A catalyst for selective hydrogenation of a carbon five fraction and a method for preparing the same

Abstract

The application provides a C5 fraction selective hydrogenation catalyst and a preparation method thereof, the carrier of the catalyst comprises alumina with a bimodal pore distribution structure, the pore diameter of small pores is 7-40 nm, and the pore diameter of large pores is 60-300 nm; the active component comprises Pd, Ni, Cu, Ce, Pt and Zn, the content of Pd is 0.2%-0.48% based on 100% of the mass of the catalyst, the content of Zn is 0.01%-3%, the content of Ni is 0.5%-5%, the mass ratio of Cu to Ni is 0.1-1:1, the content of Ce is 0.1%-0.5%, the content of Pt is 0.005%-0.05%, and Ni-Cu is loaded by a microemulsion method. The cracking C5 fraction selective hydrogenation catalyst provided by the application has good selectivity, anti-coking property and regeneration performance: after 5 times of regeneration, the catalyst still has excellent hydrogenation activity, selectivity and anti-coking property.

Description

Technical Field

[0001] This invention belongs to the field of hydrogenation catalyst technology, specifically relating to a selective hydrogenation catalyst for C5 fraction and its preparation method. Background Technology

[0002] It is projected that my country's ethylene production capacity will reach 60 million tons per year by 2025. Cracked C5 is a byproduct of the high-temperature cracking process of petroleum hydrocarbons to produce ethylene. If liquid hydrocarbons (such as naphtha and light diesel oil) are used as cracking feedstock, the yield of cracked C5 can reach 14% to 20% of ethylene production. The comprehensive utilization of the large amount of cracked C5 byproducts from ethylene plants affects not only the flexibility and advancement of the plant but also its overall economic efficiency, and directly relates to the overall benefits of the enterprise. The dienes and monoolefins contained in the C5 fraction are chemically highly reactive due to their unique molecular structures, and can be used to synthesize many high-value-added products, making them valuable chemical raw material resources. With the rapid development of the petrochemical industry, ethylene production capacity is continuously increasing, and the sources of cracked C5 are becoming increasingly abundant and have become an indispensable chemical resource. How to effectively utilize the considerable amount of C5 resources and increase their added value has become an urgent need for enterprises to achieve high-quality development.

[0003] The 2-methylbutene-1 and 2-methylbutene-2 ​​produced by selective hydrogenation of crude isoprene from the C5 cracking fraction separation unit can be used as raw materials for the production of isoprene petroleum resin. This utilization method is also one of the important ways for various ethylene plants to comprehensively utilize the C5 cracking fraction. Currently, palladium catalysts are commonly used in industry for the selective hydrogenation of crude isoprene from the C5 cracking fraction. To ensure that the 2-methylbutene-1 and 2-methylbutene-2 ​​produced by isoprene hydrogenation are not further hydrogenated to form alkanes, the catalyst must have high hydrogenation selectivity to achieve better economic benefits. In actual hydrogenation reactions, palladium catalysts exhibit high activity. However, while selectively hydrogenating isoprene, unsaturated hydrocarbons such as pentene in the feedstock also polymerize on the acidic sites of the catalyst to form oligomers with a wide molecular weight, commonly known as "green oil." This green oil adsorbs onto the catalyst surface and further forms coke, blocking the catalyst pores and preventing reactants from diffusing to the active sites of the catalyst. This leads to a decrease in catalyst activity, causing coking and deactivation, which affects catalyst performance and lifespan.

[0004] For example, Chinese patent document 201310114077.7 discloses a hydrogenation catalyst with Pd, Ag, and Ni as active components. Pd and Ag are supported by an aqueous solution impregnation method, while Ni is supported by a W / O microemulsion impregnation method. In this hydrogenation catalyst, Pd / Ag and Ni are located in channels of different pore sizes, allowing the generated green oil to undergo saturated hydrogenation in the macropores, thus reducing the amount of coking on the catalyst. However, this catalyst is mainly suitable for the selective hydrogenation of C2.

[0005] Chinese patent document 200710179443.1 discloses a selective hydrogenation catalyst and a preparation method thereof. The hydrogenation catalyst has an alumina carrier and a palladium active component. The active component is distributed in a form of eggshell on the surface of the carrier. The catalyst contains 0.2-0.5wt% of the active component Pd, 2-8wt% of the auxiliary agent lanthanum and / or cerium, and 2-8wt% of the alkaline earth metal element, and has a specific surface area of 70-150m 2 / g, a pore volume of 0.3-0.6ml / g, and a carrier crystal form of theta type or a mixed crystal form of theta and alpha types. The catalyst is suitable for selective hydrogenation of medium and low fraction oil double bonds. However, the catalyst has a poor effect on selective hydrogenation of crude isoprene.

[0006] Zhang Gongyuan et al. prepared Bi-modified Pd-Au / A12O3 catalyst for selective hydrogenation of isoprene by using an equal-volume impregnation method. The results show that the selectivity of the catalyst to mono-olefins is improved after adding Bi, but the activity is decreased. When the reaction temperature is 80℃, with the increase of Bi content (w=0.1%-0.3%), the conversion rate of isoprene is decreased from 98% to 34%, the selectivity of 2-methyl-2-butene is decreased from 82.3% to 68.6%, and the selectivity of 3-methyl-1-butene and 2-methyl-1-butene is increased from 2.1%, 13.3% to 8.6%, 22.0% respectively. However, the document focuses on mechanism and exploration research, and has little significance for scale-up and industrial application.

[0007] Chinese patent document 200810150407.7 provides a selective hydrogenation catalyst for carbon five fraction. The catalyst has a composite carrier of alumina and molecular sieve, and an active component of metals in Group IA or IIA, Group VIII, Group IVA, and Group IB of the periodic table. The composite carrier is impregnated with an aqueous solution of Group IA / IIA metal compound, and then impregnated with an aqueous solution of Group VIII metal salt, a nitrate solution of Group IVA metal, and a nitrate solution of Group IB metal. When the catalyst is used for selective hydrogenation of unsaturated compounds in carbon five fraction, the hydrogenation conversion rate of acetylenic hydrocarbons is ≥45%, and the hydrogenation conversion rate of diene hydrocarbons is 15-35%. However, the addition of molecular sieve in the carrier affects the acidity of the catalyst, resulting in a shortened service period of the catalyst.

[0008] Chinese patent document 201410827883.3 discloses a selective hydrogenation catalyst for C5 fraction, which has γ-Al2O3 modified by organic acid as carrier, metals in Group VIII, IB or IIB of the periodic table as active components; the weight content of metals in Group IB or IIB is 0.02%-0.2% and the weight content of metals in Group VIII is 0.05%-0.5% based on the total weight of the catalyst. For C5 fraction containing 15-25% of isoprene and 1-2% of alkyne, the content of alkyne after hydrogenation is <50 μg / g and the loss rate of isoprene is <2%. However, the catalyst is mainly used for selective hydrogenation to remove alkyne.

[0009] Chinese patent document 201010145234.7 discloses a method for selective hydrogenation of cracked C5 fraction, in which the main active component of the catalyst is Pd, and in the preparation process of the catalyst, the carrier loaded with the precursor of the active component is treated by ionizing radiation to make the main active component Pd in elemental state at room temperature and in air; the average particle size of the active component is less than 10 nm; and in the preparation process, the carrier loaded with the precursor of the active component is wetted by a solution containing a free radical scavenger and then irradiated by ionizing radiation in the wet state. The hydrogenation process conditions are as follows: inlet temperature 20-100℃, volume ratio of hydrogen to C5 30-100, C5 volume hourly space velocity 1-8 h-1, and reaction pressure 0.5-5 MPa, which can selectively hydrogenate C5 to C5 mono-olefin. However, the palladium particles with an average particle size less than 10 nm greatly increase the risk of agglomeration during use, especially as the inlet temperature increases.

