Catalyst for selective hydrogenation of cyclopentadiene, process for its preparation and use

Abstract

The application discloses a catalyst for selective hydrogenation of cyclopentadiene, a preparation method and application thereof, and the catalyst comprises an Al2O3-CuO-TiO2 composite oxide carrier and a main active component Ni and an optional auxiliary active component supported thereon, and the auxiliary active component is at least one selected from Ag and Ru. The catalyst has high low-temperature reaction activity and selectivity, the preparation process is simple, the reaction condition is mild, the production cost is low, the catalyst can be stably operated for a long time in production, and has industrial application value.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalyst for the selective hydrogenation of cyclopentadiene and its preparation method and application. BACKGROUND

[0002] At present, the annual output of ethylene in China has exceeded 20 million tons. The C5 and C9 fractions from ethylene cracking contain a large amount of dicyclopentadiene, and the potential annual output of dicyclopentadiene has exceeded 1 million tons. However, at present, most of the dicyclopentadiene is directly burned as fuel oil with low added value, which not only wastes resources, but also causes environmental pollution. Dicyclopentadiene can be depolymerized by heating to obtain its monomer cyclopentadiene, and cyclopentadiene can be prepared by selective hydrogenation to obtain a single olefin-cyclopentene with multiple uses. This is a high value-added utilization way of dicyclopentadiene resources.

[0003] Cyclopentene is an important organic chemical raw material, which can be used to prepare cyclopentanol, cyclopentanone, glutaric dialdehyde, glutaric acid, cyclopentane, halogenated cyclopentane and polycyclopentene rubber, and other important organic chemical intermediates and products.

[0004] The method for preparing cyclopentene by selective hydrogenation of dicyclopentadiene has the characteristics of sufficient raw materials and good economy, and can produce a large amount of cyclopentene, which is a process technology with strong application and development prospects.

[0005] The technical difficulty of preparing cyclopentene by selective hydrogenation of dicyclopentadiene is to control the hydrogenation depth of dicyclopentadiene, that is, to avoid full hydrogenation to form cyclopentane as much as possible, so as to improve the selectivity of the hydrogenation reaction to cyclopentene. In addition, due to the close boiling points of the deep hydrogenation by-product cyclopentane and the target product cyclopentene, it is not easy to separate them, and the energy consumption of the rectification process is high. For the above reasons, it is required that the selectivity of the selected hydrogenation catalyst to cyclopentene is as good as possible, and the catalytic activity is as high as possible. In addition, in the hydrogenation reaction of dicyclopentadiene, dicyclopentadiene adsorbed on the surface of the catalyst is very easy to dimerize and then polymerize to form high polymers, i.e. the formation process of so-called "green oil", which leads to the need for frequent regeneration of the catalyst, shortens the service life and greatly affects the long-term stable operation of the device. Accordingly, it is required that the catalyst has low-temperature high activity, large "green oil" capacity and high stability. Obviously, the key to the technology of preparing cyclopentene by selective hydrogenation of dicyclopentadiene lies in the selection of high-performance catalyst.

[0006] In the prior art, the selective hydrogenation catalyst for preparing cyclopentene by hydrogenation of dicyclopentadiene is typically a Pd catalyst supported on a carrier, and the carrier usually uses alumina. An auxiliary agent is often used to modify the Pd active component in such a catalyst, which is prone to loss, expensive, not easy to regenerate and not ideal in selectivity.

[0007] Ni catalysts have also been reported in the prior art for the selective hydrogenation of cyclopentadiene, typically Raney-Ni catalysts. However, Raney-Ni is a skeletal Ni-Al alloy catalyst, which is usually used in slurry bed reactions, and is often in the form of a powder dispersed in the raw material for contact reaction under violent agitation. The catalyst has poor strength and is easily pulverized and lost, and is prone to self-ignition in the presence of air, which is inconvenient for storage and separation of the product after reaction. Moreover, the hydrogenation activity of cyclopentadiene is low, and the conversion rate of the raw material is usually less than 90% under the condition of ensuring high selectivity of cyclopentene.

[0008] The carrier-supported Ni catalyst is very suitable for use in fixed bed reactions due to the large particle size, high mechanical strength, large pore volume and large specific surface area of the carrier, thus avoiding the problem of difficulty in separation of the catalyst from the product, and simplifying the hydrogenation process. However, there are few related technical reports and the use effect is poor. In addition, although the carrier-supported Ni catalyst has many advantages compared with the more typical carrier-supported Pd catalyst and Raney-Ni catalyst, it still has problems of low selectivity and low-temperature reaction activity and poor stability in the process of selective hydrogenation of cyclopentadiene.

[0009] Therefore, it is necessary to develop a catalyst for the selective hydrogenation of cyclopentadiene to prepare cyclopentene, which has high low-temperature reaction activity, good selectivity, simple process, mild reaction conditions, low production cost and long-term stable operation. SUMMARY

[0010] In view of this, in order to overcome at least one technical problem in the prior art, the present application provides a catalyst for the selective hydrogenation of cyclopentadiene and a preparation method and application thereof.

[0011] The purpose of the present application is achieved by the following technical solutions.

