Catalyst based on ten-membered ring aluminum silicate molecular sieve, and preparation method and application thereof

Abstract

The invention discloses a catalyst based on a ten-membered ring aluminum silicate molecular sieve as well as a preparation method and application thereof. The catalyst comprises the ten-membered ring aluminum silicate molecular sieve as well as a noble metal active component and an auxiliary agent which are loaded on the ten-membered ring aluminum silicate molecular sieve, the noble metal active component is selected from at least one of Pt and Pd; the auxiliary agent is WO3; the ten-membered ring aluminum silicate molecule is selected from at least one of ZSM-23, ZSM-22 and ZSM-48. Compared with the catalyst prepared in the prior art, the catalyst prepared by the method provided by the invention has higher activity and isomer yield in the isomerization reaction of long-chain n-alkanes.

Description

Technical Field

[0001] The present application relates to a catalyst based on decahedral aluminosilicate zeolite, a preparation method and an application thereof, and belongs to the technical field of the preparation and application of catalysts. Background Art

[0002] Bifunctional solid catalysts are widely used in the alkane hydroisomerization process, and are composed of a hydrogenation-dehydrogenation component and an acidic support. Among them, the hydrogenation-dehydrogenation component is mainly Group VIII metals such as Pt, Pd, Rh, Ir, and Ni, etc.; the acidic support can be divided into the following three categories: 1. Amorphous single metal oxides or composite oxides, such as Al2O3 treated with halides, SiO2 / Al2O3, superacid ZrO2 / SO4 2- , WO3 / ZrO2, etc.; 2. Zeolite series of silicon-aluminum, such as Y, Beta, ZSM-5, etc.; 3. Zeolite series of aluminum phosphate, such as SAPO-5, SAPO-11, SAPO-31, and SAPO-41, etc. Compared with amorphous oxides and superacids, zeolites show excellent performance in terms of shape selectivity, stability, anti-poisoning, and anti-coking ability. Therefore, isomerization catalysts with zeolites as carriers are widely used. Patent documents such as US5882505, US20040138051A1, US20050077209A1, CN1792451, CN1788844A, and CN101245260A have all described in detail the preparation methods of alkane hydroisomerization catalysts with zeolites as carriers.

[0003] Decahedral aluminosilicate zeolite is a kind of synthetic zeolite, and its typical representatives are ZSM-23, ZSM-22, and ZSM-48, which have the characteristics of moderate acidity and one-dimensional straight channels, and are ideal carriers for shape-selective isomerization catalysts of long-chain alkanes.

[0004] According to the reaction mechanism of normal paraffins on bifunctional catalysts, the conversion of normal paraffins on the catalyst surface mainly undergoes three chemical reaction steps and two diffusion steps. The chemical reaction steps include alkane dehydrogenation reaction and olefin hydrogenation reaction on metal centers and isomerization / cracking reaction on acidic centers. The diffusion steps include the diffusion of normal olefins from metal centers to acidic centers and the diffusion of isomer olefins from acidic centers to metal centers. From the perspective of chemical reaction steps, the isomerization performance of bifunctional catalysts is affected by factors such as the metallicity (electronic properties, loading, and dispersion, etc.) of the catalyst, acidity (acid type, acid amount, and acid strength, etc.), and pore structure. In the alkane isomerization reaction, the metallicity of the catalyst can not only ensure the progress of alkane dehydrogenation reaction and olefin hydrogenation reaction, improve the reaction activity and isomer selectivity of the catalyst, but also inhibit the formation of coke and improve the stability of the catalyst. When the metallicity is insufficient to balance the acidity, the isomerization carbocations on acidic centers are prone to further isomerization or even cracking reactions, resulting in lower isomer selectivity of the catalyst. For a long time, people often increase the number of metal active sites by increasing the metal loading and improving the dispersion, so as to maintain the balance with acidic sites, while little attention has been paid to improving the intrinsic activity of metal sites. Summary of the Invention

[0005] The purpose of the present invention is to provide a shape-selective isomerization catalyst based on ten-membered ring aluminosilicate molecular sieve and its preparation method.

[0006] The present invention also relates to the application of the above catalyst in the isomerization reaction of long-chain normal paraffins.