[0010] Chinese patent document 200810114744.0 discloses an unsaturated hydrocarbon selective hydrogenation catalyst and a preparation method thereof. The catalyst has alumina as carrier and palladium as active component, and the anti-impurity and anti-coking properties of the catalyst are improved by adding rare earth and alkaline earth metals and fluorine, but the selectivity of the catalyst is not ideal.

[0011] Chinese patent document 201010291602.9 discloses a method for selective hydrogenation removal of alkyne from cracked C5 stream containing isoprene, which uses a catalyst containing carrier, metal active component palladium and silane group. The hydrogenation method can effectively solve the influence of water content or water content fluctuation in the raw material on the hydrogenation performance of the catalyst, and also can inhibit the amount of carbon deposition on the catalyst, but the catalyst is only suitable for alkyne hydrogenation.

[0012] The currently developed carbon five selective hydrogenation catalyst still has many problems in technology, and the industrial implementation scheme is less. And the carrier is mainly alumina, the type and use of the modified additives are many, but the real palladium catalyst which can effectively improve the reaction activity, selectivity, anti-coking and regeneration performance is still less. Therefore, it is of great significance to find a palladium catalyst with high crude isoprene selective hydrogenation activity, high selectivity, good stability and regeneration performance for the comprehensive utilization of carbon five fraction. SUMMARY

[0013] The purpose of the present application is to provide a carbon five fraction selective hydrogenation catalyst, which has excellent hydrogenation activity, selectivity and anti-coking performance in the selective hydrogenation process for cracking carbon five fraction, and has good stability and regeneration performance.

[0014] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0015] A carbon five fraction selective hydrogenation catalyst, comprising a carrier and an active component, the carrier comprising alumina, the alumina having a bimodal pore distribution structure; wherein the pore size of small pores is 7-40 nm, and the pore size of large pores is 60-300 nm; the active component comprising Pd, Ni, Cu, Ce, Pt and Zn, the content of Pd being 0.2%-0.48% based on 100% of the mass of the catalyst, preferably 0.25%-0.4%, the content of Zn being 0.01%-3%, preferably 0.5%-1.5%, the content of Ni being 0.5%-5%, preferably 1%-2.5%, the mass ratio of Cu to Ni being 0.1-1:1, preferably 0.2-0.6:1, the content of Ce being 0.1%-0.5%, preferably 0.2%-0.4wt%, the content of Pt being 0.005%-0.05%, preferably 0.01%-0.03%, and Ni-Cu being loaded by a microemulsion method.

[0016] Optionally, the shape of the carrier is any one of spherical, cylindrical, trilobal and quadrilobal.

[0017] Optionally, the specific surface area of the carrier is 50-100 m 2 / g, preferably 60-85 m 2 / g.

[0018] For hydrogenation reaction, the hydrogenation catalyst needs to be reduced before application to ensure the active component exists in metallic state, so that the catalyst has hydrogenation activity. During catalyst preparation, activation is a high-temperature calcination process, in which the metal salt is generally decomposed into metal oxide, and the oxide forms clusters, which are generally nanosized. Different oxides need to be reduced at different temperatures due to different chemical properties, but for nanosized metals (especially noble metals), about 200°C is an important critical temperature, and above this temperature, the metal particles will significantly aggregate. With the use of the catalyst, macromolecules such as green oil produced in the reaction will polymerize to form carbon deposition or coke, affecting the service life of the catalyst. Therefore, how to reduce the aggregation of the main active component (especially noble metal) during reduction is of great significance to the hydrogenation catalyst.

[0019] The idea of the present application to solve the metal particle cluster and coking in the catalyst is:

[0020] The selective hydrogenation reaction of cracked C5 fraction occurs in the main active center composed of Pd and Zn. Macromolecules such as green oil produced in the reaction easily enter the large pores of the catalyst, and the Ni-Cu component is loaded in the large pores of the catalyst. Ni-Cu has a saturation hydrogenation function, and the green oil component will undergo saturation hydrogenation reaction in the Ni-Cu active center. Due to the hydrogenation saturation of the double bond, the green oil component cannot undergo polymerization reaction or the polymerization reaction rate is greatly reduced, the chain growth reaction is terminated or delayed, and large molecular weight condensed ring compounds cannot be formed, which are easily carried out of the reactor by the material, so that the degree of coking on the surface of the catalyst is greatly reduced, and the service life of the catalyst is prolonged.

[0021] Pd is loaded by solution method, and due to the siphon effect of the small pores, Pd is mainly loaded in the small pores of the catalyst. To prevent Ni from entering the small pores and covering the loaded Pd when Ni is loaded by solution method, microemulsion method is used to load Ni-Cu, but the reduction temperature of Ni-Cu is generally 350-400°C, which is too high for Pd active center. At this temperature, the aggregation of Pd active center is more obvious. The inventors have found through in-depth research that when Ce and Pt are loaded by solution method during catalyst preparation, the aggregation of Pd is significantly alleviated. Further in-depth research has found that when Ce and Pt are loaded by solution method at the same time, even after more than 5 times of coking, the decrease of the dispersion degree of the active component Pd is still not more than 20%. The reason may be that the metal salt of Ce forms Ce oxide after calcination, which exists in the form of single-layer distribution, and can also form a non-continuous cerium oxide molecular layer. When Pt is co-loaded with Ce, Pt exists in the form of single atom and is mainly loaded on the oxide of Ce. It is speculated that Pt 2+ -O2- -Ce 4+ The species has a binding force much higher than the binding force of Pt and alumina, so that the Pt 2+ -O 2- -Ce 4+ The species acts as a wall between Pd particles, preventing the growth of Pd particles, thereby preventing the agglomeration of Pd active centers at high temperatures. In order to make the wall formed by Pt and Ce effectively prevent the growth of Pd particles, Pt and Ce are also loaded by the solution method, and are mainly located in the small pores of the catalyst.

[0022] The method for controlling the positioning of Ni-Cu in the large pores of the catalyst in the present application is that Ni-Cu is loaded in the form of a microemulsion, the particle size of the microemulsion is greater than the pore size of the small pores of the carrier and less than the maximum pore size of the large pores. The Ni-Cu metal salt is contained in the microemulsion, and due to steric hindrance, it is difficult to enter the small pores of the carrier, so it mainly enters the large pores of the carrier. The role of Zn is to form an alloy with Pd to improve the selectivity of isoprene hydrogenation.

[0023] Therefore, the present application provides the following method for preparing the above-mentioned selective hydrogenation catalyst for carbon five fraction, Pd, Ce, Pt and Zn are loaded by the solution method; Ce and Pt are loaded at the same time, and the solution method for loading Ce-Pt and Zn is after the solution method for loading Pd; Ni-Cu is loaded by the microemulsion method, and the step of loading Ni-Cu by the microemulsion method is not limited; preferably, Pd and Zn are loaded by the saturation impregnation method.

[0024] Optionally, after loading Pd by the solution method, Ce-Pt and Zn are loaded by the solution method in turn.

[0025] Optionally, loading Ni-Cu by the microemulsion method is before loading Pd by the solution method.

[0026] Optionally, the process of loading Ni-Cu by the microemulsion method includes the following steps: dissolving the precursor salt of Ni and the precursor salt of Cu in water to obtain an aqueous phase, then adding an oil phase, a surfactant and a co-surfactant to the aqueous phase to control the particle size of the microemulsion to be greater than the pore size of the small pores of the carrier and less than the pore size of the large pores of the carrier, and then stirring to form a microemulsion with a particle size of 40-300 nm.

