Ni@SAPO-11 Hydrocarbon Isomerization Catalyst and Its Preparation Method and Application

Abstract

The present invention relates to a Ni@SAPO-11 hydrocarbon isomerization catalyst, a preparation method thereof and an application thereof, belonging to the technical field of catalyst preparation. The preparation steps include: preparing a nickel-based metal-organic framework material; sequentially adding a phosphorus source, an aluminum source, a silicon source, a structure-directing agent and the nickel-based metal-organic framework material into deionized water, stirring to obtain a gel, transferring the gel into a reaction kettle, heating and crystallizing. The mass ratio of the phosphorus source, the aluminum source, the silicon source, the structure-directing agent, water and the nickel-based metal-organic framework material is 10-15:7-10:4-7:5-8:10-50:1-2; after the crystallization is completed, the temperature is lowered to separate out the crystallization product, and the crystallization product is dried and calcined to obtain the catalyst. The catalyst obtained by the present invention has a high Ni dispersion degree, can effectively avoid the blockage of pores by metallic Ni, ensure a higher specific surface area, a very high total isomer selectivity and a very low cracking selectivity.

Description

Technical Field

[0001] The present invention relates to a Ni@SAPO-11 hydrocarbon isomerization catalyst, a preparation method thereof and an application thereof, belonging to the technical field of catalyst preparation. Background Art

[0002] The hydrocarbon isomerization reaction is a process of converting hydrocarbons into corresponding isomers, which is widely used in the preparation of isoparaffin solvents, the synthesis of rubber intermediates and the production of fine chemicals. In addition, hydrocarbon isomers also play an important role in improving the quality of gasoline and diesel. It can increase the octane number of gasoline and improve the cold flow performance of diesel.

[0003] In the process of hydrocarbon isomerization reaction, the catalyst plays a crucial role. The commonly used hydrocarbon isomerization catalyst is a bifunctional catalyst including a support component and a metal component. Among them, the SAPO-11 molecular sieve with ten-membered ring elliptical straight channels is an excellent support for hydrocarbon isomerization catalysts. The commonly used metals are mainly noble metals Pt, Pd and non-noble metal Ni, etc. Among them, it shows high reaction activity and high isomer selectivity in the isomerization reaction. However, due to the high cost of Pt and Pd, its industrial application is limited. The non-noble metal Ni has a low cost and good hydrogenation / dehydrogenation function, and has been widely studied as a metal component of isomerization catalysts. At present, the Ni / SAPO-11 hydroisomerization catalyst is mainly prepared by the impregnation method. The Ni particles in the Ni / SAPO-11 prepared by this method are larger in size (20-30 nm) and have a lower dispersion, showing lower isomer selectivity and higher cracking selectivity in the hydrocarbon isomerization reaction. It has been found that reducing the metal particle size in the catalyst and increasing the metal dispersion can increase the number of metal active sites and effectively improve the hydrogenation / dehydrogenation function of the catalyst.

[0004] The literature (Lyu et al., Effect of ethanol on the surface properties and n-heptane isomerization performance of Ni / SAPO-11. Applied Surface Science, 2017, 401: 57-64.) prepared a Ni / SAPO-11 catalyst by impregnating a nickel nitrate ethanol solution into SAPO-11 with equal volume. Compared with the Ni / SAPO-11 prepared by the traditional equal-volume impregnation of nickel nitrate aqueous solution, this catalyst shows smaller Ni particle size and higher Ni dispersion.

[0005] The literature (Yang et al., Citric-acid-induced mesoporous SAPO-11 loaded with highly dispersed nickel for enhanced hydroisomerization of oleic acid to iso-alkanes. Fuel Processing Technology, 2019, 187: 52-62.) prepared Ni / SAPO-11 with smaller Ni particle size by the citric acid-assisted impregnation method. Compared with the traditional Ni / SAPO-11, its isomerization reaction performance was greatly improved.

