A cobalt-molybdenum based catalyst for the preparation of m-xylene diamine and preparation and use thereof

Abstract

The application discloses a preparation method of a cobalt-molybdenum catalyst for preparing m-xylylenediamine, characterized by: X-Z-O is used as a carrier precursor, Co-Mo-M-X-Z-O is used as a catalyst precursor, and after compounding, the final catalyst precursor is obtained. Finally, the final catalyst Co-Mo-M / X-Z is obtained by reduction under H2 / N2 atmosphere. X and Z are, M is one of Ni, Cr, Fe, Zn, Ce, Rh, Ru and Pd; a fixed bed reactor is used, m-xylylenecarbonitrile solution dissolved in a small amount of tert-butyl alcohol is pumped into a bed layer filled with the Co-Mo-M / X-Z catalyst, under the conditions that the temperature is 50-150 DEG C, the pressure is 0.5-6.0 MPa, the mass space velocity of m-xylylenecarbonitrile is 1-8 h ‑1 , and the molar ratio of hydrogen to m-xylylenecarbonitrile is 5-30:1, m-xylylenecarbonitrile is reacted with hydrogen to generate m-xylylenediamine. The catalyst has the advantages of high strength, high conversion rate and selectivity, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of improved catalyst preparation technology, in particular to a preparation method of a cobalt-molybdenum-based catalyst for preparing m-xylylenediamine and application thereof. BACKGROUND

[0002] M-xylylenediamine (MHDA) is a low-toxicity curing agent for epoxy resin at room temperature, which has excellent performance, good heat resistance, water resistance and chemical corrosion resistance, and is mainly used for manufacturing high-performance epoxy resin curing agents with heat resistance, non-toxicity, underwater construction and rapid heat curing. M-xylylenediamine is also a raw material for coating production. The monomer-m-xylene dicyanate (MXDI) synthesized by using m-xylylenediamine as a raw material is less prone to aging than the commonly used diphenylmethane diisocyanate (MDI), and can obtain a paint film surface with higher hardness and better stability. In addition, it is also used as a photosensitive plastic, rubber additive, polyurethane resin and intermediate for organic synthesis. It also has applications in pesticides, nylon products, fiber finishing agents, rust inhibitors, chelating agents, lubricants, paper processing and other aspects. It has important industrial and commercial value.

[0003] In the patent WO00 / 46179 of Aikoku Central Chemical Research Institute in 2000, it is proposed to use Ni / (SiO2-Al2O3) as a catalyst, methanol as a solvent, liquid ammonia added in the solvent, and the reaction is carried out under the conditions of 1.5 MPa hydrogen pressure and 170℃ for 1h, so as to reduce m-xylylene cyanide into m-xylylenediamine, and the yield can reach more than 81%. Although the reaction conditions are mild, the alkali resistance of SiO2 and Al2O3 in the catalyst carrier is poor, the catalyst is difficult to be repeatedly used for many times, and side reactions are easy to occur. At the same time, a large amount of ammonia source is introduced in the reaction, which leads to a large amount of wastewater in the post-processing, increasing the post-processing cost.

[0004] In the patent US2002 / 0177735 Al, cobalt or nickel or cobalt-nickel bimetal is used as the main active center, ZrO2 is used as the carrier to prepare the catalyst, m-xylene is used as the solvent, liquid ammonia is introduced into the solvent, and the reaction is carried out under the conditions of 3MPa-20MPa hydrogen pressure and 20℃-200℃ for 0.1-5h, so as to reduce m-xylylene cyanide into m-xylylenediamine, and the conversion rate can reach 99.7% and the yield can reach 84.3%. The hydrogen pressure required by the reaction is large, which may cause danger in the reaction process, and the selectivity of the reaction is low, only about 84.45%. At the same time, as in the previous reaction, a large amount of ammonia source is introduced, which leads to a large amount of wastewater in the post-processing, increasing the post-processing cost.

[0005] Patent WO 2006 / 101302 A2 uses active nickel as a catalyst, methyl imidazole as a solvent, and a small amount of liquid ammonia is introduced into the solvent. The reaction is carried out at a hydrogen pressure of 1000 psig (about 6.9 MPa) and a temperature of 50-200°C for 0.5h to reduce m-xylylene cyanide to m-xylylene diamine, with a yield of more than 99%. Although the ammonia source is reduced, liquid ammonia is still used as the ammonia source. If 2-methyl imidazole is used as the solvent, the solvent and the product are difficult to separate due to their similar boiling points (the boiling point of m-xylylene diamine is 274°C, and the boiling point of 2-methyl imidazole is 267°C).

[0006] Shanghai Boyuan Fine Chemical Co., Ltd. proposed in its patent CN101062898 A in 2007 that Ni / (MgO-SiO2) is used as a catalyst, m-xylene is used as a solvent, liquid ammonia is introduced into the solvent, and a two-stage hydrogenation method is used to reduce m-xylylene cyanide. The first-stage hydrogenation temperature is 60-90°C, the second-stage hydrogenation temperature is 110-130°C, the pressure is 11-12 MPa, and the space velocity is 1-5h -1 The yield can still reach more than 96% after 800h of continuous reaction. The catalyst introduces MgO as a carrier to improve the surface acidity and basicity of the catalyst, but the amount of ammonia required increases. The process uses a two-stage hydrogenation method, and the pressure is relatively high, which poses a certain safety risk and is less economical.