[0027] In the step of loading Ni-Cu by the microemulsion method, the types and amounts of the oil phase, the surfactant and the co-surfactant are not particularly limited, and can be determined according to the precursor salt and the pore structure of the carrier.

[0028] Preferably, the mass ratio of the aqueous phase to the oil phase is 2-3, the mass ratio of the surfactant to the oil phase is 0.15-0.6, and the mass ratio of the surfactant to the co-surfactant is 1.0-1.2.

[0029] The oil phase recommended by the present application is C6-C8 saturated alkane or cycloalkane, preferably cyclohexane or n-hexane; the surfactant is ionic surfactant and / or non-ionic surfactant, preferably non-ionic surfactant, more preferably polyethylene glycol octylphenyl ether (Triton X-100) or cetyltrimethylammonium bromide (CTAB); and the co-surfactant is organic alcohol, preferably C4-C6 alcohol, more preferably n-butanol and / or n-pentanol.

[0030] The solution method for loading Pd is preferably performed after the microemulsion method for loading Ni-Cu.

[0031] Loading Ni-Cu: the precursor salt of Ni and Cu is dissolved in water, the oil phase, the surfactant and the co-surfactant are added, and the mixture is stirred to form a microemulsion; then the carrier is added to the microemulsion for impregnation, the residual liquid is filtered out, and the mixture is dried and calcined to obtain a first semi-finished catalyst;

[0032] Loading Pd: the precursor salt of Pd is dissolved in water, the pH is adjusted to 1.5-2.5, then the first semi-finished catalyst is added for impregnation and adsorption, and the mixture is dried and calcined to obtain a second semi-finished catalyst;

[0033] Loading Ce-Pt: the precursor salt of Ce and the precursor compound of Pt are dissolved in deionized water to obtain a solution containing Ce and Pt, then the second semi-finished catalyst is added for impregnation, the solution is completely absorbed, and the mixture is dried and calcined to obtain a third semi-finished catalyst;

[0034] Loading Zn: the precursor salt of Zn is dissolved in deionized water to obtain a Zn-containing solution, then the third semi-finished catalyst is added to the Zn solution for impregnation, the solution is completely absorbed, and the mixture is dried and calcined to obtain the carbon pentane fraction selective hydrogenation catalyst.

[0035] Alternatively, the method for preparing the carbon pentane fraction selective hydrogenation catalyst comprises the following steps:

[0036] Loading Pd: the precursor salt of Pd is dissolved in water, the pH is adjusted to 1.5-2.5, then the carrier is added for impregnation and adsorption, and the mixture is dried and calcined to obtain a first semi-finished catalyst;

[0037] Loading Ce-Pt: dissolving the precursor salt of Ce and the precursor compound of Pt in deionized water to obtain a solution containing Ce and Pt, adding the first semi-finished catalyst for impregnation, drying after the solution is completely absorbed, and calcining to obtain the second semi-finished catalyst;

[0038] Loading Ni-Cu: dissolving the precursor salts of Ni and Cu in water, adding the oil phase, the surfactant and the co-surfactant, and stirring to form a microemulsion; then adding the second semi-finished catalyst into the microemulsion for impregnation, filtering the remaining liquid, drying, and calcining to obtain the third semi-finished catalyst;

[0039] Loading Zn: dissolving the precursor salt of Zn in deionized water to obtain a Zn solution, then adding the third semi-finished catalyst into the Zn solution for impregnation, drying after the solution is completely absorbed, and calcining to obtain the C5 fraction selective hydrogenation catalyst.

[0040] Optionally, in the step of loading Ni-Cu, the impregnation time is 0.5-4 h, the drying temperature is 100-130℃, and the drying time is 2-6 h; the calcining temperature is 300-600℃, and the calcining time is 3-6 h.

[0041] In the step of loading Pd, the impregnation time is 0.5-4 h, the drying temperature is 100-130℃, and the drying time is 2-6 h; the calcining temperature is 400-550℃, and the calcining time is 3-6 h.

[0042] In the step of loading Ce-Pt, the impregnation time is 0.5-4 h, the drying temperature is 100-130℃, and the drying time is 2-6 h; the calcining temperature is 500-600℃, and the calcining time is 3-6 h.

[0043] In the step of loading Zn, the impregnation time is 0.5-4 h, the drying temperature is 100-130℃, and the drying time is 2-6 h; the calcining temperature is 450-550℃, and the calcining time is 3-6 h.

[0044] The precursor salt of the metal in each step above is a soluble salt, which can be a nitrate salt, a chloride salt or other soluble salt. For example, the precursor salt of Pd can be selected from any one of soluble Pd salts such as palladium chloride and palladium nitrate; the precursor salt of Ni can be selected from any one of soluble Ni salts such as nickel acetate and nickel nitrate; the precursor salt of Cu can be selected from any one of soluble Cu salts such as copper nitrate and copper chloride; the precursor salt of Zn can be selected from any one of soluble Zn salts such as zinc nitrate and zinc chloride; the precursor salt of Ce can be selected from any one of soluble Ce salts such as cerium nitrate; and the precursor compound of Pt can be selected from any one of soluble inorganic Pt compounds such as chloroplatinic acid and platinum trichloride.

[0045] Optionally, the reduction temperature of the carbon five fraction selective hydrogenation catalyst before being put into hydrogenation reaction is 350-400 DEG C.

[0046] The present application has the following advantages:

[0047] 1. The cracking carbon five fraction selective hydrogenation catalyst provided by the present application has good selectivity, anti-coking property and regeneration performance. In the catalyst system of the present application, the carrier has a bimodal pore distribution structure, Pd and Zn are loaded by using a solution method, the siphon effect of the small pores makes Pd and Zn mainly loaded in the small pores of the catalyst, and the selective hydrogenation reaction mainly occurs in the main active centers composed of Pd and Zn; Ni-Cu is loaded in the form of microemulsion, the particle size of the microemulsion is between the pore size of the small pores of the carrier and the maximum pore size of the large pores, and the steric hindrance makes it difficult for the microemulsion to enter the small pores of the carrier, so that Ni-Cu is mainly loaded in the large pores of the carrier, and the green oil generated in the reaction occurs saturated hydrogenation on the active centers composed of Ni-Cu, so that it no longer occurs polymerization reaction to form compounds with large molecular weight or the polymerization reaction rate is greatly reduced, thus the coking degree on the surface of the catalyst is greatly reduced and the service life of the catalyst is prolonged; the barrier formed by Pt and Ce loaded in the small pores can effectively prevent the growth of Pd particles and the aggregation of Pd particles due to aggregation, and improve the anti-high-temperature agglomeration of the Pd active centers; Pd and Zn form an alloy structure, so that the hydrogenation selectivity of the cracking carbon five fraction is improved.

[0048] 2. The selective hydrogenation reaction of the crude isoprene occurs in the main active centers composed of Pd and Zn, and Zn mainly improves the hydrogenation selectivity of Pd. Pd and Zn are loaded by using a solution method, preferably saturated impregnation. Ni-Cu is loaded in the form of microemulsion in the large pores of the carrier, and the green oil and other macromolecules generated in the reaction easily enter the large pores of the catalyst, and the green oil and other macromolecules occur saturated hydrogenation on the active centers composed of Ni-Cu. Ce and Pt are simultaneously loaded by using a solution method, which can effectively prevent the growth and aggregation of Pd particles. The catalyst has the following characteristics: at the beginning of the hydrogenation reaction, the hydrogenation activity of Pd is high, and Pd is mainly distributed in the small pores, so that the selective hydrogenation reaction of the cracking carbon five fraction mainly occurs in the small pores; with the extension of the running time of the catalyst, a part of the green oil and other by-products with large molecular weight are generated on the surface of the catalyst, these substances enter the large pores due to their large molecular size, and stay for a long time, so that they occur double bond hydrogenation reaction to generate saturated hydrocarbons or aromatic hydrocarbons without isolated double bonds under the action of the nickel catalyst, and it is not easy to generate substances with larger molecular weight.

