A metal and ionic liquid coupled heterogeneous catalyst, and a preparation method and application thereof

Abstract

The application discloses a metal and ionic liquid coupling heterogeneous catalyst, a preparation method and application thereof. The preparation method of the metal and ionic liquid coupling catalyst comprises the following steps: (1) mixing a carrier precursor, a metal precursor, a template agent and a solvent according to a certain mass ratio to form a mixture by grinding, aging the mixture, extruding the mixture into a strip, and then drying; placing the dried product in a tube furnace, and performing high-temperature carbonization under a certain amount of flowing inert atmosphere; after natural cooling, screening the product to obtain a granular metal carrier core-shell material; (2) loading an ionic liquid solution onto the surface of the metal carrier core-shell material by an equal-volume impregnation method, and after drying, the metal and ionic liquid coupling catalyst is obtained. The application provides the application of the metal and ionic liquid coupling heterogeneous catalyst in an ethylene selective hydrogenation reaction of acetylene, and the ethylene selectivity and the catalyst stability can be significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of heterogeneous catalysis technology, and relates to a heterogeneous catalyst, its preparation and its application in selective hydrogenation reactions. More specifically, it relates to a method for preparing a metal-ionic liquid coupled heterogeneous catalyst and its application in the selective hydrogenation of acetylene to ethylene. Background Technology

[0002] Ethylene is a fundamental raw material in the petrochemical industry, widely used in synthetic plastics, rubber, pharmaceuticals, and dyes, and is one of the largest chemical products in modern industry. Currently, ethylene mainly originates from petroleum cracking processes, and trace amounts of acetylene (0.3%–3% by volume) are inevitably present in the cracking products. Residual acetylene can poison the Ziegler-Natta catalyst in subsequent polyethylene production processes, reducing the catalytic activity and stability of the polymerization reaction and severely affecting the quality of polyethylene products. To prevent acetylene from poisoning downstream polymerization catalysts, acetylene removal is necessary. Catalytic selective hydrogenation of acetylene is the most widely used and effective method for acetylene removal (CN 1657513; Angew. Chem. Int. Ed., 2019, 131, 7750–7754). Industrial catalysts for selective hydrogenation of acetylene typically use Pd as the main active component. Based on Pd's high activation ability for unsaturated C≡C triple bonds, it exhibits good catalytic activity and acetylene removal performance. However, the acetylene hydrogenation reaction is a typical tandem reaction (C2H2→C2H4→C2H6), and the ethylene selectivity decreases sharply with increasing acetylene conversion. Furthermore, acetylene readily undergoes hydrogenation polymerization on the surface of Pd active sites to form unsaturated C4~C6 compounds. 24 Oligomers (green oil) accumulate and adhere to the catalyst surface, leading to catalyst deactivation (CN 106622223B; Nat. Nanotechnol., 2021, 16, 1141–1149). Therefore, the performance of current industrial catalysts for selective acetylene hydrogenation is not ideal.

[0003] To address the challenges of low selectivity and poor stability in catalysts, researchers have conducted extensive studies. Anderson et al. investigated the performance of Pd / TiO2 catalysts modified with phenyl sulfide (J. Catal., 2018, 364, 406–414) and triphenylphosphine (J. Catal., 2017, 355, 40–52) in the hydrogenation of acetylene. They found that the modified catalysts exhibited excellent conversion and selectivity. The authors suggested that phenyl sulfide or triphenylphosphine can coordinate with Pd, transferring electrons from the benzene ring to the Pd surface through S-Pd or P-Pd coordination bonds, placing Pd in ​​an electron-rich state and weakening the adsorption strength for ethylene. Simultaneously, the large steric hindrance of the phenyl group restricts the adsorption of ethylene, and the combined effect of these two factors leads to improved ethylene selectivity. Huang Weixing et al. (ACS Catal., 2016, 6, 3700-3707) deposited Ga2O3 on the surface of Pd using atomic layer deposition (ALD) technology to obtain Ga2O3-Pd / Al2O3. The study showed that by using ALD, Ga2O3 was selectively covered on other crystal planes besides the Pd(111) crystal plane, thus exposing more Pd(111) crystal planes that are favorable for selective hydrogenation of acetylene. Although the catalytic activity gradually decreased with the increase of the number of deposition cycles, the ethylene selectivity gradually increased. Based on recent research on the selective hydrogenation of acetylene, it is generally agreed that the low ethylene selectivity of Pd-based catalysts is due to the high adsorption heat of ethylene by Pd alone. This makes it difficult for the generated ethylene to desorb rapidly from the Pd surface, resulting in an increased ethylene concentration on the active site surface and subsequent over-hydrogenation side reactions. On the other hand, the excessively high adsorption strength of Pd for acetylene makes it prone to hydrogenation polymerization to form green oil, thus deteriorating the catalyst's stability (Nat. Commun., 2015, 6, 7938; Angew. Chem. Int. Ed., 2015, 54, 10889–10893). Current research has shown that modifying the active sites of Pd-based catalysts with metal or non-metal additives to adjust the catalyst surface geometry or electronic structure can improve ethylene selectivity to some extent. However, this significantly reduces the utilization rate of the precious metal Pd, leading to resource waste, and often at the expense of catalyst activity and stability. Therefore, the overall performance (activity, selectivity, and stability) of Pd-based catalysts remains unsatisfactory. The development of highly efficient catalysts for the selective hydrogenation of acetylene remains a major problem that urgently needs to be solved in this process.