[0007] Denner (Nanjing) Chemical Co., Ltd. proposed in its patents CN101337894 B in 2011 and CN101544570 B in 2013 that a continuous reaction device of stirred tank and slurry bed type is used, Raney nickel or nickel-based amorphous alloy is used as a catalyst, organic amine, aromatic hydrocarbon, low-carbon alcohol or water is used as a solvent, the reaction temperature is 25-120°C, the hydrogen reaction pressure is 0.5-12.0 MPa, and ammonia gas is introduced into the reactor. The conversion rate is more than 97%, and the yield can reach more than 83%. In this reaction, Raney nickel catalyst has a certain risk of spontaneous combustion in air and can easily cause explosions in a hydrogen atmosphere, so the reaction gas and reaction device have high requirements.

[0008] Nanjing University proposed in its patent CN107540556 A in 2018 that Ni / MgAlO is used as a catalyst, the temperature is 60-140°C, the pressure is 1.0-8.0 MPa, the m-xylylene cyanide mass space velocity is 0.1-5h -1The m-phenylenedicyanamide is hydrogenated and reduced into m-phenylenediamine with a yield of 100% in the reaction, in which the concentration of the m-phenylenedicyanamide solution is low (2-20% by mass), leading to a high solvent consumption and poor economy, and it is difficult to be applied to industrial production.

[0009] In summary, there is a need for a catalyst which can prevent the generation of by-products, ensure long-term catalyst activity, improve economy, reduce the safety risk of catalyst use, not use extra ammonia source, and hydrogenate and reduce m-phenylenedicyanamide into m-phenylenediamine under mild conditions. SUMMARY

[0010] In view of the prior art, the purpose of the present application is to provide a cobalt-molybdenum catalyst preparation method for preparing m-phenylenediamine and its application, which has simple catalyst preparation method, mild conditions, low cost, good activity and stability.

[0011] The present application is realized by the following technical solutions:

[0012] 1. A preparation method of a cobalt-molybdenum catalyst for preparing m-phenylenediamine, characterized in that X-Z-O is used as a carrier precursor, Co-Mo-M-X-Z-O is used as a catalyst precursor, and the final catalyst precursor is obtained after compounding, washing and drying. Finally, the final catalyst is obtained by reduction under H2 / N2 atmosphere.

[0013] Wherein X and Z are two of Mg, Al, Si, Zr and Ti, and M is one of Ni, Cr, Fe, Zn, Ce, Rh, Ru and Pd.

[0014] 2. Based on the above scheme, the catalyst precursor preparation method is characterized in that the preparation process of the X-Z-O carrier precursor is as follows: the X and Z precursor mixed solution and the carbonate solution are respectively dissolved in deionized water, and are simultaneously added dropwise into a certain volume of deionized water, and are stirred at 60-90℃. After dropwise addition, the stirring is continued for 0.5-5h, and then cooled to room temperature. Then the mixture is suction filtered and washed with deionized water until neutral, to obtain a wet X-Z-O carrier precursor. The carbonate includes one or both of sodium carbonate and potassium carbonate.

[0015] Wherein X, Z precursor is one or more than two kinds of corresponding arbitrary soluble acid or salt or sol or dispersion, for example, the precursor of magnesium is one or more than two kinds of magnesium chloride, magnesium nitrate, magnesium sulfate, etc.; the precursor of aluminum is one or more than two kinds of aluminum chloride, aluminum nitrate, aluminum sulfate, etc.; the precursor of silicon is one or more than two kinds of silica sol, silica gel, nano silica dispersion, etc.; the precursor of zirconium is one or more than two kinds of zirconium oxychloride, zirconium nitrate, zirconium sulfate, etc.; the precursor of titanium is one or more than two kinds of titanium tetrachloride, titanic acid, titanium tetranitrate, etc.

[0016] 3. Based on the above scheme, the preparation method of the catalyst precursor is characterized in that the preparation process of the Co-Mo-M-X-Z-O catalyst precursor is as follows: the mixed solution of the precursors of Co, Mo, M, X and Z and the carbonate solution are dissolved in deionized water respectively, and are added dropwise into a certain volume of deionized water at the same time, and are stirred at 60-90°C, and after the dropwise addition is completed, the stirring is continued for 0.5-5h, and then the mixture is cooled to room temperature. Then the mixture is filtered and washed with deionized water until neutral to obtain the wet Co-Mo-M-X-Z-O catalyst precursor. The carbonate includes one or both of sodium carbonate and potassium carbonate.

[0017] Wherein Co, Mo, X, Z precursor is one or more than two kinds of corresponding arbitrary soluble acid or salt or dispersion. For example, the precursor of cobalt is one or more than two kinds of cobalt chloride, cobalt nitrate, cobalt sulfate, cobalt acetate; the precursor of molybdenum is one or more than two kinds of molybdenum nitrate, phosphomolybdic acid, dichlorodioxymolybdenum; the precursor of magnesium is one or more than two kinds of magnesium chloride, magnesium nitrate, magnesium sulfate; the precursor of aluminum is one or more than two kinds of aluminum chloride, aluminum nitrate, aluminum sulfate; the precursor of silicon is one or more than two kinds of silica sol, silica gel, nano silica dispersion; the precursor of zirconium is one or more than two kinds of zirconium oxychloride, zirconium nitrate, zirconium sulfate; the precursor of titanium is one or more than two kinds of titanium tetrachloride, titanic acid, titanium tetranitrate.

