A catalyst for producing cyclohexylbenzene, a preparation method thereof, and applications thereof

Abstract

The present invention discloses a catalyst for producing cyclohexylbenzene, a preparation method thereof, and an application in the production of cyclohexylbenzene by benzene hydroalkylation. Among them, the catalyst has a schematic chemical composition shown by the formula "xM·ySiO2·zAl2O3"; wherein, M is a metal element selected from one or more of ruthenium, platinum, palladium, copper and nickel metals; in the chemical composition, 0.001 ≤ x / y ≤ 0.02, 8 ≤ y / z ≤ 80. When the catalyst of the present invention is used in the production of cyclohexylbenzene by benzene hydroalkylation, it has the characteristics of high benzene conversion rate and good product selectivity.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and specifically relates to a catalyst for producing cyclohexylbenzene and a preparation method thereof, and a method for producing cyclohexylbenzene by one-step benzene hydroalkylation using the catalyst. Background Art

[0002] Cyclohexylbenzene is an important chemical product and has important applications in the fields of liquid crystals and rechargeable batteries. Among them, cyclohexylbenzene-based liquid crystals have extremely high chemical stability, photochemical stability and excellent physical properties, and are one of the ideal materials for liquid crystal displays. Cyclohexylbenzene can also be used as an additive component in the electrolyte of lithium-ion batteries, and has an overcharge prevention effect, which can effectively improve the safety of the battery. In addition, important chemical products phenol and cyclohexanone can be prepared by further peroxidation and decomposition reactions using cyclohexylbenzene as an intermediate, and then used in the production of phenolic resins, caprolactam and nylon. Therefore, the preparation and production of cyclohexylbenzene have received extensive attention. The basic information of cyclohexylbenzene is as follows: colorless liquid, CAS number is 827-52-1, density 0.95 g / cm 3 , boiling point 238-240 °C, melting point 5 °C, flash point 98 °C.

[0003] According to different reaction raw materials, the main methods for preparing cyclohexylbenzene include: the alkylation method of benzene and cyclohexene, and the benzene hydroalkylation method. Among them, the basic principle of the benzene hydroalkylation method is: using benzene and hydrogen as raw materials, part of the benzene is hydrogenated at the metal active center to obtain a 6-membered ring olefin structure (such as cyclohexene, etc.), and further undergoes an alkylation reaction with benzene at the acidic active center position to obtain a cyclohexylbenzene product. Therefore, a bifunctional catalyst with both a hydrogenation center and an alkylation active center can be used in the production process of cyclohexylbenzene.

[0004] The research on the preparation of cyclohexylbenzene by hydroalkylation of benzene dates back to the 1980s. At present, most of the developed catalysts have the problems of slow catalytic efficiency and low selectivity. For example, the catalysts based on MCM-22 series molecular sieves (US2011 / 0015457A1, CN104105679A) have the problems of slow catalytic rate and high selectivity to the by-product cyclohexane. Other catalysts such as those with Ni-rare earth treated HY molecular sieve as the carrier (US4219689) have the problems of low benzene conversion and low yield of the product cyclohexylbenzene. Subsequently, it was reported (Molecular Catalysis 2017, 442, 27-38) that Pd / HY supported molecular sieve was used as the catalyst to catalytically prepare cyclohexylbenzene by hydroalkylation of benzene in one step. The initial conversion of benzene was 42.2%, the selectivity of cyclohexylbenzene was maintained at about 75%, and the selectivity of the over-alkylation by-product dicyclohexylbenzene was as high as about 20%. To sum up, the existing technologies mainly have the problems of low benzene conversion and poor product selectivity, which bring great problems to industrial practical applications.

[0005] Patent WO01 / 66464A2 provides a molecular sieve SSZ-55 material with a relatively large pore structure. Its special 12-membered ring pore structure provides a promising prospect for the acid-catalyzed reaction of aromatic compounds. However, it still has the problems of only being able to synthesize specific structures with a certain silicon-aluminum ratio and limited total acid amount of the material, resulting in poor application effects in acid catalysis. In addition, the template agent used is only limited to laboratory synthesis applications, and its actual industrial and economic value is limited. Summary of the Invention

[0006] The technical problems to be solved by the present invention are the problems of low benzene conversion and poor product selectivity in the production of cyclohexylbenzene by hydroalkylation of benzene in the prior art. The present invention provides a catalyst for the production of cyclohexylbenzene, its preparation method, and its application in the production of cyclohexylbenzene by hydroalkylation of benzene. Using the catalyst of the present invention in the production of cyclohexylbenzene by hydroalkylation of benzene has the characteristics of high benzene conversion and good product selectivity.