[0007] Specifically, the present invention provides a shape-selective isomerization catalyst using ten-membered ring aluminosilicate molecular sieve as the carrier, which improves the hydrogenation / dehydrogenation performance of noble metals based on metal oxide promoter WO3, thereby obtaining excellent hydroisomerization performance.

[0008] According to one aspect of the present application, a catalyst based on ten-membered ring aluminosilicate molecular sieve is provided, and the catalyst includes a ten-membered ring aluminosilicate molecular sieve and a noble metal active component and a promoter supported on the ten-membered ring aluminosilicate molecular sieve;

[0009] The noble metal active component is selected from at least one of Pt and Pd;

[0010] The promoter is WO3;

[0011] The ten-membered ring aluminosilicate molecular sieve is selected from at least one of ZSM-23, ZSM-22, and ZSM-48.

[0012] Optionally, the acid amount of the ten-membered ring aluminosilicate molecular sieve is 0.5 - 2.0 mmol(NH3) / g.

[0013] Optionally, the acid amount of the ten-membered ring aluminosilicate molecular sieve is independently selected from any value of 0.5 mmol(NH3) / g, 0.6 mmol(NH3) / g, 0.7 mmol(NH3) / g, 0.8 mmol(NH3) / g, 0.9 mmol(NH3) / g, 1.0 mmol(NH3) / g, 1.2 mmol(NH3) / g, 1.4 mmol(NH3) / g, 1.6 mmol(NH3) / g, 1.8 mmol(NH3) / g, 2.0 mmol(NH3) / g or a range value between any two of the above.

[0014] Optionally, the acid amount of the ten-membered ring aluminosilicate molecular sieve is 0.8 - 1.6 mmol(NH3) / g.

[0015] Optionally, in the catalyst, the content of the noble metal active component is 0.05 wt% - 0.2 wt%.

[0016] Optionally, in the catalyst, the content of the noble metal active component is independently selected from any value of 0.05 wt%, 0.06 wt%, 0.08 wt%, 0.1 wt%, 0.12 wt%, 0.14 wt%, 0.15 wt%, 0.16 wt%, 0.18 wt%, 0.2 wt% or a range value between any two of the above.

[0017] Optionally, in the catalyst, the content of the promoter is 0.1 wt% - 10 wt%.

[0018] Optionally, in the catalyst, the content of the promoter is independently selected from any value of 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 5 wt%, 6 wt%, 7 wt%, 10 wt% or a range value between any two of the above.

[0019] Optionally, in the catalyst, the content of the promoter is 0.5 wt% - 5 wt%.

[0020] Optionally, in the catalyst, the content of the ten-membered ring aluminosilicate molecular sieve is 95 wt% - 99.5 wt%.

[0021] Optionally, in the catalyst, the content of the ten-membered ring aluminosilicate molecular sieve is independently selected from any value of 95 wt%, 95.5 wt%, 96 wt%, 96.5 wt%, 97 wt%, 98 wt%, 99 wt%, 99.1 wt%, 99.3 wt%, 99.5 wt% or a range value between any two of the above.

[0022] According to another aspect of the present application, there is provided a method for preparing the above-mentioned catalyst, and the preparation method includes the following steps:

[0023] (1) Impregnate the promoter precursor on the ten-ring aluminosilicate molecular sieve, dry I, and calcine I to obtain the ten-ring aluminosilicate molecular sieve loaded with the promoter;

[0024] (2) Further load the noble metal active component precursor on the ten-ring aluminosilicate molecular sieve loaded with the promoter through electrostatic adsorption, dry II, calcine II, and reduce to obtain the catalyst.

[0025] Optionally, in the step (1), the promoter precursor is selected from at least one of ammonium paratungstate, ammonium metatungstate, tungsten phosphate, ammonium tungstate, tungsten oxalate, and tungsten acetate.

[0026] Optionally, the impregnation is equal-volume impregnation.

[0027] Optionally, the temperature of the calcination I is 330 °C to 740 °C, and the time of the calcination I is 0.5 to 24 h.

[0028] Optionally, the temperature of the calcination I is 350 °C to 650 °C, and the time of the calcination I is 4 to 24 h.

[0029] Optionally, the temperature of the calcination I is 400 °C to 600 °C, and the time of the calcination I is 0.5 to 24 h.

[0030] Optionally, in the step (2), the noble metal active component precursor is selected from at least one of platinum nitrate, palladium diammine dichloride, platinum tetraammine dichloride, platinum diammine dichloride, palladium tetraammine dichloride, platinum dinitro diammine, palladium chloride, and palladium dinitro diammine.