[0012] In a first aspect, the present application provides a catalyst for the selective hydrogenation of cyclopentadiene, wherein the catalyst comprises an Al2O3-CuO-TiO2 composite oxide carrier and a main active component Ni and an optional auxiliary active component supported thereon, the auxiliary active component being selected from at least one of Ag and Ru.

[0013] In the present application, by matching the specific carrier, the main active component and the auxiliary active component, a catalyst for the selective hydrogenation of cyclopentadiene is obtained, which has high low-temperature reaction activity and selectivity.

[0014] According to the catalyst provided by the present application, the content of CuO is 0.1-5 parts, the content of TiO2 is 5-25 parts, and the content of Al2O3 is 70-94.9 parts, based on 100 parts by weight of the composite oxide carrier.

[0015] In some embodiments, the content of CuO is 0.3-3 parts, the content of TiO2 is 9-20 parts, and the content of Al2O3 is 77-90.7 parts, based on 100 parts by weight of the composite oxide carrier; and in some embodiments, the content of CuO is 1.5-3 parts, the content of TiO2 is 12-18 parts, and the content of Al2O3 is 79-86.5 parts, based on 100 parts by weight of the composite oxide carrier.

[0016] According to the present application, the content of the main active component Ni is 5-25 parts, preferably 10-20 parts, more preferably 10-15 parts, and most preferably 10-12 parts, based on 100 parts by weight of the total catalyst; the content of the auxiliary active component is 0-5 parts, preferably 0.5-3 parts, more preferably 1-3 parts, and most preferably 2-3 parts, based on oxides; and the content of the composite oxide is 70-95 parts, preferably 79.5-87 parts, more preferably 82-87 parts, and most preferably 85-87 parts.

[0017] According to the present application, the specific surface area of the composite oxide carrier is 30-155 m 2 / g, preferably 55-85 m 2 / g, and more preferably 55-70 m 2 / g.

[0018] According to the present application, the pore volume of the composite oxide carrier is 0.2-0.8 mL / g, and preferably 0.3-0.4 mL / g.

[0019] According to the present application, the catalyst is an activation-treated catalyst. In some embodiments, the activation treatment is carried out under hydrogen conditions.

[0020] According to the present application, the main active component Ni and the auxiliary active component can each independently exist in the form of an atom or a compound. Such a compound can be a compound of the main active component Ni and a compound of the auxiliary active component commonly used in a nickel-based catalyst for selective hydrogenation. In some embodiments, the main active component Ni and the auxiliary active component can each independently exist in the form of an oxide, such as NiO, Ag2O, RuO2.

[0021] In a second aspect, the present application provides a preparation method of the catalyst of the first aspect, wherein the preparation method comprises the following steps:

[0022] S110, impregnating the Al2O3-CuO-TiO2 composite oxide carrier with a nickel salt solution to obtain an impregnated composite oxide carrier, and drying and calcining the impregnated composite oxide carrier to obtain a catalyst precursor;

[0023] Optionally, S120, impregnating the catalyst precursor with a salt solution of an active component promoter to obtain an impregnated catalyst precursor, and drying and calcining the impregnated catalyst precursor to obtain a catalyst.

[0024] According to the preparation method provided by the present application, the impregnation time in steps S110 and S120 is independently 1-8h, preferably 1-4h.

[0025] According to the preparation method provided by the present application, the drying conditions in steps S110 and S120 independently include: a drying temperature of 90-120℃; and / or a drying time of 2-8h.

[0026] According to the preparation method provided by the present application, the calcination conditions in steps S110 and S120 independently include: a calcination temperature of 300-800℃; and / or a calcination time of 2-10h.

[0027] According to the preparation method provided by the present application, examples of the nickel salt include but are not limited to: nickel sulfate, nickel nitrate, soluble carboxylate, hypophosphite and halide. In some embodiments, the nickel salt is nickel sulfate, nickel nitrate, nickel chloride or nickel acetate.

[0028] According to the preparation method provided by the present application, the type of nickel salt solution is not particularly limited, which can be an aqueous solution, or an organic nickel salt solution formed by using ethanol, benzene, etc. as a solvent, and is preferably an aqueous solution of inorganic nickel salt. Compared with organic nickel salt solution, the aqueous solution of inorganic nickel salt has low cost and is environmentally friendly.

[0029] According to the preparation method provided by the present application, the concentration of the nickel salt solution is 1.0-3.0mol / L, calculated as NiO.

[0030] According to the preparation method provided by the present application, the salt of the active component promoter can be a salt of an active component promoter commonly used in the field of selective hydrogenation catalysts, examples of which include but are not limited to: nitrate, soluble carboxylate and soluble halide, preferably nitrate, hydrochloride, oxalate or acetate.

[0031] According to the preparation method provided by the application, the type of the salt solution of the active component is not particularly limited, which can be an aqueous solution or an organic salt solution formed by using ethanol, benzene or the like as a solvent, and preferably an inorganic salt aqueous solution of the active component. Compared with the organic salt solution, the inorganic salt aqueous solution is low in cost and environmentally friendly. For example, the salt of the active component can be silver nitrate or ruthenium nitrate.