[0007] The first aspect of the present invention provides a catalyst for the production of cyclohexylbenzene, and the catalyst has a schematic chemical composition as shown in the formula "xM·ySiO2·zAl2O3";

[0008] wherein, M is a metal element, selected from one or more of ruthenium, platinum, palladium, copper, and nickel metals; preferably ruthenium metal;

[0009] Among them, in the chemical composition, 0.001 ≤ x / y ≤ 0.02, 8 ≤ y / z ≤ 80.

[0010] Further, in the catalyst, based on the mass of the catalyst, the mass content of metal M is 0.2% to 2%, preferably 0.2% to 1.5%, more preferably 0.3% to 1%, such as but not limited to 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, etc.

[0011] Further, the catalyst has an X-ray diffraction pattern as shown in Table A-1 below,

[0012] Table A-1

[0013]

[0014] (a) = ±0.3°, (b) varies with 2θ.

[0015] Further, the catalyst also includes an X-ray diffraction pattern as shown in Table A-2 below,

[0016] Table A-2

[0017]

[0018] (a) = ±0.3°, (b) varies with 2θ.

[0019] Further, the total acid amount of the catalyst is 500 to 1500 μmol·g -1 , preferably 800 to 1500 μmol·g -1 , and the acid amount ratio of B acid / L acid is 3 to 10, preferably 5 to 7.

[0020] Further, in the catalyst, M exists in at least one form of elemental state, oxide, chloride, nitrate. Among them, the particle size of M metal particles is 0.5 to 10 nm, preferably 1 to 5 nm.

[0021] Further, in the catalyst, the crystal has a strip-like or rod-like morphology, the average length of the crystal is 0.3 to 3 μm, and the aspect ratio is 2 to 20.

[0022] Further, the specific surface area of the catalyst is 200 to 600 m 2 / g, preferably 250 to 500 m 2 / g; the micropore volume of the catalyst is 0.05 to 0.30 cm 3 / g, preferably 0.10 to 0.25 cm 3 / g.

[0023] The second aspect of the present invention provides a preparation method of the above catalyst for producing cyclohexylbenzene, comprising the following steps:

[0024] (1) Mix a silicon source, an aluminum source, a fluorine source, an organic structure-directing agent, and water. After heating and pre-treating, carry out crystallization treatment and calcination to obtain sample B;

[0025] (2) Add a solution containing metal M to sample B obtained in step (1), and prepare the catalyst through drying and reduction.

[0026] Furthermore, in step (1), the molar ratio of the added silicon source calculated as SiO2, the aluminum source calculated as Al2O3, the fluorine source calculated as F - is 1:(0.02 - 0.2):(0.5 - 2):(0.25 - 1.5):(3 - 15), preferably 1:(0.05 - 0.15):(0.5 - 1):(0.5 - 1):(5 - 10).

[0027] Furthermore, in step (1), the silicon source is selected from at least one of silicic acid, silica gel, silicon sol, tetraethyl orthosilicate, and water glass; the aluminum source is selected from at least one of pseudo-boehmite and aluminum isopropoxide.

[0028] Furthermore, in step (1), the fluorine source is selected as hydrofluoric acid; the organic structure-directing agent is selected from 4-pyrrolidinylpyridine.

[0029] Furthermore, in step (1), the method of heating and pre-treating is rotary evaporation to remove water or open heating to remove water. The treatment conditions for open heating are heating and stirring at 50 - 100 °C, preferably heating and stirring at 70 - 90 °C.

[0030] Furthermore, in step (1), after the raw material mixture is heated and pre-treated, the molar ratio of the silicon source (calculated as SiO2) and water during crystallization is 1:(1 - 10), preferably 1:(1.5 - 6.5).

[0031] Furthermore, in step (1), the crystallization conditions are: temperature is 120 - 200 °C, time is 7 - 21 days. Preferably, the temperature is 150 - 200 °C, and the time is 7 - 15 days.

[0032] Furthermore, in step (1), the crystallization can be carried out in any manner conventionally known in the art. For example, a method can be cited in which the silicon source, aluminum source, fluorine source, organic structure-directing agent, and water are mixed in a predetermined ratio, and the obtained mixture is heated and crystallized under crystallization conditions.