[0031] Optionally, in the electrostatic adsorption, the pH value of the electrostatic adsorption mixed solution is 8 to 14.

[0032] Optionally, in the electrostatic adsorption, the pH value of the electrostatic adsorption mixed solution independently selects any value from 8, 9, 10, 11, 12, 13, 14 or the range value between any two of the above.

[0033] Optionally, in the electrostatic adsorption, the pH value regulator is selected from at least one of hydrochloric acid, liquid ammonia, oxalic acid, methylamine, sulfuric acid, ammonia water, nitric acid, methylamine, and ethylamine.

[0034] Optionally, the method of electrostatic adsorption in the step (2) is to soak the carrier in the solution containing the precursor of the loading substance, adjust the charged property of the carrier surface, and selectively adsorb the positively charged or negatively charged loading substance ions.

[0035] Optionally, in the method of electrostatic adsorption in step (2), the decahedral aluminosilicate molecular sieve loaded with metal oxide promoter is soaked in the noble metal precursor solution for 2 to 12 hours.

[0036] Optionally, in the method of electrostatic adsorption in step (2), after soaking in the noble metal precursor solution, the solid is filtered and washed with deionized water 1 to 6 times until the eluate is neutral.

[0037] Optionally, the temperatures of the first drying and the second drying are independently selected from 50°C to 200°C.

[0038] Optionally, the times of the first drying and the second drying are independently selected from 0.5 to 24 hours.

[0039] Optionally, the reduction temperature is 200 to 400°C, and the reduction time is 2 to 8 hours.

[0040] Optionally, the reduction temperature is 250 to 350°C, and the reduction time is 4 to 8 hours.

[0041] Optionally, the reduction atmosphere is a hydrogen atmosphere.

[0042] Optionally, the gas flow rate of the hydrogen atmosphere is 2 to 200 mL / min / g 催化剂 。

[0043] Optionally, the temperature of the second calcination is 350°C to 650°C, and the time of the second calcination is 0.5 to 24 hours.

[0044] Optionally, the atmospheres of the first calcination and the second calcination are independently selected from oxygen-containing atmospheres, and the oxygen-containing atmosphere is pure oxygen, oxygen-nitrogen mixture or oxygen-argon mixture.

[0045] According to another aspect of the present application, there is provided an application of the above-mentioned catalyst in the isomerization reaction of long-chain alkanes.

[0046] Optionally, the conditions of the isomerization reaction of long-chain alkanes are as follows:

[0047] The reaction pressure is 0.1 to 10 MPa, the reaction temperature is 200 to 400°C, the hydrogen-oil ratio (mol / mol) is 5 to 50, and the feed volume space velocity is 0.5 to 5 h -1 。

[0048] Optionally, the long-chain alkane is a C8-C50 long-chain alkane.

[0049] Optionally, the reaction temperature is 280 to 350°C.

[0050] The catalyst provided by the present invention can be widely applied to the processing processes of petroleum fractions, biomass, and Fischer-Tropsch synthesis products, such as isomerization dewaxing, isodewaxing, and other processes.

[0051] The preparation method of the above catalyst provided by the present invention: First, a metal oxide promoter is loaded on a ten-ring aluminosilicate molecular sieve, and after calcination, a noble metal active component is loaded, and then through calcination and reduction, the target catalyst is obtained, including the following steps:

[0052] (1) A promoter precursor is loaded on a ten-ring aluminosilicate molecular sieve by an impregnation method, dried, and calcined in an oxygen-containing atmosphere to obtain a ten-ring aluminosilicate molecular sieve loaded with a metal oxide promoter;

[0053] (2) A noble metal precursor is further loaded on the ten-ring aluminosilicate molecular sieve loaded with the metal oxide promoter obtained in step (1) by an electrostatic adsorption method, dried, calcined in an oxygen-containing atmosphere, and reduced in hydrogen at 200-400 °C for 2-8 h to prepare the shape-selective isomerization catalyst.

[0054] Optionally, the metal oxide promoter is WO3.