[0006] In summary, it can be seen that the Ni / SAPO-11 catalyst with smaller Ni particle size can be prepared by the above method and its isomerization performance can be improved, but the improvement degree is limited. Summary of the Invention

[0007] In order to further improve the isomerization reaction activity and isomer selectivity of the Ni / SAPO-11 catalyst, the present invention provides a Ni@SAPO-11 hydrocarbon isomerization catalyst, its preparation method and application from the perspective of improving high metal dispersion while ensuring a high specific surface area of the support. By using the CPO-27 metal-organic framework material as the nickel source, a Ni@SAPO-11 catalyst with highly dispersed Ni is prepared in-situ.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A preparation method of a Ni@SAPO-11 hydrocarbon isomerization catalyst, which comprises the following steps:

[0010] Adding a nickel metal source into water and a ligand into a polar organic solvent, fully dissolving, and then mixing the two obtained solutions to obtain a suspension, wherein the mass ratio of the nickel metal source, the ligand, water and the polar solvent is 2-3: 1-2: 20-30: 15-25;

[0011] Carrying out crystallization on the suspension;

[0012] Drying the crystallization product to obtain a nickel-based metal-organic framework material;

[0013] Adding the nickel-based metal-organic framework material into the SAPO-11 synthesis gel and carrying out crystallization on it;

[0014] Drying and calcining the crystallization product to obtain a Ni@SAPO-11 hydrocarbon isomerization catalyst.

[0015] Further, it specifically comprises the following steps:

[0016] (1) Dissolve the nickel metal source in deionized water and stir evenly to obtain solution A;

[0017] (2) Dissolve the ligand in a polar organic solvent and stir evenly to obtain solution B;

[0018] (3) Mix solution A and solution B and stir evenly to obtain solution C;

[0019] (4) Transfer solution C in step (3) into a reaction kettle, raise the temperature to the reaction temperature and crystallize;

[0020] (5) After the crystallization is completed, lower the temperature of the reaction kettle, take out the solution in the kettle, separate the crystallization product, and obtain the nickel-based metal-organic framework material after drying and calcination;

[0021] (6) Add the phosphorus source, aluminum source, silicon source, structure-directing agent and nickel-based metal-organic framework material to deionized water in sequence and stir to obtain gel D;

[0022] (7) Transfer gel D in step (6) into a reaction kettle, raise the temperature to the reaction temperature and crystallize;

[0023] (8) After the crystallization is completed, lower the temperature of the reaction kettle, take out the solution in the kettle, separate the crystallization product, and obtain the Ni@SAPO-11 catalyst after drying and calcination;

[0024] In the above preparation method, preferably, in step (1), the nickel metal source is one or a combination of two or more of nickel acetate, nickel nitrate, and nickel chloride;

[0025] And / or, in step (1), the amount of water used is 10 - 15 g / g of the nickel metal source.

[0026] In the above preparation method, in order to accelerate dissolution, preferably, in step (1), the stirring temperature is 10 - 50 °C and the stirring time is 0.5 - 2 h.

[0027] In the above preparation method, preferably, in step (2), the ligand includes one or a combination of two or more of trimesic acid, terephthalic acid, and 2,5-dihydroxyterephthalic acid.

[0028] In the above preparation method, preferably, in step (2), the polar organic solvent includes one or a combination of two or more of methanol, ethanol, and ethylene glycol;

[0029] And / or, in step (2), the amount of the polar organic solvent used is 15 - 25 g / g of the ligand.

[0030] In the above preparation method, preferably, in step (2), the stirring temperature is 10 - 50 °C and the stirring time is 0.5 - 2 h.

[0031] In the above preparation method, to accelerate dissolution, preferably, in step (3), the stirring temperature is 10 - 50 °C and the stirring time is 0.5 - 2 h.

[0032] In the above preparation method, preferably, in step (4), the crystallization temperature is 100 - 140 °C and the crystallization time is 12 - 72 h.

[0033] In the above preparation method, preferably, in step (5), after crystallization, the reaction kettle is cooled to 10 - 50 °C.

[0034] In the above preparation method, preferably, in step (5), the drying temperature is 70 - 120 °C and the drying time is 4 - 12 h.

[0035] In the above preparation method, preferably, in step (6), the phosphorus source includes phosphoric acid, etc.

[0036] In the above preparation method, preferably, in step (6), the aluminum source includes any one or more of pseudo - boehmite, aluminum isopropoxide, etc.

[0037] In the above preparation method, preferably, in step (6), the silicon source includes one or a combination of two or more of silica sol, tetraethyl orthosilicate, tetrapropyl orthosilicate, etc.

[0038] In the above preparation method, preferably, in step (6), the structure - directing agent includes any one or more of di - n - propylamine, di - isopropylamine, etc.

