Preparation method of supported catalyst for hydrogenation reaction of 2-methylglutaronitrile

Abstract

The invention relates to the technical field of supported catalysts, and discloses a preparation method of a supported catalyst for hydrogenation reaction of 2-methylglutaronitrile, which comprises the following steps: (1) dispersing a nickel precursor in water containing disodium ethylene diamine tetraacetate to obtain a nickel precursor solution; (2) dispersing a carrier in a nickel precursor solution, stirring, filtering, and drying to obtain an intermediate I; (3) dispersing a metal precursor in ammonia water to obtain a metal precursor solution; (4) dispersing the intermediate I in a metal precursor solution, stirring, filtering, and roasting in argon to obtain an intermediate II; and (5) reducing the intermediate II in a mixed gas of hydrogen and argon to obtain the supported catalyst. Through cooperation of the carrier and the active component and optimization of a preparation process, the load rate of the active component is improved, active center distribution inside and on the surface of the catalyst is improved, and the catalytic effect is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of supported catalysts, and in particular to a method for preparing a supported catalyst for hydrogenation reaction of 2-methylglutaronitrile. Background Art

[0002] At present, in the reports on the catalytic hydrogenation of 2-methylglutaronitrile to synthesize 2-methylpentanediamine, Raney nickel / cobalt catalytic system is mostly used as hydrogenation catalyst. However, when Raney nickel / cobalt catalyst is applied to the catalytic hydrogenation of dinitrile compounds, more heavy products will be produced, and it is often necessary to add additional alkaline additives to reduce the yield of heavy products. In addition, Raney nickel / cobalt catalyst also has problems such as easy spontaneous combustion, poor stability, and easy breakage.

[0003] Therefore, the reaction of hydrogenating 2-methylglutaronitrile to synthesize 2-methylpentanediamine urgently needs to find an efficient and stable catalytic system. The invention patent with publication number CN102344373A discloses a preparation method of 2-methyl-1,5-pentanediamine, using 2-methyl-1,5-pentanediamine as raw material and Co-Mo / γ-Al2O3 catalyst as catalyst, the composition of Co-Mo / γ-Al2O3 catalyst is: Co is 1.0-50.0%, Pt is 0.005-0.3%, Mo is 0.1-5.0%, and the rest is γ-Al2O3; the reaction is carried out in the gas phase, using a continuous process, 2-methyl-1,5-pentanediamine is pumped into a preheater and mixed with ammonia and hydrogen for preheating and vaporization, and then enters a fixed bed reactor for reaction, and the material after the reaction is condensed and cooled, and separated from the gas and liquid, and then enters the distillation and refining process. This process has a high conversion rate and few by-products, but the process requires vaporization of 2-methylglutaronitrile, which consumes a lot of energy and makes it difficult to separate the mixed ammonia and hydrogen after the reaction. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing a supported catalyst for the hydrogenation reaction of 2-methylglutaronitrile. By selecting active components and carriers and optimizing the preparation process, the catalyst can be easily prepared and has a stable catalytic effect while efficiently converting 2-methylglutaronitrile to 2-methylpentanediamine.

[0005] The purpose of the present invention is achieved through the following technical solutions: The present invention provides a method for preparing a supported catalyst for 2-methylglutaronitrile hydrogenation reaction, comprising the following steps: (1) dispersing a nickel precursor in water containing disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) dispersing the support in the nickel precursor solution and stirring, and then filtering and drying to obtain intermediate I; (3) dispersing a metal precursor in aqueous ammonia to obtain a metal precursor solution; (4) Dispersing intermediate I in a metal precursor solution and stirring, filtering, and calcining in argon to obtain intermediate II; (5) Reducing intermediate II in a mixture of hydrogen and argon to obtain a supported catalyst.

[0006] At present, the catalytic synthesis process of 2-methylglutaronitrile hydrogenation usually requires the presence of a high content of alkaline substances, and still generates more by-products, with poor 2-methylglutaronitrile conversion rate and 2-methylpentanediamine selectivity. The supported catalyst in the present invention achieves higher catalytic activity through the coordination of a specifically selected carrier and an optimized ratio of active components, and also improves the loading rate of the active components by optimizing the catalyst preparation process, and improves the distribution of active centers inside and on the surface of the catalyst, thereby improving the selectivity of 2-methylpentanediamine. In addition, the preparation process of the catalyst is simple, the catalytic effect is stable, and it is suitable for large-scale industrial production. The catalyst recovery and treatment process after the reaction is also simple, which is conducive to repeated use.