[0055] The beneficial effects that this application can produce include:

[0056] 1) The noble metal content in the shape-selective isomerization catalyst provided by this application is 0.05 wt% - 0.2 wt%, which is greatly reduced compared with the noble metal loading of about 0.5 wt% in traditional hydroisomerization catalysts;

[0057] 2) The shape-selective isomerization catalyst provided by this application has higher activity, isomer selectivity, and isomer yield in the alkane isomerization reaction;

[0058] 3) The preparation process of the shape-selective isomerization catalyst provided by this application is simple and easy to implement. Detailed implementation mode

[0059] The following describes this application in detail with reference to the examples, but this application is not limited to these examples.

[0060] Unless otherwise specified, the raw materials in the examples of this application are all purchased through commercial channels.

[0061] Conversion rate (Conv) = C 所有产物 / (C 所有产物 +C 剩余正十四烷 )×100%;

[0062] Selectivity (S) = C 异十四烷 / C 所有产物 ×100%;

[0063] Yield (Y) = Conv×S×100%.

[0064] Comparative Example 1

[0065] Take 50 g of ZSM-22 molecular sieve after removing the template agent, and its acid amount is 1.6 mmol(NH3) / g. Immerse 50 g of the above carrier with 25 mL of H2PtCl6 solution containing 0.01 g / mL of Pt, air-dry naturally and dry at 120 °C for 4 h, calcine at 500 °C for 4 h, and then use hydrogen with a flow rate of 60 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain 0.5 wt% Pt / ZSM-22 catalyst. The evaluation results of the catalytic reaction are shown in Table 1.

[0066] Comparative Example 2

[0067] Take 50 g of ZSM-23 molecular sieve after removing the template agent, and its acid amount is 1.1 mmol(NH3) / g. Immerse 50 g of the above carrier with 25 mL of H2PtCl6 solution containing 0.01 g / mL of Pt, air-dry naturally and dry at 120 °C for 4 h, calcine at 500 °C for 4 h, and then use hydrogen with a flow rate of 60 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain 0.5 wt% Pt / ZSM-23 catalyst. The evaluation results of the catalytic reaction are shown in Table 1.

[0068] Comparative Example 3

[0069] Take 50 g of ZSM-48 molecular sieve after removing the template agent, and its acid amount is 1.5 mmol(NH3) / g. Immerse 50 g of the above carrier with 25 mL of H2PtCl6 solution containing 0.01 g / mL of Pt, air-dry naturally and dry at 120 °C for 4 h, calcine at 500 °C for 4 h, and then use hydrogen with a flow rate of 80 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain 0.5 wt% Pt / ZSM-48 catalyst. The evaluation results of the catalytic reaction are shown in Table 1.

[0070] Comparative Example 4

[0071] Take 50 g of the ZSM-22 molecular sieve in Comparative Example 1, immerse 50 g of the above carrier with 25 mL of (NH3)4PtCl2 solution containing 0.01 g / mL of Pt, air-dry naturally and dry at 120 °C for 4 h, calcine at 500 °C for 4 h, and then use hydrogen with a flow rate of 80 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain 0.5 wt% Pt / ZSM-22 catalyst. The evaluation results of the catalytic reaction are shown in Table 1.

[0072] Comparative Example 5

[0073] Take 50 g of the ZSM-23 molecular sieve in Comparative Example 2, impregnate 50 g of the above carrier with 25 mL of an (NH3)2PtCl2 solution containing 0.01 g / mL of Pt, air-dry naturally and dry at 120 °C for 4 h, calcine at 500 °C for 4 h, and then use hydrogen with a flow rate of 80 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain a 0.5 wt% Pt / ZSM-23 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0074] Comparative Example 6

[0075] Take 50 g of the ZSM-48 molecular sieve in Comparative Example 3, impregnate 50 g of the above carrier with 25 mL of an (NH3)2PdCl2 solution containing 0.01 g / mL of Pd, air-dry naturally and dry at 120 °C for 4 h, calcine at 500 °C for 4 h, and then use hydrogen with a flow rate of 80 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain a 0.5 wt% Pd / ZSM-48 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0076] Example 1

