CN117753427A - Preparation method of a catalyst and its application - Google Patents

Abstract

The application discloses a preparation method and application of a catalyst, wherein the preparation method at least comprises the following steps: impregnating a carrier precursor into a mixture containing an active component precursor, an auxiliary agent precursor and a surfactant, drying and roasting to obtain the catalyst; the carrier precursor is at least one of alumina, magnesia and zirconia; the active component precursor is cobalt nitrate; the auxiliary agent precursor is lanthanum nitrate; the surfactant is L-arginine. Compared with a sample without L-arginine, the catalyst prepared by the invention has the advantages of higher acetonitrile selectivity, better stability and the like.

Description

Preparation method of a catalyst and its application

Technical field

The present application relates to a catalyst preparation method and its application, belonging to the technical field of chemical catalyst preparation.

Background technique

Acetonitrile is a widely used organic chemical raw material. In addition to being used as an extractant for extracting butadiene and isoprene from olefins and paraffins in petrochemical industry, it is also widely used in organic synthesis, medicine, Synthetic raw materials for fine chemicals such as pesticides, surfactants, and dyes, as well as mobile phase solvents for thin layer chromatography, paper chromatography, spectroscopy, polarography, and high-performance liquid chromatography (HPLC). The latest application is as a solvent for DNA synthesis and purification. Solvents for the synthesis of organic EL materials, cleaning solvents for electronic components such as chips, etc. These applications have high requirements on the purity of acetonitrile (≥99.9%). Acetonitrile with a purity of ≥99.9% is popular in the market and has a wide range of uses. It accounts for more than 66% of consumption.

Today, acetonitrile globally is mainly recycled as a crude by-product in the ammonia oxidation of propylene to produce acrylonitrile. However, only 20-30 kilograms of acetonitrile can be obtained from 1 ton of acrylonitrile, and the purity is not high. In particular, it is difficult to achieve a purity of ≥99.9%. Acetonitrile. The production of acetonitrile by ammonification and dehydrogenation of ethanol is a useful supplement to the source of acetonitrile. Compared with other methods for obtaining acetonitrile, the production of acetonitrile through ammoniation and dehydrogenation of ethanol has a simple process, low energy consumption, high atom utilization, high acetonitrile selectivity, few side reactions, low investment, and low operating costs, and can be industrialized.

The existing dehydrogenation amination of acetonitrile to acetonitrile has problems or defects such as low ethanol conversion rate, low acetonitrile selectivity, and poor catalyst stability.

Contents of the invention

This application aims to develop a highly selective and stable CoLa/Al catalyst for the dehydrogenation amination of ethanol to acetonitrile. This is the first report of this catalyst being used for the dehydrogenation amination of ethanol to acetonitrile.

Catalysts used in the ammoniation dehydrogenation of ethanol to produce acetonitrile are divided into two categories: dehydrogenation/hydrogenation catalysts and dehydration catalysts. Dehydrogenation/hydrogenation catalysts mostly use Ni, Cu, Fe, Cr, Co, Rh, Zr, Pb and Ag as the main active components, among which nickel is the most widely used. Usually, it is also necessary to add the second and third components as cocatalysts, such as Cu, Co, Na, Mg, Ca, etc. and rare earth elements. These catalysts show good catalytic activity under suitable reaction conditions. At the same time, the introduction of cocatalysts Product distribution can also be improved. Al ₂ O ₃ , SiO ₂ and HZSM-5 are often used as catalysts for dehydration condensation reactions because their surfaces have a certain acidity. Among them, Al ₂ O ₃ is an excellent catalyst for alcohol dehydration and is also a carrier widely used in metal carrier catalysts in industry.

According to one aspect of the present application, a preparation method of a catalyst is provided, which preparation method at least includes the following steps:

Impregnating the carrier precursor into a mixture containing active component precursor, auxiliary precursor and surfactant, drying and roasting to obtain the catalyst;

The carrier precursor is selected from at least one of alumina, magnesium oxide, and zirconium oxide;

The active component precursor is cobalt nitrate; the auxiliary precursor is lanthanum nitrate; and the surfactant is L-arginine.

Optionally, the mass of the surfactant is 1.0 to 3.0 wt% of the mass of the carrier precursor, and the mass of the surfactant is calculated as the mass of L-arginine.