[0039] In the above preparation method, preferably, in step (6), the stirring temperature is 10 - 50 °C and the stirring time is 0.5 - 6 h.

[0040] In the above preparation method, preferably, in step (6), the mass ratio of the phosphorus source, aluminum source, silicon source, structure - directing agent, water and nickel - based metal - organic framework material is 10 - 15:7 - 10:4 - 7:5 - 8:10 - 50:1 - 2.

[0041] In the above preparation method, preferably, in step (7), the crystallization temperature is 180 - 230 °C and the crystallization time is 12 - 72 h.

[0042] In the above preparation method, preferably, in step (8), after crystallization, the reaction kettle is cooled to 10 - 50 °C.

[0043] In the above preparation method, preferably, in step (8), the drying temperature is 70 - 120 °C, and the drying time is 4 - 12 h.

[0044] In the above preparation method, preferably, in step (8), the calcination temperature is 500 - 700 °C, and the calcination time is 4 - 12 h.

[0045] The present invention also provides a Ni@SAPO-11 composite material, which is prepared according to the above preparation method.

[0046] The present invention also provides the application of the above hydrocarbon isomerization catalyst in the hydrocarbon hydroisomerization reaction. Preferably, the reaction temperature of the hydrocarbon hydroisomerization reaction is 210 - 400 °C, the reaction pressure is 0.5 - 4.0 MPa, the volume ratio of hydrogen to hydrocarbon is 100 - 600:1, and the liquid hourly space velocity is 0.5 - 6 h -1 。

[0047] In summary, the preparation method of the Ni@SAPO-11 catalyst provided by the present invention has a high Ni dispersion degree on the one hand, and effectively avoids the blockage of pores by metallic Ni on the other hand, thereby ensuring a higher specific surface area. The Ni@SAPO-11 catalyst provided by the present invention has a very high total isomer selectivity and a very low cracking selectivity. Applying this catalyst to the hydrocarbon isomerization reaction can produce isoparaffins, increase the octane number of gasoline, and improve the cold flow performance of diesel. Description of the Drawings

[0048] Figure 1 XRD patterns of Ni@SAPO-11-3 and Ni / SAPO-11-1 prepared in Example 3 and Comparative Example 1.

[0049] Figure 2 TEM images of Ni@SAPO-11-3 and Ni / SAPO-11-1 prepared in Example 3 and Comparative Example 1.

[0050] Figure 3 N2 adsorption-desorption isotherms of Ni@SAPO-11-3 and Ni / SAPO-11-1 prepared in Example 3 and Comparative Example 1. Detailed Description of the Invention

[0051] The present invention is not limited to the following specific embodiments. Those of ordinary skill in the art can implement the present invention in other various specific embodiments according to the content disclosed in the present invention, or any simple changes or modifications made by adopting the design structure and concept of the present invention fall within the protection scope of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0052] The present invention will be further described in detail below with reference to embodiments:

[0053] Example 1

[0054] This example provides a hydrocarbon isomerization catalyst of Ni@SAPO-11, which is prepared by the following steps:

[0055] Add 2.8 g of nickel acetate tetrahydrate to 30.0 g of deionized water, and stir at 35 °C for 0.5 h to obtain solution A;

[0056] Add 1.2 g of 2,5-dihydroxyterephthalic acid to 23.7 g of ethanol, and stir at 35 °C for 0.5 h to obtain solution B;

[0057] Mix the above solution A and solution B, and stir at 35 °C for 1 h to obtain solution C;

[0058] Transfer the above solution C to a 100 mL stainless steel autoclave, heat up to 110 °C, and crystallize at a constant temperature for 24 h;

[0059] Cool the above stainless steel autoclave to 30 °C, wash the obtained product, and dry it at 120 °C for 12 h to obtain CPO-27 nickel-based metal-organic framework material powder;

[0060] Add 12.2 g of phosphoric acid, 8.4 g of pseudoboehmite, 4.7 g of tetraethyl orthosilicate, 6.8 g of di-n-propylamine, and 1.0 g of CPO-27 to 40.0 g of deionized water in sequence, and stir at 35 °C for 7 h to obtain gel D;

[0061] Transfer the above gel D to a 100 mL stainless steel autoclave, heat up to 200 °C, and crystallize at a constant temperature for 24 h;

[0062] Cool the above stainless steel autoclave to 30 °C, wash the obtained product, dry it at 120 °C for 12 h, and calcine it at 600 °C for 6 h to obtain Ni@SAPO-11-1 catalyst.

