CN109718780B

CN109718780B - Preparation method of catalyst for preparing trichlorosilane through silicon tetrachloride hydrogenation

Info

Publication number: CN109718780B
Application number: CN201711019751.8A
Authority: CN
Inventors: 王永林; 张�成; 关月明; 杨刚
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2017-10-27
Filing date: 2017-10-27
Publication date: 2022-01-04
Anticipated expiration: 2037-10-27
Also published as: CN109718780A

Abstract

The invention discloses a preparation method of a catalyst for preparing trichlorosilane by hydrogenation of silicon tetrachloride. The method comprises the steps of carrying out primary acidification treatment on a silicon source acidic solution, adding an acidic solution containing an active component and an auxiliary agent to further acidify the silicon source, and adding pseudo-boehmite and a curing agent to prepare a slurry; the slurry is sprayed and formed, and then washed, dried and roasted to prepare the catalyst of the invention. The catalyst prepared by the method has good activity and stability, good mechanical strength and wear resistance, and simultaneously increases the impact and friction capacity of the catalyst with silicon powder in the use process of a fluidized bed, and avoids the phenomenon of 'running loss' in the use process of the catalyst.

Description

Preparation method of catalyst for preparing trichlorosilane through silicon tetrachloride hydrogenation

Technical Field

The invention relates to a preparation method of a hydrogenation catalyst, in particular to a preparation method of a catalyst for preparing trichlorosilane through hydrogenation of silicon tetrachloride.

Background

With the gradual exhaustion of fossil energy and the increasing aggravation of environmental pollution problems, it is urgent to search for a pollution-free renewable energy source. Solar energy is the most abundant renewable energy, and compared with other energy sources, the solar energy has the advantages of cleanliness, safety, universality, resource sufficiency, potential economy and the like. The solar energy is fully utilized, and the method has important economic and strategic significance for realizing sustainable development in a low-carbon mode.

In recent years, the yield of polycrystalline silicon is increased sharply, and the main production processes of polycrystalline silicon comprise an improved siemens method, a silane method and a fluidized bed method, wherein the improved siemens method is the mainstream technology for producing polycrystalline silicon at present, is the most mature, minimum investment risk and easiest expansion process for producing polycrystalline silicon, and the produced polycrystalline silicon accounts for 70-80% of the total world production. At present, the polysilicon factory of the Siemens process adopts the synthesis of silicon powder and hydrogen chloride to prepare trichlorosilane. In the synthesized product, trichlorosilane accounts for 80 percent, and silicon tetrachloride accounts for 20 percent. In the process of reducing trichlorosilane at 1100 ℃ and decomposing to generate high-purity polysilicon products, the by-product silicon tetrachloride per ton of the products is nearly 6 t. Therefore, the silicon tetrachloride of the byproduct of each ton of polysilicon product in a polysilicon plant adopting the Siemens process is about 10 t.

Silicon tetrachloride is a toxic and harmful gas, and if the toxic and harmful gas is discharged randomly without treatment, the silicon tetrachloride can be combined with water vapor in the atmosphere to generate hydrogen chloride gas, so that the environment is seriously polluted, in addition, the resource waste is also caused, and the production cost of enterprises is increased. How to safely treat silicon tetrachloride becomes a bottleneck restricting the development of polysilicon, and finding a way for effectively treating silicon tetrachloride is a problem to be solved urgently at present. The silicon tetrachloride is reasonably recycled, so that the environmental pollution is reduced, the production cost of enterprises is reduced, and the sustainable development of polycrystalline silicon production enterprises is facilitated.