[0004] Ionic liquids, due to their advantages such as low vapor pressure, wide liquid range, unique solubility, and designable structure, have become a research focus in the field of catalysis. In particular, supported ionic liquid catalysts, combining the advantages of homogeneous catalysis (e.g., high activity and high selectivity) and heterogeneous catalysis (e.g., easy catalyst recovery), have been widely applied in reactions such as esterification (Bioresour Technol., 2012, 125, 332–334), coupling (J. Catal., 2000, 196, 86–94), and alkylation (Appl. Catal. A: Gen., 2008, 346, 189–193). In these reactions, ionic liquid catalysts have exhibited excellent catalytic performance. However, in metal-based catalyst systems supported on ionic liquids, metal agglomeration caused by dispersing the metal in the ionic liquid layer and the mass transfer resistance caused by the high viscosity of the ionic liquid itself are important reasons for the reduced catalytic activity and poor lifetime of these catalysts. Against this backdrop, our research group has conducted studies on the use of metal-ionic liquid coupled catalysts for the selective hydrogenation of acetylene, achieving a series of significant results. This patent application provides a novel carbon-based porous material-confined, highly dispersed metal-ionic liquid coupled catalyst to improve the activity, selectivity, and stability of the selective hydrogenation of acetylene. There are few published reports on the use of heterogeneous catalysts prepared by metal-ionic liquid coupling in the selective hydrogenation of acetylene. Further exploration of its application as a novel hydrogenation catalyst is of significant scientific and practical value, both for the development of metal-ionic liquid coupled catalysts and for the development of selective hydrogenation catalytic reactions. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a highly efficient metal-ionic liquid coupled catalyst, its preparation method and application. The catalyst, in conjunction with the confinement effect of the support framework, enables the metal centers to be highly dispersed on the support surface in a stable cluster state, which significantly improves the thermal stability and anti-sintering ability of the metal. At the same time, the coordination effect and solvent effect between the metal active centers and the ionic liquid solve the problem of the difficulty in achieving high activity and high selectivity in previous literature reports. When this catalyst is used in the selective hydrogenation of acetylene to ethylene, it can significantly improve the ethylene selectivity and catalyst stability.

[0006] The solution to this technical problem in this invention is:

[0007] In a first aspect, the present invention provides a method for preparing a metal-ionic liquid coupled catalyst, comprising the following steps:

[0008] (1) The carrier precursor, metal precursor, template agent and solvent are mixed in a certain mass ratio and ground at 10-100℃ for a certain time to form a mixture; the mixture is aged at 10-120℃ for 1-120h, then extruded into strips and dried at 30-180℃ for 6-120h; the dried product is placed in a tube furnace and heated to 200-1000℃ for 2-72h at a rate of 1-20℃ / min under a certain amount of flowing inert atmosphere; after natural cooling, the product is sieved to obtain granular metal@carrier core-shell material;

[0009] The template agent is one or a mixture of two or more of the following: ammonium bicarbonate, ammonium dihydrogen phosphate, dicyandiamide, triethylamine, calcium cyanamide, silicon dioxide, magnesium oxide, zinc oxide, and calcium carbonate.

[0010] The carrier precursor is one or a mixture of two or more of the following in any proportion: polyvinyl alcohol, glucose, methylcellulose, sucrose, corn starch, wheat flour, sucralose, potato starch, and cationic starch.

[0011] The metal precursor is one of the following: chloropalladium, sodium chloropalladium, dichlorodiaminepalladium, palladium acetylacetonate, dinitrosodiaminepalladium, palladium nitrate, palladium acetate, and dichlorotetraaminepalladium.

[0012] (2) An ionic liquid solution is loaded onto the surface of a metal@support core-shell material using an equal-volume impregnation method. After drying, a metal-ionic liquid coupling catalyst is obtained. The cation of the ionic liquid is at least one of 1,3-dimethylimidazolium, 1-ethyl-3-methylimidazolium, 1-ethylimidazolium, 1,3-dimethyl-2-imidazolinone, 1-propyl-3-methylimidazolium, triphenylmethylphosphine, N-butyl-4-methylpyridine, N-methylpropylpiperidine, tetramethylammonium, or 1-hydroxyethyl-3-methylimidazolium. The anion of the ionic liquid is at least one of trifluoromethanesulfonate, chloride, bromine, hexafluorophosphate, benzenesulfonate, methanesulfonate, tetrafluoroborate, bis(trifluoromethanesulfonyl)imide, or dicyandiamide.