Optionally, the upper limit of the quality of the surfactant is independently selected from 3.0wt%, 2.8wt%, 2.5wt%, 2.0wt%, 1.5wt%, and the lower limit is independently selected from 1.0wt% , 1.2wt%, 1.5wt%, 2.0wt%.

Optionally, the mass of the auxiliary precursor is 0.1 to 1.0 wt% of the mass of the carrier precursor, and the mass of the auxiliary precursor is calculated based on the mass of the lanthanum element in lanthanum nitrate.

Optionally, the upper limit of the mass of the auxiliary precursor is independently selected from the group consisting of 1.0wt%, 0.9wt%, 0.8wt%, 0.7wt%, 0.6wt%, and 0.5wt%, and the lower limit is independently selected from the group consisting of 1.0wt%, 0.9wt%, 0.8wt%, 0.5wt% Selected from 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%.

Optionally, the mass of the active component precursor is 5 to 30 wt% of the mass of the carrier precursor, and the mass of the active component precursor is calculated based on the mass of the cobalt element in cobalt nitrate.

Alternatively, the upper limit of the quality of the active component precursor is independently selected from 30wt%, 25wt%, 20wt%, 15wt%, 10wt%, and the lower limit is independently selected from 5wt%, 10wt%, 15wt%, 20wt%, 25wt%.

Optionally, the impregnation is vacuum equal volume impregnation; the impregnation time is 2 to 5 hours.

Optionally, the vacuum degree of the vacuum equal volume impregnation is 1 to 10 Pa.

Optionally, the impregnation time is selected from any value among 2h, 3h, 4h, 5h or a range value between any two points mentioned above.

Optionally, the drying temperature is 110-130°C; the drying time is 6-12 hours.

Optionally, the drying temperature is selected from any value among 110°C, 115°C, 120°C, 125°C, 130°C or a range value between any two points mentioned above.

Optionally, the drying time I is selected from any value among 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours or a range value between any two points mentioned above.

Optionally, the roasting temperature is 500-700°C; the roasting atmosphere is air atmosphere; and the roasting time is 2-4 hours.

Optionally, the calcining temperature is selected from any value among 500°C, 550°C, 600°C, 650°C, 700°C or any value between any two points mentioned above.

Optionally, the roasting time is selected from any value among 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours or a range value between any two points mentioned above.

According to another aspect of the present application, a catalyst is provided, which is prepared by the above-mentioned preparation method.

According to another aspect of the present application, a method for producing acetonitrile by dehydrogenation amination of ethanol is provided, which at least includes the following steps:

Mix the raw materials containing ethanol and ammonia, contact with the catalyst, and react to obtain a product containing acetonitrile;

The catalyst is selected from the catalyst prepared by the above-mentioned preparation method or at least one of the above-mentioned catalysts.

Optionally, the molar ratio of ammonia gas and ethanol is 8 to 2:1;

The mass space velocity of the ethanol is 0.1~1.0h ^-1 ;

The pressure of the reaction is 0.1~0.2MPa;

The temperature of the reaction is 400-470°C.

Optionally, the mass space velocity of the ethanol is selected from 0.1h ^-1 , 0.2h ^-1 , 0.3h ^-1 , 0.4h ^-1 , 0.5h -1 , 0.6h ^-1 , 0.7h ^-1 , ^0.8h Any value among ^-1 , 0.9h ^-1 , 1.0h ^-1 or the range value between any two points above.

Optionally, the pressure of the reaction is selected from any value among 0.1MPa, 0.15MPa, 0.2MPa or the range between any two points mentioned above.

Optionally, the temperature of the reaction is selected from any value among 400°C, 430°C, 450°C, 460°C, 470°C or a range value between any two points mentioned above.

The beneficial effects this application can produce include:

In the CoLa/Al catalyst prepared by the present invention, cobalt and lanthanum are evenly distributed in the catalyst and are not easy to agglomerate during the reaction process, thereby affecting the diffusion of reactants and products in the catalyst and the reaction performance of the catalyst.

The catalyst prepared by the invention can be used in the process of ethanol dehydrogenation amination to produce acetonitrile. Compared with the conventional CoLa/Al catalyst without adding L-arginine, the catalyst has higher acetonitrile selectivity and better stability. advantage.