[0077] Step 1: Take 50 g of the ZSM-22 molecular sieve in Comparative Example 1, impregnate it with 25 mL of a tungstic acid acetate solution containing 0.08 g / mL of W, then air-dry naturally and dry at 120 °C for 4 h, and calcine at 450 °C for 4 h for standby; Step 2: Dissolve (NH3)4PtCl2 in ammonia water and dilute to a concentration containing 0.0005 g / mL of Pt, and measure 200 ml of this (NH3)4PtCl2 ammonia water solution; Step 3: Immerse the 50 g of ZSM-22 loaded with tungsten oxide promoter obtained in Step 1 in the 200 ml of (NH3)4PtCl2 ammonia water solution prepared in Step 2, further adjust its pH value to 12.5 with ammonia water, soak for 6 h, filter and wash with deionized water 4 times until the eluate is neutral, air-dry the obtained solid naturally and dry at 120 °C for 4 h, calcine at 450 °C for 4 h, and then use hydrogen with a flow rate of 60 mL / min / g 催化剂 to reduce at 400 °C for 4 h to obtain a 0.2 wt% Pt-4 wt% WO3 / ZSM-22 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0078] Example 2

[0079] Step 1: Take 50 g of the ZSM-23 molecular sieve in Comparative Example 2, impregnate it with 25 mL of an ammonium metatungstate solution containing 0.06 g / mL of W, then air-dry it naturally and dry it at 120 °C for 4 h, and calcine it at 380 °C for 4 h for standby; Step 2: Dissolve (NH3)2PtCl2 in ammonia water and dilute it to a concentration containing 0.00025 g / mL of Pt, and measure 200 ml of this (NH3)2PtCl2 ammonia water solution; Step 3: Immerse the 50 g of ZSM-23 loaded with tungsten oxide promoter obtained in Step 1 in the 200 ml of (NH3)2PtCl2 ammonia water solution prepared in Step 2, further adjust its pH value to 12.1 with ammonia water, soak for 4 h, filter and wash it 4 times with deionized water until the eluate is neutral, and the obtained solid is air-dried naturally and dried at 120 °C for 4 h, calcined at 420 °C for 4 h, and then hydrogen with a flow rate of 60 mL / min / g 催化剂 is reduced at 350 °C for 4 h to prepare a 0.1 wt% Pt-3 wt% WO3 / ZSM-23 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0080] Example 3

[0081] Step 1: Take 50 g of the ZSM-48 molecular sieve in Comparative Example 3, impregnate it with 25 mL of a tungsten oxalate solution containing 0.06 g / mL of W, then air-dry it naturally and dry it at 120 °C for 4 h, and calcine it at 420 °C for 5 h for standby; Step 2: Dissolve (NH3)2PdCl2 in ammonia water and dilute it to a concentration containing 0.00025 g / mL of Pd, and measure 200 ml of this (NH3)2PdCl2 ammonia water solution; Step 3: Immerse the 50 g of ZSM-48 loaded with tungsten oxide promoter obtained in Step 1 in the 200 ml of (NH3)2PdCl2 ammonia water solution prepared in Step 2, further adjust its pH value to 11.0 with ammonia water, soak for 6 h, filter and wash it 4 times with deionized water until the eluate is neutral, and the obtained solid is air-dried naturally and dried at 120 °C for 4 h, calcined at 450 °C for 4 h, and then hydrogen with a flow rate of 60 mL / min / g 催化剂 is reduced at 360 °C for 4 h to prepare a 0.1 wt% Pd-3 wt% WO3 / ZSM-48 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0082] Catalyst performance evaluation of Example 4

[0083] The catalyst evaluation was carried out in a stainless steel tube fixed-bed reactor. 10 mL of the catalysts prepared in Comparative Examples 1-6 and Examples 1-3 were loaded into the reactor, heated to the reaction temperature under a hydrogen atmosphere, and the raw material oil n-tetradecane was passed for reaction, and the products were analyzed by gas chromatography. Reaction conditions: reaction temperature 280-350 °C, 3 MPa, n-tetradecane feed volume space velocity 1.0 h -1, the hydrogen-oil ratio (mol / mol) was 15, and the specific experimental results are shown in Table 1.

[0084] Table 1. Catalyst evaluation results in comparative examples and examples

[0085]

[0086] As can be seen from Table 1, compared with the catalysts prepared by the conventional methods in Comparative Examples 1-6, the catalysts prepared by the present method in Examples 1-3 can obtain higher activity, higher isomer selectivity and isomer yield in the hydroisomerization reaction of long-chain alkanes.