[0032] According to the preparation method provided by the application, the concentration of the salt solution of the active component is 0.01-0.3 mol / L in terms of the metal oxide.

[0033] According to the preparation method provided by the application, the preparation method of the composite oxide carrier comprises the following steps:

[0034] S210. The copper salt solution, the titanium salt solution and the alkaline solution are added into the aluminum salt solution in parallel at a temperature of 50-90 ℃, and after staying at a pH value of 5.5-7.0 for 15-20 min, the alkaline solution is continuously added until the pH value is 8-10, and the staying time is 15-20 min, so as to obtain a precipitate;

[0035] S220. The precipitate is washed, dried and calcined to obtain a composite oxide carrier.

[0036] According to the preparation method provided by the application, in step S210, the pH value is adjusted to fully mix the several solutions. Further, the alkaline solution is continuously added until the pH value is 8-10, so as to make the precipitation more complete and improve the utilization rate of the metal, and at the same time, the pore structure is optimized to obtain a moderate pore volume and specific surface area.

[0037] According to the preparation method provided by the application, the aluminum salt is selected from aluminum sulfate, aluminum chloride, aluminum nitrate and an organic aluminum salt, and / or the concentration of the aluminum salt solution is 0.5-2.5 mol / L.

[0038] According to the preparation method provided by the application, the titanium salt solution is selected from acid solutions of soluble titanium salts such as metatitanic acid, titanium tetrachloride and tetraethyl titanate, for example, a sulfuric acid solution; and / or the concentration of the titanium salt solution is 0.2-1.2 mol / L.

[0039] According to the preparation method provided by the application, the copper salt is a soluble copper salt, which is preferably selected from copper chloride, copper sulfate and copper nitrate; and / or the concentration of the copper salt aqueous solution is 0.1-0.6 mol / L.

[0040] According to the preparation method provided by the application, the alkaline solution comprises an ammonium salt solution and a lye. The ammonium salt is selected from ammonium bicarbonate, ammonium carbonate and an organic ammonium salt; and / or the concentration of the ammonium salt in the alkaline solution is 0.1-0.3 mol / L.

[0041] Similarly, the alkali solution is selected from ammonia, sodium hydroxide, potassium hydroxide and organic alkali, and / or the alkali solution has a concentration of 0.2-0.4 mol / L.

[0042] According to the preparation method provided by the present application, the washing of the precipitate in step S220 includes washing with deionized water until no acid radical ion is detected.

[0043] According to the preparation method provided by the present application, the drying condition in step S220 includes a drying temperature of 100-150°C and a drying time of 4-12 h.

[0044] According to the preparation method provided by the present application, the calcination condition in step S220 includes a calcination temperature of 500-1100°C and a calcination time of 4-12 h.

[0045] According to the preparation method provided by the present application, the preparation method of the titanium salt solution includes dissolving a soluble titanium salt such as metatitanic acid, titanium tetrachloride or tetraethyl titanate in a sulfuric acid solution to form a titanium salt solution.

[0046] According to the preparation method provided by the present application, the preparation method further includes activating the catalyst prepared in step S120.

[0047] In some embodiments, the preparation method further includes:

[0048] S310, activating the catalyst prepared in step S120 with hydrogen.

[0049] Preferably, the activation condition in step S310 includes an activation temperature of 300-600°C, an activation pressure of 0-3.0 MPa, a hydrogen flow rate relative to the catalyst of 1-15 mL / min·g, and an activation time of 6-18 h.

[0050] In a third aspect, the present application provides a catalyst prepared by the preparation method of the second aspect.

[0051] In a fourth aspect, the present application provides an application of the catalyst of the first aspect or the third aspect to the preparation of cyclopentene by selective hydrogenation of cyclopentadiene.

[0052] In a fifth aspect, the present application provides a method for preparing cyclopentene by selective hydrogenation of cyclopentadiene, wherein the method includes mixing cyclopentadiene and a dilution solvent, and allowing the cyclopentadiene and hydrogen to react in the presence of the catalyst to generate cyclopentene.

[0053] According to the method provided by the present application, the dilution solvent is selected from alkanes such as n-heptane, isooctane and cyclohexane, and is preferably selected from n-heptane and isooctane.

[0054] According to the method provided by the application, the conditions of the hydrogenation reaction include that the reaction temperature is 20-70℃, the reaction pressure is 0.1-1.5 MPa, the feed volume space velocity is 0.5-15 h -1 , the molar ratio of cyclopentadiene to hydrogen is 1:(1.0-3.0), and the volume ratio of cyclopentadiene to the dilution solvent is 1:(0.1-20).

[0055] In some embodiments, the conditions of the hydrogenation reaction include that the reaction temperature is 25-40℃, the reaction pressure is 0.2-1.0 MPa, the feed volume space velocity is 1-8 h -1 , the molar ratio of cyclopentadiene to hydrogen is 1:(1.1-1.5), and the volume ratio of cyclopentadiene to the dilution solvent is 1:(0.5-10).

[0056] The application has the following advantages:

[0057] (1) The catalyst of the application has high low-temperature reaction activity and selectivity, and has the advantages of simple preparation process, mild reaction conditions, low production cost, long-time stable operation in production and industrial application value.