[0049] 3. After being regenerated, the reduction of the catalyst provided by the present application is still at 350-400 DEG C, and the activity selectivity of the catalyst after regeneration does not change obviously: after being regenerated for about 5 times, the activity selectivity of the catalyst does not change obviously, and the catalyst still has excellent hydrogenation activity and anti-coking property. Detailed Implementation

[0050] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0051] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0052] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

[0053] The catalyst of this invention was characterized using the following methods during preparation: Dynamic light scattering particle size analyzer (M286572) was used to analyze the particle size distribution of the Ni / Cu alloy microemulsion; a Micromercury porosimeter (McClone) 9510 and a Tristar 3000 automated physical adsorption analyzer (Tristar 3000) were used to determine the pore volume, specific surface area, and pore size distribution of the support. The contents of Pd, Zn, Ni, Cu, Ce, and Pt in the catalyst were determined using an A240FS atomic absorption spectrometer.

[0054] The present invention is further illustrated below by way of examples, but it is not intended to be limited thereto.

[0055] Example 1

[0056] Carrier: Commercially available bimodal pore distribution clover-shaped alumina carrier with a diameter of 2.0–2.2 mm was used. After calcination at 1010℃, the bimodal pore size distribution ranged from 10–30 nm and 70–240 nm, with a specific surface area of ​​79 m². 2 / g. Weigh 100g of the carrier.

[0057] Catalyst preparation:

[0058] (1) Dissolve nickel nitrate and copper nitrate in 56g of deionized water, add 21.4g of cyclohexane, 8.1g of Triton X-100, and 7.7g of n-butanol, and stir thoroughly to form a microemulsion. Impregnate 100g of the carrier into the prepared microemulsion, shake for 40min, and filter out the residual liquid. Dry at 100℃ for 6 hours and calcine at 400℃ for 4 hours to obtain semi-finished catalyst A.

[0059] (2) The palladium chloride was prepared into active component impregnation solution, and the pH was adjusted to 2.3. The semi-finished catalyst A was immersed into the prepared palladium active component solution, and after 60 min of immersion, it was dried at 110°C for 5 hours and calcined at 550°C for 3 hours to obtain semi-finished catalyst B.

[0060] (3) The chloroplatinic acid and cerium nitrate were prepared into active component impregnation solution. The semi-finished catalyst B was immersed into the prepared Pt and Ce impregnation solution, and after 50 min of immersion, it was dried at 120°C for 4 hours and calcined at 550°C for 4 hours to obtain semi-finished catalyst C.

[0061] (4) The zinc nitrate was prepared into active component impregnation solution. The semi-finished catalyst C was immersed into the prepared Zn impregnation solution, and after 50 min of immersion, it was dried at 130°C for 3 hours and calcined at 550°C for 3 hours to obtain catalyst S1.

[0062] The particle size of the microemulsion prepared in step (1) was 70 nm as determined by dynamic light scattering method.

[0063] Reduction of the catalyst:

[0064] Before use, it was placed in a fixed bed reaction device and reduced at a temperature of 380°C for 10 h in a hydrogen atmosphere.

[0065] Comparative Example 1

[0066] The same carrier as in Example 1 was used, and the catalyst preparation conditions were the same as in Example 1, except that no Ce was loaded.

[0067] (1) The nickel nitrate and copper nitrate were dissolved in 56 g of deionized water, 21.4 g of cyclohexane, 8.1 g of Triton X-100, and 7.7 g of n-butanol were added, and the mixture was stirred to form a microemulsion. 100 g of the carrier was immersed in the prepared microemulsion, shaken for 40 min, and the remaining liquid was filtered out. The mixture was dried at 100°C for 6 hours and calcined at 400°C for 4 hours to obtain semi-finished catalyst A1.

[0068] (2) The palladium chloride was prepared into active component impregnation solution, and the pH was adjusted to 2.3. The semi-finished catalyst A1 was immersed into the prepared palladium active component solution, and after 60 min of immersion, it was dried at 110°C for 5 hours and calcined at 550°C for 3 hours to obtain semi-finished catalyst B1.

[0069] (3) The chloroplatinic acid was prepared into active component impregnation solution. The semi-finished catalyst B1 was immersed into the prepared platinum impregnation solution, and after 50 min of immersion, it was dried at 120°C for 4 hours and calcined at 550°C for 4 hours to obtain semi-finished catalyst C1.

[0070] (4) The zinc nitrate was prepared into an active component impregnation solution, the semi-finished catalyst C1 was impregnated into the prepared Zn impregnation solution, after impregnation for 50 min, drying at 130°C for 3 hours, and calcination at 550°C for 3 hours, the catalyst Z1 was obtained.

[0071] The particle size of the microemulsion prepared in step (1) was 70 nm, which was determined by dynamic light scattering method.

[0072] Reduction of the catalyst:

[0073] Before use, it was placed in a fixed bed reaction device, and was reduced at a hydrogen atmosphere and a temperature of 380°C for 10 h.

[0074] Example 2

[0075] Support: A commercially available bimodal pore distribution spherical alumina support with a diameter of 3.5 mm was used. After calcination at 1000°C, the bimodal pore size distribution range was 8-28 nm and 65-220 nm, and the specific surface area was 85 m 2 / g. 100 g of the support was weighed.

[0076] Catalyst preparation:

[0077] (1) The palladium chloride was prepared into an active component impregnation solution, and the pH was adjusted to 2.2. The weighed 100 g of the support was impregnated into the prepared palladium active component solution, after impregnation for 70 min, drying at 120°C for 4 hours, and calcination at 480°C for 5 hours, the semi-finished catalyst D was obtained.

[0078] (2) The chloroplatinic acid and cerium nitrate were prepared into an active component impregnation solution, the semi-finished catalyst D was impregnated into the prepared Pt and Ce impregnation solution, after impregnation for 60 min, drying at 130°C for 3 hours, and calcination at 520°C for 5 hours, the semi-finished catalyst E was obtained.

[0079] (3) The nickel nitrate and copper chloride were dissolved in 59 g of deionized water, 20.3 g of cyclohexane, 7.2 g of polyoxyethylene octylphenol ether-10, and 7.1 g of n-butanol were added, and the mixture was fully stirred to form a microemulsion. The semi-finished catalyst E was impregnated into the prepared microemulsion, shaken for 40 min, and the residual liquid was filtered out. Drying at 110°C for 5 hours and calcination at 380°C for 5 h, the semi-finished catalyst F was obtained.

[0080] (4) The zinc nitrate was prepared into an active component impregnation solution, and the semi-finished catalyst F was impregnated into the prepared Zn impregnation solution, after impregnation for 60 min, drying at 110°C for 3 hours, and calcination at 500°C for 5 hours, the catalyst S2 was obtained.

[0081] The particle size of the microemulsion prepared in step (3) was 45 nm, which was determined by dynamic light scattering method.

[0082] Reduction of the catalyst:

[0083] Before use, place in a fixed bed reactor, reduce treatment under hydrogen atmosphere, 370°C temperature for 12h.

[0084] Comparative Example 2

[0085] Use the same carrier as Example 2, the same catalyst preparation conditions as Example 2, the difference is that no Ni is loaded.