[0007] Specifically, the supported catalyst utilizes the coupling effect of disodium ethylenediaminetetraacetate to load nickel ions more effectively on the carrier, thereby improving the stability and loading rate of the load, and disodium ethylenediaminetetraacetate also provides sodium ion loading, which can cooperate with various metal active centers on the carrier to exert better synergistic catalytic effects. After that, other metal ions are loaded, and the step-by-step loading can optimize the loading effect of various metal active centers and improve the distribution of active centers inside and on the surface of the catalyst. Disodium ethylenediaminetetraacetate will decompose and produce gas during the high-temperature roasting process, thereby expanding the pore structure and exposing more metal active centers, which is conducive to improving the reduction efficiency, thereby improving the catalytic efficiency, and can obtain a higher selectivity and conversion rate of the 2-methylglutaronitrile hydrogenation reaction in the presence of a relatively low alkaline auxiliary.

[0008] Preferably, the concentration of the nickel precursor in the nickel precursor solution is 0.01-0.05 g / mL, and the concentration of disodium ethylenediaminetetraacetate is 0.01-0.03 g / mL. More preferably, the concentration of the nickel precursor in the nickel precursor solution is 0.01-0.03 g / mL.

[0009] Preferably, the carrier is silicon dioxide, aluminum oxide, zirconium dioxide or ZSM-5 molecular sieve.

[0010] Preferably, the mass ratio of the nickel precursor to the carrier is 5-30%, more preferably 5-10%.

[0011] Preferably, the total concentration of the metal precursor in the metal precursor solution is 0.01-0.05 g / mL, more preferably, the total concentration of the metal precursor in the metal precursor solution is 0.02-0.04 g / mL; the mass concentration of the ammonia water is 20-25%.

[0012] Preferably, the mass ratio of the metal precursor to the carrier is 10-30%, more preferably 10-20%.

[0013] Preferably, the metal is one or more of ruthenium, rhodium, palladium, platinum and molybdenum; and the metal precursor is one or more of metal nitrate, metal chloride and metal ammonium salt.

[0014] Preferably, the metal is one or more of molybdenum, ruthenium, rhodium, palladium and platinum.

[0015] Preferably, the metals are molybdenum and rhodium, and the mass ratio of the molybdenum precursor to the rhodium precursor is 6-8:2-4.

[0016] Preferably, the calcination temperature is 300-600° C., the heating rate is 3-8° C. / min, and the calcination time is 3-9 h.

[0017] Preferably, the molar ratio of hydrogen to argon is 0.5-1:1.

[0018] Preferably, the reduction temperature is 300-600° C., the heating rate is 3-8° C. / min, and the reduction time is 3-9 h.

[0019] Preferably, the stirring time is 6-24 hours, more preferably 8-15 hours.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) A higher catalytic activity is achieved by synergizing a specifically selected carrier and an optimized ratio of active components, and the catalyst preparation process is optimized to increase the loading rate of the active components and improve the distribution of active centers inside and on the surface of the catalyst, thereby improving the selectivity of 2-methylpentanediamine; (2) The catalyst has a simple preparation process and a stable catalytic effect, and is suitable for large-scale industrial production. The catalyst recovery process after reaction is also simple, which is conducive to repeated use. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described below with specific embodiments, but the protection scope of the present invention is not limited thereto: Example 1 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.3 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 8 h. After filtering, the solution was dried at 80 °C for 5 h to obtain intermediate I. (3) dispersing 0.8 g of ruthenium trichloride in 30 mL of 20% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 80 ° C for 5 h, and then heating from room temperature to 450 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 4 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 450°C at a heating rate of 5°C / min for 8 hours to obtain a supported catalyst Ni-Ru / SiO2.

[0022] Example 2 (1) dispersing 0.5 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 90 °C for 4 h to obtain intermediate I. (3) dispersing 0.6 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 5 h, filtering, drying at 90 ° C for 4 h, and then heating from room temperature to 550 ° C at a heating rate of 5 ° C / min in an argon atmosphere, and calcining for 3 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.8:1, and the temperature was increased from room temperature to 550°C at a heating rate of 5°C / min for 5 h to obtain a supported catalyst Ni-Rh / SiO2.

[0023] Example 3 (1) dispersing 0.5 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 90 ° C for 4 h to obtain intermediate I. (3) dispersing 0.5 g of palladium nitrate monohydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 5 h, filtering, drying at 90 ° C for 4 h, and then heating from room temperature to 500 ° C in argon at a heating rate of 5 ° C / min, and calcining for 4 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.6:1, and the temperature was increased from room temperature to 550°C at a heating rate of 5°C / min for 4 hours to obtain a supported catalyst Ni-Pd / SiO2.