The silicon tetrachloride recycling mainly has two directions, namely, silicon tetrachloride is used as a raw material to produce other chemical products, including fumed silica, organic silicon products, optical fiber production and the like; and secondly, the silicon tetrachloride is hydrogenated and converted into trichlorosilane in the production process of the polysilicon for recycling. The former has limited demand, can not consume a large amount of silicon tetrachloride as a byproduct, and research focuses on recycling the silicon tetrachloride. The silicon tetrachloride hydrogenation technology mainly comprises a thermal hydrogenation method, a cold hydrogenation method, a plasma hydrogenation method and a catalytic hydrogenation method. The thermal hydrogenation method is to hydrogenate the silicon tetrachloride to trichlorosilane at 1250 ℃, the product is easy to separate, but the reaction temperature is high, and the energy consumption is large; the cold hydrogenation method is to react silicon tetrachloride, silicon powder and hydrogen in a fluidized bed reactor at 400 ℃ to produce trichlorosilane, wherein the reaction temperature is relatively low, but the product is difficult to separate, the conversion rate is low, and the reactor is seriously abraded; the plasma hydrogenation method is carried out under the conditions of normal pressure and 3000 ℃, the highest conversion rate of the silicon tetrachloride can reach 74 percent, but the energy consumption is very high, and the industrialization is difficult to realize; the catalytic hydrogenation method is characterized in that a catalyst is added on the basis of a thermal hydrogenation process, namely, silicon powder, hydrogen and silicon tetrachloride are used as raw materials, and a mixture of trichlorosilane, dichlorosilane and the like is generated under the conditions of the existence of the catalyst and the reaction temperature of 500-550 ℃ and the reaction pressure of 2.0-3.0 MPa.

Because the catalytic hydrogenation of silicon tetrachloride is carried out at a relatively low reaction temperature and reaction pressure, and meanwhile, the product is easy to separate and maintains a high conversion rate, the method becomes an ideal way for recovering silicon tetrachloride, and therefore, the selection and preparation of a catalyst in the catalytic hydrogenation process of silicon tetrachloride are particularly important.

CN102626630A and CN105967189A separate a method for preparing a trichlorosilane catalyst by hydrogenating silicon tetrachloride. The method comprises the steps of contacting soluble nickel salt, soluble salt compounds of metal M, a silicon source capable of providing silicon dioxide and a precipitator capable of precipitating nickel and/or metal M ions in a solvent, filtering a product obtained by the contact, and drying and roasting the obtained solid in sequence to obtain the catalyst. Wherein M is selected from one or more of IB, IIB, IIA and group VIII metals other than Ni. However, the catalyst prepared by the method is powdery, and is easy to run out when used in a fluidized bed, so that the loss and the activity reduction of the catalyst are caused, and meanwhile, the specific surface area of the catalyst is not given in the patent, and the activity and the stability of the catalyst are lower.

CN105536789A discloses a method for preparing a catalyst for trichlorosilane by hydrodechlorination of silicon tetrachloride. The method directly mixes the calcined amorphous silica-alumina powder with a certain amount of cuprous chloride, carries out high-temperature treatment in an inert atmosphere, and cools the product to obtain the finished catalyst. Although the preparation method is simple and low in preparation cost, the activity of the obtained catalyst is low.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of a catalyst for preparing trichlorosilane by hydrogenating silicon tetrachloride. The catalyst prepared by the method has centralized particle size distribution, higher activity, active metal dispersibility and wear resistance, meets the requirement of preparing trichlorosilane by hydrogenating silicon tetrachloride of an industrial fluidized bed, and has higher activity and stability in the process of preparing trichlorosilane by hydrogenating silicon tetrachloride.

The invention provides a preparation method of a catalyst for preparing trichlorosilane by hydrogenation of silicon tetrachloride, which comprises the following steps:

(1) adding an acidic solution into a silicon source;

(2) adding an acidic solution containing a group VIII metal and an auxiliary component M to the mixture obtained in step (1);

(3) adding pseudo-boehmite, a curing agent and deionized water into the mixture obtained in the step (2) to prepare slurry;

(4) carrying out spray forming on the slurry obtained in the step (3) to obtain spherical gel;

(5) and (4) washing, drying and roasting the spherical gel obtained in the step (4) to obtain the catalyst.

In the method, the silicon source in the step (1) is water glass and/or silica sol, and the mass content of the silicon source is 20-40% by weight, preferably 25-35% by weight based on silicon oxide; the acid solution is preferably an organic acid solution, and the mass concentration of the organic acid solution is 65-85%, preferably 70-80%. The organic acid is selected from one or more of formic acid, acetic acid and citric acid. The addition amount of the acidic solution is such that the pH value of the system is 4.0-7.0, preferably 5.5-6.5.