[0063] After X-ray fluorescence spectrometry test, the content of Ni in this catalyst is 1.1 wt.%. Its pore structure parameters are shown in Table 1.

[0064] Hydrocarbon isomerization test:

[0065] Take 2.0 mL of Ni@SAPO-11-1, mix it with an equal volume of quartz sand, and load it into a stainless steel reaction tube with an inner diameter of 8 mm; introduce hydrogen into the reaction tube to make the pressure reach 1.5 MPa, heat up to 500 °C, and maintain for 4 h; heat up the temperature to 340 °C, introduce hydrogen and n-octane, the hydrogen / n-octane volume ratio is 400:1, and the weight hourly space velocity is 1.2 h -1, sampling and analysis were carried out after 6 h of reaction, and the reaction results are shown in Table 2.

[0066] Example 2

[0067] This example provides a hydrocarbon isomerization catalyst of Ni@SAPO-11, which is prepared by the following steps:

[0068] 2.8 g of nickel acetate tetrahydrate was added to 30.0 g of deionized water, and stirred at 35 °C for 0.5 h to obtain solution A;

[0069] 1.2 g of 2,5-dihydroxyterephthalic acid was added to 23.7 g of ethanol, and stirred at 35 °C for 0.5 h to obtain solution B;

[0070] The above solution A and solution B were mixed and stirred at 35 °C for 1 h to obtain solution C;

[0071] The above solution C was transferred to a 100 mL stainless steel autoclave, heated to 110 °C, and crystallized at a constant temperature for 24 h;

[0072] The above stainless steel autoclave was cooled to 30 °C, the obtained product was washed, and dried at 120 °C for 12 h to obtain CPO-27 nickel-based metal-organic framework material powder;

[0073] 12.2 g of phosphoric acid, 8.4 g of pseudo-boehmite, 4.7 g of tetraethyl orthosilicate, 6.8 g of di-n-propylamine and 1.5 g of CPO-27 were successively added to 40.0 g of deionized water and stirred at 35 °C for 0.5 h to obtain gel D;

[0074] The above gel D was transferred to a 100 mL stainless steel autoclave, heated to 200 °C, and crystallized at a constant temperature for 24 h;

[0075] The above stainless steel autoclave was cooled to 30 °C, the obtained product was washed, dried at 120 °C for 12 h, and calcined at 600 °C for 6 h to obtain Ni@SAPO-11-2 catalyst.

[0076] After X-ray fluorescence spectroscopy test, the content of Ni in this catalyst is 2.2 wt.%.

[0077] Hydrocarbon isomerization test:

[0078] Take 2.0 mL of Ni@SAPO-11-2, mix it with an equal volume of quartz sand, and load it into a stainless steel reaction tube with an inner diameter of 8 mm; hydrogen was introduced into the reaction tube to make the pressure reach 1.5 MPa, and heated to 500 °C and maintained for 4 h; the temperature was raised to 340 °C, hydrogen and n-octane were introduced, and the hydrogen / n-octane volume ratio was 400:1, and the weight hourly space velocity was 1.2 h -1, sampling and analysis were carried out after 6 h of reaction, and the reaction results are shown in Table 2.

[0079] Example 3

[0080] This example provides a hydrocarbon isomerization catalyst of Ni@SAPO-11, which is prepared by the following steps:

[0081] 2.8 g of nickel acetate tetrahydrate was added to 30.0 g of deionized water, and the mixture was stirred at 35 °C for 0.5 h to obtain solution A;

[0082] 1.2 g of 2,5-dihydroxyterephthalic acid was added to 23.7 g of ethanol, and the mixture was stirred at 35 °C for 0.5 h to obtain solution B;

[0083] The above solution A and solution B were mixed and stirred at 35 °C for 1 h to obtain solution C;

[0084] The above solution C was transferred to a 100 mL stainless steel autoclave, heated to 110 °C, and crystallized at a constant temperature for 24 h;

[0085] The temperature of the above stainless steel autoclave was cooled to 30 °C, the obtained product was washed, and dried at 120 °C for 12 h to obtain CPO-27 nickel-based metal-organic framework material powder;