[0018] The precursor of M is one or more than two kinds of corresponding arbitrary soluble acid or salt. For example, the precursor of nickel is one or more than two kinds of nickel chloride, nickel sulfate, nickel nitrate, nickel acetate; the precursor of chromium is one or more than two kinds of chromium chloride, chromium sulfate, chromium nitrate; the precursor of iron is one or more than two kinds of ferrous chloride, ferrous sulfate, ferrous nitrate, etc.

[0019] 4. Based on the above scheme, the preparation method of the catalyst precursor is characterized in that the carrier precursor and the catalyst precursor are compounded in a mass ratio of 1-8:1, and then washed with deionized water until neutral, and then dried to remove water to obtain the final catalyst precursor.

[0020] 5. Based on the above scheme, the preparation method of the precursor of the catalyst is characterized in that the precursor of the final catalyst is heated to 200-500 DEG C under an atmosphere with a H2 / N2 volume ratio of 1:3-19 for 0.5-5 h, and is cooled to room temperature under the atmosphere, to obtain the final catalyst Co-Mo-M / X-Z.

[0021] 6. Based on the above scheme, the content of Co, Mo and M in the final catalyst Co-Mo-M / X-Z is 0.5wt%-10wt%, 0.5wt%-10wt% and 0.1wt%-5wt% respectively, and preferably 1wt%-5wt%, 1wt%-5wt% and 1wt%-3wt% respectively; the content of X and Z is 50%-95% and 3%-40% respectively, and preferably 60%-90% and 5%-30% respectively.

[0022] 7. Based on the above scheme, the catalyst obtained by the preparation method.

[0023] 8. Based on the above scheme, the application of the catalyst in the synthesis of m-xylylenediamine is characterized in that rectified n-butanol obtained by rectifying commercially available tert-butanol to remove water is used as a solvent, commercially available m-xylylene cyanide is used as a raw material, and m-xylylenediamine is obtained by further hydrogenating the m-xylylene cyanide.

[0024] The catalyst has advantages of high strength, high conversion rate and selectivity, and is suitable for industrial production.

[0025] 1) The tert-butanol is used as a solvent, which can be separated from the raw material and the product by simple distillation, reducing the loss of the product, and the solvent can be recycled and used.

[0026] 2) In the reaction, a larger space velocity can be achieved, the catalyst has a stronger ability to treat reactants per unit time, and the utilization rate of the catalyst is higher.

[0027] 3) The preparation steps of the catalyst are simple, and the preparation raw materials are relatively cheap, so the industrialization is easy to realize.

[0028] 4) The catalyst still has a high conversion rate and selectivity after being recycled for 1000 hours, and is not easy to be deactivated. DETAILED DESCRIPTION

[0029] The application will be further described in detail in combination with specific embodiments, and the protection scope of the application includes but is not limited to the following embodiments, and any modification made to the technical scheme of the application without departing from the meaning and category of the application falls within the protection scope of the application.

[0030] Example 1

[0031] Preparation of the support precursor:

[0032] Dissolve 22.7050 g of magnesium nitrate hexahydrate and 3.7513 g of aluminum nitrate nonahydrate in 100 ml of deionized water; dissolve 10.9750 g of sodium carbonate solution in 100 ml of deionized water. Add both solutions simultaneously into a beaker containing 250 ml of deionized water and stir at 80 °C, continue stirring for 2 h after the addition is completed, then cool to room temperature. Then the mixture is suction filtered and washed with deionized water until neutral, to obtain the wet Mg-Al-O support precursor.

[0033] Preparation of the catalyst precursor:

[0034] Dissolve 0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, 0.3751 g of aluminum nitrate nonahydrate in 100 ml of deionized water; dissolve 1.3016 g of sodium carbonate in 100 ml of deionized water. Add both solutions simultaneously into a beaker containing 250 ml of deionized water and stir at 80 °C, continue stirring for 2 h after the addition is completed, then cool to room temperature. Then the mixture is suction filtered and washed with deionized water until neutral, to obtain the wet Co-Mo-Ni-Mg-Al-O catalyst precursor.

[0035] Compounding of the catalyst precursor with the support precursor:

[0036] Take 4.5 g of the wet Co-Mo-Ni-Mg-Al-O catalyst precursor and 18.9 g of the Mg-Al-O support precursor, add into 200 ml of deionized water, mix and wash, then centrifuge at a speed of 8000 rpm for 3 min, remove the supernatant, repeat the operation for 3 times, then take out the wet solid, mix with 200 ml of n-butanol, and evaporate at 80 °C overnight. Finally, the obtained solid is further dried at 120 °C for 12 h, to obtain the final catalyst precursor.