Description of the drawings

Figure 1 shows the TEM and HRTEM images of the 20Co/Al ₂ O ₃ catalyst of the present application (A: TEM image of the 20Co/Al ₂ O ₃ catalyst; B: HRTEM image of the 20Co/Al ₂ O ₃ catalyst).

Figure 2 is the TEM and HRTEM images of the 20Co0.125La/Al ₂ O ₃ catalyst of the present application (C: TEM image of the 20Co0.125La/Al ₂ O ₃ catalyst; D: HRTEM image of the 20Co0.125La/Al ₂ O ₃ catalyst) .

Figure 3 is the TEM and HRTEM images of the 20Co0.25La/Al ₂ O ₃ catalyst of the present application (E: TEM image of the 20Co0.25La/Al ₂ O ₃ catalyst; F: HRTEM image of the 20Co0.25La/Al ₂ O ₃ catalyst) .

Figure 4 is the TEM and HRTEM images of the 20Co0.5La/Al ₂ O ₃ catalyst of the present application (G: TEM image of the 20Co0.5La/Al ₂ O ₃ catalyst; H: HRTEM image of the 20Co0.5La/Al ₂ O ₃ catalyst) .

Detailed ways

The present application will be described in detail below with reference to examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials in the examples of this application were all purchased through commercial channels.

In the examples of this application, Agilent 7890A GC analysis and FID detector were used, and hydrogen was used as the carrier gas.

In the examples of this application, the catalyst activity evaluation indicators, namely ethanol conversion rate, ammonia conversion rate and acetonitrile selectivity, are calculated based on mass:

Calculation of conversion rate of main reactants and selectivity of acetonitrile:

Ethanol conversion rate:

Ammonia conversion rate:

Acetonitrile selectivity:

In the above formula, m represents mass.

Comparative example 1

Dissolve 9.86g Co(NO ₃ ) ₂ ·6H ₂ O in 5.5g water, place 7.975g alumina in a closed container, use the vacuum equal volume impregnation method to suck the impregnation liquid into the carrier, evacuate to 10Pa, and then 25 The Co content in the catalyst Cat-A prepared by immersing at 120°C for 3 hours, drying in an oven at 120°C for 6 hours, and calcining at 700°C for 3 hours was 20wt%.

Comparative example 2

Dissolve 9.86g Co(NO ₃ ) ₂ ·6H ₂ O and 0.120g L-arginine in 5.5g water, place 7.975g alumina in a closed container, and use the vacuum equal volume impregnation method to suck the impregnation liquid into the carrier , the vacuum was set to 10 Pa, then immersed at 25°C for 3 hours, dried in an oven at 120°C for 6 hours, and calcined at 700°C for 3 hours. The Co content in the catalyst Cat-B prepared was 20wt%.

Comparative example 3

Dissolve 9.86g Co(NO ₃ ) ₂ ·6H ₂ O and 0.079g La(NO ₃ ) ₂ ·6H ₂ O in 5.5g water, place 7.975g alumina in a closed container, and use vacuum equal volume impregnation method to The impregnating liquid is sucked into the carrier, and the vacuum is 10Pa, then immersed at 25°C for 3 hours, dried in an oven at 120°C for 6 hours, and roasted at 700°C for 3 hours. The contents of Co and La in the prepared catalyst Cat-C are 20wt% and 0.25wt respectively. %.

Example 1

Dissolve 9.86g Co(NO ₃ ) ₂ ·6H ₂ O, 0.079g La(NO ₃ ) ₂ ·6H ₂ O, 0.120g L-arginine in 5.5g water, and place 7.975g alumina in a closed container , use the vacuum equal volume impregnation method to suck the impregnation liquid into the carrier, evacuate to 10 Pa, then impregnate at 25°C for 3 hours, dry in an oven at 120°C for 6 hours, and roast at 700°C for 3 hours. The obtained catalyst Cat-D contains Co and La The contents are 20wt% and 0.25wt% respectively.

Example 2

Dissolve 2.47g Co(NO ₃ ) ₂ ·6H ₂ O, 0.032g La(NO ₃ ) ₂ ·6H ₂ O, 0.08g L-arginine in 5.5g water, and place 7.975g alumina in a closed container , use the vacuum equal volume impregnation method to suck the impregnation liquid into the carrier, evacuate to 10 Pa, then impregnate at 25°C for 2 hours, dry in an oven at 130°C for 8 hours, and roast at 500°C for 4 hours. The obtained catalyst Cat-E contains Co and La The contents are 5wt% and 0.1wt% respectively.