In the method of the present invention, the group VIII metal in step (2) is Ni and/or Co, preferably Ni. And M is one or more of Cu, Fe, Cr, Mg, Ba and the like. The assistant component M preferably adopts M1 and M2, wherein M1 is one or more of Cu, Mg and Fe, preferably one or more of Cu and Mg, and M2 is one or more of Cr and Ba, preferably Ba. The molar ratio of the added M1 to M2 calculated by oxide is 1: 10-10: 1, preferably 2: 1-8: 1.

in the method, in the acidic solution containing the VIII group metal and the assistant component M in the step (2), the VIII group metal source and the assistant component M source are inorganic salts, can be selected from one or more of nitrate, sulfate and chloride, and preferably are nitrate. And (2) adding an acidic solution containing a group VIII metal and an auxiliary component M into the mixture obtained in the step (1) to reduce the pH value of the system to 1.0-4.0, preferably 2.5-3.5, and at least reducing the pH value of the mixture obtained in the step (1) by 1.0.

In the method, the dry basis weight of the pseudo-boehmite in the step (3) is more than 70 percent, and the pseudo-boehmite is converted into gamma-Al by high-temperature roasting₂O₃The latter properties are as follows: the pore volume is more than 0.95mL/g, the preferable pore volume is 0.95-1.2 mL/g, and the specific surface area is 330m²More than g, preferably the specific surface area is 330-400 m²(ii) in terms of/g. The curing agent is one or more of urea and organic ammonium salt. The organic ammonium salt is hexamethinetetrammonium. The molar ratio of the addition amount of the curing agent to the addition amounts of the active metal and the auxiliary agent in terms of oxides is 0.5: 1.0-1.2: 1.0, preferably 0.6: 1.0-1.0: 1.0. the total mass of the silicon source in the slurry obtained in the step (3) calculated by silicon dioxide, the pseudo-boehmite calculated by alumina, the active component and the auxiliary component calculated by oxide accounts for 25-45%, preferably 30-35% of the total weight of the slurry.

In the method of the present invention, the spray forming in the step (4) is pressure type spray forming. The spray forming is carried out in a spray forming tower, the diameter of a spray nozzle is 0.3-1.2 mm, preferably 0.6-1.0 mm, the spraying pressure is 0.5-1.5 MPa, the formed product sprayed out of the spray nozzle is in countercurrent contact with a hot gas medium, the temperature of the hot gas medium is 70-200 ℃, preferably 90-120 ℃, the gas medium adopts ammonia-containing gas, and can adopt air containing ammonia, wherein NH is₃The volume fraction of (A) is 5% -10%.

In the method, the washing in the step (5) is to wash the spherical gel to be neutral by using deionized water; the drying conditions are as follows: drying at 80-200 ℃ for 4-10 hours, preferably at 100-150 ℃ for 6-8 hours; the roasting conditions are as follows: roasting at 500-900 ℃ for 3-8 hours, preferably at 550-700 ℃ for 3-5 hours.

The materials added in the steps (1) to (3) of the preparation method of the invention enable the obtained catalyst to meet the following requirements: based on the weight of the catalyst, the content of alumina is 10 to 20 percent, the content of silica is 14.5 to 25 percent, the content of active components is 55 to 75 percent calculated by the oxide of the VIII group metal, and the content of auxiliary components is 0.5 to 2.0 percent calculated by the oxide of the metal M.

The method of the inventionThe prepared catalyst has the following properties: specific surface area > 60m²Per g, preferably 80 to 150m²(ii) in terms of/g. In the present invention, the specific surface area is measured by a low-temperature liquid nitrogen adsorption method.

The attrition rate of the catalyst prepared by the process of the invention is < 2.0 wt.%, preferably < 1.5 wt.%. In the invention, the abrasion rate is measured by a fluidized abrasion strength tester.

The catalyst prepared by the process of the invention has the following particle size distribution (in volume fraction): the content of particles with the particle size of less than 150mm is less than 10%, preferably less than 8%; 75-95%, preferably 80-92% of particles with the particle diameter of 150-500 mm, and less than 15%, preferably less than 12% of particles with the particle diameter of more than 500 mm. In the present invention, the particle size is measured using a laser particle sizer.

Compared with the prior art, the method has the following advantages:

1. the catalyst adopts the silicon-aluminum composite material as the carrier component, under the synergistic effect of the auxiliary agent, the active metal component and the carrier component, the mechanical strength and the wear resistance of the catalyst are improved, the dispersion degree of the active metal and the auxiliary agent component is further improved, the activity and the stability of the catalyst are obviously improved, the application of the catalyst in a fluidized bed process is facilitated, the impact and the friction capacity of the catalyst and silicon powder are increased, and the phenomenon of 'running loss' in the use process of the catalyst is avoided.