[0033] Further, in step (1), after the crystallization step, the product can be obtained from the resulting mixture by any conventionally known separation method and calcination treatment. As the separation method, for example, methods such as filtering, washing, and drying the obtained mixture can be cited. Here, the filtering, washing, and drying can be carried out in any manner conventionally known in the art. Specifically, for example, as the filtering, the obtained product mixture can be simply suction-filtered. As the washing, for example, washing with deionized water and / or ethanol can be cited. As the drying temperature, for example, 40 to 250 °C can be cited, preferably 60 to 150 °C. As the drying time, for example, 8 to 30 hours can be cited, preferably 10 to 20 hours. The drying can be carried out under normal pressure or under reduced pressure.

[0034] Further, in step (1), the calcination can be carried out in any manner conventionally known in the art. For example, the calcination temperature is generally 300 to 800 °C, preferably 400 to 650 °C, and the calcination time is generally 1 to 12 hours, preferably 2 to 6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as in an air or oxygen atmosphere.

[0035] Further, in step (2), the solution containing metal M can be prepared from soluble metal compounds, and the metal is selected from one or more of ruthenium, platinum, palladium, copper, and nickel metals; for the metal solution, taking ruthenium as an example, for example, ruthenium nitrate or ruthenium chloride is used to prepare a ruthenium solution.

[0036] Further, in step (2), the concentration of the solution containing metal M is 2 to 50 g / L.

[0037] Further, in step (2), the solution containing metal M is added to sample B in step (1) by dropwise addition. The present invention has no particular limitation on the dropwise addition conditions. For example, it can be added dropwise at room temperature and then mixed for 1 to 10 hours.

[0038] Further, in step (2), the drying can be carried out in a conventional manner, preferably: the drying temperature is 40 to 90 °C, and the drying time is 4 to 12 hours. The calcination can be carried out in a conventional manner, preferably: the calcination temperature is 300 to 550 °C, and the calcination time is 3 to 8 hours. The reduction can be carried out by hydrogen reduction, and the reduction conditions are preferably as follows: the reduction temperature is 300 to 450 °C, and the reduction time is 3 to 6 hours.

[0039] The third aspect of the present invention provides a method for preparing cyclohexylbenzene by one-step hydrogenation of benzene using the above catalyst.

[0040] Further, the method includes contacting the raw material benzene with the catalyst for reaction to obtain cyclohexylbenzene using hydrogen as the hydrogen source.

[0041] Furthermore, the mass ratio of the raw material benzene to the catalyst is 8 to 40, preferably 10 to 40.

[0042] Furthermore, the reaction temperature is 100 to 220 °C, preferably 120 to 200 °C. The reaction time is 2 to 8 hours, preferably 2.5 to 6 hours.

[0043] Furthermore, the reaction hydrogen pressure is 0.8 to 2.5 MPa, preferably 1.0 to 2.5 MPa.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] 1. The catalyst provided by the present invention, wherein the molecular sieve belongs to ATS type silica-alumina molecular sieve, and the silica-alumina ratio of the molecular sieve is relatively low, and its chemical composition has never been obtained in the prior art. The catalyst also contains a metal with hydrogenation activity and has strong hydrogenation performance. In addition, the catalyst has special acid properties, with a large amount of acid and high acid strength.

[0046] 2. According to the preparation method of the present invention, 4-pyrrolidinylpyridine is used as the organic structure directing agent, and no base needs to be added during the reaction process, and it can be used as a catalyst without ammonium ion exchange.

[0047] 3. The catalyst provided by the present invention has both hydrogenation and solid acid bifunctions, realizing the hydrogenation alkylation reaction of benzene to produce cyclohexylbenzene under mild reaction conditions. The benzene conversion rate and the selectivity of the main product cyclohexylbenzene are both very high, and the reaction system has good stability. Description of the Drawings

[0048] Figure 1 XRD spectrum of the catalyst prepared in Example 1;

[0049] Figure 2 TEM image of the catalyst prepared in Example 1;

[0050] Figure 3 SEM image of the catalyst prepared in Example 1. Detailed Description of the Invention

[0051] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited to the following description.

[0052] For those not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchase.

[0053] In the context of this specification, the structure of the sample is determined by the X-ray diffraction pattern (XRD), and the X-ray diffraction pattern (XRD) is measured by an X-ray powder diffractometer using a Cu-Kα ray source and a nickel filter.