[0086] 12.2 g of phosphoric acid, 8.4 g of pseudoboehmite, 4.7 g of tetraethyl orthosilicate, 6.8 g of di-n-propylamine and 2.0 g of CPO-27 were successively added to 40.0 g of deionized water and stirred at 35 °C for 0.5 h to obtain gel D;

[0087] The above gel D was transferred to a 100 mL stainless steel autoclave, heated to 200 °C, and crystallized at a constant temperature for 24 h;

[0088] The temperature of the above stainless steel autoclave was cooled to 30 °C, the obtained product was washed, dried at 120 °C for 12 h, and calcined at 600 °C for 6 h to obtain Ni@SAPO-11-2 catalyst.

[0089] After X-ray fluorescence spectroscopy test, the content of Ni in this catalyst is 3.0 wt.%.

[0090] Hydrocarbon isomerization test:

[0091] Take 2.0 mL of Ni@SAPO-11-3, mix it with an equal volume of quartz sand, and load it into a stainless steel reaction tube with an inner diameter of 8 mm; hydrogen was introduced into the reaction tube to make the pressure reach 1.5 MPa, and the temperature was raised to 500 °C and maintained for 4 h; the temperature was raised to 340 °C, hydrogen and n-octane were introduced, and the hydrogen / n-octane volume ratio was 400:1, and the weight hourly space velocity was 1.2 h -1, sampling and analysis were carried out after 6 h of reaction, and the reaction results are shown in Table 2.

[0092] Example 4

[0093] This example provides a hydrocarbon isomerization catalyst of Ni@SAPO-11, which is prepared by the following steps:

[0094] 2.8 g of nickel acetate tetrahydrate was added to 30.0 g of deionized water, and the mixture was stirred at 35 °C for 0.5 h to obtain solution A;

[0095] 1.2 g of 2,5-dihydroxyterephthalic acid was added to 23.7 g of ethanol, and the mixture was stirred at 35 °C for 0.5 h to obtain solution B;

[0096] The above solution A and solution B were mixed and stirred at 35 °C for 1 h to obtain solution C;

[0097] The above solution C was transferred to a 100 mL stainless steel autoclave, heated to 110 °C, and crystallized at a constant temperature for 24 h;

[0098] The temperature of the above stainless steel autoclave was cooled to 30 °C, the obtained product was washed, and dried at 120 °C for 12 h to obtain CPO-27 nickel-based metal-organic framework material powder;

[0099] 12.2 g of phosphoric acid, 8.4 g of pseudoboehmite, 4.7 g of tetraethyl orthosilicate, 6.8 g of di-n-propylamine and 2.5 g of CPO-27 were successively added to 40.0 g of deionized water and stirred at 35 °C for 0.5 h to obtain gel D;

[0100] The above gel D was transferred to a 100 mL stainless steel autoclave, heated to 200 °C, and crystallized at a constant temperature for 24 h;

[0101] The temperature of the above stainless steel autoclave was cooled to 30 °C, the obtained product was washed, dried at 120 °C for 12 h, and calcined at 600 °C for 6 h to obtain Ni@SAPO-11-4 catalyst;

[0102] After X-ray fluorescence spectroscopy test, the content of Ni in this catalyst is 3.9 wt.%.

[0103] Hydrocarbon isomerization test:

[0104] Take 2.0 mL of Ni@SAPO-11-4, mix it with an equal volume of quartz sand, and load it into a stainless steel reaction tube with an inner diameter of 8 mm; hydrogen was introduced into the reaction tube to make the pressure reach 1.5 MPa, and the temperature was raised to 500 °C and maintained for 4 h; the temperature was raised to 340 °C, hydrogen and n-octane were introduced, and the hydrogen / n-octane volume ratio was 400:1, and the weight hourly space velocity was 1.2 h -1, sampling and analysis were carried out after 6 h of reaction, and the reaction results are shown in Table 2.