2. The catalyst of the invention preferably adopts two assistants of M1 and M2, so that the dispersion degree of active metals and the wear resistance of the catalyst are further improved by the synergistic effect of the two assistants, and the activity stability of the catalyst are further improved.

3. In the preparation method of the catalyst, the acidic solution is added into a silicon source, the acidic solution containing the VIII family metal and the auxiliary agent component M is added, then the pseudo-boehmite, the curing agent and the water are added to form the slurry, and the spray forming mode is adopted to enable the components to act synergistically, so that the prepared catalyst has better strength and larger specific surface area, more reaction sites are provided for reactants, and the activity of the catalyst can be effectively improved.

4. In the preparation method of the catalyst, the organic acid solution is preferably added into the silicon source, and then the inorganic hydrochloric acid solution of the VIII family metal and the auxiliary agent component M is added, so that the pore structure of the catalyst is favorably maintained, the specific surface area of the catalyst is further improved, the dispersion of the active metal is promoted, and the activity stability of the catalyst are favorably improved.

5. In the preparation method of the catalyst, the spray forming adopts pressure forming and the ammonia-containing gas is in countercurrent contact with the formed product, so that the formed product is cured under the dual actions of external ammonia gas and internal curing agent pyrolysis to form spherical gel, and the catalyst not only has good and uniform spherical shape and good wear resistance, but also has good pore structure, is beneficial to the reaction of producing trichlorosilane by silicon tetrachloride hydrogenation, and has higher activity and stability.

6. The preparation method of the catalyst integrates the molding of the catalyst and the loading of the active metal, thereby shortening the preparation process of the catalyst.

Detailed Description

The technical solution of the present invention is further illustrated by the following examples, but is not limited to the following examples. In the present invention, wt% is a mass fraction.

Example 1

Adding 56.8g of water glass with the mass content of 35 percent calculated by silicon oxide into a preparation tank, starting a stirring device, slowly adding 75 percent citric acid solution to ensure that the pH value of the acidified water glass solution is 5.5, adding 259.6g of nickel nitrate hexahydrate, 1.85g of copper nitrate trihydrate and 1.05g of barium nitrate into the preparation tank after uniform mixing, stirring until the nickel nitrate hexahydrate, the 1.85g of copper nitrate trihydrate and the 1.05g of barium nitrate are dissolved to ensure that the pH value of the solution is 2.5, adding 1.06mL/g of pore volume into the solution, and ensuring that the specific surface area is 342m²24.1g of pseudo-boehmite with a dry basis of 70wt%, adding 49.6g of curing agent urea after uniformly stirring, adding deionized water after the urea is completely dissolved, enabling the total mass of a silicon source in the slurry in the preparation tank, calculated as silicon dioxide, the pseudo-boehmite, an active component and an auxiliary agent component, calculated as alumina, to account for 33% of the total weight of the slurry, and keeping the slurry to be slurry with certain fluidityAnd (4) liquid.

And (2) spray-forming the slurry with certain fluidity in a spray forming tower, setting the diameter of a nozzle to be 0.8mm, setting the drying temperature in the spray drying tower to be 100 ℃, and using hot air containing ammonia as a drying medium, wherein the volume fraction of the ammonia is 8%, and the flow direction of the drying medium in the spray forming tower is from bottom to top, so that the materials are cured and shrunk to obtain the spherical gel.

The resulting spherical gel was washed with deionized water to pH 7.0, dried at 130 ℃ for 8 hours, and calcined at 550 ℃ for 3 hours to obtain catalyst A of the present invention, the catalyst properties are shown in Table 1, and the catalyst evaluation results are shown in Table 2.

Example 2

The preparation procedure was as in example 1, the citric acid was changed to acetic acid, the curing agent was changed to hexamethynyltetramine 105.1g, the amount of copper nitrate trihydrate added was changed to 2.75g, and the amount of barium nitrate added was changed to 0.49g, to prepare catalyst B of the present invention, the properties of which are shown in Table 1, and the catalyst evaluation results are shown in Table 2.

Example 3

The procedure of preparation was as in example 1, the nozzle diameter was changed to 1.0mm, the drying temperature in the spray drying tower was 120 ℃, catalyst C of the present invention was prepared, the properties are shown in table 1, and the catalyst evaluation results are shown in table 2.

Example 4

The preparation process was as in example 1, except that cobalt nitrate hexahydrate was added instead of nickel nitrate hexahydrate, and the amount of water glass added was 43.83g, to prepare catalyst D of the present invention, the properties of which are shown in Table 1, and the evaluation results of which are shown in Table 2.

