Isomerization catalyst, synthesis method and use thereof

Abstract

The application belongs to the technical field of catalysts, and discloses an isomerization catalyst, a synthesis method and application thereof. The catalyst composition comprises 92-99.99wt% of *MRE molecular sieve and 0.01%-8% of active metal component. The catalyst is applied to the processing of petroleum distillates and Fischer-Tropsch synthesis products. The shaped catalyst is prepared in one step, and the catalyst preparation process is simplified. The shaped body is entirely composed of the active metal component and the molecular sieve, the amount of active sites of the catalyst per unit volume is increased, and the catalytic activity is improved. The method directly obtains the shaped catalyst, avoids the filtering and washing steps in the conventional catalyst production process, has low waste liquid discharge and is environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to an isomerization catalyst, its synthesis method, and its application. Background Technology

[0002] In recent years, with the continuous growth of the global economy, the market has increasingly higher requirements for the quality of gasoline, diesel, and lubricating oil. To improve the quality of fuels, n-alkanes must be removed as much as possible. For gasoline, octane rating is an important quantitative indicator of its quality; high-octane gasoline has higher combustion efficiency than low-octane gasoline. Isoalkanes with the same number of carbon atoms generally have a higher octane rating than n-alkanes. Therefore, isomerizing n-alkanes to isoalkanes can increase the octane rating of gasoline. For diesel, low-temperature flow performance is one of the main standards for measuring its quality. If n-alkanes can be selectively isomerized to isoalkanes, their pour point or cold filter plugging point can be lowered, thereby improving their low-temperature performance. As for lubricating oil, its quality is closely related to the performance of the base oil, because the content of base oil in lubricating oil is usually 70% to 99%. The long-chain n-alkanes (also known as waxes) in the base oil have high pour points and freezing points, and poor low-temperature fluidity, which cannot meet the needs of current engines. To obtain lubricating oil with good low-temperature fluidity, the wax in the base oil must be removed.

[0003] Currently, the main industrial processes for removing n-alkanes from oil products include solvent dewaxing, catalytic dewaxing, and isomerization dewaxing. Compared with the first two processes, isomerization dewaxing involves an isomerization reaction of wax molecules, thereby converting the wax into the desired components. This process has the advantages of high product yield and good quality.

[0004] Selective isomerization of n-alkanes into short-chain isoalkanes with fewer side chains can effectively improve the low-temperature fluidity of diesel and lubricating oils. Catalysts supported on ZSM-48 molecular sieves have shown excellent performance in the hydroisomerization reaction of long-chain n-alkanes and have attracted much attention in recent years.

[0005] ZSM-48 molecular sieve is a type of molecular sieve with a one-dimensional ten-membered ring straight-through channel framework and a *MRE-type disordered structure, with an ideal channel diameter of 0.53 nm * 0.56 nm. Catalysts based on ZSM-48 molecular sieve exhibit excellent catalytic performance in the hydroisomerization reaction of long-chain n-alkanes. In recent years, with the rapid development of the national economy, the market demand for ZSM-48 molecular sieve has gradually increased. When ZSM-48 molecular sieve is used as a catalyst in actual industrial applications, it often needs to be prepared into granular products of specific shapes and sizes. The finished product preparation process includes the synthesis of molecular sieve powder and the processing and shaping of catalyst particles.

[0006] In general, a complete isomerization catalyst requires two parts: the synthesis of molecular sieves and the loading of active metal components. Industrially, ZSM-48 molecular sieve powder is synthesized using a hydrothermal method. This method uses water as a solvent, and materials are mixed in a specific ratio to form a sol. The sol is then crystallized at 80-200 °C under the autogenous pressure of water. After crystallization, the product is filtered, washed, and dried to obtain molecular sieve powder. Loading the active metal component requires first shaping the molecular sieve. Specifically, the molecular sieve powder is mixed with additives such as binders, plasticizers, extrusion aids, and pore-forming agents to obtain a plastic body. This body is then kneaded, cured, dried, and calcined to obtain the finished product. A certain amount of active metal component solution is then mixed with and impregnated with the molecular sieve particles to finally obtain the active metal component / molecular sieve catalyst. Patent documents such as US5882505, CN1792451, 1788844, and 101245260 describe in detail the preparation methods of alkane isomerization catalysts using molecular sieves as supports.