[0013] The metal@carrier core-shell material obtained in step (1) of this invention has a low impurity content (ash content <1%), a carrier crystal grain size of 30-50 nm, and a specific surface area of ​​600-800 m². 2The mesoporous pore size is 5–30 nm, with a pore volume of approximately 0.83 mL / g. The particle size of the active metal component is approximately 3 nm. The particle size of the metal@carrier core-shell material can be determined according to actual needs; in the specific embodiment of this invention, it is 20–40 mesh. The core-shell material shell is one of titanium carbide, silicon carbide, boron carbide, calcium carbide, carbon nitride, and activated carbon. The metal@carrier core-shell material prepared by the method of this invention contains a certain amount of strong alkaline sites in addition to the metal. It can produce a well-formed mesoporous material with good mechanical strength without removing the template agent, and features simple preparation process, safe operation, low price, and environmental friendliness.

[0014] Preferably, the metal loading in the metal@carrier core-shell material is 0.01% to 1%, where the metal loading refers to the percentage of the metal element by mass in the carrier within the metal@carrier core-shell material. Under the method of this invention, the metal element can be considered as the entire load; therefore, the mass of the metal element can be calculated based on the amount of metal precursor fed into the material. 载体 =m 金属@载体核壳材料 -m 金属元素 .

[0015] Preferably, the mass ratio of the template agent to the carrier precursor is 0.1 to 10:20, more preferably 1 to 5:20; the mass ratio of the solvent to the carrier precursor is 0.01 to 1:1.

[0016] Preferably, the template agent in step (1) is one or a mixture of two or more of calcium cyanamide, silicon dioxide, zinc oxide, dicyandiamide, and ammonium bicarbonate.

[0017] Preferably, the solvent in step (1) is one of methanol, ethanol, deionized water, N,N-dimethylformamide and acetone.

[0018] Preferably, the aging temperature in step (1) is 20 to 100°C, and more preferably 30 to 80°C.

[0019] Preferably, the aging time in step (1) is 6 to 72 hours, and more preferably 12 to 36 hours.

[0020] Preferably, the drying temperature in step (1) is 50–160°C, and more preferably 60–150°C.

[0021] Preferably, the drying time in step (1) is 12 to 96 hours, and more preferably 12 to 72 hours.

[0022] Preferably, the inert atmosphere in step (1) is one or more of nitrogen, argon and helium; its flow rate is 10 to 1000 mL / min.

[0023] Preferably, in step (1), the heating rate is 1 to 10 °C / min, and more preferably 1 to 5 °C / min.

[0024] Preferably, the carbonization temperature in step (1) is 300–900°C, and more preferably 400–800°C.

[0025] Preferably, the carbonization time in step (1) is 4 to 48 hours, and more preferably 6 to 36 hours.

[0026] Preferably, in step (2), the ionic liquid is a combination of 1-propyl-3-methylimidazolium dicyandiamide salt and 1-propyl-3-methylimidazolium chloride salt, or 1-propyl-3-methylimidazolium chloride salt or triphenylmethylphosphine bis(trifluoromethanesulfonyl)imide salt, more preferably a combination of 1-propyl-3-methylimidazolium dicyandiamide salt and 1-propyl-3-methylimidazolium chloride salt, and most preferably the mass ratio of the two is 1:1.

[0027] Preferably, in step (2), the ionic liquid loading in the catalyst is 5–50 wt%, more preferably 9–25 wt%, where the ionic liquid loading refers to the mass percentage of the ionic liquid in the catalyst. Under the operation of the method of this invention, the ionic liquid can be considered as the entire load.

[0028] As a preferred embodiment, the preparation process of the ionic liquid supported by the equal volume impregnation method in step (2) is as follows: a certain amount of ionic liquid is dissolved in a solvent, and ultrasonically dissolved for a certain time at room temperature (20-30℃, the same below). The prepared metal@carrier core-shell material is added to the ionic liquid solution, and allowed to stand at room temperature for 12-24 hours. Then, it is dried at 60-180℃ for 12-24 hours to obtain the metal-ionic liquid coupled catalyst.

[0029] As a further preferred embodiment, in step (2), the solvent of the ionic liquid solution is one or more of the following solvents in any proportion: toluene, carbonate, alkylpyrrolidone, thioacetic acid, ethyl acetate, deionized water, sulfoxide, acetone, methanol, and dichloromethane. Even more preferably, when preparing the ionic liquid solution, the feeding ratio of the ionic liquid to the solvent is 1 g: 5-15 mL.

[0030] As a further preferred option, in step (2), the drying temperature is 80–160°C.

[0031] Secondly, the present invention provides a metal-ionic liquid coupled catalyst prepared according to the above preparation method.

[0032] Thirdly, the present invention provides the application of the aforementioned metal-ionic liquid coupled heterogeneous catalyst in the selective hydrogenation of acetylene to ethylene.