Example 5

The procedure is as in example 1, the copper nitrate trihydrate added is replaced by magnesium nitrate hexahydrate, the amount of barium nitrate added is 1.62g, catalyst E according to the invention is prepared, the properties are shown in Table 1, and the catalyst evaluation results are shown in Table 2.

Example 6

The preparation process was as in example 1, the first acidification PH of the silicon source was adjusted to 6.5, the second acidification PH was 3.0, the catalyst calcination temperature was changed to 700 ℃, the amount of copper nitrate trihydrate was changed to 2.84g, and the amount of barium nitrate was changed to 0.42g, to prepare catalyst F of the present invention, the properties are shown in table 1, and the catalyst evaluation results are shown in table 2.

Example 7

The procedure is as in example 1 except that no auxiliary barium nitrate is added to prepare catalyst G of the present invention, the properties are shown in Table 1, and the evaluation results are shown in Table 2.

Example 8

The procedure is as in example 1, except that no copper nitrate adjuvant is added, catalyst H according to the invention is prepared, the properties are shown in Table 1, and the evaluation results are shown in Table 2.

Example 9

The procedure is as in example 1, the citric acid solution at the first acidification is changed to a nitric acid solution of 62% by mass concentration, to obtain comparative catalyst I, the properties of which are shown in Table 1, and the evaluation results of which are shown in Table 2.

Example 10

The procedure is as in example 1, the drying medium is hot air and no ammonia is present, giving catalyst J, the catalyst properties are shown in Table 1 and the catalyst evaluation results are shown in Table 2.

Comparative example 1

The procedure is as in example 1 except that no pseudoboehmite is added and the pseudoboehmite is replaced by water glass to give comparative catalyst K, the catalyst properties are shown in Table 1 and the catalyst evaluation results are shown in Table 2.

Comparative example 2

The catalyst prepared by the preparation method of example 2 in CN105967189A was used to obtain comparative catalyst L, the properties of which are shown in table 1, and the evaluation results of which are shown in table 2. The preparation process comprises the following steps:

dissolving 42.5 kg of nickel chloride hexahydrate and 18 kg of copper nitrate trihydrate into deionized water to prepare 500L of solution, adding 80 kg of silica sol with the solid content of 20 weight percent into the mixed salt solution, uniformly mixing to obtain slurry, and adjusting the pH value of the slurry to be 5 by using a 5 weight percent sodium hydroxide aqueous solution; dissolving 40 kg of ammonium carbonate with 400L of deionized water to obtain an ammonium carbonate aqueous solution;

the slurry and an aqueous ammonium carbonate solution were put into a 2000-liter reaction vessel to contact each other at a temperature of 80 ℃ and a pH was adjusted with a 5wt% aqueous sodium hydroxide solution so that the contact pH was 7, and after contacting for 4 hours, a solid was obtained by filtration, and after drying the solid, it was calcined at 500 ℃ for 6 hours in a muffle furnace to obtain a catalyst L.

TABLE 1 Properties of the examples and comparative catalysts

Catalyst numbering	A	B	C	D	E	F
							Catalyst shape	Microspheres	Microspheres	Microspheres	Microspheres	Microspheres	Microspheres
Specific surface area, m²/g	88	82	89	81	92	80
							Abrasion of catalyst, wt%	0.80	0.79	0.80	0.83	0.81	0.81
Catalyst composition in wt%
							Al₂O₃	16.72	16.83	16.78	16.74	16.82	16.65
SiO₂	19.40	19.81	19.62	15.32	19.86	19.61
							NiO or CoO	62.66	62.15	62.39	66.74	62.09	62.55
M1 oxide	0.62	0.88	0.61	0.61	0.29	0.95
							M2 oxide	0.60	0.33	0.60	0.59	0.94	0.24
Particle size distribution of%
							<150μm	2.7	3.0	2.0	3.1	2.4	2.4
150～500μm	90.3	89.8	89.0	90.1	90.1	89.8
							>500μm	7.0	7.2	9.0	6.8	7.5	7.8