[0087] As described above, these are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, making some changes or modifications using the technical content disclosed above is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A catalyst based on decahedral aluminosilicate zeolite, characterized in that, The catalyst comprises a ten - membered ring aluminosilicate molecular sieve, a noble metal active component and an additive supported on the ten - membered ring aluminosilicate molecular sieve; The noble metal active component is selected from at least one of Pt and Pd; The additive is WO3; The ten - membered ring aluminosilicate molecular sieve is selected from at least one of ZSM - 23, ZSM - 22 and ZSM - 48.

2. The catalyst according to claim 1, characterized in that, The acid amount of the ten - membered ring aluminosilicate molecular sieve is 0.5 - 2.0 mmol(NH3) / g; Preferably, the acid amount of the ten - membered ring aluminosilicate molecular sieve is 0.8 - 1.6 mmol(NH3) / g; Preferably, in the catalyst, the content of the noble metal active component is 0.05 wt% - 0.2 wt%; Preferably, in the catalyst, the content of the additive is 0.1 wt% - 10 wt%; Preferably, in the catalyst, the content of the additive is 0.5 wt% - 5 wt%; Preferably, in the catalyst, the content of the ten - membered ring aluminosilicate molecular sieve is 95 wt% - 99.5 wt%.

3. A method for preparing the catalyst according to any one of claims 1 to 2, characterized in that, The preparation method comprises the following steps: (1) Impregnating the additive precursor on the ten - membered ring aluminosilicate molecular sieve, drying I and calcining I to obtain the ten - membered ring aluminosilicate molecular sieve loaded with the additive; (2) Further loading the noble metal active component precursor on the ten - membered ring aluminosilicate molecular sieve loaded with the additive through electrostatic adsorption, drying II, calcining II and reducing to obtain the catalyst.

4. The preparation method according to claim 3, characterized in that, In the step (1), the additive precursor is selected from at least one of ammonium paratungstate, ammonium metatungstate, tungsten phosphate, ammonium tungstate, tungsten oxalate and tungsten acetate; Preferably, the impregnation is equal - volume impregnation; Preferably, the temperature of calcining I is 330°C - 740°C, and the time of calcining I is 0.5 - 24 h; Preferably, the temperature of calcining I is 350°C - 650°C, and the time of calcining I is 4 - 24 h; Preferably, the temperature of calcining I is 400°C - 600°C, and the time of calcining I is 0.5 - 24 h.

5. The preparation method according to claim 3, characterized in that, In the step (2), the noble metal active component precursor is selected from at least one of platinum nitrate, dichlorodiamminepalladium, dichlorotetraammineplatinum, dichlorodiammineplatinum, dichlorotetraamminepalladium, dinitrodiammineplatinum, palladium chloride and dinitrodiamminepalladium.

6. The preparation method according to claim 3, characterized in that, In the electrostatic adsorption, the pH value of the electrostatic adsorption mixed solution is 8 - 14; Preferably, the pH value regulator in the electrostatic adsorption is selected from at least one of hydrochloric acid, liquid ammonia, oxalic acid, methylamine, sulfuric acid, ammonia water, nitric acid, methylamine and ethylamine.

7. The preparation method according to claim 3, characterized in that, The temperatures of drying I and drying II are independently selected from 50°C - 200°C; Preferably, the times of drying I and drying II are independently selected from 0.5 - 24 h; Preferably, the temperature of reduction is 200 - 400°C, and the time of reduction is 2 - 8 h; Preferably, the temperature of reduction is 250 - 350°C, and the time of reduction is 4 - 8 h; Preferably, the reduction atmosphere is a hydrogen atmosphere; Preferably, the gas flow rate of the hydrogen atmosphere is 2 to 200 mL / min / g 催化剂 ; Preferably, the temperature of calcining II is 350°C - 650°C, and the time of calcining II is 0.5 - 24 h.

8. Application of the catalyst according to any one of claims 1 to 2 in the isomerization reaction of long-chain alkanes.

9. The application according to claim 8, characterized in that, The conditions for the long - chain alkane isomerization reaction are: The reaction pressure is 0.1 to 10 MPa, the reaction temperature is 200 to 400 °C, the hydrogen-oil ratio (mol / mol) is 5 to 50, and the feed volume space velocity is 0.5 to 5 h -1 ; The long-chain alkane is a C8-C50 long-chain alkane.

10. The application according to claim 9, wherein, The reaction temperature is 280-350 °C.

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