[0105] Comparative Example 1

[0106] This comparative example provided a hydrocarbon isomerization catalyst, which was prepared by the following steps:

[0107] Dissolve 12.2 g of phosphoric acid in 40.0 g of deionized water, and stir at 35 °C for 0.5 h to obtain solution A;

[0108] Slowly add 8.4 g of pseudo-boehmite, 4.7 g of tetraethyl orthosilicate and 6.8 g of di-n-propylamine to the above solution A, and stir vigorously at 35 °C for 6 h to obtain gel B;

[0109] Transfer the above gel B to a 100 mL stainless steel autoclave, heat up to 200 °C, and crystallize at a constant temperature for 24 h;

[0110] Cool the above stainless steel autoclave to 30 °C, wash the obtained product, dry it at 120 °C for 12 h, and calcine it at 600 °C for 6 h to obtain SAPO-11 powder; its pore structure parameters are shown in Table 1.

[0111] Press SAPO-11 at 15 MPa and screen it into 20-40 mesh particles. Load 3 wt.% Ni by equal-volume impregnation with nickel nitrate solution, dry it at 120 °C for 6 h, and calcine it at 450 °C for 4 h to obtain the hydrocarbon isomerization catalyst Ni / SAPO-11.

[0112] After X-ray fluorescence spectroscopy test, the content of Ni in this catalyst is 3.1 wt.%. Its pore structure parameters are shown in Table 1.

[0113] Take 2.0 mL of Ni / SAPO-11, mix it with an equal volume of quartz sand, and load it into a stainless steel reaction tube with an inner diameter of 8 mm; introduce hydrogen into the reaction tube to make the pressure reach 1.5 MPa, and heat up to 500 °C and keep it for 4 h; raise the temperature to 340 °C, introduce hydrogen and n-octane, and the volume ratio of hydrogen / n-octane is 400:1, and the weight hourly space velocity is 1.2 h -1 , sampling and analysis were carried out after 6 h of reaction, and the reaction results are shown in Table 2.

[0114] Figure 1 XRD patterns of Ni@SAPO-11-3 and Ni / SAPO-11 prepared in Example 3 and Comparative Example 1.

[0115] Figure 2 TEM images of Ni@SAPO-11-3 and Ni / SAPO-11 prepared in Example 3 and Comparative Example 1.

[0116] Figure 3 N2 adsorption - desorption isotherms of Ni@SAPO - 11 - 3 and Ni / SAPO - 11 prepared in Example 3 and Comparative Example 1.

[0117] Table 1 Pore structure parameters of different samples

[0118]

[0119] It can be seen from Table 1 that compared with SAPO - 11, Ni@SAPO - 11 - 3 prepared in the present invention has a comparable specific surface area. Compared with Ni / SAPO - 11, Ni@SAPO - 11 - 3 prepared in the present invention has a higher specific surface area, which is increased by 1.5 times; the mesopore volume is increased by nearly 1.8 times.

[0120] Table 2 Reaction performance results of different catalysts

[0121]

[0122] Note: The above data are measured at 340 °C, with a hydrogen / n - octane volume ratio of 400:1 and a weight hourly space velocity of 1.2 h -1 determined data.

[0123] The hydrocarbon isomerization catalysts prepared in Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 were used in the hydroisomerization reaction of n - octane, and the reaction results are shown in Table 2. It can be seen from Table 2 that the selectivity of multi - branched - chain isomers of the hydrocarbon isomerization catalyst prepared in the present invention is increased by nearly 1.7 times compared with the conventional hydrocarbon isomerization catalyst, while its cracking selectivity is only nearly 0.3 times that of the conventional hydrocarbon isomerization catalyst. This is because compared with Ni / SAPO - 11, Ni@SAPO - 11 - 3 prepared in the present invention has smaller Ni particle size, which can provide more hydrogenation / dehydrogenation active sites for the n - octane isomerization reaction and can effectively inhibit the cracking reaction of n - octane isomer intermediates; at the same time, Ni@SAPO - 11 - 3 has a higher specific surface area and mesopore volume, which can promote the diffusion of n - octane isomer intermediates, reduce the residence time in the SAPO - 11 pore channels, and thus reduce the occurrence of cracking reactions. Therefore, the isomerization catalyst provided by the present invention exhibits excellent total isomer selectivity, multi - branched - chain isomer selectivity and low cracking selectivity.