[0086] Catalyst preparation:

[0087] (1) The palladium chloride is prepared into an active component impregnation solution, the pH is adjusted to 2.2, 100g of the carrier is weighed and impregnated with the prepared palladium active component solution, after impregnation for 70min, it is dried at 120°C for 4h and calcined at 480°C for 5h. The semi-finished catalyst D1 is obtained.

[0088] (2) The chloroplatinic acid and cerium nitrate are prepared into an active component impregnation solution, the semi-finished catalyst D1 is impregnated into the prepared Pt and Ce impregnation solution, after impregnation for 60min, it is dried at 130°C for 3h and calcined at 520°C for 5h. The semi-finished catalyst E1 is obtained.

[0089] (3) The copper chloride is dissolved in 59g of deionized water, 20.3g of cyclohexane, 7.2g of polyoxyethylene octylphenol ether-10 and 7.1g of n-butanol are added, and the mixture is stirred to form a microemulsion. The semi-finished catalyst E1 is impregnated into the prepared microemulsion, shaken for 40min, and the residual liquid is filtered out. It is dried at 110°C for 5h and calcined at 380°C for 5h. The semi-finished catalyst F1 is obtained.

[0090] (4) The zinc nitrate is prepared into an active component impregnation solution, and then the semi-finished catalyst F1 is impregnated into the prepared Zn impregnation solution. After impregnation for 60min, it is dried at 110°C for 3h and calcined at 500°C for 5h. The catalyst Z2 is obtained.

[0091] The particle size of the microemulsion prepared in step (3) is 45nm as determined by dynamic light scattering method.

[0092] Reduction of the catalyst:

[0093] Before use, place in a fixed bed reactor, reduce treatment under hydrogen atmosphere, 370°C temperature for 12h.

[0094] Example 3

[0095] Carrier: A commercially available bimodal pore distribution clover-shaped strip-shaped alumina carrier with a diameter of 2.2-2.5mm is used. After calcination at 980°C, the bimodal pore size distribution ranges from 7-25nm and 60-200nm, and the specific surface area is 97m 2 / g. 100g of the carrier is weighed.

[0096] Catalyst preparation:

[0097] (1) Dissolve nickel acetate in 62 g of deionized water, add n-heptane 22.3 g, Triton X-100 11.9 g, n-pentanol 10.2 g, and stir thoroughly to form a microemulsion. Dip 100 g of the carrier weighed into the prepared microemulsion, shake for 60 min, and filter out the remaining liquid. Dry at 120°C for 4 h and calcine at 350°C for 6 h to obtain semi-finished catalyst G.

[0098] (2) Prepare a palladium chloride impregnation solution as an active component, adjust the pH to 2.1, and then dip semi-finished catalyst G into the prepared palladium active component solution. After impregnation for 80 min, dry at 130°C for 3 h and calcine at 500°C for 6 h to obtain semi-finished catalyst H.

[0099] (3) Prepare a platinum trichloride and cerium nitrate impregnation solution as an active component, and then dip semi-finished catalyst H into the prepared Pt and Ce impregnation solution. After impregnation for 70 min, dry at 110°C for 3 h and calcine at 550°C for 4 h to obtain semi-finished catalyst I.

[0100] (4) Prepare a zinc nitrate impregnation solution as an active component, and then dip semi-finished catalyst I into the prepared Zn impregnation solution. After impregnation for 100 min, dry at 120°C for 2 h and calcine at 450°C for 6 h to obtain catalyst S3.

[0101] The particle size of the microemulsion prepared in step (1) is 57 nm as determined by dynamic light scattering.

[0102] Reduction of the catalyst:

[0103] Before use, place in a fixed bed reaction device and reduce at a hydrogen atmosphere and a temperature of 360°C for 16 h.

[0104] Comparative Example 3

[0105] Use the same carrier as in Example 3, and the catalyst preparation conditions are the same as in Example 3, except that no Cu is loaded.

[0106] Catalyst preparation:

[0107] (1) Dissolve nickel acetate in 62 g of deionized water, add n-heptane 22.3 g, Triton X-100 11.9 g, n-pentanol 10.2 g, and stir thoroughly to form a microemulsion. Dip 100 g of the carrier weighed into the prepared microemulsion, shake for 60 min, and filter out the remaining liquid. Dry at 120°C for 4 h and calcine at 350°C for 6 h to obtain semi-finished catalyst G1.

[0108] (2) The palladium chloride is prepared into an active component impregnation solution, the pH is adjusted to 2.1, and the semi-finished catalyst G1 is impregnated into the prepared palladium active component solution. After impregnation for 80 min, drying at 130°C for 3 hours, and calcination at 500°C for 6 hours, the semi-finished catalyst H1 is obtained.

[0109] (3) The platinum trichloride and cerium nitrate are prepared into an active component impregnation solution, and the semi-finished catalyst H1 is impregnated into the prepared Pt and Ce impregnation solution. After impregnation for 70 min, drying at 110°C for 3 hours, and calcination at 550°C for 4 hours, the semi-finished catalyst I1 is obtained.

[0110] (4) The zinc nitrate is prepared into an active component impregnation solution, and the semi-finished catalyst I1 is impregnated into the prepared Zn impregnation solution. After impregnation for 100 min, drying at 120°C for 2 hours, and calcination at 450°C for 6 hours, the catalyst Z3 is obtained.

[0111] The particle size of the microemulsion prepared in step (1) is 57 nm as determined by dynamic light scattering method.

[0112] Reduction of the catalyst:

[0113] Before use, it is placed in a fixed bed reaction device and reduced at a hydrogen atmosphere and a temperature of 360°C for 16 h.

[0114] Example 4

[0115] Support: A commercially available bimodal pore distribution clover-shaped strip-shaped alumina-titania support (5 wt% of titania content) with a diameter of 2.0-2.3 mm is used. After calcination at 1020°C, the bimodal pore size distribution ranges from 15-32 nm and 75-230 nm, and the specific surface area is 72 m 2 / g. 100 g of the support is weighed.

[0116] Catalyst preparation:

[0117] (1) The palladium chloride is prepared into an active component impregnation solution, the pH is adjusted to 2.0, and the weighed 100 g of the support is impregnated into the prepared palladium active component solution. After impregnation for 90 min, drying at 110°C for 3 hours, and calcination at 450°C for 4 hours, the semi-finished catalyst J is obtained.

[0118] (2) The chloroplatinic acid and cerium nitrate are prepared into an active component impregnation solution, and the semi-finished catalyst J is impregnated into the prepared Pt and Ce impregnation solution. After impregnation for 80 min, drying at 120°C for 2 hours, and calcination at 600°C for 3 hours, the semi-finished catalyst K is obtained.

[0119] (3) Dissolve nickel nitrate and copper chloride in 55 g of deionized water, add cyclohexane 20.4 g, CTAB 6.1 g, n-butanol 5.5 g, and fully stir to form a microemulsion. Dip the semi-finished catalyst K into the prepared microemulsion, shake for 30 min, and filter out the residual liquid. Dry at 130°C for 3 hours, and calcine at 550°C for 3 hours to obtain the semi-finished catalyst L.

[0120] (4) Prepare a zinc nitrate active component impregnation solution, and then dip the semi-finished catalyst L into the prepared Zn impregnation solution. After impregnation for 60 min, dry at 100°C for 4 hours, and calcine at 520°C for 4 hours to obtain the catalyst S4.

[0121] The particle size of the microemulsion prepared in step (3) is 62 nm as determined by dynamic light scattering.

[0122] Reduction of the catalyst:

[0123] Before use, place in a fixed bed reaction device, and reduce at a hydrogen atmosphere and a temperature of 350°C for 18 h.

[0124] Comparative Example 4

[0125] Use the same carrier as in Example 4, and use the same catalyst preparation conditions as in Example 4, except that no Pt is loaded.