[0033] The acetylene selective hydrogenation to ethylene reaction described in this invention uses a fixed-bed reactor. The specific application method includes the following steps: 1) Place an appropriate amount of quartz wool in the center of a quartz tube, weigh an appropriate amount of metal-ion liquid coupled catalyst and an appropriate amount of quartz sand, mix them and pour them into the quartz tube, then place an appropriate amount of quartz sand on top of the catalyst, purge with N2 for a certain period of time to remove air and H2O from the pipeline, then switch to H2, raise the temperature to the reduction temperature at a certain rate, reduce for a certain period of time, purge with N2 and lower to the reaction temperature; 2) Introduce a feed gas containing acetylene to start the reaction.

[0034] Preferably, the reduction temperature is 80–200℃ and the reduction treatment time is 0.5–4 hours.

[0035] Preferably, the reaction temperature range is 50–250℃ and the H2 pressure is 0.1–2 MPa.

[0036] In one specific embodiment, the raw material gas ratio is 0.1 vol% to 5 vol% C2H2, 10 vol% to 50 vol% C2H4, 0.5 vol% to 20 vol% H2, with the balance being N2.

[0037] The main evaluation indicators for the catalytic performance of this invention are acetylene conversion, ethylene selectivity, and ethylene yield. Their calculation methods are as follows:

[0038]

[0039]

[0040] yield of ethylene=acetylene conversion(%)×selectivity towardethylene(%)

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] 1. Special characteristics of the structure: The metal-encapsulated core-shell material is prepared by in-situ carbonization. This material has the characteristics of uniform distribution of metal active centers, small particle size and high dispersion. At the same time, due to the encapsulation of metal inside the carrier, the pore confinement effect gives it excellent thermal stability and regeneration performance.

[0043] 2. Special characteristics of the carrier: By utilizing the bonding between the abundant organic functional groups on the surface of the carrier and the ionic liquid, a uniform ionic liquid film is constructed on the surface of the active center, which reduces mass transfer resistance. At the same time, the preparation method in this application results in higher stability of the ionic liquid, which is not easy to flow from the surface of the carrier.

[0044] 3. The unique interaction mechanism between ionic liquids and metals: Through the synergistic effect of the coordination effect between the ionic liquid and the metal, and the solvent effect of the ionic liquid on the reactants and products, the concentrations of hydrogen, ethylene, and acetylene on the surface of the active center are efficiently controlled. This catalyst exhibits excellent catalytic performance in the selective hydrogenation of acetylene to ethylene. Studies show that the metal-ionic liquid coupled catalyst exhibits excellent low-temperature activity (achieving 100% complete conversion of acetylene at around 100℃, meeting industrial application requirements), and effectively suppresses the side reactions of excessive hydrogenation of ethylene to ethane and hydrogenation polymerization of acetylene to green oil under high acetylene conversion conditions, achieving high ethylene selectivity (>90%) and excellent catalytic stability (no catalyst deactivation was observed after 1000 hours of continuous operation). The catalyst synthesis method designed in this invention effectively improves the utilization rate of precious metals, prepares a catalyst with good dispersibility and high stability, and has a low ionic liquid loading, making it recyclable and suitable for large-scale synthesis, with broad development potential and market application value. Attached Figure Description

[0045] Figure 1 The graph shows the performance of the metal-ion liquid coupled catalyst prepared in Example 23 for catalyzing the selective hydrogenation of acetylene under simulated industrial conditions for 1000 hours.

[0046] Figure 2 The image shows the SEM characterization results of the metal-ionic liquid coupled catalyst prepared by the method of the present invention in Example 23. The SEM characterization results show that the support crystal particles are uniformly distributed and have a uniform particle size of 30-50 nm. After loading the ionic liquid, a uniform film structure is formed on the surface of the support.

[0047] Figure 3 The image shows the HRTEM image and metal particle size distribution of the metal-ion liquid coupled catalyst prepared by the method of the present invention in Example 23. The HRTEM characterization results show that the metal particles at the active center of the catalyst are uniform in size and evenly distributed. The metal particle size obtained by the above preparation method of the present invention is about 3 nm.

[0048] Figure 4The image shows the rotation angle HRTEM characterization results of the metal-ion liquid coupled catalyst prepared by the method of the present invention in Example 23, where (a) 0°, (b) 10°, (c) 20°, (d) 30°, (e) 45°, (f) -10°, (g) -20°, (h) -30°, (i) -40°, and (j) -45°. The HRTEM results at different angles indicate that the metal particles are distributed inside the pores of the support, confirming that it has a core-shell structure.

[0049] Figure 5 Thermogravimetric (TG) characterization results are shown for the metal@support core-shell materials prepared in Examples 7, 9, and 10, and the metal-ionic liquid coupled catalysts prepared in Examples 23, 28, and 29. The characterization results show that the catalysts have good stability before 280°C and no obvious decomposition phenomenon is observed, which can meet the practical application of selective hydrogenation of acetylene (the reaction temperature is usually below 200°C).

[0050] Figure 6 Flowchart of a fixed-bed reactor for selective hydrogenation of acetylene in all application examples. Detailed Implementation

[0051] The present invention will be illustrated below with specific embodiments. It should be noted that the 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, which is not limited thereto in any way. Those skilled in the art can make some non-essential improvements and adjustments based on the above description of the invention.