[0007] The above method involves first preparing molecular sieve powder, then molding, drying, and calcining it, followed by impregnation with loaded metal active components to obtain the finished catalyst. This process is lengthy and complex. Furthermore, the hydrothermal crystallization of molecular sieves is carried out under high pressure, posing safety hazards; the filtration and washing process of the powder generates a large amount of wastewater, causing environmental pollution; and the catalyst molding requires the addition of binders and other additives. Due to the introduction of these additives, the molecular sieve content in the finished catalyst is generally only 60-80%, failing to reach 100%, thus affecting the performance of the molecular sieve.

[0008] To address these issues, extensive research has been conducted on two aspects: simplifying the molecular sieve molding process and increasing the molecular sieve content in the molded body.

[0009] Researchers have been able to directly produce molecular sieves with the same shape as the raw materials by using raw materials with a certain shape, without the need for further shaping, which simplifies the preparation process of molecular sieve catalysts.

[0010] For example, Sachse et al. prepared a shaped ZSM-5 catalyst using monolithic SiO2 material as the raw material. This method involves placing the monolithic SiO2 material in a solution with a molar ratio of SiO2:NaOH:NaAlO2:TPAOH:H2O = 1:0.15:0.09:0.004:33 and crystallizing it at 150 °C for 24 h to obtain the shaped catalyst (Micropor. Mesopor. Mater., 2011, 140(1-3): 58-68). This method uses monolithic SiO2 material as the silicon source for molecular sieve synthesis. The crystallization process maintains a solid phase, but other raw materials such as the aluminum source NaAlO2 still exist in the aqueous solution, making the crystallization a hydrothermal process. Although the finished molecular sieve retains the shape of the monolithic material, the reaction process is limited by mass transfer due to the reactants being located in both solid and liquid phases, resulting in incomplete crystallization and a ZSM-5 content of only 38% in the finished product.

[0011] To increase the molecular sieve content in finished molecular sieve catalysts, researchers have conducted extensive work, crystallizing additives such as binders added during the molding process into molecular sieves. For example, patent CN106745057A discloses a method for preparing an AEI / MFI eutectic molecular sieve catalyst. This method mixes MFI-type aluminosilicate molecular sieves and FAU-type aluminosilicate molecular sieves with silica sol, and then converts them into an integrated AEI / MFI eutectic molecular sieve catalyst through hydrothermal treatment in an aqueous solution containing organic amines. The catalyst is then calcined to obtain the finished catalyst product.

[0012] The above methods crystallize some raw materials as a monolithic material under hydrothermal conditions, producing a monolithic catalyst in one step and simplifying the preparation process. However, other raw materials still remain in the aqueous solution, and the crystallization process is still hydrothermal, posing safety risks. The reactants are separated into solid and liquid phases, limiting the reaction process due to mass transfer limitations. The finished product contains unconverted raw materials, resulting in a low molecular sieve content. Furthermore, although a molded body composed entirely of molecular sieves can be obtained, the synthesis of molecular sieve powder is still required; the molding process adds a crystallization step, increasing manufacturing costs. Additionally, these methods use monolithic material raw materials, limiting the shape to a single type due to the material properties. Currently, molded catalysts come in a wide variety of shapes, including spheres, strips, cylinders, honeycomb shapes, four-leaf clover shapes, three-leaf clover shapes, external gear shapes, non-porous external gear shapes, plum blossom shapes, porous plum blossom shapes, seven-hole spheres, non-porous spheres, seven-ribbed wheel shapes, four-hole shapes, four-leaf butterfly shapes, and so on.

[0013] The above work has been conducted on molded molecular sieves. Molded catalysts, especially molded catalysts that combine metal active components with molecular sieves in one step, still need further research. There is currently no similar work. Summary of the Invention

[0014] To overcome the shortcomings of existing technologies, this invention provides an isomerization catalyst, its synthesis method, and its application. This method can simultaneously achieve the goals of simplifying the isomerization catalyst preparation process and increasing the molecular sieve content in the shaped catalyst. Catalysts based on ZSM-48 molecular sieves exhibit excellent catalytic performance in the hydroisomerization reaction of long-chain n-alkanes. This invention specifically provides a method for directly synthesizing shaped catalysts using active metal components and ZSM-48 molecular sieves.

[0015] The above-mentioned objective of this invention is achieved through the following technical solution: a method for synthesizing an isomerization catalyst, comprising the following steps: 1. A gel is prepared by mixing an aluminum source, an alkali source, a template agent, a silicon source, a metal source, an ionic liquid, and deionized water; 2. The gel obtained in step 1 is fed into a forming system and processed into a molded gel with the desired shape; 3. The molded gel obtained in step 2 is crystallized in a reactor to obtain the molded Pt / ZSM-48 molded catalyst.

