molecular sieve as a catalyst support in the acid solution, with a mass ratio of acid solution-a to catalyst support of 10. Heat acid solution-a to 100℃ and stir for 24 hours. After treatment, wash the catalyst support until neutral and then dry it.
[0031] Step (2): Take ZrCl4 as metal salt-a, with a mass ratio of 3 to the catalyst support obtained in step (1), and take FeCl3 as metal salt-b, with a mass ratio of 0.05% to the support. Mix metal salt-a, metal salt-b with the catalyst support obtained in step (1), and then add the mixture to a planetary ball mill with a ball-to-material ratio of 1. Start the ball mill at a speed of 300 rpm for 10 min to obtain the catalyst precursor.
[0032] Step (3): Add the catalyst precursor to the electric furnace and continuously purge with nitrogen to maintain an inert atmosphere inside the furnace. Turn on the heating, process at 600℃, and calcine for 3 hours to obtain the supported catalyst.
[0033] Step (4): Prepare a 3% hydrochloric acid solution as acid solution-b, and place the supported catalyst in acid solution-b. The mass ratio of acid solution-b to catalyst support is 10. Heat the acid solution to 50°C and stir for 24 hours. After the treatment is completed, wash the supported catalyst obtained in step (3) until it is neutral, and then dry it to obtain the ammonolysis reaction catalyst.
[0034] Example 2 Step (1): Prepare a 30% sulfuric acid solution as acid solution-a. Place the Y molecular sieve in the acid solution, with a mass ratio of acid solution-a to catalyst support of 4. Heat acid solution-a to 50°C and stir for 12 hours. After treatment, wash the catalyst support until neutral and then dry it.
[0035] Step (2): Take Zr(SO4)2 as metal salt-a, with a mass ratio of 5 to the catalyst support obtained in step (1), and take CuSO4 as metal salt-b, with a mass ratio of 0.3% to the catalyst support obtained in step (1). Mix metal salt-a, metal salt-b with the catalyst support, and then add the mixture to a planetary ball mill with a ball-to-material ratio of 0.2. Start the ball mill at a speed of 50 rpm for 30 min to obtain the catalyst precursor.
[0036] Step (3): Add the catalyst precursor obtained in step (2) into an electric furnace, and continuously introduce nitrogen gas to maintain an inert atmosphere inside the furnace. Turn on the heating, process at a temperature of 500℃, and calcinate for 10 hours to obtain the supported catalyst.
[0037] Step (4): Prepare an acetic acid solution with a mass concentration of 15% as acid solution-b. Place the supported catalyst in acid solution-b, and the mass ratio of acid solution-b to the supported catalyst obtained in step (3) is 2. Heat the acid solution to 100°C and stir for 4 hours. After the treatment is completed, clean the catalyst support until it is neutral and then dry it to obtain the ammonolysis reaction catalyst.
[0038] Example 3 Step (1): Prepare a 30% (w / w) nitric acid solution as acid solution-a. Place the mordenite molecular sieve in the acid solution, with a mass ratio of acid solution-a to catalyst support of 5. Heat acid solution-a to 90°C and stir for 18 hours. After treatment, wash the catalyst support until neutral and then dry it.
[0039] Step (2): Take ZrO(NO3)2 as metal salt-a, with a mass ratio of 1 to the catalyst support obtained in step (1), and take Zn2O(NO3)2 as metal salt-b, with a mass ratio of 0.10% to the catalyst support obtained in step (1). Mix metal salt-a, metal salt-b with the catalyst support obtained in step (1), and then add the mixture to a planetary ball mill with a ball-to-material ratio of 0.5. Start the ball mill at a speed of 40 rpm for 10 min to obtain the catalyst precursor.
[0040] Step (3): Add the catalyst precursor to the electric furnace and continuously purge with nitrogen to maintain an inert atmosphere inside the furnace. Turn on the heating, process at 400℃, and calcine for 6 hours to obtain the supported catalyst.