[0037] Preparation of the final catalyst:

[0038] Place the dried catalyst precursor in an atmosphere furnace, and calcine at 500 °C for 4 h with an air speed of 1000 h-1. -1The carrier precursor was prepared as in Example 1. The catalyst precursor was prepared as in Example 1, except that in the preparation step of the catalyst precursor, 0.3809 g of cobalt nitrate hexahydrate was removed, i.e., "0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, and 0.3751 g of aluminum nitrate nonahydrate were dissolved in 100 ml of deionized water" was used instead of "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, and 0.3751 g of aluminum nitrate nonahydrate were dissolved in 100 ml of deionized water". The subsequent catalyst precursor, the carrier precursor, and the preparation of the final catalyst were the same as in Example 1, and the final catalyst Co-Mo-Ni / Mg-Al was obtained. The mass fraction of Co in the Co-Mo-Ni / Mg-Al catalyst was 2.58%, the mass fraction of Mo was 5.82%, the mass fraction of Ni was 1.29%, the mass fraction of Mg was 80.23%, and the mass fraction of Al was 10.08%.

[0039] Comparative Example 1

[0040] The carrier precursor was prepared as in Example 1. The catalyst precursor was prepared as in Example 1, except that in the preparation step of the catalyst precursor, 0.3809 g of cobalt nitrate hexahydrate was removed, i.e., "0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, and 0.3751 g of aluminum nitrate nonahydrate were dissolved in 100 ml of deionized water" was used instead of "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, and 0.3751 g of aluminum nitrate nonahydrate were dissolved in 100 ml of deionized water". The subsequent catalyst precursor, the carrier precursor, and the preparation of the final catalyst were the same as in Example 1, and the final catalyst Co-Mo-Ni / Mg-Al was obtained. The mass fraction of Co in the Co-Mo-Ni / Mg-Al catalyst was 2.58%, the mass fraction of Mo was 5.82%, the mass fraction of Ni was 1.29%, the mass fraction of Mg was 80.23%, and the mass fraction of Al was 10.08%.

[0041] Comparative Example 2

[0042] The preparation of the support precursor is the same as in Example 1. The preparation of the catalyst precursor is the same as in Example 1, except that in the preparation of the catalyst precursor, 0.3751 g of aluminum nitrate nonahydrate is removed, i.e., "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate are dissolved in 100 ml of deionized water" is used instead of "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, 0.3751 g of aluminum nitrate nonahydrate are dissolved in 100 ml of deionized water". The subsequent compounding of the catalyst precursor with the support precursor and the preparation of the final catalyst are the same as in Example 1, and the final catalyst Co-Mo-Ni / Mg is obtained. The mass fraction of Co in the Co-Mo-Ni / Mg catalyst is 2.87%, the mass fraction of Mo is 6.47%, the mass fraction of Ni is 1.44%, and the mass fraction of Mg is 89.22%.

[0043] Comparative Example 3

[0044] The preparation of the support precursor is the same as in Example 1, except that in the preparation of the support precursor, 3.7513 g of aluminum nitrate nonahydrate is removed, i.e., "22.7050 g of magnesium nitrate hexahydrate is dissolved in 100 ml of deionized water" is used instead of "22.7050 g of magnesium nitrate hexahydrate, 3.7513 g of aluminum nitrate nonahydrate are dissolved in 100 ml of deionized water". The preparation of the catalyst precursor is the same as in Example 1, except that in the preparation of the catalyst precursor, 0.3751 g of aluminum nitrate nonahydrate is removed, i.e., "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate are dissolved in 100 ml of deionized water" is used instead of "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, 0.3751 g of aluminum nitrate nonahydrate are dissolved in 100 ml of deionized water". The subsequent compounding of the catalyst precursor with the support precursor and the preparation of the final catalyst are the same as in Example 1, and the final catalyst Co-Mo-Ni / Mg is obtained. The mass fraction of Co in the Co-Mo-Ni / Mg catalyst is 2.87%, the mass fraction of Mo is 6.47%, the mass fraction of Ni is 1.44%, and the mass fraction of Mg is 89.22%.

[0045] Example 2

[0046] Preparation of the support precursor:

[0047] Dissolve 18.0024g of magnesium chloride hexahydrate and 1.5021g of silica sol 40 in 100ml of deionized water. Dissolve 10.9750g of sodium carbonate solution in 100ml of deionized water. Add both mixtures dropwise to a beaker containing 250ml of deionized water and stir at 60°C. Continue stirring for 3 hours after the addition is complete, then cool to room temperature. Filter the mixture and wash with deionized water until the filtrate is free of chloride ions, yielding a wet Mg-Si-O support precursor.

[0048] Preparation of catalyst precursor:

[0049] Dissolve 0.3114g of cobalt chloride hexahydrate, 0.2603g of molybdenum dioxide dichloride, 0.1744g of chromium trichloride hexahydrate, 1.8002g of magnesium chloride hexahydrate, and 0.1502g of Silica Sol 40 in 100ml of deionized water. Dissolve 1.3016g of sodium carbonate in 100ml of deionized water. Add both solutions dropwise to a beaker containing 250ml of deionized water and stir at 60°C. Continue stirring for 3 hours after the addition is complete, then cool to room temperature. Filter the mixture and wash with deionized water until the filtrate is free of chloride ions, obtaining a wet Co-Mo-Cr-Mg-Si-O catalyst precursor.