Example 3

Dissolve 14.79g Co(NO ₃ ) ₂ ·6H ₂ O, 0.316g La(NO ₃ ) ₂ ·6H ₂ O, 0.240g L-arginine in 5.5g water, and place 7.975g alumina in a closed container , use the vacuum equal volume impregnation method to suck the impregnation liquid into the carrier, evacuate to 10 Pa, then impregnate at 25°C for 5 hours, dry in an oven at 110°C for 12 hours, and roast at 600°C for 2 hours. The obtained catalyst Cat-F contains Co and La The contents are 30wt% and 1.0wt% respectively.

Example 4

Dissolve 7.40g Co(NO ₃ ) ₂ ·6H ₂ O, 0.158g La(NO ₃ ) ₂ ·6H ₂ O, 0.160g L-arginine in 5.5g water, and place 7.975g alumina in a closed container , use the vacuum equal volume impregnation method to suck the impregnation liquid into the carrier, evacuate to 10 Pa, then impregnate at 25°C for 4 hours, dry at 110°C for 12 hours, and roast at 550°C for 4 hours. The obtained catalyst Cat-G contains Co and La The contents are 15wt% and 0.5wt% respectively.

Example 5

The reaction performance of the catalysts prepared in Comparative Examples 1 and 2 was evaluated in a fixed bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 430°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 3h. The reaction conditions are: temperature is 430°C, pressure is 0.1MPa, ethanol mass space velocity is 0.5h ^-1 , and the molar ratio of ammonia to ethanol is 6:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 6

The reaction performance of the catalyst prepared in Comparative Example 3 was evaluated in a fixed-bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 430°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 3h. The reaction conditions are: temperature is 430°C, pressure is 0.1MPa, ethanol mass space velocity is 0.5h ^-1 , and the molar ratio of ammonia to ethanol is 6:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 7

The reaction performance of the catalyst prepared in Comparative Example 3 was evaluated in a fixed-bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 430°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 98 hours. The reaction conditions are: temperature is 430°C, pressure is 0.1MPa, ethanol mass space velocity is 0.5h ^-1 , and the molar ratio of ammonia to ethanol is 6:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 8

The reaction performance of the catalyst prepared in Example 1 was evaluated in a fixed bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 430°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 3h. The reaction conditions are: temperature is 430°C, pressure is 0.1MPa, ethanol mass space velocity is 0.5h ^-1 , and the molar ratio of ammonia to ethanol is 6:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 9

The reaction performance of the catalyst prepared in Example 1 was evaluated in a fixed bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 430°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 98 hours. The reaction conditions are: temperature is 430°C, pressure is 0.1MPa, ethanol mass space velocity is 0.5h ^-1 , and the molar ratio of ammonia to ethanol is 6:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 10

The reaction performance of the catalyst prepared in Example 2 was evaluated in a fixed bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 430°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 26h. The reaction conditions are: temperature is 430°C, pressure is 0.2MPa, ethanol mass space velocity is 0.1h ^-1 , and the molar ratio of ammonia to ethanol is 2:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 11

The reaction performance of the catalyst prepared in Example 3 was evaluated in a fixed bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 470°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 4h. The reaction conditions are: temperature is 470°C, pressure is 0.1MPa, ethanol mass space velocity is 1.0h ^-1 , and the molar ratio of ammonia to ethanol is 8:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Example 12

The reaction performance of the catalyst prepared in Example 4 was evaluated in a fixed bed reactor through dehydrogenation amination of ethanol to acetonitrile. The diameter of the reactor is 14mm, and the catalyst loading is 4g. Under ammonia gas conditions, the temperature is raised to 400°C at a heating rate of 3°C/min, ethanol is introduced, and the reaction time is 20h. The reaction conditions are: temperature is 400°C, pressure is 0.1MPa, ethanol mass space velocity is 0.3h ^-1 , and the molar ratio of ammonia to ethanol is 4:1. The product was analyzed using an Agilent 7890A GC FID detector and hydrogen as the carrier gas. The specific evaluation results are shown in Table 1.