[0041] Step (4): Prepare a 5% (w / w) lemon solution as acid solution-b. Place the supported catalyst in acid solution-b, with a mass ratio of acid solution-a to the supported catalyst of 4. Heat the acid solution to 80°C and stir for 12 hours. After treatment, wash the supported catalyst until neutral and then dry it to obtain the ammonolysis catalyst.
[0042] Example 4 Step (1): Prepare a mixed solution of 10% oxalic acid and 10% hydrochloric acid as acid solution-a. Place the S-1 molecular sieve in the acid solution, with a mass ratio of acid solution-a to catalyst support of 4. Heat acid solution-a to 80°C and stir for 12 hours. After treatment, wash the catalyst support until neutral and then dry it.
[0043] Step (2): Take Zr(C5H8O2)4 as metal salt-a, with a mass ratio of 3 to the catalyst support obtained in step (1). Take Ni(C5H8O2)2 as metal salt-b, with a mass ratio of 0.15% to the catalyst support obtained in step (1). Mix metal salt-a, metal salt-b with the catalyst support obtained in step (1), and then add the mixture to a planetary ball mill with a ball-to-material ratio of 0.3. Start the ball mill at a speed of 400 rpm for 10 min to obtain the catalyst precursor.
[0044] Step (3): Add the catalyst precursor to the electric furnace and continuously purge with nitrogen to maintain an inert atmosphere inside the furnace. Turn on the heating, process at 550℃, and calcinate for 8 hours to obtain the supported catalyst.
[0045] Step (4): Prepare a 15% benzenesulfonic acid solution as acid solution-b. Place the supported catalyst obtained in step (3) into acid solution-b. The mass ratio of acid solution-b to the supported catalyst support is 10. Heat acid solution-b to 50°C and stir for 24 hours. After the treatment is completed, wash the catalyst support until it is neutral and then dry it to obtain the ammonolysis catalyst.
[0046] Example 5 Step (1): Prepare a 15% (w / w) benzenesulfonic acid solution as acid solution-a. Place the ZSM-5 molecular sieve in the acid solution, with a mass ratio of acid solution-a to catalyst support of 10. Heat acid solution-a to 100℃ and stir for 24 hours. After treatment, wash the catalyst support until neutral and then dry it.
[0047] Step (2): Take ZrOCl2 as metal salt-a, with a mass ratio of 5 to the catalyst support obtained in step (1), and take SnOCl2 as metal salt-b, with a mass ratio of 0.3% to the catalyst support obtained in step (1). Mix metal salt-a, metal salt-b with the catalyst support obtained in step (1), and then add the mixture to a planetary ball mill with a ball-to-material ratio of 1. Start the ball mill at a speed of 400 rpm for 20 min to obtain the catalyst precursor.
[0048] Step (3): Add the catalyst precursor obtained in step (2) into the electric furnace, and continuously introduce nitrogen gas to maintain an inert atmosphere inside the furnace. Turn on the heating, process at a temperature of 450℃, and calcinate for 8 hours to obtain the supported catalyst.
[0049] Step (4): Prepare a 10% sulfuric acid solution as acid solution-b, and place the supported catalyst in acid solution-b. The mass ratio of acid solution-b to catalyst support is 2. Heat the acid solution to 75°C and stir for 10 hours. After the treatment is completed, wash the catalyst support until it is neutral and then dry it to obtain the ammonolysis catalyst.
[0050] Example 6 Step (1): Prepare a mixed solution of 10% nitric acid and 10% hydrochloric acid as acid solution-a. Place the S-1 molecular sieve in the acid solution, with a mass ratio of acid solution-a to catalyst support of 5. Heat acid solution-a to 80°C and stir for 24 hours. After treatment, wash the catalyst support until neutral and then dry it.
[0051] Step (2): Take Zr(CH3COO)4 as metal salt-a, with a mass ratio of 4 to the catalyst support obtained in step (1), and take Mn(CH3COO)4 as metal salt-b, with a mass ratio of 0.12% to the catalyst support obtained in step (1). Mix metal salt-a, metal salt-b with the catalyst support obtained in step (1), and then add the mixture to a planetary ball mill with a ball-to-material ratio of 0.2. Start the ball mill at a speed of 200 rpm for 10 min to obtain the catalyst precursor.