[0050] Compounding of catalyst precursor and carrier precursor:

[0051] 4.5 g of the wet Co-Mo-Cr-Mg-Si-O catalyst precursor and 18.9 g of the Mg-Si-O support precursor were added to 200 ml of deionized water, mixed, and washed. The mixture was then centrifuged at 8000 rpm for 3 minutes, and the supernatant was removed. This process was repeated three times. The wet solid was removed, mixed with 200 ml of n-butanol, and evaporated at 80°C overnight. Finally, the resulting solid was dried at 120°C for 12 hours to obtain the final catalyst precursor.

[0052] Preparation of the final catalyst:

[0053] The dried catalyst precursor was placed in an atmosphere furnace at a space velocity of 1000 h -1 In an H2 / N2 atmosphere with an H2 volume fraction of 10%, the mixture was first heated to 200°C at a heating rate of 5°C / min and maintained for 2 hours, then heated to 450°C at a heating rate of 5°C / min and maintained for 5 hours, and finally cooled to room temperature to obtain the final catalyst Co-Mo-Cr / Mg-Si. The mass fraction of Co in the Co-Mo-Cr / Mg-Si catalyst is 2.58%, the mass fraction of Mo is 5.81%, the mass fraction of Cr is 1.14%, the mass fraction of Mg is 80.09%, and the mass fraction of Si is 10.38%.

[0054] Example 3

[0055] The preparation of the carrier precursor is the same as that of Example 2.

[0056] The preparation of the catalyst precursor is the same as that of Example 2, except that 0.1744 g of chromium trichloride hexahydrate is replaced by 0.1301 g of ferrous chloride tetrahydrate in the preparation of the catalyst precursor, i.e. “0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1301 g of ferrous chloride tetrahydrate, 1.8002 g of magnesium chloride hexahydrate, 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water” instead of “0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1744 g of chromium trichloride hexahydrate, 1.8002 g of magnesium chloride hexahydrate, 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water”, and then a wet Co-Mo-Fe-Mg-Si-O catalyst precursor is obtained.

[0057] The preparation of the catalyst precursor and the carrier precursor is the same as that of Example 2, except that “4.5 g of the wet Co-Mo-Cr-Mg-Si-O catalyst precursor and 18.9 g of the Mg-Si-O carrier precursor” instead of “4.5 g of the wet Co-Mo-Fe-Mg-Si-O catalyst precursor and 18.9 g of the Mg-Si-O carrier precursor” in the preparation of the catalyst precursor and the carrier precursor.

[0058] The preparation of the final catalyst is the same as that of Example 2, and the final catalyst obtained is Co-Mo-Fe / Mg-Si. The mass fraction of Co in the Co-Mo-Fe / Mg-Si catalyst is 2.57%, the mass fraction of Mo is 5.81%, the mass fraction of Fe is 1.22%, the mass fraction of Mg is 80.01%, and the mass fraction of Si is 10.39%.

[0059] Example 4

[0060] The preparation of the carrier precursor is the same as that of Example 2.

[0061] The preparation procedure of the catalyst precursor is the same as that in Example 2, except that 0.1744 g of chromium chloride trihydrate is replaced by 0.1882 g of zinc sulfate heptahydrate in the preparation procedure of the catalyst precursor, i.e., "0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dichloride dioxide, 0.1882 g of zinc sulfate heptahydrate, 1.8002 g of magnesium chloride hexahydrate, and 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water" instead of "0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dichloride dioxide, 0.1744 g of chromium chloride trihydrate, 1.8002 g of magnesium chloride hexahydrate, and 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water", and then a wet Co-Mo-Zn-Mg-Si-O catalyst precursor is obtained.

[0062] The preparation procedure of the catalyst precursor and the carrier precursor is the same as that in Example 2, except that "4.5 g of the wet Co-Mo-Zn-Mg-Si-O catalyst precursor and 18.9 g of the Mg-Si-O carrier precursor" are replaced by "4.5 g of the wet Co-Mo-Zn-Mg-Si-O catalyst precursor and 18.9 g of the Mg-Si-O carrier precursor" in the preparation procedure of the catalyst precursor and the carrier precursor.

[0063] The preparation of the final catalyst is the same as that in Example 2, and a Co-Mo-Zn / Mg-Si catalyst is obtained. In the Co-Mo-Zn / Mg-Si catalyst, the mass fraction of Co is 2.57%, the mass fraction of Mo is 5.79%, the mass fraction of Zn is 1.43%, the mass fraction of Mg is 79.84%, and the mass fraction of Si is 10.37%.

[0064] Example 5

[0065] The preparation procedure of the carrier precursor is the same as that in Example 1, except that 3.7513 g of aluminum nitrate nonahydrate is replaced by 4.2932 g of zirconium nitrate pentahydrate in the preparation procedure of the carrier precursor, i.e., "22.7050 g of magnesium nitrate hexahydrate and 4.2932 g of zirconium nitrate pentahydrate are dissolved in 100 ml of deionized water" instead of "22.7050 g of magnesium nitrate hexahydrate and 3.7513 g of aluminum nitrate nonahydrate are dissolved in 100 ml of deionized water".