[0124] For Examples 1, 2, 3 and 4, the Ni content in their catalysts gradually increases. When the Ni content is low, Ni@SAPO-11-1 and Ni@SAPO-11-2 exhibit relatively low n-octane conversion and high cracking selectivity. This is because the number of Ni active sites is small and cannot meet the hydrogenation / dehydrogenation requirements of n-octane isomerization, resulting in the formation of fewer reaction intermediates. At the same time, the reaction intermediates cannot be hydrogenated in a timely manner to form isomer products, leading to further cracking reactions. As the Ni content increases and reaches 3.0 wt.%, Ni@SAPO-11-3 shows high n-octane conversion, isomer selectivity and low cracking selectivity. This is because the increase in the number of Ni active sites helps to generate a large number of reaction intermediates during the reaction process. At the same time, the reaction intermediates can also undergo hydrogenation reactions on the Ni active sites in a timely manner to form isomer products, effectively reducing the formation of cracking products. When the Ni content is further increased, the changes in n-octane conversion, isomer selectivity and cracking selectivity are small, indicating that a Ni content of 3 wt.% can meet the hydrogenation / dehydrogenation requirements of the n-octane hydroisomerization reaction.

[0125] Finally, it should be noted that the above examples are only used to illustrate the implementation process and characteristics of the present invention, rather than limiting the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above examples, those of ordinary skill in the art should understand that: the present invention can still be modified or equivalently replaced, and any modification or partial replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the present invention.

Claims

1. Application of a Ni@SAPO-11 hydrocarbon isomerization catalyst in a hydrocarbon hydroisomerization reaction, characterized in that: The reaction temperature of the hydrocarbon isomerization reaction is 210 - 400 °C, the reaction pressure is 0.5 - 4.0 MPa, the volume ratio of hydrogen to hydrocarbon is 100 - 600:1, and the liquid hourly space velocity is 0.5 - 6 h -1 ; The preparation method of the Ni@SAPO-11 hydrocarbon isomerization catalyst comprises the following steps: Adding a nickel metal source to water and a ligand to a polar organic solvent, fully dissolving them, and then mixing the obtained two solutions to obtain a suspension, wherein the mass ratio of the nickel metal source, the ligand, water and the polar solvent is 2-3:1-2:20-30:15-25, wherein the nickel metal source and the ligand are calculated in terms of molar amount of the whole molecule; crystallizing the suspension; Drying the crystallized product to obtain a nickel-based metal organic framework material; Adding a phosphorus source, an aluminum source, a silicon source, a structure directing agent and a nickel-based metal organic framework material into deionized water in sequence, stirring to obtain a gel, and transferring the gel into a reaction kettle for heating and crystallization, wherein the mass ratio of the phosphorus source, the aluminum source, the silicon source, the structure directing agent, water and the nickel-based metal organic framework material is 10-15: 7-10: 4-7: 5-8: 10-50: 1-2; After the crystallization is completed, the temperature is lowered to separate the crystallization product, and the crystallization product is dried and calcined to obtain the Ni@SAPO-11 catalyst.

2. Use of the Ni@SAPO-11 hydrocarbon isomerization catalyst according to claim 1 in a hydrocarbon hydroisomerization reaction, characterized in that: The nickel metal source is one or a combination of two or more of nickel acetate, nickel nitrate and nickel chloride; And / or, in the step of adding the nickel metal source to water, the amount of water used is 10-15 g / g of the nickel metal source.

3. Use of the Ni@SAPO-11 hydrocarbon isomerization catalyst according to claim 1 in a hydrocarbon hydroisomerization reaction, characterized in that: The ligand includes one or a combination of two or more of trimesic acid, terephthalic acid, and 2,5-dihydroxyterephthalic acid.

4. Use of the Ni@SAPO-11 hydrocarbon isomerization catalyst according to claim 1 in a hydrocarbon hydroisomerization reaction, characterized in that: The polar organic solvent includes one or a combination of two or more of methanol, ethanol and ethylene glycol; And / or, the amount of polar organic solvent used is 15-25 g / g ligand.

5. Use of the Ni@SAPO-11 hydrocarbon isomerization catalyst according to claim 1 in a hydrocarbon hydroisomerization reaction, characterized in that: In the preparation step of the nickel-based metal organic framework material, the crystallization temperature is 100-140 °C and the crystallization time is 12-72 h.

6. Use of the Ni@SAPO-11 hydrocarbon isomerization catalyst according to claim 1 in a hydrocarbon hydroisomerization reaction, characterized in that: In the gel crystallization step, the temperature is 180-230 °C, the crystallization time is 12-72 h, the calcination temperature is 500-700 °C, and the calcination time is 4-12 h.

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