[0052] Step (3): Add the catalyst precursor to the electric furnace and continuously purge with nitrogen to maintain an inert atmosphere inside the furnace. Turn on the heating, process at 400℃, and calcinate for 12 hours to obtain the supported catalyst.
[0053] Step (4): Prepare a 3% nitric acid solution as acid solution-b. Place the supported catalyst obtained in step (3) into acid solution-b, with a mass ratio of acid solution-b to catalyst support of 3. Heat the acid solution to 50°C and stir for 18 hours. After the treatment is completed, wash the catalyst support until it is neutral and then dry it to obtain the ammonolysis catalyst.
[0054] Comparative Example 1 A 30% (w / w) nitric acid solution was prepared as acid solution-a. The mordenite molecular sieve was placed in the acid solution, with a mass ratio of acid solution-a to catalyst support of 5. Acid solution-a was heated to 90°C and stirred for 18 hours. After treatment, the catalyst support was washed until neutral and then dried.
[0055] A 10% (w / w) ZrO(NO3)2 solution was prepared, and the mordenite zeolite catalyst was impregnated in the metal salt solution. The solution was heated to 50°C and stirred for 24 hours. After treatment, the molecular sieve was removed and dried.
[0056] The impregnated molecular sieve was placed in an electric furnace, heated, and processed at a temperature of 500℃ for 6 hours to obtain an ammonolysis catalyst.
[0057] Comparative Example 2 ZrO(NO3)2 was selected as metal salt-a, with a mass ratio of 1% to the catalyst support. Zn2O(NO3)2 was selected as metal salt-b, with a mass ratio of 0.10% to the catalyst support. Metal salt-a and metal salt-b were mixed with the catalyst support, and then the mixture was added to a planetary ball mill with a ball-to-material ratio of 0.5. The ball mill was started at a speed of 40 rpm for 10 minutes to obtain the catalyst precursor.
[0058] The catalyst precursor was added to an electric furnace, and nitrogen gas was continuously introduced to maintain an inert atmosphere inside the furnace. Heating was then initiated, and the treatment temperature was set at 400℃ for 6 hours to obtain the supported catalyst.
[0059] A 5% (w / w) lemon solution was prepared as acid solution-b. The supported catalyst was placed in acid solution-b, with a mass ratio of acid solution-a to the supported catalyst of 4. The acid solution was heated to 80°C and stirred for 12 hours. After treatment, the catalyst support was washed until neutral and then dried to obtain the ammonolysis catalyst.
[0060] Comparative Example 3 A 30% (w / w) nitric acid solution was prepared as acid solution-a. The mordenite molecular sieve was placed in the acid solution, with a mass ratio of acid solution-a to catalyst support of 5. Acid solution-a was heated to 90°C and stirred for 18 hours. After treatment, the catalyst support was washed until neutral and then dried.
[0061] ZrO(NO3)2 was selected as metal salt-a, with a mass ratio of 1% to the catalyst support. Zn2O(NO3)2 was selected as metal salt-b, with a mass ratio of 0.10% to the support. Metal salt-a and metal salt-b were mixed with the catalyst support, and then the mixture was added to a planetary ball mill with a ball-to-material ratio of 0.5. The ball mill was started at a speed of 40 rpm for 10 minutes to obtain the catalyst precursor.
[0062] The catalyst precursor was added to an electric furnace, and nitrogen gas was continuously introduced to maintain an inert atmosphere inside the furnace. Heating was then initiated, and the treatment temperature was set at 400°C for 6 hours to obtain the supported catalyst.