[0066] The preparation procedure of the catalyst precursor is the same as that in Example 1, except that in the preparation procedure of the catalyst precursor, 0.1903 g of nickel nitrate hexahydrate and 0.3751 g of aluminum nitrate nonahydrate are replaced by 0.1882 g of zinc sulfate heptahydrate and 0.4293 g of zirconium nitrate pentahydrate, namely, "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1882 g of zinc sulfate heptahydrate, 2.2705 g of magnesium nitrate hexahydrate, and 0.4293 g of zirconium nitrate pentahydrate are dissolved in 100 ml of deionized water" instead of "0.3809 g of cobalt nitrate hexahydrate, 0.5803 g of molybdenum nitrate pentahydrate, 0.1903 g of nickel nitrate hexahydrate, 2.2705 g of magnesium nitrate hexahydrate, and 0.3751 g of aluminum nitrate nonahydrate are dissolved in 100 ml of deionized water", and then the wet Co-Mo-Zn-Mg-Zr-O catalyst precursor is obtained.

[0067] The preparation procedure of the catalyst precursor and the carrier precursor is the same as that in Example 1, except that in the preparation procedure of the catalyst precursor and the carrier precursor, "4.5 g of the wet Co-Mo-Zn-Mg-Zr-O catalyst precursor and 18.9 g of the Mg-Zr-O carrier precursor" instead of "4.5 g of the wet Co-Mo-Ni-Mg-Al-O catalyst precursor and 18.9 g of the Mg-Al-O carrier precursor"

[0068] The preparation of the final catalyst is the same as that in Example 2, and the final catalyst obtained is Co-Mo-Zn / Mg-Zr. In the Co-Mo-Zn / Mg-Si catalyst, the mass fraction of Co is 2.08%, the mass fraction of Mo is 4.70%, the mass fraction of Zn is 1.16%, the mass fraction of Mg is 64.75%, and the mass fraction of Zr is 27.31%.

[0069] Example 6

[0070] The preparation procedure of the carrier precursor is the same as that in Example 2, except that in the preparation procedure of the carrier precursor, 18.0024 g of magnesium chloride hexahydrate is replaced by 21.3785 g of aluminum chloride hexahydrate, namely, "21.3785 g of aluminum chloride hexahydrate and 1.5021 g of silica sol 40 are dissolved in 100 ml of deionized water" instead of "18.0024 g of magnesium chloride hexahydrate and 1.5021 g of silica sol 40 are dissolved in 100 ml of deionized water".

[0071] The preparation procedure of catalyst precursor is the same as that of Example 2, except that in the preparation procedure of catalyst precursor, 0.1744 g of chromium chloride hexahydrate and 1.8002 g of magnesium chloride hexahydrate are replaced by 0.2842 g of cerium nitrate hexahydrate and 2.1379 g of aluminum chloride hexahydrate, i.e. "0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.2842 g of cerium nitrate hexahydrate, 2.1379 g of aluminum chloride hexahydrate, 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water" instead of "0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1744 g of chromium chloride hexahydrate, 1.8002 g of magnesium chloride hexahydrate, 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water", and then a wet Co-Mo-Ce-Al-Si-O catalyst precursor is obtained.

[0072] The preparation procedure of catalyst precursor and carrier precursor compounding is the same as that of Example 1, except that in the preparation procedure of catalyst precursor and carrier precursor compounding, "4.5 g of the wet Co-Mo-Ce-Al-Si-O catalyst precursor and 18.9 g of the Al-Si-O carrier precursor" instead of "4.5 g of the wet Co-Mo-Ni-Mg-Al-O catalyst precursor and 18.9 g of the Mg-Al-O carrier precursor"

[0073] The preparation of the final catalyst is the same as that of Example 2, and a Co-Mo-Ce / Al-Si catalyst is obtained. In the Co-Mo-Ce / Al-Si catalyst, the mass fraction of Co is 2.31%, the mass fraction of Mo is 5.22%, the mass fraction of Ce is 2.75%, the mass fraction of Al is 80.37%, and the mass fraction of Si is 9.35%.

[0074] Example 7

[0075] The preparation procedure of carrier precursor is the same as that of Example 6, except that in the preparation procedure of carrier precursor, 21.3785 g of aluminum chloride hexahydrate is replaced by 18.9680 g of titanium chloride, i.e. "18.9680 g of titanium chloride and 1.5021 g of silica sol 40 are dissolved in 100 ml of deionized water" instead of "21.3785 g of aluminum chloride hexahydrate and 1.5021 g of silica sol 40 are dissolved in 100 ml of deionized water".

[0076] The preparation procedure of catalyst precursor is the same as that of Example 2, except that in the preparation procedure of catalyst precursor, 0.1744 g of chromium trichloride hexahydrate and 1.8002 g of magnesium chloride hexahydrate are replaced by 0.1476 g of ruthenium trichloride hydrate and 1.8968 g of titanium tetrachloride, i.e. "0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1476 g of ruthenium trichloride hydrate, 1.8968 g of titanium tetrachloride, 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water" instead of "0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1744 g of chromium trichloride hexahydrate, 1.8002 g of magnesium chloride hexahydrate, 0.1502 g of silica sol 40 are dissolved in 100 ml of deionized water", and then a wet Co-Mo-Ru-Ti-Si-O catalyst precursor is obtained.