[0052] Example 1:

[0053] 10g of wheat flour and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0054] Example 2:

[0055] 10g of wheat flour and 2.5g of silica nanospheres were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0056] Example 3:

[0057] 10g of wheat flour and 0.5g of ammonium bicarbonate were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and the mixture was ground for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0058] Example 4:

[0059] 10g of wheat flour and 0.5g of dicyandiamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0060] Example 5:

[0061] 10g of wheat flour and 2.5g of zinc oxide nanospheres were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0062] Comparative Example 1:

[0063] 10g of corn starch and 2.5g of silica nanospheres were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0064] Comparative Example 2:

[0065] 10g of corn starch and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0066] Comparative Example 3:

[0067] 10g of methylcellulose and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, the mixture was heated to 90°C, cooled to room temperature, and ground for another hour. After kneading into a ball, the mixture was aged at 30°C for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0068] Comparative Example 4:

[0069] 10g of potato starch and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0070] Comparative Example 5:

[0071] A mixture of 10g glucose and polyvinyl alcohol was mechanically mixed with 0.5g calcium cyanamide and then ground thoroughly at room temperature for 1 hour to form a final mixture. 10mL of deionized water was then added, and grinding continued for another hour. After kneading the mixture into a ball, it was aged at 30°C for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the carrier material. The metal loading was 0 wt%.

[0072] Table 1 shows the physical structural parameters of the carrier materials prepared in Examples 1-5 and Comparative Examples 1-2. As can be seen from Table 1, comparing the pore size of Example 1 and Comparative Example 1 demonstrates that the method of the present invention can effectively prepare mesoporous carrier materials. Comparing the nitrogen content of Examples 1-5 and Comparative Examples 1-2 shows that using different precursors can effectively control the nitrogen content of the carrier materials.

[0073] Table 1 Physical structural parameters of carrier materials prepared from different precursors

[0074]

[0075]

[0076] Example 6:

[0077] 10g of wheat flour and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. Then, 10mL of 0.003g / mL palladium chloroacetic acid solution was added, and grinding continued for 1 hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 450℃ at a rate of 3℃ / min under a nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the metal@carrier core-shell material. The loading of the metal precursor was 0.5 wt%, designated as 0.5Pd@NMC-450.

[0078] Example 7:

[0079] 10g of wheat flour and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. Then, 10mL of 0.003g / mL palladium chloroacetic acid solution was added, and grinding continued for 1 hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under a nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the metal@carrier core-shell material. The loading of the metal precursor was 0.5 wt%, designated as 0.5Pd@NMC-650.

[0080] Example 8:

[0081] 10g of wheat flour and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. Then, 10mL of 0.003g / mL palladium chloroacetic acid solution was added, and grinding continued for 1 hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 850℃ at a rate of 3℃ / min under a nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the metal@carrier core-shell material. The loading of the metal precursor was 0.5 wt%, designated as 0.5Pd@NMC-850.

[0082] Example 9:

[0083] 10g of wheat flour and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. Then, 10mL of 0.001g / mL palladium chloroacetic acid solution was added, and grinding continued for 1 hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under a nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the metal@carrier core-shell material. The loading of the metal precursor was 0.2 wt%, designated as 0.2Pd@NMC-650.

[0084] Example 10:

[0085] 10g of wheat flour and 0.5g of calcium cyanamide were mechanically mixed and then ground thoroughly at room temperature for 1 hour to form a mixture. 10mL of 0.005g / mL palladium chloroacetic acid solution was then added, and grinding continued for 1 hour. After kneading into a dough, the mixture was aged at 30℃ for 12 hours, and then extruded into strips. The product was dried in air at 110℃ for 12 hours. The dried product was then placed in a tube furnace and heated to 650℃ at a rate of 3℃ / min under a nitrogen atmosphere at a rate of 50 mL / min for 10 hours. After natural cooling, the product was crushed and sieved, and particles of 20–40 mesh size were selected to obtain the metal@carrier core-shell material. The loading of the metal precursor was 0.7 wt%, designated as 0.7Pd@NMC-650.

[0086] Example 11:

[0087] The core-shell material prepared in Example 6 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid 1-propyl-3-methylimidazolium chloride was weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 6 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0088] Example 12:

[0089] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid 1-propyl-3-methylimidazolium chloride was weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 9%.

[0090] Example 13:

[0091] The core-shell material prepared in Example 8 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid 1-propyl-3-methylimidazolium chloride was weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 8 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0092] Example 14:

[0093] The core-shell material prepared in Example 9 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid 1-propyl-3-methylimidazolium chloride was weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 9 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0094] Example 15:

[0095] The core-shell material prepared in Example 10 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid 1-propyl-3-methylimidazolium chloride was weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 10 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 9%.

[0096] Example 16:

[0097] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid triphenylmethylphosphine bis(trifluoromethanesulfonyl)imide salt was weighed and dissolved in 0.9 mL of acetone, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the acetone solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0098] Example 17:

[0099] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid N-pentyl-ethylpiperidine chloride was weighed and dissolved in 0.9 mL of methanol, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid methanol solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0100] Example 18:

[0101] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid 1-propyl-3-methylimidazolium dicyandiamide salt was weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 9%.