[0058] (2) In the application, the Al2O3-CuO-TiO2 composite oxide is prepared by uniformly mixing titanium oxide and aluminum oxide and enriching them on the surface of the composite oxide, and CuO is uniformly dispersed on the skeleton structure of the composite oxide. Surprisingly, the application finds that a strong interaction is formed among Al2O3, CuO and TiO2 at high temperature, so that the composite oxide has high thermal stability and overcomes the defect that elemental copper is unstable at high temperature. Further, the TiO2 can still maintain the active phase of anatase at a high temperature of 700-1000℃, thereby ensuring the activity of the catalyst. In addition, it is believed that Al2O3 can maintain the crystal phase of γ-Al2O3, thereby ensuring the crushing strength and pore structure of the catalyst and meeting the requirements of industrial application.

[0059] (3) The catalyst for preparing cyclopentene by selective hydrogenation of cyclopentadiene provided by the application has the advantages of high selectivity and low-temperature activity, large amount of "green oil", stable hydrogenation activity, long-period use, convenient regeneration, continuous operation, easy separation from the product and the like. The method for preparing cyclopentene by selective hydrogenation of cyclopentadiene using the catalyst has the advantages of simple process, mild reaction conditions, low production cost, long-time stable operation and the like. The catalyst can ensure excellent selective hydrogenation effect of cyclopentadiene under the process conditions of the application. DETAILED DESCRIPTION

[0060] The application will be further described below in conjunction with specific examples, but the examples do not constitute any limitation on the application.

[0061] Example 1

[0062] Preparation of the support

[0063] An aluminum sulfate deionized water solution of 0.8 mol / L was prepared in 1 L, a metatitanic acid dilute sulfuric acid solution of 0.46 mol / L was prepared in 0.5 L, a copper nitrate solution of 0.39 mol / L was prepared in 0.1 L, a 0.22 mol / L ammonium bicarbonate solution was mixed with 25% ammonia water, and a mixed alkali solution of pH = 11-12 was prepared in 1 L.

[0064] At a temperature of 65°C, the above aluminum sulfate deionized water solution was added with the copper nitrate solution of 0.1 L and the metatitanic acid dilute sulfuric acid solution of 0.5 L in parallel flow, and an appropriate amount of mixed alkali solution was added to keep the pH value of the mixed solution system at 6.2, and it was kept for 20 min; the mixed alkali solution was continuously added to make the pH = 9.1, and it was kept for 20 min, to obtain a precipitate, which was filtered to obtain a filter cake.

[0065] The filter cake was repeatedly washed with 20 times the volume of deionized water for 5 times, and the washed filter cake was dried at 110°C for 6 h and calcined at 860°C for 5 h to obtain an Al2O3-CuO-TiO2 composite oxide support A.

[0066] Example 2

[0067] An aluminum sulfate deionized water solution of 0.88 mol / L was prepared in 1 L, a metatitanic acid dilute sulfuric acid solution of 0.35 mol / L was prepared in 0.5 L, a copper nitrate solution of 0.2 mol / L was prepared in 0.13 L, a 0.22 mol / L ammonium bicarbonate solution was mixed with 25% ammonia water, and a mixed alkali solution of pH = 11-12 was prepared in 1 L.

[0068] At a temperature of 75°C, the aluminum sulfate deionized water solution was added with the copper nitrate solution and the metatitanic acid dilute sulfuric acid solution in parallel flow, and an appropriate amount of mixed alkali solution was added to keep the pH value of the mixed solution system at 6.8, and it was kept for 15 min; the mixed alkali solution was continuously added to make the pH = 8.5, and it was kept for 15 min, to obtain a precipitate, which was filtered to obtain a filter cake.

[0069] The filter cake was repeatedly washed with 30 times the volume of deionized water for 7 times, and the washed filter cake was dried at 120°C for 6 h and calcined at 950°C for 4 h to obtain an Al2O3-CuO-TiO2 composite oxide support B.

[0070] Example 3

[0071] The procedure is basically the same as that for preparing the carrier in Example 1, except that the concentrations of the solutions prepared are different, specifically, 1 L of 0.9 mol / L aluminum sulfate aqueous solution, 0.5 L of 0.25 mol / L metatitanic acid dilute sulfuric acid solution, and 0.1 L of 0.1 mol / L copper nitrate solution. An Al2O3-CuO-TiO2 composite oxide carrier C is prepared.

[0072] Example 4

[0073] The procedure is basically the same as that for preparing the carrier in Example 1, except that the concentrations of the solutions prepared are different, specifically, 1 L of 0.8 mol / L aluminum sulfate aqueous solution, 0.5 L of 0.55 mol / L metatitanic acid dilute sulfuric acid solution, and 0.05 L of 0.1 mol / L copper nitrate solution. An Al2O3-CuO-TiO2 composite oxide carrier D is prepared.