[0016] Furthermore, the metal source mentioned in step 1 refers to one or more of Group VIII metal acids, metal salts, chlorides, ammonia complexes, carbonyl complexes, or mixtures thereof, selected from Pt, Pd, and Ir. The Group VIII noble metals are composed of one or more of Pt, Pd, and Ir.

[0017] In a further preferred embodiment of the present invention, the metal source in step 1 is Pt and Pd.

[0018] Furthermore, the template agent mentioned in step 1 is one or more of hexamethylammonium bromide, hexamethylbisammonium hydroxide, and 1,6-hexanediamine.

[0019] Furthermore, the ionic liquid mentioned in step 1 is Br - I - Cl - BF4 - NO3 - CH3COO - One or more of the following; the cation is an alkyl-substituted imidazole ion [Rim]. + Alkyl-substituted pyridinium ions [Rpy] + Alkyl quaternary ammonium salt ion [NR4] + One or more of them, where R is a C1-C16 alkyl group.

[0020] Furthermore, the aluminum source mentioned in step 1 is one or both of sodium aluminate and boehmite; the silicon source is silica sol; and the alkali source is one or both of sodium hydroxide and potassium hydroxide.

[0021] Furthermore, the molar ratio of aluminum source, alkali source, template agent, silicon source, metal source, ionic liquid and deionized water in step 1 is (0.005-0.009): (0.01-1): (0.1-0.25): 1: (0.008-0.1): (0.2-1): (10-45).

[0022] Furthermore, the material forming system in step 2 is specifically composed of a conveyor belt, a cavity, and a receiving hopper connected in sequence. The conveyor belt is controlled by a motor switch with an operation panel. The cavity is equipped with a housing shell, an ultrasonic vibrator is installed at the bottom of the housing shell, and a support is also installed at the bottom of the housing shell.

[0023] Furthermore, step 2 specifically involves: placing the gel in the molding mold and then placing it on the conveyor belt, turning on the motor to convey it into the cavity, and using the bottom ultrasonic vibrator to vibrate the gel until it is uniformly formed. The formed gel is then sent to the receiving hopper.

[0024] Furthermore, the crystallization conditions in step 3 are: crystallization at 170-190℃ for 5-24 hours.

[0025] Another objective of this invention is to protect an isomerization catalyst comprising 92-99.99 wt% *MRE molecular sieve and 0.01%-8% active metal components, which is synthesized by the above-described isomerization catalyst synthesis method.

[0026] Another object of the present invention is to claim protection for the application of the above-mentioned isomerization catalyst, specifically in the processing of petroleum fractions and Fischer-Tropsch synthesis products.

[0027] Furthermore, isomerization catalysts are applied to isomerization dewaxing and isomerization dewaxing.

[0028] In this invention, the crystallization process involves placing the formed gel in a container, which may contain a certain amount of water pre-placed, but it is not necessary for the water to directly contact the formed gel. The heating methods used in the crystallization process include, for example, oil bath heating, oven heating, and microwave heating.

[0029] Once crystallization is complete, the molded product obtained by this invention does not require filtration or washing, retains the same shape and size as the molded gel, and is entirely composed of active metal components and molecular sieves. The molecular sieve framework structure is ZSM-48 molecular sieve confirmed by the International Zeolite Association.

[0030] To aid in understanding this invention, the term "direct molding" is defined below. This defined term has the meaning commonly understood by one of ordinary skill in the art related to this invention.

[0031] Unless otherwise stated, "direct molding" in this article refers to the process or step of pre-processing the gel used to synthesize molecular sieves into a shaped gel with a certain shape, size and mechanical strength through methods such as compression, extrusion, rotation, spraying, etc., and then directly obtaining a shaped molecular sieve with the same shape as the shaped gel by heating.

[0032] The advantages of this invention compared to existing technologies are as follows: This invention produces a shaped catalyst in one step, simplifying the catalyst preparation process. The shaped body is entirely composed of active metal components and molecular sieves, increasing the amount of active sites per unit volume of catalyst and thus enhancing its catalytic activity. This method directly obtains the shaped catalyst, avoiding the filtration and washing steps of conventional catalyst production processes, resulting in low wastewater discharge and environmental friendliness. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the material forming system of the present invention; Figure 2 This is the XRD pattern of the sample in Example 1 of this invention; Figure 3 This is the HAADF image of the sample in Example 1 of this invention; Figure 4 This is a photograph of the molded gel in Embodiment 1 of the present invention; Figure 5 This is a physical image of the Pt / ZSM-48 catalyst formed in Example 1 of the present invention.