[0126] Catalyst preparation:

[0127] (1) Prepare a palladium chloride active component impregnation solution with a pH of 2.0, and dip 100 g of the carrier into the prepared palladium active component solution. After impregnation for 90 min, dry at 110°C for 3 hours, and calcine at 450°C for 4 hours to obtain the semi-finished catalyst J1.

[0128] (2) Prepare a cerium nitrate active component impregnation solution, and dip the semi-finished catalyst J1 into the prepared impregnation solution. After impregnation for 80 min, dry at 120°C for 2 hours, and calcine at 600°C for 3 hours to obtain the semi-finished catalyst K1.

[0129] (3) Dissolve nickel nitrate and copper chloride in 55 g of deionized water, add cyclohexane 20.4 g, CTAB 6.1 g, n-butanol 5.5 g, and fully stir to form a microemulsion. Dip the semi-finished catalyst K1 into the prepared microemulsion, shake for 30 min, and filter out the residual liquid. Dry at 130°C for 3 hours, and calcine at 550°C for 3 hours to obtain the semi-finished catalyst L1.

[0130] (4) Prepare a zinc nitrate active component impregnation solution, and then dip the semi-finished catalyst L1 into the prepared Zn impregnation solution. After impregnation for 60 min, dry at 100°C for 4 hours, and calcine at 520°C for 4 hours to obtain the catalyst Z4.

[0131] The particle size of the microemulsion prepared in step (1) was 62 nm as determined by dynamic light scattering method.

[0132] Reduction of the catalyst:

[0133] Before use, the catalyst was placed in a fixed bed reactor and reduced under hydrogen atmosphere at a temperature of 350°C for 18 hours.

[0134] Example 5

[0135] Support: A commercially available bimodal pore distribution clover leaf shaped alumina support with a diameter of 2.3-2.5 mm was used. After calcination at 980°C, the bimodal pore size distribution was in the range of 7-25 nm and 60-200 nm, and the specific surface area was 97 m 2 / g. 100 g of the support was weighed.

[0136] Preparation of the catalyst:

[0137] (1) Nickel acetate and copper nitrate were dissolved in 52 g of deionized water, and n-heptane 17.7 g, bis-2-ethylhexyl sodium sulfide succinate 4.7 g, and n-pentanol 4.2 g were added, and the mixture was stirred to form a microemulsion. 100 g of the weighed support was immersed in the prepared microemulsion, shaken for 70 min, and the remaining liquid was filtered out. The catalyst was dried at 110°C for 3 hours and calcined at 420°C for 5 hours to obtain a semi-finished catalyst M.

[0138] (2) Palladium chloride was prepared into an active component impregnation solution, and the pH was adjusted to 1.9. The semi-finished catalyst M was then immersed in the prepared palladium active component solution, and after 100 min of immersion, the catalyst was dried at 120°C for 2 hours and calcined at 420°C for 5 hours to obtain a semi-finished catalyst N.

[0139] (3) Chloroplatinic acid and cerium nitrate were prepared into an active component impregnation solution, and the semi-finished catalyst N was then immersed in the prepared Pt and Ce impregnation solution. After 90 min of immersion, the catalyst was dried at 100°C for 4 hours and calcined at 540°C for 5 hours to obtain a semi-finished catalyst O.

[0140] (4) Zinc nitrate was prepared into an active component impregnation solution, and the semi-finished catalyst O was then immersed in the prepared Zn impregnation solution. After 80 min of immersion, the catalyst was dried at 100°C for 6 hours and calcined at 480°C for 5 hours to obtain a catalyst S5.

[0141] The particle size of the microemulsion prepared in step (1) was 89 nm as determined by dynamic light scattering method.

[0142] Reduction of the catalyst:

[0143] Before use, the catalyst was placed in a fixed bed reactor and reduced under hydrogen atmosphere at a temperature of 390°C for 11 hours.

[0144] Comparative Example 5

[0145] The same support as in Example 5 was used, and the catalyst preparation conditions were the same as in Example 5, except that steps (2) and (3) were interchanged.

[0146] Catalyst preparation:

[0147] (1) Nickel acetate and copper nitrate were dissolved in 52 g of deionized water, and n-heptane 17.7 g, bis-2-ethylhexyl sodium sulfide succinate 4.7 g, and n-pentanol 4.2 g were added, and the mixture was stirred to form a microemulsion. 100 g of the weighed support was immersed in the prepared microemulsion, shaken for 70 min, and the residual liquid was filtered off. The product was dried at 110°C for 3 h and calcined at 420°C for 5 h to obtain a semi-finished catalyst M1.

[0148] (2) Chloroplatinic acid and cerium nitrate were prepared into an active component impregnation solution, and the semi-finished catalyst M1 was immersed in the prepared Pt and Ce impregnation solution. After 90 min of immersion, the product was dried at 100°C for 4 h and calcined at 540°C for 5 h to obtain a semi-finished catalyst N1.

[0149] (3) Palladium chloride was prepared into an active component impregnation solution, and the pH was adjusted to 1.9. The semi-finished catalyst N1 was immersed in the prepared palladium active component solution. After 100 min of immersion, the product was dried at 120°C for 2 h and calcined at 420°C for 5 h to obtain a semi-finished catalyst O1.

[0150] (4) Zinc nitrate was prepared into an active component impregnation solution, and the semi-finished catalyst O1 was immersed in the prepared Zn impregnation solution. After 80 min of immersion, the product was dried at 100°C for 6 h and calcined at 480°C for 5 h to obtain a catalyst Z5.

[0151] The particle size of the microemulsion prepared in step (1) was 89 nm as determined by dynamic light scattering.

[0152] Reduction of the catalyst:

[0153] Before use, the catalyst was placed in a fixed bed reaction device and reduced at a temperature of 390°C under a hydrogen atmosphere for 11 h.

[0154] Example 6

[0155] Support: A commercially available bimodal pore distribution spherical alumina support with a diameter of 3.2 mm was weighed. The support was calcined at 1030°C, and the bimodal pore size distribution was in the range of 16-35 nm and 80-250 nm. The specific surface area was 66 m 2 / g. 100 g of the support was weighed.

[0156] Catalyst preparation:

[0157] (1) Dissolve nickel nitrate and copper nitrate in 46 g of deionized water, add 21.3 g of n-hexane, 5.4 g of Triton X-100 and 4.5 g of n-hexanol, and stir thoroughly to form a microemulsion. Dip 100 g of the carrier weighed into the prepared microemulsion, shake for 80 min, and filter out the residual liquid. Dry at 120°C for 2 h and calcine at 450°C for 6 h to obtain the semi-finished catalyst P.

[0158] (2) Prepare a palladium chloride active component impregnation solution with pH 1.9, and then dip the semi-finished catalyst P into the prepared palladium active component solution. After impregnation for 110 min, dry at 100°C for 4 h and calcine at 400°C for 6 h to obtain the semi-finished catalyst Q.

[0159] (3) Prepare a chloroplatinic acid and cerium nitrate active component impregnation solution, and then dip the semi-finished catalyst Q into the prepared Pt and Ce impregnation solution. After impregnation for 100 min, dry at 100°C for 6 h and calcine at 500°C for 6 h to obtain the semi-finished catalyst R.

[0160] (4) Prepare a zinc nitrate active component impregnation solution, and then dip the semi-finished catalyst R into the prepared Zn impregnation solution. After impregnation for 50 min, dry at 110°C for 5 h and calcine at 510°C for 6 h to obtain the catalyst S6.

[0161] The particle size of the microemulsion prepared in step (1) is 97 nm as determined by dynamic light scattering.