[0102] Example 19:

[0103] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid propylpiperidine tetrafluoroborate was weighed and dissolved in 0.9 mL of thionyl chloride, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the thionyl chloride solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0104] Example 20:

[0105] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.10 g of the ionic liquid N-butyl-4-methylpyridine hexafluorophosphate was weighed and dissolved in 0.9 mL of a nitrogen-based alkylpyrrolidone, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0106] Example 21:

[0107] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst via an equal-volume impregnation method. 0.05 g of ionic liquid 1-propyl-3-methylimidazolium dicyandiamide salt and 0.05 g of ionic liquid 1-propyl-3-methylimidazolium chloride salt were weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 9%.

[0108] Example 22:

[0109] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst via an equal-volume impregnation method. 0.05 g of ionic liquid 1-hydroxyethyl-3-methylimidazolium methanesulfonate and 0.05 g of ionic liquid N-methyltrifluoromethanesulfonate were weighed and dissolved in 0.9 mL of acetone, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation of acetylene was obtained, with an ionic liquid loading of 9%.

[0110] Example 23:

[0111] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.15 g of ionic liquid 1-propyl-3-methylimidazolium dicyandiamide salt and 0.15 g of ionic liquid 1-propyl-3-methylimidazolium chloride salt were weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst 0.5Pd@NMC@IL, which can be directly used for the selective hydrogenation reaction of acetylene, was obtained, with an ionic liquid loading of 23%.

[0112] Example 24:

[0113] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst via an equal-volume impregnation method. 0.25 g of ionic liquid 1-propyl-3-methylimidazolium dicyandiamide salt and 0.25 g of ionic liquid 1-propyl-3-methylimidazolium chloride salt were weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 33%.

[0114] Example 25:

[0115] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.20 g of ionic liquid 1-propyl-3-methylimidazolium dicyandiamide salt and 0.40 g of ionic liquid 1-propyl-3-methylimidazolium chloride salt were weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 37.5%.

[0116] Example 26:

[0117] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst using an equal-volume impregnation method. 0.40 g of ionic liquid 1-propyl-3-methylimidazolium dicyandiamide salt and 0.20 g of ionic liquid 1-propyl-3-methylimidazolium chloride salt were weighed and dissolved in 0.9 mL of deionized water, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 37.5%.

[0118] Example 27:

[0119] The core-shell material prepared in Example 7 was used to prepare a metal-ionic liquid coupled catalyst via an equal-volume impregnation method. 0.05 g of ionic liquid 1-ethyl-3-methylimidazolium dicyandiamide salt and 0.05 g of ionic liquid tetramethylammonium tetrafluoroborate salt were weighed and dissolved in 0.9 mL of thioacetic acid, and sonicated until completely dissolved. 1.0 g of the core-shell material prepared in Example 7 was weighed and added to the ionic liquid aqueous solution, sonicated for 10 min, and then allowed to stand at room temperature for 24 h. After drying at 110 °C for 24 h, a catalyst that can be directly used for the selective hydrogenation reaction of acetylene was obtained, with an ionic liquid loading of 9%.

[0120] Example 28

[0121] Referring to Example 23, the only difference is that the core-shell material prepared in Example 7 is replaced with the core-shell material prepared in Example 9, 0.2Pd@NMC-650, and finally a catalyst 0.2Pd@NMC@IL that can be directly used for the selective hydrogenation reaction of acetylene is obtained.

[0122] Example 29

[0123] Referring to Example 23, the only difference is that the core-shell material prepared in Example 7 is replaced with the core-shell material prepared in Example 10, 0.7Pd@NMC-650, and finally a catalyst 0.7Pd@NMC@IL that can be directly used for the selective hydrogenation reaction of acetylene is obtained.

[0124] Example 30:

[0125] 0.20 g of the core-shell material 0.5 Pd@NMC-6500 prepared in Example 7 was weighed and diluted with quartz sand. The lower part of the reaction tube was supported by a stainless steel inner liner and quartz wool, the middle part was filled with the catalyst diluted with quartz sand, and the upper part was filled with quartz sand for preheating. After fixed-bed aeration and leak detection, the temperature was raised to 200°C for 2 h under normal pressure hydrogen atmosphere, and then lowered to the reaction temperature. Feeding was started, and the raw material was a mixture of acetylene / ethylene / hydrogen (0.351 vol% C2H2, 0.697 vol% H2, 30.5 vol% C2H4, balance N2). The reaction pressure was 0.1 MPa and the space velocity was 15000 h⁻¹. -1 Two hours after feeding, the reaction products were sampled and directly entered into a gas chromatograph for online analysis via a six-way valve and an insulated tube. Example 7 investigated the catalytic performance of the metal@supported core-shell material in the selective hydrogenation of acetylene at different reaction temperatures; the results are shown in Table 1.