[0074] Example 5

[0075] The procedure is basically the same as that for preparing the carrier in Example 1, except that the concentrations of the solutions prepared are different, specifically, 1 L of 0.9 mol / L aluminum sulfate aqueous solution, 0.4 L of 0.2 mol / L metatitanic acid dilute sulfuric acid solution, and 0.4 L of 0.2 mol / L copper nitrate solution. An Al2O3-CuO-TiO2 composite oxide carrier E is prepared.

[0076] Example 6

[0077] The procedure is basically the same as that for preparing the carrier in Example 1, except that the concentrations of the solutions prepared are different, specifically, 1 L of 0.8 mol / L aluminum sulfate aqueous solution, 0.5 L of 0.75 mol / L metatitanic acid dilute sulfuric acid solution, and 0.015 L of 0.1 mol / L copper nitrate solution. An Al2O3-CuO-TiO2 composite oxide carrier F is prepared.

[0078] Comparative Example 1

[0079] 1. Preparation of the carrier

[0080] 1 L of 0.8 mol / L aluminum sulfate aqueous solution, 0.56 L of 0.46 mol / L metatitanic acid dilute sulfuric acid solution, and a mixed alkali solution having a pH of 11-12 are prepared by mixing 0.22 mol / L ammonium bicarbonate solution with 25% ammonia water.

[0081] The three solutions of aluminum sulfate deionized aqueous solution, metatitanic acid dilute sulfuric acid solution and mixed alkali solution were co-precipitated under the conditions of normal pressure and 65℃. The flow rate of the mixed alkali solution was controlled so that the pH value of the precipitate was kept in the range of 5.0-6.0 for 8 min, then the flow rate of the mixed alkali solution was increased so that the pH value of the mixed solution was kept in the range of 8.5-9.5 for 8 min, then the flow rate of the mixed alkali solution was decreased so that the pH value of the mixed solution was kept in the range of 5.0-6.0 for 8 min, and then the flow rate of the mixed alkali solution was increased so that the pH value of the precipitate was kept in the range of 8.5-9.5, and the process was repeated until the solution was completely added. The reaction liquid was kept at 70℃ for 30 min, then the precipitate was filtered, washed with deionized water at a volume of 15 times of the precipitate for 30 min, then filtered and washed again, and the process was repeated four times. Finally, the precipitate was dried at 110℃ for 10 h and calcined at 950℃ for 5 h to obtain the titanium oxide-aluminum oxide composite G.

[0082] Comparative Example 2

[0083] γ-Al2O3 97 g produced by Yantai Henghui Company was impregnated in 0.1 L of copper nitrate solution with a concentration of 0.38 mol / L, the impregnation time was 4 h, and the impregnated sample was dried at 110℃ for 8 h and calcined at 550℃ for 5 h to obtain Al2O3 with a CuO content of 3%. 3- CuO composite oxide carrier H.

[0084] Comparative Example 3

[0085] γ-Al2O3 produced by Yantai Henghui Company was used as the carrier, which was recorded as carrier I.

[0086] Carrier characterization

[0087] 1. Specific surface area, pore volume

[0088] The specific surface area and pore volume of the carrier were determined by using ASAP 2020 adsorption instrument (N2 adsorption-desorption method) of American Micromeritics Company. Specifically, the carrier sample was degassed at 623 K for 4 h before testing, and nitrogen was adsorbed at liquid nitrogen temperature. The sample data were processed using AMS software, and the specific surface area of the sample was obtained using the Brunauer-Emmet-Teller (BET) method. The average pore diameter was obtained from the nitrogen adsorption isotherm curve using the Barrett-Joyner-Halenda (BJH) method, and the pore volume was obtained from the P / Po single-point desorption curve. The results are shown in Table 1.

[0089] 2. Determination of carrier components

[0090] The components in the carrier were determined by using UV-2100 ultraviolet spectrophotometer, and the results are shown in Table 1.

[0091] Table 1 Support parameters of Examples 1 to 6 and Comparative Examples 1 to 3

[0092]

[0093] Example 7

[0094] Method for preparing a Ni / Al2O3-CuO-TiO2 catalyst.

[0095] Take 100 g of the Al2O3-CuO-TiO2 composite oxide support A prepared in Example 1, immerse it in 0.2 L of a 1.0 mol / L nickel nitrate solution for 2 h, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to produce a catalyst Al having a NiO content of 10.6 parts by weight.

[0096] Example 8

[0097] Prepare a catalyst according to the method for preparing a Ni / Al2O3-CuO-TiO2 catalyst of Example 7, except that use the Al2O3-CuO-TiO2 composite oxide supports B, C, and D prepared above, and change the concentration of the nickel nitrate solution to produce catalysts Bl, Cl, and Dl having different Ni contents.

[0098] Example 9

[0099] Method for preparing a Ni-Ag / Al2O3-CuO-TiO2 catalyst.

[0100] Take 100 g of the Al2O3-CuO-TiO2 composite oxide support A prepared in Example 1, immerse it in 0.2 L of a 1.0 mol / L nickel nitrate solution for 2 h, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to produce a catalyst Al having a NiO content of 10.6 parts by weight.

[0101] Take 100 g of the catalyst precursor above, immerse it in 0.2 L of a 0.18 mol / L silver nitrate aqueous solution for 1 h, dry it at 110°C for 6 h, and then calcine it at 600°C for 6 h to produce catalyst A2 having a composition of 3 parts by weight of Ag2O, 10 parts by weight of NiO, and 87 parts by weight of the composite oxide support.