[0077] The preparation procedure of catalyst precursor and carrier precursor compounding is the same as that of Example 1, except that in the preparation procedure of catalyst precursor and carrier precursor compounding, "4.5 g of the wet Co-Mo-Ru-Ti-Si-O catalyst precursor and 18.9 g of the Ti-Si-O carrier precursor" instead of "4.5 g of the wet Co-Mo-Ni-Mg-Al-O catalyst precursor and 18.9 g of the Mg-Al-O carrier precursor"

[0078] The preparation of final catalyst is the same as that of Example 2, and the final catalyst obtained is Co-Mo-Ru / Ti-Si. In the Co-Mo-Ru / Ti-Si catalyst, the mass fraction of Co is 1.44%, the mass fraction of Mo is 3.25%, the mass fraction of Ru is 1.24%, the mass fraction of Ti is 87.05%, and the mass fraction of Si is 7.02%.

[0079] Example 8

[0080] The preparation of carrier precursor is the same as that of Example 7.

[0081] The preparation steps of the catalyst precursor are the same as those in Example 2, except that 0.1744 g of chromium trichloride hexahydrate and 1.8002 g of magnesium chloride hexahydrate are replaced by 0.1161 g of palladium dichloride and 1.8968 g of titanium tetrachloride, that is, 0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1476 g of ruthenium trichloride hydrate, 1.8968 g of The method of “dissolving 0.3114 g of cobalt chloride hexahydrate, 0.2603 g of molybdenum dioxide dichloride, 0.1161 g of palladium dichloride, 1.8002 g of magnesium chloride hexahydrate, and 0.1502 g of silica sol 40 in 100 ml of deionized water” was replaced by “dissolving titanium tetrachloride and 0.1502 g of silica sol 40 in 100 ml of deionized water” to obtain a wet Co-Mo-Pb-Ti-Si-O catalyst precursor.

[0082] The preparation steps of the composite catalyst precursor and the carrier precursor are the same as those in Example 1, except that in the preparation steps of the composite catalyst precursor and the carrier precursor, "4.5 g of the wet Co-Mo-Pd-Ti-Si-O catalyst precursor and 18.9 g of the Ti-Si-O carrier precursor" is replaced by "4.5 g of the wet Co-Mo-Pd-Mg-Al-O catalyst precursor and 18.9 g of the Mg-Al-O carrier precursor".

[0083] The final catalyst was prepared in the same manner as in Example 2, except that the final catalyst obtained was Co-Mo-Pd / Ti-Si. The Co-Mo-Pd / Ti-Si catalyst had a Co mass fraction of 1.44%, a Mo mass fraction of 3.25%, a Pd mass fraction of 1.30%, a Ti mass fraction of 88.20%, and a Si mass fraction of 5.81%.

[0084] Example 9

[0085] The catalysts obtained in Examples 1-8 and Comparative Examples 1-3 were placed in fixed beds respectively, tert-butyl alcohol was used as the solvent, the concentration of isophthalonitrile was 0.5 mol / L, and the air velocity was 6 h -1 The reaction was conducted at 130°C with 100% isophthalonitrile and 4 MPa of hydrogen at a molar ratio of hydrogen to isophthalonitrile of 5-30:1. Portions of the product were removed at regular intervals, nitrobenzene was added as an internal standard, and the reaction results were analyzed by gas chromatography (GC). The conversion of isophthalonitrile and the selectivity for meta-xylylenediamine were calculated after 500 and 1000 hours of reaction, respectively.

[0086]

[0087] Note:

[0088] 1. “-” indicates not tested.

[0089] Comparing examples 1-8 with comparative examples 1-3 in the table, the two-component support improves the effective load of the active component and prevents the deactivation of the catalytic center, while the introduction of cobalt and molybdenum maintains the conversion of the substrate and the selectivity of the product, so that the catalytic center still maintains high activity and product selectivity under long-time reaction.

Claims

1. A method for preparing a cobalt-molybdenum catalyst for preparing meta-xylylenediamine, characterized by: XZO is used as a carrier precursor and Co-Mo-MXZO as a catalyst precursor. After compounding, washing and drying, the final catalyst precursor is obtained; finally, the final catalyst is reduced under H2 / N2 atmosphere. Wherein, X and Z are two different kinds of Mg, Al, Si, Zr, and Ti, and M is one or more kinds of Ni, Cr, Fe, Zn, Ce, Rh, Ru, and Pd.