[0034] In the diagram: 1. Conveyor belt; 2. Motor; 3. Control panel; 4. Ultrasonic vibrator; 5. Support frame; 6. Housing shell; 7. Receiving hopper; 8. Cavity. Detailed Implementation

[0035] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0036] Example 1

[0037] 0.05 g of boehmite (78.6 wt% Al2O3) was placed in a 100 ml beaker, and 50.75 g of deionized water was added. The mixture was stirred at room temperature for 30 minutes. Then, 0.03 g of potassium hydroxide was added, and the mixture was stirred at room temperature for 30 minutes. Next, 5.4 g of hexamethylammonium bromide was added, and the mixture was stirred for 30 minutes. Then, 15 g of silica sol with a concentration of 30 wt% was added, and the mixture was stirred for another 30 minutes. Finally, 23.4 mL of H2PtCl6 solution (containing 0.005 g of Pt per mL) was added, and the mixture was stirred for 30 minutes. Then, 2.87 g of 1-ethyl-3-methylimidazolium bromide ionic liquid was added, and the mixture was stirred until homogeneous. The mixture was then treated at 90°C and extruded into cylindrical strips. The cylindrical strip gels were then placed in a crystallization vessel lined with polytetrafluoroethylene and crystallized at 180°C for 18 hours.

[0038] After crystallization, the crystallization vessel was cooled to room temperature to obtain the shaped catalyst. The shaped catalyst was ground into powder, and XRD analysis showed that the molecular sieve was ZSM-48. Figure 1 As shown; the shaped catalyst was calcined at 550℃ for 6 hours in air, and then reduced at 400 °C in H2 atmosphere (25 ml / min) for 4 hours to prepare 0.48 wt% Pt / ZSM-48. HAADF imaging showed that the Pt particles in the catalyst were uniformly distributed. Figure 2 As shown; the molded gel and the molded Pt / ZSM-48 catalyst have the same shape, such as Figure 3 As shown.

[0039] Example 2

[0040] 0.09 g of boehmite (78.6 wt% Al2O3) was placed in a 100 ml beaker, and 13.5 g of deionized water was added. The mixture was stirred at room temperature for 30 minutes. Then, 3 g of potassium hydroxide was added, and the mixture was stirred at room temperature for 30 minutes. Next, 3.15 g of hexamethyldiamine hydroxide was added, and the mixture was stirred for 30 minutes. Then, 15 g of silica sol with a concentration of 30 wt% was added, and the mixture was stirred for another 30 minutes. Finally, 292.5 mL of H2PtCl6 solution (containing 0.005 g of Pt per mL) was added, and the mixture was stirred for 30 minutes. Then, 14.3 g of 1-ethyl-3-methylimidazolium bromide ionic liquid was added, and the mixture was stirred until homogeneous. The mixture was then treated at 90°C and extruded into cylindrical strips. The cylindrical strip gels were then placed in a crystallization vessel lined with polytetrafluoroethylene and crystallized at 170°C for 24 hours.

[0041] After crystallization, the crystallization vessel was cooled to room temperature to obtain the shaped catalyst. The shaped catalyst was ground into powder, and XRD analysis showed that the molecular sieve was ZSM-48. The shaped catalyst was calcined in air at 550°C for 6 hours to remove the template agent, and then reduced at 400°C in H2 atmosphere (25 ml / min) for 4 hours to prepare a 5 wt% Pt / ZSM-48 catalyst.

[0042] Example 3

[0043] 0.07 g of sodium aluminate was placed in a 100 ml beaker, and 60.75 g of deionized water was added. The mixture was stirred at room temperature for 30 minutes. 2.1 g of potassium hydroxide was added, and the mixture was stirred at room temperature for 30 minutes. 5.4 g of hexamethylammonium bromide and 0.45 g of 1,6-hexanediamine were added, and the mixture was stirred for 30 minutes. 15 g of 30 wt% silica sol was added, and the mixture was stirred for another 30 minutes. 29.2 mL of H2PtCl6 solution (containing 0.005 g of Pt per mL) was added, and the mixture was stirred for 30 minutes. 7.16 g of 1-ethyl-3-methylimidazolium bromide ionic liquid was added, and the mixture was stirred until homogeneous and treated at 90°C. The mixture was then extruded into clover-shaped strips. The cylindrical strip gels were placed in a crystallization vessel lined with polytetrafluoroethylene and crystallized at 190°C for 5 hours.