[0102] Example 10

[0103] Prepare a catalyst according to the method for preparing a Ni-Ag / Al2O3-CuO-TiO2 catalyst of Example 9, except that use the Al2O3-CuO-TiO2 composite oxide supports B, C, and D prepared above, and change the concentration of the nickel nitrate solution and the concentration of the silver nitrate aqueous solution to produce catalysts B2, C2, and D2 having different Ni and Ag contents.

[0104] Example 11

[0105] A method for preparing a Ni-Ru / Al2O3-CuO-TiO2 catalyst.

[0106] Take 100 g of the Al2O3-CuO-TiO2 composite oxide carrier D prepared in Example 4, immerse it in 0.4 L of a 1.0 mol / L nickel nitrate solution for 3 h, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to prepare a catalyst precursor with a NiO content of 20.8 parts by weight.

[0107] Take 100 g of the catalyst precursor described above, immerse it in 0.2 L of a 0.025 mol / L ruthenium nitrate aqueous solution for 1 h, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to prepare catalyst D3, which has a composition of: a Ru content of 0.5 parts by weight, a NiO content of 20 parts by weight, and a composite oxide carrier content of 79.5 parts by weight.

[0108] Example 12

[0109] Prepare a catalyst according to the method for preparing a Ni-Ru / Al2O3-CuO-TiO2 catalyst of Example 11, except that take the Al2O3-CuO-TiO2 composite oxide carriers A, B, and C prepared above, and change the concentration of the nickel nitrate solution and the concentration of the ruthenium nitrate aqueous solution to prepare catalysts A3, B3, and C3 with different Ni and Ru contents.

[0110] Example 13

[0111] A method for preparing a Ni-Ag / Al2O3-CuO-TiO2 catalyst.

[0112] Take 100 g of the Al2O3-CuO-TiO2 composite oxide carrier A prepared in Example 1, immerse it in 0.2 L of a 1.0 mol / L nickel nitrate solution for 150 min, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to prepare a catalyst precursor with a NiO content of 10.6 parts by weight.

[0113] Take 100 g of the catalyst precursor described above, and change the concentration of the silver nitrate aqueous solution to prepare catalysts A4, A5, and A6, which have the same carrier and the same Ni content but different Ag contents.

[0114] Comparative Example 4

[0115] The Al2O3-TiO2 composite oxide support G 100 g prepared in Comparative Example 1 was put into 0.2 L of a 1.0 mol / L nickel nitrate solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 550°C for 6 h to produce a catalyst precursor having a NiO content of 10.6 parts by weight.

[0116] The above catalyst was used as a precursor 100 g, put into 0.2 L of a 0.18 mol / L silver nitrate aqueous solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 600°C for 6 h to produce a catalyst G1 having a composition of Ag content of 0.5 parts by weight, NiO content of 10 parts by weight, and composite oxide support content of 89.5 parts by weight.

[0117] Comparative Example 5

[0118] The Al2O3-TiO2 composite oxide support G 100 g prepared in Comparative Example 1 was put into 0.2 L of a 1.0 mol / L nickel nitrate solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 550°C for 6 h to produce a catalyst precursor having a NiO content of 10.6 parts by weight.

[0119] The above catalyst was used as a precursor 100 g, put into 0.2 L of a 0.15 mol / L ruthenium nitrate aqueous solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst G2 having a composition of Ru content of 0.5 parts by weight, NiO content of 10 parts by weight, and composite oxide support content of 89.5 parts by weight.

[0120] Comparative Example 6

[0121] The Al2O3-CuO composite oxide support H 100 g prepared in Comparative Example 2 was put into 0.2 L of a 1.0 mol / L nickel nitrate solution, impregnated for 150 min, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst precursor having a NiO content of 10.6 parts by weight.

[0122] The above catalyst was used as a precursor 100 g, put into 0.2 L of a 0.18 mol / L silver nitrate aqueous solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 600°C for 6 h to produce a catalyst H1 having a composition of Ag content of 3 parts by weight, NiO content of 10 parts by weight, and composite oxide support content of 89.5 parts by weight.

[0123] Comparative Example 7

[0124] The Al2O3-CuO composite oxide support H 100 g prepared in Comparative Example 2 was put into 0.2 L of a 1.0 mol / L nickel nitrate solution, impregnated for 150 min, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst precursor having a NiO content of 10.6 parts by weight.

[0125] The above catalyst was used as a precursor 100 g, put into 0.2 L of a 0.15 mol / L aqueous ruthenium nitrate solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst H2 having a composition of Ru content of 0.5 parts by weight, NiO content of 10 parts by weight, and composite oxide support content of 89.5 parts by weight.

[0126] Comparative Example 8

[0127] The γ-Al2O3 support 100 g of Comparative Example 3 was put into 0.2 L of a 1.0 mol / L nickel nitrate solution, impregnated for 150 min, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst precursor having a NiO content of 10.6 parts by weight.