[0063] Implement Test Example 1 The catalyst obtained in Example 1 was evaluated in a fixed-bed reaction evaluation apparatus. The reactants were acetic acid, with an ammonia-to-acetic acid molar ratio of 10:1. The reaction temperature was 300°C, and the reaction space velocity was 4.0 h⁻¹. -1 The product is acetonitrile, with a single-pass conversion rate of 74.93% for acetic acid and an acetonitrile selectivity of 97.63%.
[0064] Implement Test Example 2 The catalyst obtained in Example 2 was evaluated in a fixed-bed reaction evaluation device. The reactants were methanol, ammonia and acetic acid in a molar ratio of 50:1, the reaction temperature was 400°C, and the reaction space velocity was 0.2 h⁻¹. -1 The products are methylamine, dimethylamine and trimethylamine. The single-pass conversion rate of methanol is 53.84%, the selectivity of methylamine is 96.85%, the selectivity of dimethylamine is 1.41%, and the selectivity of trimethylamine is 0.13%.
[0065] Implement Test Example 3 The catalyst obtained in Example 3 was evaluated in a fixed-bed reaction evaluation device. The reactants were caprolactam, ammonia and acetic acid in a molar ratio of 30:1, the reaction temperature was 330°C, and the reaction space velocity was 2.0 h⁻¹. -1 The product is aminocaproic acid, with a single-pass conversion rate of 64.63% for caprolactam and a selectivity of 98.55% for aminocaproic acid.
[0066] Implement Test Example 4 The catalyst obtained in Example 4 was evaluated in a fixed-bed reaction evaluation apparatus. The reactants were ethylene oxide, ammonia to acetic acid in a molar ratio of 15:1, the reaction temperature was 350°C, and the reaction space velocity was 1.0 h⁻¹. -1 The product is ethanolamine, with a single-pass conversion rate of 92.51% for ethylene oxide and a selectivity of 99.58% for ethanolamine.
[0067] Implement test example 5 The catalyst obtained in Example 5 was evaluated in a fixed-bed reaction evaluation device. The reactants were β-naphthol, the molar ratio of ammonia to acetic acid was 10:1, the reaction temperature was 300°C, and the reaction space velocity was 0.5 h⁻¹. -1 The product is β-naphthylamine, with a single-pass conversion rate of 52.73% for β-naphthol and a selectivity of 95.73% for β-naphthylamine.
[0068] Implement Test Example 6 The catalyst obtained in Example 6 was evaluated in a fixed-bed reaction evaluation apparatus. The reactants were benzoic acid, ammonia and acetic acid in a molar ratio of 50:1, the reaction temperature was 330°C, and the reaction space velocity was 2.0 h⁻¹. -1 The product is benzonitrile, with a single-pass conversion rate of 76.84% for benzoic acid and a selectivity of 97.79% for benzonitrile.
[0069] Comparative Test Example 1 The catalyst obtained in Comparative Example 3 was evaluated in a fixed-bed reaction evaluation apparatus. The reactants were caprolactam, ammonia and acetic acid in a molar ratio of 30:1, the reaction temperature was 330℃, and the reaction space velocity was 2.0 h⁻¹. -1 The product is aminocaproic acid, with a single-pass conversion rate of 41.74% for caprolactam and a selectivity of 92.74% for aminocaproic acid.
[0070] Comparative Test Example 2 The catalyst obtained in Comparative Example 3 was evaluated in a fixed-bed reaction evaluation apparatus. The reactants were caprolactam, ammonia and acetic acid in a molar ratio of 30:1, the reaction temperature was 330℃, and the reaction space velocity was 2.0 h⁻¹. -1 The product is aminocaproic acid, with a single-pass conversion rate of 47.74% for caprolactam and a selectivity of 92.12% for aminocaproic acid.
[0071] Comparative Test Case 3 The catalyst obtained in Example 3 was evaluated in a fixed-bed reaction evaluation device. The reactants were caprolactam, ammonia and acetic acid in a molar ratio of 30:1, the reaction temperature was 330°C, and the reaction space velocity was 2.0 h⁻¹. -1 The product is aminocaproic acid, with a single-pass conversion rate of 69.51% for caprolactam and a selectivity of 95.86% for aminocaproic acid.