[0054] In the context of this specification, including in the following examples and comparative examples, the model of the X-ray powder diffractometer for the sample is the Panalytical X PERPRO X-ray powder diffractometer, which analyzes the phase of the sample, with a CuKα ray source Nickel filter, 2θ scanning range 2 - 50°, operating voltage 40 kV, current 40 mA, scanning rate 10° / min.

[0055] In the context of this specification, including in the following examples and comparative examples, the model of the scanning electron microscope (SEM) for the sample is the S-4800II field emission scanning electron microscope. The method for measuring the crystal particle size of the sample is as follows: Observe the molecular sieve with this scanning electron microscope at a magnification of 10,000 times, randomly select an observation field of view, calculate the average value of the sum of the particle sizes of all crystals in this observation field of view, and repeat this operation a total of 10 times. Take the average value of the sum of the 10 average values as the crystal particle size.

[0056] In the context of this specification, including in the following examples and comparative examples, the method for measuring the sample size is as follows: Observe the molecular sieve with a transmission electron microscope (the G2 F30 transmission electron microscope of FEI Company in the Netherlands, operating voltage 300 kV) at a magnification of 100,000 times, randomly select an observation field of view, calculate the average value of the sum of the sizes of all particles in this observation field of view, repeat this operation a total of 10 times, and take the average value of the sum of the 10 average values as the size of the nanoparticles.

[0057] In the context of this specification, including in the following examples and comparative examples, the pyridine adsorption infrared method (Nicolet Model 710 spectrometer) is used to determine the acid amount and acid type of the molecular sieve. The specific operation steps are as follows: a. Sample pretreatment. Press the sample (about 30 mg) into a thin round tablet with a diameter of 13 mm and load it into an infrared sample cell. Then, the sample is pretreated at 400 °C for 1 h under vacuum cell conditions. After the sample cell cools to room temperature, scan the infrared data of the sample as the background. b. Pyridine adsorption. Under room temperature and vacuum environment, introduce pyridine vapor into the in-situ until the adsorption reaches equilibrium, and the adsorption time is 1 h. c. Pyridine desorption. After the adsorption ends, evacuate to a constant internal pressure at 100 °C, and the desorption time is 40 min, and scan and record the infrared absorption spectra respectively. The difference spectrum before and after pyridine adsorption is the obtained pyridine adsorption-infrared absorption spectrum. The acid amount of the sample was semi-quantitatively calculated based on the spectrum:

[0058]

[0059] Where r and w are the diameter (cm) and mass (g) of the catalyst disc, A is the integral value of the absorbance at the specified wave number peak based on the scanning pyridine adsorption-infrared absorption spectrum. IMEC is the integrated molar extinction coefficient, IMEC L 2.22, IMEC B 1.67 in. 1545 cm -1 The nearby peak is B acid, 1455cm -1 The nearby peaks are L acids.

[0060] The reaction product caprolactone was qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the yield of the product caprolactone and the conversion rate of the reaction substrate cyclohexanone were analyzed by gas chromatography (GC). The gas chromatography-mass spectrometry instrument was Agilent 7890A of Agilent Corporation of the United States, the chromatographic column was HP-5 non-polar capillary column (30m, 0.53mm), the gas chromatograph was Agilent 7890B, the detector was hydrogen flame ionization detector (FID), and the chromatographic column was SE-54 capillary column (30m, 0.53mm).

[0061] The product cyclohexylbenzene yield and selectivity calculation formula is:

[0062] The yield of the product cyclohexylbenzene (%) = (molar amount of cyclohexylbenzene generated by the reaction * 2) / (molar amount of reaction substrate benzene) × 100%.

[0063] The selectivity of the product cyclohexylbenzene (%) = (molar amount of cyclohexylbenzene produced by the reaction * 2) / (molar amount of benzene reacted) × 100%.

[0064] Example 1

[0065] 1. Catalyst preparation:

[0066] 4 g of deionized water, 0.75 g of 4-pyrrolidinopyridine, 0.42 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.5 g of hydrofluoric acid were mixed to obtain a composition of 1SiO2:0.1Al2O3:1F - :29H2O:0.5OSDA, then openly heated at 80°C for pretreatment to obtain a block mixture, the raw material mixture after heating pretreatment, the molar ratio of silicon source (in terms of SiO2) and water during crystallization is 1:5, then crystallized at 170°C in a crystallization kettle for 15 days. After taking out the product, it was washed with deionized water 3 times, dried and calcined at 550°C for 6h to obtain the desired sample B.