TABLE 1 Properties of the examples and comparative catalysts

Catalyst numbering	G	H	I	J	K	L
							Catalyst shape	Microspheres	Microspheres	Microspheres	Microspheres	Microspheres	Amorphous form
Specific surface area, m²/g	87	86	74	61	34	31
							Abrasion of catalyst, wt%	0.83	0.77	0.90	3.6	2.3	4.8
Catalyst composition in wt%
							Al₂O₃	16.82	16.82	16.72	16.72	0	0
SiO₂	19.52	19.53	19.40	19.40	36.12	49.7
							NiO or CoO	63.04	63.05	62.66	62.66	62.66	40.2
M1 oxide	0.62	-	0.62	0.62	0.62	10.1
							M2 oxide	-	0.60	0.60	0.60	0.60
Particle size distribution of%
							<150μm	1.9	2.0	3.4	15.2	2.8	-
150～500μm	88.7	88.7	88.4	81.4	89.9	-
							>500μm	9.4	9.3	8.2	3.4	7.3	-

The catalyst activity evaluation was carried out by using a fixed bed evaluation apparatus, the catalyst was packed in an amount of 10g, the reaction pressure was 1.2MPa, and the reaction pressure was H₂/SiCl₄(molar ratio) 25, silicon powder/SiCl₄(molar ratio) is 10, and gas hourly space velocity is 30000h^-1The reaction temperatures were 400 ℃ and 450 ℃ respectively, and the evaluation results are shown in Table 2.

TABLE 2 evaluation results of catalyst Activity

Catalyst numbering	Conversion,% (400 ℃, 10 hours)	Conversion,% (400 ℃, 150 hours)	Conversion,% (450 ℃, 10 hours)	Conversion,% (450 ℃, 150 hours)
					A	28.9	28.7	37.5	37.3
B	29.2	29.1	37.8	37.7
					C	28.3	28.0	36.5	36.1
D	28.5	28.1	37.0	36.0
					E	28.2	27.9	36.4	36.0
F	29.0	28.8	37.4	37.3
					G	27.7	27.0	36.2	35.6
H	27.4	27.1	36.0	35.7
					I	28.0	27.6	36.3	35.9
J	26.4	22.5	32.9	30.7
					K	22.3	21.6	31.4	30.9
L	22.5	21.2	31.5	29.9

Claims

1. A preparation method of a catalyst for preparing trichlorosilane by hydrogenating silicon tetrachloride is characterized by comprising the following steps:

(1) adding an acidic solution into a silicon source;

(2) adding an acidic solution containing a VIII group metal and an auxiliary component M into the mixture obtained in the step (1), wherein M is one or more of Cu, Fe, Cr, Mg and Ba;

(3) adding pseudo-boehmite, a curing agent and deionized water into the mixture obtained in the step (2) to prepare slurry, wherein the curing agent is one or more of urea and organic ammonium salt, and the organic ammonium salt is hexamethylenetetramine;

2. The method of claim 1, wherein: in the step (1), the silicon source is water glass and/or silica sol, the mass content of the silicon source is 20-40% in terms of silicon oxide, the acidic solution is an organic acid solution, the mass concentration of the acidic solution is 65-85%, and the organic acid is selected from one or more of formic acid, acetic acid and citric acid.

3. The method of claim 2, wherein: the silicon source accounts for 25-35% of the mass content of the silicon oxide, and the mass concentration of the acidic solution is 70-80%.

4. The method of claim 1, wherein: the adding amount of the acidic solution is such that the pH value of the system is 4.0-7.0.

5. The method of claim 4, wherein: the adding amount of the acidic solution is such that the pH value of the system is 5.5-6.5.

6. The method of claim 1, wherein: and (3) the group VIII metal in the step (2) is Ni and/or Co.

7. The method of claim 6, wherein: the group VIII metal is Ni.

8. The method of claim 1, wherein: the auxiliary component M adopts M1 and M2, wherein M1 is one or more of Cu, Mg and Fe, M2 is one or more of Cr and Ba, and the molar ratio of the added M1 to the added M2 calculated by oxides is 1: 10-10: 1.

9. the method of claim 8, wherein: the M1 is one or more of Cu and Mg, the M2 is Ba, and the molar ratio of the added M1 to the added M2 calculated by oxides is 2: 1-8: 1.

10. the method of claim 1 or 4, wherein: in the acidic solution containing the group VIII metal and the auxiliary component M in the step (2), the group VIII metal source and the auxiliary component M source are inorganic salts, the inorganic salts are one or more of nitrate, sulfate and chloride, the acidic solution containing the group VIII metal and the auxiliary component M is added into the mixture obtained in the step (1), the pH value of the system is reduced to 1.0-4.0, and the pH value of the mixture obtained in the step (1) is at least reduced by 1.0.