[0126] Table 2 Catalytic performance of metal@supported core-shell materials in selective acetylene hydrogenation at different reaction temperatures.

[0127] Reaction temperature (°C) Acetylene conversion rate (%) Ethylene selectivity (%) Ethylene yield (%) 50 89.7 78.6 70.5 55 98.1 69.3 68.0 60 100 47.7 47.7 65 100 26.6 26.6 75 100 3.7 3.7 100 100 -8.8 -8.8 125 100 -7.3 -7.3 150 100 -3.3 -3.3 175 100 7.9 7.9 200 100 35.6 35.6

[0128] Example 31:

[0129] 0.20 g of the core-shell material prepared in Examples 1 and 6-10 were weighed and diluted with quartz sand. The lower part of the reaction tube was supported by a stainless steel inner liner and quartz wool, the middle part was filled with the catalyst diluted with quartz sand, and the upper part was filled with quartz sand for preheating. After fixed-bed aeration and leak detection, the temperature was raised to 200°C for 2 h under atmospheric hydrogen atmosphere, and then lowered to 60°C. Feeding was started, and the raw material was a mixture of acetylene / ethylene / hydrogen (0.351 vol% C2H2, 0.697 vol% H2, 30.5 vol% C2H4, balance N2). The reaction pressure was 0.1 MPa and the space velocity was 15000 h⁻¹. -1 Two hours after feeding, the reaction products were directly introduced into the gas chromatograph via a six-way valve and an insulated tube for online analysis. The catalytic performance of the metal@supported core-shell material in the selective hydrogenation of acetylene at the same reaction temperature was investigated, and the results are shown in Table 3.

[0130] Table 3 Catalytic performance of different metal@support core-shell materials in the selective hydrogenation of acetylene at the same reaction temperature (60℃).

[0131] Core-shell materials Pd loading (wt%) Acetylene conversion rate (%) Ethylene selectivity (%) Ethylene yield (%) Example 1 0 0 / / Example 6 0.5 98.1 49.3 48.4 Example 7 0.5 100 47.7 47.7 Example 8 0.5 100 40.8 40.8 Example 9 0.2 100 42.6 42.6 Example 10 0.7 100 43.7 43.7

[0132] Example 32:

[0133] 0.20 g of the catalysts prepared in Examples 11 to 15 were weighed and diluted with quartz sand. The lower part of the reaction tube was supported by a stainless steel inner liner and quartz wool, the middle part was filled with the catalyst diluted with quartz sand, and the upper part was filled with quartz sand for preheating. After fixed-bed aeration and leak detection, the temperature was raised to 200°C for reduction for 2 h under a normal pressure hydrogen atmosphere, and then lowered to the reaction temperature of 100°C. Feeding was started, and the raw material was a mixture of acetylene / ethylene / hydrogen (0.351 vol% C2H2, 0.697 vol% H2, 30.5 vol% C2H4, with the balance being N2). The reaction pressure was 0.1 MPa and the space velocity was 15000 h⁻¹. -1 Two hours after feeding, the reaction products were directly introduced into the gas chromatograph for online analysis via a six-way valve and an insulated tube. Examples 11 to 15 investigated the catalytic performance of the metal-ionic liquid coupled catalyst for the selective hydrogenation of acetylene, and the results are shown in Table 4.

[0134] Table 4. Catalytic performance of metal-ion liquid coupled catalysts in the selective hydrogenation of acetylene.

[0135] Core-shell materials Pd loading rate (%) Acetylene conversion rate (%) Ethylene selectivity (%) Ethylene yield (%) Example 11 0.5 100 78.1 78.1 Example 12 0.5 100 90.3 90.3 Example 13 0.5 100 80.2 80.2 Example 14 0.5 99.9 70.8 70.7 Example 15 0.5 100 82.6 82.6

[0136] Example 33:

[0137] Weigh 0.2 g of the metal-ionic liquid coupled catalyst prepared in Examples 16 to 21 and dilute it with quartz sand (Pd loading is 0.5%, ionic liquid loading is 10-40%). The lower part of the reaction tube is supported by a stainless steel inner liner and quartz wool, the middle part is filled with the catalyst diluted with quartz sand, and the upper part is filled with quartz sand for preheating. After the fixed bed is vented and leak-tested, the temperature is raised to 200°C for 2 h under a normal pressure hydrogen atmosphere, and then lowered to the reaction temperature. Feeding begins with an acetylene / ethylene / hydrogen mixture (0.351 vol% C2H2, 0.697 vol% H2, 30.5 vol% C2H4, balance N2), reaction pressure is 0.1 MPa, and space velocity is 15000 h⁻¹. -1 Two hours after feeding, the reaction products were directly introduced into the gas chromatograph for online analysis via a six-way valve and an insulated tube. Examples 16 to 21 and 24 to 27 investigated the performance of the metal-ion liquid coupled catalyst in the selective hydrogenation of acetylene at the same reaction temperature (100°C), and the results are shown in Table 5.