[0024] Example 4 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 80 ° C for 6 h to obtain intermediate I. (3) dispersing 0.6 g of platinum chloride in 30 mL of 20% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 80 ° C for 6 h, and then heating from room temperature to 450 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 5 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Pt / SiO2.

[0025] Example 5 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo / SiO2.

[0026] Example 6 The difference from Example 5 is that the carrier is replaced by alumina.

[0027] (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier alumina was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo / Al2O3.

[0028] Example 7 The difference from Example 5 is that the carrier is zirconium dioxide.

[0029] (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) dispersing 5 g of carrier zirconium dioxide in the nickel precursor solution and stirring for 10 h, filtering, and drying at 100 ° C. for 3 h to obtain intermediate I; (3) dispersing 0.6 g of ammonium molybdate tetrahydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then calcining at 400 ° C in argon for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixture of hydrogen and argon with a molar ratio of 0.5:1 at 500°C for 6 h to obtain a supported catalyst Ni-Mo / ZrO2.

[0030] Example 8 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.2 g of ruthenium trichloride in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Ru / SiO2.

[0031] Example 9 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.2 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Rh / SiO2.

[0032] Example 10 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.2 g of palladium nitrate monohydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Pd / SiO2.

[0033] Embodiment 11 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.2 g of platinum chloride in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Pt / SiO2.

[0034] Example 12 The difference from Example 9 is that the carrier is alumina.

[0035] (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier alumina was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.2 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Rh / Al2O3.

[0036] Example 13 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.4 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Rh / SiO2.

[0037] Embodiment 14 (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.8 g of ammonium molybdate tetrahydrate and 0.2 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Rh / SiO2.

[0038] Comparative Example 1 The difference from Example 5 is that the carrier is cerium oxide.

[0039] (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) dispersing 5 g of supported cerium oxide in the nickel precursor solution and stirring for 10 h, filtering, and drying at 100 ° C. for 3 h to obtain intermediate I; (3) dispersing 0.6 g of ammonium molybdate tetrahydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo / CeO2.

[0040] Comparative Example 2 The difference from Example 5 is: no disodium edetate is added.

[0041] (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.6 g of ammonium molybdate tetrahydrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo / SiO2.

[0042] Comparative Example 3 The difference from Example 5 is that step-by-step loading is not adopted.

[0043] (1) dispersing 0.4 g of nickel nitrate hexahydrate and 0.6 g of ammonium molybdate tetrahydrate in 30 mL of 25% ammonia water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a metal precursor solution; (2) 5 g of carrier silica was dispersed in the metal precursor solution and stirred for 14 h. After filtering, it was dried at 100 °C for 3 h to obtain intermediate I. (3) In an argon atmosphere, the intermediate I was heated from room temperature to 400°C at a heating rate of 5°C / min and calcined for 6 h to obtain the intermediate II; (4) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo / SiO2.

[0044] Comparative Example 4 The difference from Example 9 is that no nickel precursor is added.

[0045] (1) dispersing 0.6 g of ammonium molybdate tetrahydrate and 0.2 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (2) 5 g of carrier silica was dispersed in the metal precursor solution and stirred for 4 h. After filtering, the solution was dried at 100 °C for 3 h. Then, the temperature was increased from room temperature to 400 °C at a rate of 5 °C / min under an argon atmosphere and calcined for 6 h to obtain intermediate I. (3) The intermediate I was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Mo-Rh / SiO2.

[0046] Comparative Example 5 The difference from Example 9 is that the proportion of molybdenum is too low.

[0047] (1) dispersing 0.4 g of nickel nitrate hexahydrate in 30 mL of water containing 0.4 g of disodium ethylenediaminetetraacetate to obtain a nickel precursor solution; (2) 5 g of carrier silica was dispersed in the nickel precursor solution and stirred for 10 h. After filtering, the solution was dried at 100 °C for 3 h to obtain intermediate I. (3) dispersing 0.2 g of ammonium molybdate tetrahydrate and 0.6 g of rhodium nitrate in 30 mL of 25% ammonia water to obtain a metal precursor solution; (4) Dispersing intermediate I in the metal precursor solution and stirring for 4 h, filtering, drying at 100 ° C for 3 h, and then heating from room temperature to 400 ° C at a heating rate of 5 ° C / min under argon atmosphere, and calcining for 6 h to obtain intermediate II; (5) The intermediate II was reduced in a mixed gas with a molar ratio of hydrogen to argon of 0.5:1, and the temperature was increased from room temperature to 500°C at a heating rate of 5°C / min for 6 hours to obtain a supported catalyst Ni-Mo-Rh / SiO2.