11. The method of claim 10, wherein: the inorganic salt is nitrate; and (2) adding an acidic solution containing a group VIII metal and an auxiliary component M into the mixture obtained in the step (1), and then reducing the pH value of the system to 2.5-3.5.

12. The method of claim 1, wherein: the dry basis weight of the pseudo-boehmite in the step (3) is more than 70 percent, and the pseudo-boehmite is converted into gamma-Al by high-temperature roasting₂O₃The latter properties are as follows: the specific surface area is 330m, the pore volume is more than 0.95mL/g²More than g.

13. The method of claim 12, wherein: step (3) the pseudo-thin filmThe diaspore is converted into gamma-Al by high-temperature roasting₂O₃The latter properties are as follows: the pore volume is 0.95-1.2 mL/g, the specific surface area is 330-400 m²/g。

14. The method of claim 1, wherein: the molar ratio of the addition amount of the curing agent to the addition amounts of the VIII family metal and the auxiliary agent in terms of oxides is 0.5: 1.0-1.2: 1.0.

15. the method of claim 14, wherein: the molar ratio of the addition amount of the curing agent to the addition amounts of the VIII family metal and the auxiliary agent in terms of oxides is 0.6: 1.0-1.0: 1.0.

16. the method of claim 1, wherein: the total mass of the silicon source in the slurry obtained in the step (3) is calculated by silicon dioxide, the pseudo-boehmite is calculated by alumina, and the active component and the auxiliary component are calculated by oxide and account for 25-45% of the total mass of the slurry.

17. The method of claim 16, wherein: the total mass of the silicon source in the slurry obtained in the step (3) is calculated by silicon dioxide, the pseudo-boehmite is calculated by alumina, and the active component and the auxiliary component are calculated by oxide and account for 30-35% of the total mass of the slurry.

18. The method of claim 1, wherein: the spray forming in the step (4) is pressure type spray forming; the spray forming is carried out in a spray forming tower, the diameter of a nozzle is 0.3-1.2 mm, the spraying pressure is 0.5-1.5 MPa, the formed product sprayed out of the nozzle is in countercurrent contact with a hot gas medium, the temperature of the hot gas medium is 70-200 ℃, the gas medium is ammonia-containing gas, wherein NH is₃The volume fraction of (A) is 5% -10%.

19. The method of claim 18, wherein: the diameter of the nozzle is 0.6 mm-1.0 mm, the temperature of the hot gas medium is 90-120 ℃, and the gas medium is air containing ammonia.

20. The method of claim 1, wherein: the drying conditions in the step (5) are as follows: drying for 4-10 hours at 80-200 ℃, wherein the roasting conditions are as follows: roasting for 3-8 hours at 500-900 ℃.

21. The method of claim 20, wherein: the drying conditions in the step (5) are as follows: drying for 6-8 hours at 100-150 ℃, wherein the roasting conditions are as follows: roasting at 550-700 ℃ for 3-5 hours.

22. The method of claim 1, wherein: the materials added in the steps (1) to (3) enable the obtained catalyst to meet the following requirements: based on the weight of the catalyst, the content of alumina is 10 to 20 percent, the content of silica is 14.5 to 25 percent, the content of active components is 55 to 75 percent calculated by the oxide of the VIII group metal, and the content of auxiliary components is 0.5 to 2.0 percent calculated by the oxide of the metal M.

23. The method of claim 1, wherein: the properties of the catalyst obtained were as follows: specific surface area > 60m²The attrition rate of the catalyst obtained is < 2.0 wt. -%.

24. The method of claim 23, wherein: the properties of the catalyst obtained were as follows: the specific surface area is 80-150 m²(ii)/g; the abrasion rate was 1.5 wt%.

25. The method of claim 1, wherein: the particle size distribution of the catalyst obtained is as follows, in volume fractions: the content of particles with the particle size of less than 150mm is less than 10%, the content of particles with the particle size of 150-500 mm is 75% -95%, and the content of particles with the particle size of more than 500mm is less than 15%.

26. The method of claim 25, wherein: the particle size distribution of the catalyst obtained is as follows, in volume fractions: the content of particles with the particle size of less than 150mm is less than 8 percent; the particles with the particle size of 150-500 mm account for 80% -92%, and the particles with the particle size of more than 500mm account for less than 12%.