[0044] After crystallization, the crystallization vessel was cooled to room temperature to obtain the shaped catalyst. The shaped catalyst was ground into powder, and XRD analysis showed that the molecular sieve was ZSM-48. The shaped catalyst was calcined in air at 550°C for 6 hours to remove the template agent, and then reduced at 400°C in H2 atmosphere (25 ml / min) for 4 hours to prepare a 0.5 wt% Pt / ZSM-48 catalyst.

[0045] Example 4

[0046] 0.09 g of boehmite was placed in a 100 ml beaker, and 60.75 g of deionized water was added. The mixture was stirred at room temperature for 30 minutes. Then, 0.84 g of potassium hydroxide was added, and the mixture was stirred at room temperature for 30 minutes. Next, 5.4 g of hexamethylammonium bromide and 0.45 g of 1,6-hexanediamine were added, and the mixture was stirred for 30 minutes. Then, 15 g of silica sol with a concentration of 30 wt% was added, and the mixture was stirred for another 30 minutes. Finally, 146.25 mL of H2PtCl6 solution (containing 0.005 g of Pt per mL) was added, and the mixture was stirred for 30 minutes. Then, 11.5 g of 1-ethyl-3-methylimidazolium bromide ionic liquid was added, and the mixture was stirred until homogeneous. The mixture was then treated at 90°C and extruded into clover-shaped strips. The cylindrical strip gels were then placed in a crystallization vessel lined with polytetrafluoroethylene and crystallized at 190°C for 5 hours.

[0047] After crystallization, the crystallization vessel was cooled to room temperature to obtain the shaped catalyst. The shaped catalyst was ground into powder, and XRD analysis showed that the molecular sieve was ZSM-48. The shaped catalyst was calcined in air at 550°C for 6 hours to remove the template agent, and then reduced at 400°C in H2 atmosphere (25 ml / min) for 4 hours to prepare a 2.5 wt% Pt / ZSM-48 catalyst.

[0048] Comparative Examples 1-4

[0049] The ZSM-48 molecular sieves of Comparative Examples 1-4 were prepared according to the method described in patent CN111137905B. The specific steps are as follows: (1) 1,6-hexanediamine, sodium hydroxide, and water were mixed together and dissolved by electric stirring. Under electric stirring at 25°C, alkaline silica sol was gradually added to it by peristaltic pump. The mixture was aged at 25°C for 2 hours. The molar ratio of each substance was Na2O:SiO2:C6H 16 N2:H2O=0.15:6:1:150. (2) Transfer to a pressure vessel with a polytetrafluoroethylene liner, and then crystallize at 165°C for 10h in a homogenizing reactor (dynamic oven, 800rpm). (3) After cooling to room temperature, open the vessel and add an alkaline aluminum solution containing sodium aluminate and hexamethylammonium bromide (the concentration of the aluminum source is 0.003mol% based on Al2O3) at one time. Adjust the pH of the alkaline aluminum solution to 12 with sodium hydroxide so that SiO2:Al2O3:hexamethylammonium bromide=125:1:0.004. Then seal the pressure vessel and crystallize dynamically at 170°C in a homogenizer at 800rpm for 24h. (4) After cooling to room temperature, open the vessel. After separation, washing and drying, the product is finally obtained as ZSM-48 molecular sieve powder.

[0050] ZSM-48 molecular sieve raw powder was calcined at 550℃ for 6 hours, and then 2% of guar gum powder, 0.3% sodium carboxymethyl cellulose, 8% nitric acid, and 0.85 water-to-powder ratio were added. The mixture was then extruded to obtain cylindrical strip-shaped ZSM-48 molecular sieves, which were then calcined at 550℃ for 5 hours.

[0051] Comparative Example 1

[0052] Take 2g of the above ZSM-48 molecular sieve, impregnate it with 2.0mL of H2PtCl6 solution (each mL contains 0.0048g of Pt), place it at room temperature for 12h, dry it at 120℃ for 2h, and then reduce it at 500℃ for 4h in a hydrogen atmosphere to obtain a catalyst containing 0.5wt.%Pt.

[0053] Comparative Example 2

[0054] Take 2g of the above ZSM-48 molecular sieve, impregnate it with 2.0mL of H2PtCl6 solution (each mL contains 0.05g of Pt), place it at room temperature for 12h, dry it at 120℃ for 2h, and then reduce it at 500℃ for 4h in a hydrogen atmosphere to obtain a catalyst containing 5wt.%Pt.