[0138] Table 5 Reaction performance of different metal-ion liquid coupled catalysts

[0139]

[0140]

[0141] Example 34:

[0142] 0.2 g of the metal-ionic liquid coupled catalyst prepared in Example 23 was weighed and diluted with quartz sand. The lower part of the reaction tube was supported by a stainless steel inner liner and quartz wool, the middle part was filled with the catalyst diluted with quartz sand, and the upper part was filled with quartz sand for preheating. After fixed bed aeration and leak detection, the temperature was raised to 200°C for 2 h under atmospheric hydrogen atmosphere, and then lowered to the reaction temperature of 100°C. Feeding was started, and the raw material was a mixture of acetylene / ethylene / hydrogen (0.351 vol% C2H2, 0.697 vol% H2, 30.5 vol% C2H4, balance N2). The reaction pressure was 0.1 MPa and the space velocity was 15000 h⁻¹. -1 Two hours after feeding, the reaction products were sampled and directly introduced into the gas chromatograph via a six-way valve and an insulated tube for online analysis. Example 23 investigated the long-term continuous evaluation of the selective hydrogenation reaction of acetylene catalyzed by a metal-ionic-liquid coupled catalyst; the results are shown below. Figure 1 As shown.

Claims

1. A method for preparing a metal-ionic liquid coupled catalyst, characterized in that: The preparation method includes the following steps: (1) The carrier precursor, metal precursor, template agent and solvent are mixed in a certain mass ratio and ground at 10-100 °C for a certain time to form a mixture; the mixture is aged at 10-120 °C for 1-120 h, then extruded into strips and dried at 30-180 °C for 6-120 h; the dried product is placed in a tube furnace and heated to 200-1000 °C for 2-72 h at a rate of 1-20 °C / min under a certain amount of flowing inert atmosphere; after natural cooling, the product is sieved to obtain granular metal@carrier core-shell material; The template agent is one or a mixture of two or more of the following: ammonium bicarbonate, ammonium dihydrogen phosphate, dicyandiamide, triethylamine, calcium cyanamide, silicon dioxide, magnesium oxide, zinc oxide, and calcium carbonate. The carrier precursor is one or a mixture of two or more of the following in any proportion: polyvinyl alcohol, glucose, methylcellulose, sucrose, corn starch, wheat flour, sucralose, potato starch, and cationic starch. The metal precursor is one of the following: chloropalladium, sodium chloropalladium, dichlorodiaminepalladium, palladium acetylacetonate, dinitrosodiaminepalladium, palladium nitrate, palladium acetate, and dichlorotetraaminepalladium. (2) The ionic liquid solution is loaded onto the surface of the metal@support core-shell material by the equal volume impregnation method, and after drying, the metal-ionic liquid coupled catalyst is obtained; the ionic liquid is a combination of 1-propyl-3-methylimidazolium dicyandiamide salt and 1-propyl-3-methylimidazolium chloride salt in a mass ratio of 1:1, or 1-propyl-3-methylimidazolium chloride salt or triphenylmethylphosphine bis(trifluoromethanesulfonyl)imide salt; the ionic liquid loading in the catalyst is 9 to 25 wt%, and the ionic liquid loading refers to the mass percentage of the ionic liquid in the catalyst.

2. The preparation method according to claim 1, characterized in that: The metal loading in the metal@carrier core-shell material is 0.01% to 1%, where the metal loading refers to the percentage of the metal element in the carrier by mass in the metal@carrier core-shell material.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the template agent to the carrier precursor is 0.1 to 10:20; the mass ratio of the solvent to the carrier precursor is 0.01 to 1:

1.

4. The preparation method according to claim 3, characterized in that: The mass ratio of the template agent to the carrier precursor is 1 to 5:

20.

5. The preparation method according to claim 1, characterized in that: The solvent mentioned in step (1) is one of methanol, ethanol, deionized water, N,N-dimethylformamide and acetone.

6. The preparation method according to claim 1, characterized in that: In step (1), the aging temperature is 20-100 ℃; the aging time is 6-72 h; the carbonization temperature is 300-900 ℃; and the carbonization time is 4-48 h.

7. The preparation method according to claim 6, characterized in that: In step (1), the aging temperature is 30-80 ℃ and the aging time is 12-36 h.

8. The preparation method according to claim 6, characterized in that: In step (1), the carbonization temperature is 400–800 °C and the carbonization time is 6–36 h.

9. The preparation method according to claim 1, characterized in that: The preparation process of the ionic liquid supported by the equal volume impregnation method in step (2) is as follows: a certain amount of ionic liquid is dissolved in a solvent, and ultrasonically dissolved for a certain time at room temperature until completely dissolved. The prepared metal@support core-shell material is added to the ionic liquid solution, and left to stand at room temperature for 12-24 h. Then it is dried at 60-180℃ for 12-24 h to obtain the metal-ionic liquid coupled catalyst.

10. A metal-ionic liquid coupled catalyst prepared by the method according to claim 1.

11. The application of the metal-ionic liquid coupled heterogeneous catalyst as described in claim 10 in the selective hydrogenation of acetylene to ethylene.

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