[0048] The catalytic activity of the supported catalysts of Examples 1-14 and Comparative Examples 1-5 was evaluated. The specific conditions were as follows: an ethanol solution containing 40 wt% of 2-methylglutaronitrile, a supported catalyst (15 wt% of 2-methylglutaronitrile), and sodium hydroxide (0.8 wt% of 2-methylglutaronitrile) were mixed and placed in an autoclave, hydrogen was introduced, a constant pressure of 4 MPa was maintained, the reaction temperature was 100° C., the reaction was stopped after 1 h, and the reaction product was analyzed.

[0049] Table 1 Catalytic activity of different supported catalysts As shown in Table 1, Examples 1-7 and Comparative Example 1 are catalysts composed of different carriers loaded with bimetallic components, among which the catalytic effect of CeO2-loaded catalysts loaded with Ni and Mo is poor. For the same SiO2 carrier, the synergistic catalytic effect of different bimetallic components will also be different, and Ni and Mo can synergistically exert better catalytic activity when SiO2 is used as a carrier. Comparative Examples 2-3 are catalysts prepared by different preparation methods, indicating that the failure to add disodium ethylenediaminetetraacetate and the failure to perform step-by-step loading will lead to poor catalytic effects.

[0050] Examples 8-11 are three-metal component catalysts prepared based on Example 5 with better catalytic effect. The data show that the catalytic effects of the three metal components are also different. Ni, Mo, and Rh metals can synergistically exert better catalytic activity when SiO2 is used as a carrier. Combined with Examples 13-14, it is also shown that the Ni-Mo-Rh / SiO2 supported catalyst can achieve a 2-methylglutaronitrile conversion rate of 100% and a 2-methylpentanediamine selectivity of more than 85%. Example 12 is a catalyst prepared by using Ni, Mo, and Rh metals with Al2O3 as a carrier. Compared with the catalyst prepared with SiO2 as a carrier, its catalytic effect is poor, but the 2-methylpentanediamine selectivity can also be greater than 80%.

[0051] Compared with Example 9, Comparative Example 4 did not add a nickel precursor, and added a metal precursor of the same mass as that of Example 5, but the conversion rate and selectivity of Comparative Example 4 were inferior to those of Example 5 and Example 9, indicating that the nickel precursor in the present invention will have a greater impact on the catalytic effect. In Comparative Example 5, a lower content of molybdenum precursor was used, and its selectivity was also reduced, indicating that the ratio of Ni, Mo, and Rh metals has a greater impact on the catalytic effect.

[0052] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the specification of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile, characterized in that: The steps include: (1) dispersing a nickel precursor in water containing disodium ethylenediaminetetraacetic acid to obtain a nickel precursor solution; (2) dispersing the support in the nickel precursor solution and stirring, and then filtering and drying to obtain intermediate I; (3) dispersing the metal precursor in aqueous ammonia to obtain a metal precursor solution; (4) Dispersing intermediate I in a metal precursor solution and stirring, then filtering and calcining in argon to obtain intermediate II; (5) The intermediate II is reduced in a mixture of hydrogen and argon to obtain a supported catalyst.

2. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that: The concentration of the nickel precursor in the nickel precursor solution is 0.01-0.05 g / mL, and the concentration of disodium ethylenediaminetetraacetate is 0.01-0.03 g / mL.

3. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that: The carrier is silicon dioxide, aluminum oxide, zirconium dioxide or ZSM-5 molecular sieve.

4. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to any one of claims 1 to 3, characterized in that: The mass ratio of the nickel precursor to the carrier is 5-30%.

5. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that: The total concentration of the metal precursor in the metal precursor solution is 0.01-0.05 g / mL; the mass concentration of the ammonia water is 20-25%.

6. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1 or 5, characterized in that: The mass ratio of the metal precursor to the carrier is 10-30%.

7. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1 or 5, characterized in that: The metal is one or more of ruthenium, rhodium, palladium, platinum and molybdenum.

8. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that: The calcination temperature is 300-600° C., and the calcination time is 3-9 hours.

9. The method for preparing a supported catalyst for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that: The molar ratio of hydrogen to argon is 0.5-1:

1.

10. The method for preparing a supported catalyst for 2-methylglutaronitrile hydrogenation reaction according to claim 1, 8 or 9, characterized in that: The reduction temperature is 300-600° C., and the reduction time is 3-9 hours.

Images