[0072] Comparative Test Case 4 The magnesium phosphate catalyst was evaluated in a fixed-bed reaction evaluation apparatus. The reactants were caprolactam, ammonia to acetic acid in a molar ratio of 30:1, the reaction temperature was 330℃, and the reaction space velocity was 2.0 h⁻¹. -1 The product is aminocaproic acid, with a single-pass conversion rate of 40.73% for caprolactam and a selectivity of 94.67% for aminocaproic acid.
[0073] The above experimental results show that the catalysts prepared in Examples 1-6 have higher single-pass conversion rates and better selectivity.
[0074] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.
Claims
1. A method for preparing an ammonolysis catalyst, characterized in that, Includes the following steps: (1) Prepare acid solution-a, then add the catalyst support to acid solution-a, heat and stir the acid solution to acid treat the catalyst support; after the treatment is completed, wash the catalyst support until neutral, and then dry it; (2) The catalyst support obtained in step (1) is mixed with metal salt-a and metal salt-b, and the mixture is placed in a planetary ball mill for ball milling to obtain the catalyst precursor; (3) The catalyst precursor obtained in step (2) is placed in an electric furnace and calcined in a flowing atmosphere to obtain a supported catalyst. (4) Prepare acid solution-b, place the supported catalyst obtained in step (3) in acid solution-b, heat and stir the mixed acid solution-b to treat the supported catalyst obtained in step (3) with acid; after the treatment is completed, wash the supported catalyst obtained in step (3) until neutral, and then dry it to obtain the ammonolysis reaction catalyst.
2. The preparation method according to claim 1, characterized in that, The acid solution-a is prepared by dissolving an acid in water, wherein the mass ratio of the acid solution-a to the supported catalyst is 3 to 5; the acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, and benzenesulfonic acid, and the mass concentration of the acid solution-a is 10 to 30%.
3. The preparation method according to claim 1, characterized in that, The catalyst support is a molecular sieve, and the selected molecular sieve is one of the following: S-1 type molecular sieve, β type molecular sieve, mordenite molecular sieve, Y type molecular sieve, and ZSM-5 type molecular sieve.
4. The preparation method according to claim 1, characterized in that, In step (1), the acid treatment temperature is 50~100℃ and the acid treatment time is 4~24h.
5. The preparation method according to claim 1, characterized in that, In step (2), metal salt-a is one of ZrCl4, Zr(SO4)2, Zr(C5H8O2)4, ZrO(NO3)2, ZrOCl2, and Zr(CH3COO)4, and the cation of metal salt-b is Fe. 3+ Cu 2+ Zn 2+ Sn 4+ Mn 4+ Ni 2+ One of them, the anion of metal salt-b is the same as the anion of metal salt-a, the mass ratio of metal salt-a to the catalyst support obtained in step (1) is 1~5, and the mass ratio of metal salt-b to the catalyst support obtained in step (1) is 0.05~0.3%.
6. The preparation method according to claim 1, characterized in that, In step (3), the calcination atmosphere is nitrogen atmosphere, the calcination temperature is 400~600℃, and the calcination time is 3~10h.
7. The preparation method according to claim 1, characterized in that, In step (4), the acid solution-b is prepared by dissolving an acid in water, wherein the acid is one of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, citric acid, or benzenesulfonic acid, and the mass concentration of the acid solution-b is 3-15%.
8. The preparation method according to claim 1, characterized in that, In step (4), the mass ratio of the acid solution-b to the supported catalyst is 2~10, the acid treatment temperature is 50~100℃, and the acid treatment time is 4~24h.
9. The ammonolysis catalyst prepared according to any one of claims 1-8.
10. An ammonolysis reaction, characterized in that, The reactants of this reaction are chemical substances containing one of the functional groups of hydroxyl group, carboxylic acid group, lactam group or epoxy group. The reactants react with ammonia gas in the presence of the ammonolysis catalyst as described in claim 9 to generate nitriles.