[0162] Reduction of the catalyst:

[0163] Before use, place in a fixed bed reaction device and reduce at a hydrogen atmosphere and a temperature of 390°C for 11 h.

[0164] Comparative Example 6

[0165] Use the same carrier as in Example 6, and the same catalyst preparation conditions as in Example 6, except that step (1) does not use the microemulsion method.

[0166] Catalyst preparation:

[0167] (1) Dissolve nickel nitrate and copper nitrate in deionized water to prepare an active component impregnation solution, and dip 100 g of the carrier weighed into the prepared active component solution, shake for 80 min, and filter out the residual liquid. Dry at 120°C for 2 h and calcine at 450°C for 6 h to obtain the semi-finished catalyst P1.

[0168] (2) Prepare a palladium chloride active component impregnation solution with pH 1.9, and then dip the semi-finished catalyst P1 into the prepared palladium active component solution. After impregnation for 110 min, dry at 100°C for 4 h and calcine at 400°C for 6 h to obtain the semi-finished catalyst Q1.

[0169] (3) The chloroplatinic acid and cerium nitrate are prepared into an active component impregnation solution, and then the semi-finished catalyst Q1 is impregnated into the prepared Pt and Ce impregnation solution. After impregnation for 100 min, drying at 100°C for 6 hours, and calcination at 500°C for 6 hours, the semi-finished catalyst R1 is obtained.

[0170] (4) The zinc nitrate is prepared into an active component impregnation solution, and then the semi-finished catalyst R1 is impregnated into the prepared Zn impregnation solution. After impregnation for 50 min, drying at 110°C for 5 hours, and calcination at 510°C for 6 hours, the catalyst Z6 is obtained.

[0171] Reduction of the catalyst:

[0172] Before use, the catalyst is placed in a fixed bed reaction device and subjected to reduction treatment at a hydrogen atmosphere and a temperature of 400°C for 10 h.

[0173] Example 7

[0174] Support: A commercially available bimodal pore distribution clover-shaped strip-shaped alumina support with a diameter of 2.0-2.3 mm is weighed. After calcination at 1080°C, the bimodal pore size distribution ranges from 20-40 nm and 95-300 nm, and the specific surface area is 48 m 2 / g. 100 g of the support is weighed.

[0175] Catalyst preparation:

[0176] (1) The nickel acetate and copper nitrate are dissolved in 49 g of deionized water, 20.8 g of n-hexane, 4.2 g of CTAB, and 3.7 g of n-pentanol are added, and the mixture is stirred to form a microemulsion. 100 g of the weighed support is impregnated into the prepared microemulsion, shaken for 90 min, and the remaining liquid is filtered out. After drying at 100°C for 4 hours and calcination at 500°C for 4 h, the semi-finished catalyst T is obtained.

[0177] (2) The palladium chloride is prepared into an active component impregnation solution, and the pH is adjusted to 1.9. Then the semi-finished catalyst T is impregnated into the prepared palladium active component solution. After impregnation for 120 min, drying at 100°C for 6 hours, and calcination at 520°C for 4 hours, the semi-finished catalyst U is obtained.

[0178] (3) The chloroplatinic acid and cerium nitrate are prepared into an active component impregnation solution, and then the semi-finished catalyst U is impregnated into the prepared Pt and Ce impregnation solution. After impregnation for 110 min, drying at 110°C for 5 hours, and calcination at 580°C for 4 hours, the semi-finished catalyst W is obtained.

[0179] (4) The zinc nitrate is prepared into an active component impregnation solution, and then the semi-finished catalyst W is impregnated into the prepared Zn impregnation solution. After impregnation for 40 min, drying at 120°C for 4 hours, and calcination at 470°C for 4 hours, the catalyst S7 is obtained.

[0180] The particle size of the microemulsion prepared in step (1) is 85 nm.

[0181] Reduction of the catalyst:

[0182] Before use, the catalyst is placed in a fixed bed reaction device and reduced at a temperature of 380°C for 14 h in a hydrogen atmosphere.

[0183] Comparative Example 7

[0184] The catalyst is prepared under the same conditions as in Example 7, except that the pore size distribution of the catalyst carrier is unimodal. The unimodal pore distribution clover-shaped alumina carrier has a diameter of 2.0-2.3 mm. After calcination at 1080°C, the pore size distribution ranges from 20 to 40 nm, and the specific surface area is 51 m 2 / g. 100 g of the carrier is weighed.

[0185] Preparation of the catalyst:

[0186] (1) Nickel acetate and copper nitrate are dissolved in 49 g of deionized water, 20.8 g of n-hexane, 4.2 g of CTAB, and 3.7 g of n-pentanol are added, and the mixture is stirred thoroughly to form a microemulsion. 100 g of the carrier is immersed in the prepared microemulsion, shaken for 90 min, and the remaining liquid is filtered out. The catalyst is dried at 100°C for 4 h and calcined at 500°C for 4 h to obtain a semi-finished catalyst T1.

[0187] (2) Palladium chloride is prepared into an active component impregnation solution, and the pH is adjusted to 1.9. The semi-finished catalyst T1 is then immersed in the prepared palladium active component solution, and after 120 min of immersion, the catalyst is dried at 100°C for 6 h and calcined at 520°C for 4 h to obtain a semi-finished catalyst U1.

[0188] (3) Chloroplatinic acid and cerium nitrate are prepared into an active component impregnation solution. The semi-finished catalyst U1 is then immersed in the prepared Pt and Ce impregnation solution, and after 110 min of immersion, the catalyst is dried at 110°C for 5 h and calcined at 580°C for 4 h to obtain a semi-finished catalyst W1.

[0189] (4) Zinc nitrate is prepared into an active component impregnation solution. The semi-finished catalyst W1 is then immersed in the prepared Zn impregnation solution, and after 40 min of immersion, the catalyst is dried at 120°C for 4 h and calcined at 470°C for 4 h to obtain a catalyst Z7.

[0190] The particle size of the microemulsion prepared in step (1) is 85 nm.

[0191] Reduction of the catalyst:

[0192] Before use, the catalyst is placed in a fixed bed reaction device and reduced at a temperature of 380°C for 14 h in a hydrogen atmosphere.

[0193] The compositions of the catalysts prepared in each example and the comparative example are shown in the following table.

[0194] Table 1 Catalyst composition

[0195]

[0196]

[0197] The performances of the catalysts in the selective hydrogenation reaction of the crude isoprene raw material of the pyrolysis C5 fraction separation device are as follows:

[0198] The catalysts were carried out in a fixed bed reactor, the loading amount was 50 mL, the packing was 40 mL, the reaction material space velocity was 0.8 h-1, the operating pressure was 1.5 MPa, the hydrogen / oil volume ratio was 100:1, and the reactor inlet temperature was 35-45℃. -1

[0199] The hydrogenation reaction material composition is shown in Table 2.

[0200] Table 2 Main composition of unsaturated hydrocarbons in the crude isoprene raw material

[0201] Component Content (%) Component Content (%) Component Content (%) Component Content (%) cis-butene-2 isoprene cyclopentadiene 0.51 1,4-pentadiene 44.18 trans-2-pentene 4.53 trans-1,3-pentadiene 5.32 2-butyne 3.56 cis-2-pentene 0.14 2-methyl-butene-1 1.47 1-pentene 1.89 2-methyl-butene-2 7.67 ​ 6.35 ​ 2.01

[0202] The hydrogenation evaluation results of the catalysts are shown in Tables 3 and 4.

[0203] Table 3 Performance evaluation results 1 of the catalysts prepared in each example and the comparative example

[0204]

[0205]

[0206] Table 4 Performance evaluation results 2 of the catalysts prepared in each example and the comparative example

[0207]

[0208] From the evaluation results of the catalysts prepared in each example and the comparative example in the above table, it can be seen that the catalyst provided by the present application not only has excellent hydrogenation activity, selectivity and anti-coking performance, but also has excellent stability.