Table 1 Catalyst catalytic performance of ethanol dehydrogenation amination to acetonitrile reaction

Catalyst number Cat-A Cat-B Cat-C Cat-C Cat-D Cat-D Cat-E Cat-F Cat-G Reaction pressure (Mpa) 0.10 0.10 0.10 0.10 0.10 0.10 0.20 0.10 0.10 Ethanol gravimetric space velocity (h ^-1 ) 0.5 0.5 0.5 0.5 0.5 0.5 0.1 1.0 0.3 Reaction temperature (℃) 430 430 430 430 430 430 430 470 400 Amino alcohol molar ratio 6:1 6:1 6:1 6:1 6:1 6:1 2:1 8.0 4.0 Reaction time(h) 3 3 3 98 3 98 26 4 20 Ethanol conversion rate (%) 99.02 99.12 99.42 96.72 99.99 99.95 99.78 99.65 99.50 Acetonitrile selectivity (%) 78.60 79.20 82.10 77.66 84.40 84.20 84.13 84.74 85.13

The experimental results in Table 1 show that only adding L-arginine has little effect on the reaction performance on Co/Al ₂ O ₃ (Cat-A vs Cat-B), while the addition of lanthanum can promote the reaction on Co/Al ₂ O ₃ Performance (Cat-A vs Cat-C), compared with the alumina carrier-loaded cobalt lanthanum catalyst (Cat-C) without adding L-arginine during the catalyst preparation process, the oxidation rate prepared by adding L-arginine The acetonitrile selectivity and stability of the aluminum-supported cobalt lanthanum catalyst (Cat-D) are higher and the stability is better. Under the investigated reaction conditions, the reaction performance of the prepared Cat-E, Cat-F and Cat-G catalysts excellent.

Table 2 Structural properties of Co/Al ₂ O ₃ catalysts with different La contents

S _BET ^a (m ² /g) V ^b (cm ³ /g) 20Co/Al ₂ O ₃ 80 0.548 20Co0.125La/Al ₂ O ₃ 95 0.537 20Co0.25La/Al ₂ O ₃ 97 0.533 20Co0.50La/Al ₂ O ₃ 91 0.512

In Table 2, a refers to the specific surface area; b refers to the cumulative desorption pore volume. The experimental results from Table 2 show that the porous structure and specific surface area of La-modified Co/Al ₂ O ₃ samples were characterized using N ₂ physical adsorption. It can be seen that compared with the 20Co/Al ₂ O ₃ catalyst, the La modified catalyst has a larger specific surface area and smaller pore volume, which may be the result of better dispersion of crystallites on the catalyst surface. It can be seen that adding La to the Co/Al ₂ O ₃ catalyst can increase the specific surface area of the catalyst and thereby improve the reaction performance.

Figure 1 shows the TEM and HRTEM characterization of the Co/Al ₂ O ₃ catalyst (A is the TEM image of the 20Co/Al ₂ O ₃ catalyst; B is the HRTEM image of the 20Co/Al ₂ O ₃ catalyst). It can be seen that there are large particles of Co ₃ O ₄ or CoAl ₂ O ₄ in the 20Co/Al ₂ O ₃ catalyst. High-resolution transmission electron microscopy analysis identified the particles as Co ₃ O ₄ or CoAl ₂ O ₄ , corresponding to Co ₃ The (2 2 0) crystal plane of O ₄ or CoAl ₂ O ₄ .

Figure 2 shows the TEM and HRTEM characterization of the 20Co0.125La/Al ₂ O ₃ catalyst (C is the TEM image of the 20Co0.125La/Al ₂ O ₃ catalyst; D is the HRTEM image of the 20Co0.125La/Al ₂ O ₃ catalyst). It can be seen that after the addition of La, the particles of Co ₃ O ₄ or CoAl ₂ O ₄ in the catalyst appear smaller than those in 20Co/Al ₂ O ₃ , which shows that the addition of La makes the active components in the catalyst more dispersed. good. At the same time, high-resolution transmission electron microscopy analysis identified the particles as still Co ₃ O ₄ or CoAl ₂ O ₄ , which is consistent with the 20Co/Al ₂ O ₃ catalyst and corresponds to the (2 2 0) crystal plane of Co ₃ O ₄ or CoAl ₂ O ₄ .