[0128] The above catalyst was used as a precursor 100 g, put into 0.2 L of a 0.18 mol / L aqueous silver nitrate solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 600°C for 6 h to produce a catalyst I1 having a composition of Ag content of 3 parts, NiO content of 10 parts, and composite oxide support content of 89.5 parts.

[0129] Comparative Example 9

[0130] The γ-Al2O3 support 100 g of Comparative Example 3 was put into 0.2 L of a 1.0 mol / L nickel nitrate solution, impregnated for 150 min, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst precursor having a NiO content of 10.6 parts by weight.

[0131] The above catalyst was used as a precursor 100 g, put into 0.2 L of a 0.15 mol / L aqueous ruthenium nitrate solution, impregnated for 1 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to produce a catalyst I2 having a composition of Ru content of 0.5 parts by weight, NiO content of 10 parts by weight, and composite oxide support content of 89.5 parts by weight.

[0132] The respective compositions of the catalysts according to Examples 7 to 13 and Comparative Examples 4 to 9 are shown in Table 2.

[0133] Table 2 Compositions of the respective catalysts

[0134]

[0135] Application Example

[0136] The catalysts used in this application example are the catalysts prepared in the examples and comparative examples, which are evaluated under the same conditions.

[0137] The reaction conditions for the preparation of cyclopentene from cyclopentadiene are as follows: a trickle-bed hydrogenation reactor with a catalyst loading volume of 100 mL is used, the catalyst loading is 100 mL, the reaction pressure is 0.6 MPa, the reaction temperature is 30°C, the molar ratio of hydrogen to cyclopentadiene is 1.2:1, the volume ratio of cyclopentadiene to dilution solvent cyclohexane is 1:5, the feed volume space velocity (the volume ratio of the amount of liquid raw material fed per hour to the catalyst loading) is 6.0 h -1 .

[0138] Table 3 Results of selective hydrogenation of cyclopentadiene

[0139]

[0140] As can be seen from Table 3, the catalyst provided by the present application can be used to prepare cyclopentene from cyclopentadiene with high conversion and high selectivity. In combination with Tables 1 and 2, it is believed that the Al2O3-CuO-TiO2 composite oxide used in the present application has titanium oxide uniformly mixed with aluminum oxide and enriched on the surface of the composite oxide, and CuO is uniformly dispersed on the framework structure of the composite oxide. At high temperatures, strong interactions are formed among Al2O3, CuO and TiO2, so that the thermal stability of the composite oxide is high, overcoming the defect that elemental copper is unstable at high temperatures. Further, the TiO2 is still able to maintain the active phase of anatase at high temperatures of 700-1000°C, ensuring the activity of the catalyst.

[0141] Any numerical values recited herein include all values from the lower value and up to the upper value. Values that are near to or close to the recited value are also considered as being the recited value, especially if this makes the application easier to understand. Unless otherwise stated, the recited parameter values are approximate, and are provided "as an average under the conditions used to determine the value", i.e. the value is an average value. In this application, the use of "or" means "and / or" unless stated otherwise. Furthermore, "consisting essentially of can be substituted with "consisting of to provide "consisting of", in order to remove the words "essentially sub-combination" from the claim. In this application, the use of "a" or "an" means "one or more" unless otherwise stated.

[0142] It should be noted that the foregoing examples have been provided merely for the purposes of illustration and are not intended to limit the application in any way. Descriptions and examples of materials and processes of the application are intended to be illustrative not limiting. Any modifications of the application and other applications of the application will occur to those skilled in the art to which the application pertains and many options for modification of the application will suggest themselves. The application lies in the broadest aspects of the art, and there are many alternatives for carrying out the application. Accordingly, the scope of the application should be determined not with reference to the above description but with reference to the claims that follow.

Claims

1. A catalyst for the selective hydrogenation of cyclopentadiene, wherein, The catalyst comprises an Al2O3-CuO-TiO2 composite oxide carrier and a main active component Ni and an optional auxiliary active component supported thereon, the auxiliary active component being at least one selected from Ag and Ru; The content of CuO is 1.5-3 parts, the content of TiO2 is 12-18 parts, and the content of Al2O3 is 79-86.5 parts, based on 100 parts by weight of the composite oxide carrier; The content of the main active component Ni is 5-25 parts in terms of NiO, the content of the auxiliary active component is 0-5 parts in terms of oxide, and the content of the composite oxide is 70-95 parts, based on 100 parts by weight of the total weight of the catalyst.

2. The catalyst according to claim 1, characterized in that, The content of the main active component Ni is 10-20 parts in terms of NiO, the content of the auxiliary active component is 0.5-3 parts in terms of oxide, and the content of the composite oxide is 79.5-87 parts, based on 100 parts by weight of the total weight of the catalyst.

3. The catalyst of claim 2, wherein The content of the main active component Ni is 10-15 parts in terms of NiO, the content of the auxiliary active component is 1-3 parts in terms of oxide, and the content of the composite oxide is 82-87 parts, based on 100 parts by weight of the total weight of the catalyst.

4. The catalyst of claim 3, wherein The content of the main active component Ni is 10-12 parts in terms of NiO, the content of the auxiliary active component is 2-3 parts in terms of oxide, and the content of the composite oxide is 85-87 parts, based on 100 parts by weight of the total weight of the catalyst.