[0055] Comparative Example 3

[0056] Take 2g of the above ZSM-48 molecular sieve, impregnate it with 2.0mL of H2PtCl6 solution (each mL contains 0.005g of Pt), place it at room temperature for 12h, dry it at 120℃ for 2h, and then reduce it at 500℃ for 4h in a hydrogen atmosphere to obtain a catalyst containing 0.5wt.%Pt.

[0057] Comparative Example 4

[0058] Take 2g of the above ZSM-48 molecular sieve, impregnate it with 2.0mL of H2PtCl6 solution (each mL contains 0.025g of Pt), place it at room temperature for 12h, dry it at 120℃ for 2h, and then reduce it at 500℃ for 4h in a hydrogen atmosphere to obtain a catalyst containing 2.5wt.%Pt.

[0059] 1.0 mL of catalyst from each of Examples 1-4 and Comparative Examples 1-4 was charged into a stainless steel tube reactor and evaluated using the hydroisomerization reaction of n-dodecane. The reaction conditions were: reaction pressure 0.1 MPa, n-dodecane liquid hourly space velocity 1.0 h⁻¹. -1 The molar ratio of hydrogen to n-dodecane was 15. The reaction products were analyzed by online gas chromatography, and the results are listed in Table 1.

[0060] Table 1. Results of applying the catalyst to the hydroisomerization reaction of n-dodecane.

[0061] n-Dodecane conversion rate (%) = 1 - (Amount of unconverted n-dodecane) / (N-dodecane feed rate) × 100% Isomerization selectivity (%) = Amount converted to isomerized (branched) dodecane / Total amount of n-dodecane converted × 100% Isomerization yield (%) = Isomerization selectivity (%) × n-dodecane conversion (%) × 100% As shown in Table 1, the shaped catalyst prepared by this method has improved the conversion rate of n-dodecane and the selectivity of isoalkanes compared with the catalyst in the comparative example.

[0062] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for synthesizing an isomerization catalyst, characterized in that the step... include: S1. A gel is prepared by mixing an aluminum source, an alkali source, a template agent, a silicon source, a metal source, an ionic liquid, and deionized water; The metal source refers to one or more of Group VIII metal acids, metal salts, chlorides, ammonia complexes, and carbonyl complexes, or a mixture thereof; the Group VIII metal is composed of one or more of Pt, Pd, and Ir; the template agent is one or more of hexamethylammonium bromide, hexamethylbisammonium hydroxide, and 1,6-hexanediamine; and the anion of the ionic liquid is Br₂. - I - Cl - BF4 - NO3 - CH3COO - One or more of the following; the cation is an alkyl-substituted imidazole ion [Rim]. + Alkyl-substituted pyridinium ions [Rpy] + Alkyl quaternary ammonium salt ion [NR4] + One or more of the following, where R is a C1-C16 alkyl group; the aluminum source is one or two of sodium aluminate and boehmite; the silicon source is silica sol; the alkali source is one or two of sodium hydroxide and potassium hydroxide; and the molar ratio of aluminum source, alkali source, template agent, silicon source, metal source, ionic liquid, and deionized water is (0.005-0.009):(0.01-1):(0.1-0.25):1:(0.008-0.1):(0.2-1):(10-45); S2. The gel obtained in step S1 is fed into a forming system to be processed into a molded gel with the desired shape. The forming system consists of a conveyor belt, a cavity, and a receiving hopper connected in sequence. The conveyor belt is controlled by a motor with an operation panel. The cavity is equipped with a housing, an ultrasonic vibrator at the bottom of the housing, and a support at the bottom of the housing. The specific operation involves placing the gel in a molding mold and then placing it on the conveyor belt. The motor is turned on to convey the gel into the cavity. The ultrasonic vibrator at the bottom vibrates the gel until it is uniformly formed. The molded gel is then sent to the receiving hopper. S3. The molded gel obtained in step S2 is placed in a reactor and crystallized at 170-190℃ for 5-24 hours to obtain the molded Pt / ZSM-48 molded catalyst; In the molding catalyst, The content of molecular sieve is 92~99.99wt%, and the content of active metal components is 0.01%~8%.

2. The application of the isomerization catalyst synthesized by the method described in claim 1, characterized in that, Specifically, it is used in the processing of petroleum fractions or Fischer-Tropsch synthesis products.

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