2. The method for preparing the catalyst according to claim 1, wherein The preparation process of the XZO carrier precursor is as follows: dissolving X and Z precursors in water to obtain a precursor solution, dissolving carbonate in water to obtain a carbonate solution, and simultaneously adding the precursor solution and the carbonate solution dropwise to water while stirring at 60-90° C., continuing stirring for 0.5-5 hours after the dropwise addition is complete, and then cooling to room temperature; then filtering the mixture and washing it with deionized water until neutral to obtain a wet XZO carrier precursor, wherein the carbonate comprises one or both of sodium carbonate and potassium carbonate; The X and Z precursors are one or more of any corresponding soluble acids, salts or dispersions; the magnesium precursor is one or more of magnesium chloride, magnesium nitrate and magnesium sulfate; the aluminum precursor is one or more of aluminum chloride, aluminum nitrate and aluminum sulfate; the silicon precursor is one or more of silica sol, silica gel and nano-silica dispersion; the zirconium precursor is one or more of zirconium oxychloride, zirconium nitrate and zirconium sulfate; and the titanium precursor is one or more of titanium tetrachloride, titanic acid and titanium tetranitrate.

3. The method for preparing the catalyst according to claim 1, wherein The Co-Mo-MXZO catalyst precursor preparation process comprises: dissolving the precursors of Co, Mo, M, X, and Z in water to obtain a precursor solution; dissolving the carbonate in water to obtain a carbonate solution; dropping the precursor solution and the carbonate solution into water simultaneously, and stirring at 60-90° C., continuing stirring for 0.5-5 hours after the dropwise addition is complete, and then cooling to room temperature; then filtering the mixture and washing it with deionized water until neutral to obtain a wet Co-Mo-MXZO catalyst precursor; wherein the carbonate comprises one or both of sodium carbonate and potassium carbonate; Wherein the precursors of Co, Mo, X and Z are one or more of any corresponding soluble acid, salt or dispersion; the precursor of cobalt is one or more of cobalt chloride, cobalt nitrate, cobalt sulfate and cobalt acetate; the precursor of molybdenum is one or more of molybdenum nitrate, phosphomolybdic acid and molybdenum dioxide dichloride; the precursor of magnesium is one or more of magnesium chloride, magnesium nitrate and magnesium sulfate; the precursor of aluminum is one or more of aluminum chloride, aluminum nitrate and aluminum sulfate; the precursor of silicon is one or more of silica sol, silica gel and nano-silica dispersion; the precursor of zirconium is one or more of zirconium oxychloride, zirconium nitrate and zirconium sulfate; the precursor of titanium is one or more of titanium tetrachloride, titanic acid and titanium tetranitrate; The precursor of M is one or more of any corresponding soluble acids or salts, the precursor of nickel is one or more of nickel chloride, nickel sulfate, nickel nitrate, and nickel acetate; the precursor of chromium is one or more of chromium chloride, chromium sulfate, and chromium nitrate; the precursor of iron is one or more of ferrous chloride, ferrous sulfate, and ferrous nitrate; the precursor of Zn is one or more of zinc nitrate, zinc sulfate, and zinc chloride; the precursor of Ce is one or more of cerium nitrate, cerium sulfate, and cerium chloride; the precursor of Rh is one or more of rhodium nitrate, rhodium sulfate, and rhodium acetate; the precursor of Ru is one or more of ruthenium chloride, ruthenium acetate, and carbonylruthenium chloride; the precursor of Pd is one or more of palladium nitrate, palladium sulfate, and palladium chloride.

4. The method for preparing the catalyst according to claim 1, wherein The carrier precursor and the catalyst precursor are compounded in a mass ratio of 1-8:1, and then washed with deionized water until neutral and then dried to remove water to obtain the final catalyst precursor.

5. The method for preparing the catalyst according to claim 1, wherein The precursor of the final catalyst is heated to 200°C-500°C in an atmosphere with a H2 / N2 volume ratio of 1:3-19 for 0.5-5 hours, and then cooled to room temperature in this atmosphere to obtain the final catalyst Co-Mo-M / XZ.

6. The method for preparing the catalyst according to claim 1, wherein The contents of Co, Mo, and M in the final catalyst Co-Mo-M / XZ are 0.5wt%-10wt%, 0.5wt%-10wt%, and 0.1wt%-5wt%, respectively; the contents of X and Z are 50%-95% and 3%-40%, respectively.

7. The method for preparing the catalyst according to claim 6, characterized in that: The contents of Co, Mo, and M in the final catalyst Co-Mo-M / XZ are 1wt%-5wt%, 1wt%-5wt%, and 1wt%-3wt%, respectively; the contents of X and Z are 60%-90% and 5%-30%, respectively.

8. A catalyst prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the catalyst according to claim 8 in catalyzing the synthesis of m-xylylenediamine.

10. Use of the catalyst according to claim 9 in catalyzing the synthesis of m-xylylenediamine, characterized in that: Using tert-butyl alcohol as a solvent and isophthalonitrile as a raw material, isophthalonitrile is further hydrogenated to obtain meta-xylylenediamine.

11. Use of the catalyst according to claim 9 or 10 in catalyzing the synthesis of m-xylylenediamine, characterized in that: A fixed bed reactor is used to pump a solution of isophthalonitrile dissolved in tert-butyl alcohol into a bed filled with Co-Mo-M / XZ catalyst. The catalyst is stirred at a temperature of 50-150°C, a pressure of 0.5-6.0 MPa, and a mass space velocity of isophthalonitrile of 1-8 h -1 Under the condition that the molar ratio of hydrogen to isophthalonitrile is 5-30:1, isophthalonitrile reacts with hydrogen to generate meta-xylylenediamine.

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