[0209] The catalysts prepared in Example 1 and Comparative Example 1 were applied to the selective hydrogenation reaction of the crude isoprene raw material of the pyrolysis C5 fraction separation device according to the above conditions, and were regenerated every 300 h, and after regeneration, the performance test was continued according to the above conditions, and the cycle was repeated for 5 times, and the specific results are shown in the following table.

[0210] The catalysts were regenerated in the reactor, and the hydrogen hot stripping method was used for regeneration, and the stripping temperature was 160℃, and the regeneration steps were as follows:​

[0211] (1) First, cut off the carbon five material, reactor slowly depressurized to 0.5 MPa or less;

[0212] (2) Increase the amount of hydrogen, using cold hydrogen to gradually reduce the bed temperature to room temperature, continue to purge 10 h;

[0213] (3) Slowly heat the bed temperature to 160℃ by hot hydrogen (heating rate < 15℃ / h);

[0214] (4) After the reactor inlet temperature reaches 160℃, maintain for 12 h;

[0215] (5) Regeneration is over, the bed temperature is reduced to the reaction temperature at a cooling rate of 25℃ / h.

[0216] Table 5 catalyst regeneration performance

[0217]

[0218] The evaluation results of the catalyst prepared from example 1 and comparative example 1 in the above table after five times of regeneration show that the catalyst provided by the present application still has excellent hydrogenation activity and strong anti-coking property after five times of regeneration.

[0219] Of course, the present application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.

Claims

1. A selective hydrogenation catalyst for C5 fraction, characterized in that, The catalyst comprises a support and an active component. The support consists of alumina with a bimodal pore structure, wherein the pore size is 7–40 nm and the macropore size is 60–300 nm. The active component comprises Pd, Ni, Cu, Ce, Pt, and Zn. Based on 100% of the catalyst mass, the Pd content is 0.2%–0.48%, the Zn content is 0.01%–3%, the Ni content is 0.5%–5%, the Cu to Ni mass ratio is 0.1–1:1, the Ce content is 0.1%–0.5%, and the Pt content is 0.005%–0.05%. Ni-Cu is supported by a microemulsion method. Pd, Ce, Pt, and Zn were all loaded using the solution method. Ce and Pt were loaded simultaneously, and the solution-loaded Ce-Pt and Zn were loaded after the solution-loaded Pd.

2. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The carrier can be any one of the following shapes: spherical, cylindrical, clover-shaped, and four-leaf clover-shaped.

3. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The Pd content is 0.25% to 0.4%.

4. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The Zn content is 0.5%~1.5%.

5. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The Ni content is 1% to 2.5%.

6. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The mass ratio of Cu to Ni is 0.2 to 0.6:

1.

7. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The Ce content is 0.2% to 0.4 wt%.

8. The C5 fraction selective hydrogenation catalyst as described in claim 1, characterized in that, The Pt content is 0.01%~0.03%.

9. A method for preparing a C5 fraction selective hydrogenation catalyst according to any one of claims 1-8, characterized in that, Pd, Ce, Pt, and Zn were all loaded using the solution method. Ce and Pt were loaded simultaneously, and the solution-loaded Ce-Pt and Zn were loaded after the solution-loaded Pd.

10. The preparation method according to claim 9, characterized in that, After loading Pd by solution method, Ce-Pt and Zn were loaded by solution method in sequence.

11. The preparation method according to claim 9 or 10, characterized in that, Ni-Cu was loaded via microemulsion before Pd was loaded via solution method.

12. The preparation method according to claim 9, characterized in that, The process of loading Ni-Cu using the microemulsion method includes the following steps: dissolving the precursor salts of Ni and Cu in water to obtain an aqueous phase, then adding an oil phase, a surfactant, and a co-surfactant to the aqueous phase and stirring to form a microemulsion.

13. The preparation method according to claim 12, characterized in that, The oil phase is a C6-C8 saturated alkane or cycloalkane; The surfactant is an ionic surfactant and / or a nonionic surfactant; The co-surfactant is an organic alcohol.

14. The preparation method according to claim 9, characterized in that, Includes the following steps: Ni-Cu supported: Ni and Cu precursor salts are dissolved in water, and oil phase, surfactant and co-surfactant are added and stirred thoroughly to form a microemulsion; then the support is added to the microemulsion for impregnation, the residual liquid is filtered off, dried and calcined to obtain the first semi-finished catalyst; Pd loading: Dissolve the Pd precursor salt in water, adjust the pH to 1.5-2.5, then add the first semi-finished catalyst for impregnation and adsorption, and then dry and calcine to obtain the second semi-finished catalyst. Ce-Pt supported: Ce precursor salt and Pt precursor compound are dissolved in deionized water to obtain a solution containing Ce and Pt. The second semi-finished catalyst is added for impregnation. After the solution is completely absorbed, it is dried and calcined to obtain the third semi-finished catalyst. Zn loading: The precursor salt of Zn is dissolved in deionized water to obtain a Zn-containing solution. Then, the third semi-finished catalyst is added to the Zn solution for impregnation. After the solution is completely absorbed, it is dried and calcined to obtain the C5 fraction selective hydrogenation catalyst.

15. The preparation method according to claim 9, characterized in that, Includes the following steps: Pd loading: The precursor salt of Pd is dissolved in water, the pH is adjusted to 1.5-2.5, and then the carrier is added for impregnation and adsorption. After drying and calcination, the first semi-finished catalyst is obtained. Ce-Pt supported: Ce precursor salt and Pt precursor compound are dissolved in deionized water to obtain a solution containing Ce and Pt. The first semi-finished catalyst is added for impregnation. After the solution is completely absorbed, it is dried and calcined to obtain the second semi-finished catalyst. Ni-Cu supported: Ni and Cu precursor salts are dissolved in water, and oil phase, surfactant and co-surfactant are added and stirred thoroughly to form a microemulsion; then the second semi-finished catalyst is added to the microemulsion for impregnation, the residual liquid is filtered off, dried and calcined to obtain the third semi-finished catalyst; Zn loading: The precursor salt of Zn is dissolved in deionized water to obtain a Zn solution. Then, the third semi-finished catalyst is added to the Zn solution for impregnation. After the solution is completely absorbed, it is dried and calcined to obtain the C5 fraction selective hydrogenation catalyst.

16. The preparation method according to claim 14 or 15, characterized in that, In the step of supporting Ni-Cu, the calcination temperature is 300–600°C; and / or In the step of loading Pd, the calcination temperature is 400–550°C; and / or In the step of loading Ce-Pt, the calcination temperature is 500–600°C; and / or In the step of loading Zn, the calcination temperature is 450–550°C.

17. The preparation method according to claim 12, characterized in that, The mass ratio of the aqueous phase to the oil phase is 2 to 3, the mass ratio of the surfactant to the oil phase is 0.15 to 0.6, and the mass ratio of the surfactant to the co-surfactant is 1.0 to 1.

2.

18. The preparation method according to claim 13, characterized in that, The oil phase is cyclohexane or n-hexane.

19. The preparation method according to claim 13, characterized in that, The surfactant is a nonionic surfactant.

20. The preparation method according to claim 19, characterized in that, The nonionic surfactant is polyethylene glycol octylphenyl ether or hexadecyltrimethylammonium bromide.

21. The preparation method according to claim 13, characterized in that, The co-surfactant is a C4-C6 organic alcohol.

22. The preparation method according to claim 21, characterized in that, The co-surfactant is n-butanol and / or n-pentanol.

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