5. The catalyst according to any one of claims 1 to 4, characterized in that, The specific surface area of the composite oxide support is 30 to 155 m 2 / g; And / or, the pore volume of the composite oxide carrier is 0.2-0.8 mL / g.

6. The catalyst of claim 5, wherein The specific surface area of the composite oxide support is 55 to 85 m 2 / g; And / or, the pore volume of the composite oxide carrier is 0.3-0.4 mL / g.

7. The catalyst of claim 6, wherein The specific surface area of the composite oxide support is 55 to 70 m 2 / g.

8. A process for the preparation of the catalyst of any one of claims 1-7, wherein, The preparation method comprises the following steps: S110, impregnating the Al2O3-CuO-TiO2 composite oxide carrier with a nickel salt solution to obtain an impregnated composite oxide carrier, and drying and calcining the impregnated composite oxide carrier to obtain a catalyst precursor; Optionally, S120, impregnating the catalyst precursor with a salt solution of an auxiliary active component to obtain an impregnated catalyst precursor, and drying and calcining the impregnated catalyst precursor to obtain a catalyst.

9. The production method according to claim 8, characterized by, The impregnation time in steps S110 and S120 is independently 1-8 h; And / or, the drying conditions in steps S110 and S120 independently include a drying temperature of 90-120°C and / or a drying time of 2-8 h; And / or, the calcination conditions in steps S110 and S120 independently include a calcination temperature of 300-800°C and / or a calcination time of 2-10 h.

10. The method of claim 9, wherein, The impregnation time in steps S110 and S120 is independently 1-4 h.

11. The method of any one of claims 8-10, wherein the method further comprises, The nickel salt is selected from sulfates, nitrates, soluble carboxylates, hypophosphites, and halides of nickel; And / or, the concentration of the nickel salt solution is 1.0-3.0 mol / L in terms of NiO; And / or, the salt of the auxiliary active component is selected from nitrates, soluble carboxylates, and soluble halides. And / or, the concentration of the salt solution of the co-activator is 0.01-0.3 mol / L in terms of its metal oxide.

12. The method of any one of claims 8-10, wherein the method further comprises, The preparation method of the composite oxide carrier comprises: S210. At a temperature of 50-90℃, the copper salt solution, the titanium salt solution and the alkaline solution are added into the aluminum salt solution in parallel, and after staying for 15-20 min at a pH value of 5.5-7.0, the alkaline solution is continuously added until the pH value is 8-10, and stays for 15-20 min to obtain a precipitate; S220. The precipitate is washed, dried and calcined to obtain the composite oxide carrier.

13. The method of claim 12, wherein, The aluminum salt is selected from aluminum sulfate, aluminum chloride, aluminum nitrate and organic aluminum salt, and / or the concentration of the aqueous aluminum salt solution is 0.5-2.5 mol / L.

14. The method of claim 12, wherein, The titanium salt solution is selected from acid solutions of soluble titanium salts of metatitanic acid, titanium tetrachloride and tetraethyl titanate; and / or, the concentration of the titanium salt solution is 0.2-1.2 mol / L.

15. The preparation method according to claim 14, characterized in that, The acid solution is a sulfuric acid solution.

16. The method of claim 12, wherein, The copper salt is selected from copper chloride, copper sulfate and copper nitrate; and / or, the concentration of the copper salt solution is 0.1-0.6 mol / L.

17. The method of claim 12, wherein, The alkaline solution comprises an ammonium salt and lye.

18. The method of claim 17, wherein, The ammonium salt is selected from ammonium bicarbonate, ammonium carbonate and organic ammonium salt, and / or the concentration of the ammonium salt in the alkaline solution is 0.1-0.3 mol / L.

19. The method of claim 12, wherein, The drying conditions in step S220 include: the drying temperature is 100-150℃, and the drying time is 4-12 h.

20. The method of claim 12, wherein, The calcination conditions in step S220 include: the calcination temperature is 500-1100℃, and the calcination time is 4-12 h.

21. Use of the catalyst of any one of claims 1-7 in the selective hydrogenation of cyclopentadiene to prepare cyclopentene.

22. A process for the selective hydrogenation of cyclopentadiene to prepare cyclopentene, wherein, The method comprises: Cyclopentadiene and a dilution solvent are mixed, and the cyclopentadiene and hydrogen are subjected to a hydrogenation reaction in the presence of the catalyst of any one of claims 1-7 to generate cyclopentene.

23. The method of claim 22, wherein The dilution solvent is selected from n-heptane, isooctane and cyclohexane.

24. The method of claim 23, wherein, The dilution solvent is selected from n-heptane and isooctane.

25. The method of claim 22, wherein, The conditions of the hydrogenation reaction include: a reaction temperature of 20-70℃, a reaction pressure of 0.1-1.5 MPa, a feed volume space velocity of 0.5-15 h -1 , a molar ratio of cyclopentadiene to hydrogen of 1:(1.0-3.0), and a volume ratio of cyclopentadiene to the dilution solvent of 1:(0.1-20).

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