Figure 3 shows the TEM and HRTEM characterization of the 20Co0.25La/Al ₂ O ₃ catalyst (E is the TEM image of the 20Co0.25La/Al ₂ O ₃ catalyst; F: is the HRTEM image of the 20Co0.25La/Al ₂ O ₃ catalyst). It can be seen that the particles of Co ₃ O ₄ or CoAl ₂ O ₄ in the catalyst after La addition appear smaller than those in 20Co/Al ₂ O ₃ , and in these four catalysts when the La addition amount is 0.25, Co ₃ O ₄ or CoAl ₂ O ₄ has the smallest particles and the best dispersion of active components. High-resolution transmission electron microscopy analysis identified the particles as Co ₃ O ₄ or CoAl ₂ O ₄ , corresponding to the (2 2 0) crystal plane of Co ₃ O ₄ or CoAl ₂ O ₄ .

Figure 4 shows the TEM and HRTEM characterization of the 20Co0.5La/Al ₂ O ₃ catalyst (G is the TEM image of the 20Co0.5La/Al ₂ O ₃ catalyst; H is the HRTEM image of the 20Co0.5La/Al ₂ O ₃ catalyst). It can be seen that the particles of Co ₃ O ₄ or CoAl ₂ O ₄ in the catalyst appear smaller than those in 20Co/Al ₂ O ₃ after the addition of La, and the active components are well dispersed. High-resolution transmission electron microscopy analysis identified the particles as Co ₃ O ₄ or CoAl ₂ O ₄ , corresponding to the (1 1 1) crystal plane of Co ₃ O ₄ or CoAl ₂ O ₄ .

The above are only a few embodiments of the present application, and are not intended to limit the present application in any way. Although the present application is disclosed as above with preferred embodiments, they are not intended to limit the present application. Any skilled person familiar with this field, Without departing from the scope of the technical solution of this application, slight changes or modifications made using the technical content disclosed above are equivalent to equivalent implementation examples and fall within the scope of the technical solution.

Claims (10)

1. A method for preparing a catalyst, characterized in that the preparation method at least includes the following steps: Impregnating the carrier precursor into a mixture containing active component precursor, auxiliary precursor and surfactant, drying and roasting to obtain the catalyst; The carrier precursor selects at least one of alumina, magnesium oxide, and zirconium oxide; The active component precursor is cobalt nitrate; the auxiliary precursor is lanthanum nitrate; and the surfactant is L-arginine. 2. The preparation method according to claim 1, characterized in that the mass of the surfactant is 1.0-3.0wt% of the mass of the carrier precursor, and the mass of the surfactant is expressed as the mass of L-arginine. count. 3. The preparation method according to claim 1, characterized in that the quality of the auxiliary precursor is 0.1 to 1.0 wt% of the quality of the carrier precursor, and the quality of the auxiliary precursor is expressed as the lanthanum element in lanthanum nitrate. quality meter. 4. The preparation method according to claim 1, characterized in that the mass of the active component precursor is 5-30 wt% of the mass of the carrier precursor, and the mass of the active component precursor is expressed as cobalt in cobalt nitrate. Mass meter for elements. 5. The preparation method according to claim 1, characterized in that the impregnation is vacuum equal volume impregnation; the impregnation time is 2 to 5 hours. 6. The preparation method according to claim 5, characterized in that the vacuum degree of the vacuum equal volume impregnation is 1 to 10 Pa. 7. The preparation method according to claim 1, characterized in that the drying temperature is 110-130°C; The drying time is 6 to 12 hours. 8. The preparation method according to claim 1, characterized in that the roasting temperature is 500-700°C; the roasting atmosphere is air atmosphere; The roasting time is 2 to 4 hours. 9. A method for producing acetonitrile through dehydrogenation amination of ethanol, characterized in that it at least includes the following steps: Mix the raw materials containing ethanol and ammonia, contact with the catalyst, and react to obtain a product containing acetonitrile; The catalyst is selected from at least one catalyst prepared by the preparation method described in any one of claims 1 to 8. 10. The application according to claim 9, characterized in that the molar ratio of ammonia gas and ethanol is 8 to 2:1; The mass space velocity of the ethanol is 0.1~1.0h ^-1 ; The pressure of the reaction is 0.1~0.2MPa; The temperature of the reaction is 400-470°C.