[0067] Take 4 mL of a ruthenium chloride solution with a concentration of 3.2 g / L and drop it onto 1 g of sample B. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C under a hydrogen flow rate of 10 mL / min for 3 h to obtain the required catalyst.

[0068] The XRD pattern data of the catalyst is shown in Table I-1, and the XRD pattern is as Figure 1 shown, and the TEM and SEM photos are as Figure 2 shown. Among them, the composition is n(SiO2):n(Al2O3) = 10, the Ru mass fraction is 0.3%, that is, x / y = 0.0021, and y / z = 10.

[0069] According to SEM Figure 3 , in the said catalyst, the crystal has a strip-like morphology, the average length of the crystal is 0.4 - 1.5 μm, and the aspect ratio is 2 - 10.

[0070] Table I-1

[0071]

[0072]

[0073] Example 2

[0074] 1. Catalyst preparation:

[0075] Mix 4 g of deionized water, 0.75 g of 4-pyrrolidinopyridine, 0.42 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.5 g of hydrofluoric acid evenly to obtain a composition of 1SiO2:0.1Al2O3:1F - :29H2O:0.5OSDA, and then pre-treat it by heating in an open container at 80 °C to obtain a blocky mixture. After the raw material mixture is pre-treated by heating, the molar ratio of the silicon source (calculated as SiO2) to water during crystallization is 1:5, and then crystallize it in a crystallization kettle at 170 °C for 15 days. After taking out the product, wash it 3 times with deionized water, dry it, and calcine it at 550 °C for 6 h to obtain the required sample B.

[0076] Take 8 mL of a ruthenium chloride solution with a concentration of 3.2 g / L and drop it onto 1 g of sample B. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C under a hydrogen flow rate of 10 mL / min for 3 h to obtain the required catalyst.

[0077] The XRD pattern data of the catalyst is shown in Table I-2, and the XRD pattern is similar to Figure 1 . Among them, the composition is n(SiO2):n(Al2O3) = 10, the Ru mass fraction is 0.6%, that is, x / y = 0.0041, and y / z = 10.

[0078] SEM and Figure 3 Similarly, in the catalyst, the crystals have an elongated strip shape, the average length of the crystals is 0.4-1.5 μm, and the aspect ratio is 2-10.

[0079] Table I-2

[0080]

[0081]

[0082] Example 3

[0083] 1. Catalyst preparation:

[0084] 4 g of deionized water, 0.75 g of 4-pyrrolidinopyridine, 0.42 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.5 g of hydrofluoric acid were mixed to obtain a composition of 1SiO2:0.1Al2O3:1F - :29H2O:0.5OSDA, then openly heated at 80°C for pretreatment to obtain a block mixture, the raw material mixture after heating pretreatment, the molar ratio of silicon source (in terms of SiO2) and water during crystallization is 1:5, then crystallized at 170°C in a crystallization kettle for 15 days. After taking out the product, it was washed with deionized water 3 times, dried and calcined at 550°C for 6h to obtain the desired sample B.

[0085] Take 20 mL of 3.2 g / L ruthenium chloride solution and add it dropwise onto 1 g of sample B. After drying at 80°C for 2 h, reduce it in a fixed bed reactor at 350°C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the desired catalyst.

[0086] The XRD spectrum data of the catalyst are shown in Table I-4. Figure 1 The composition is n(SiO2):n(Al2O3)=10, and the mass fraction of Ru is 1.5%, that is, x / y=0.0104, y / z=10.

[0087] SEM and Figure 3 Similarly, in the catalyst, the crystals have an elongated strip shape, the average length of the crystals is 0.4-1.5 μm, and the aspect ratio is 2-10.

[0088] Table I-3

[0089]

[0090]

[0091] Example 4

[0092] 1. Catalyst preparation:

[0093] Mix 4 g of deionized water, 1.1 g of 4-pyrrolidinopyridine, 0.42 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.75 g of hydrofluoric acid uniformly to obtain a composition of 1SiO2:0.1Al2O3:1.5F - :29H2O:0.75OSDA. Subsequently, perform an open heating pretreatment at 80 °C to obtain a massive mixture. After the raw material mixture undergoes the heating pretreatment, the molar ratio of the silicon source (calculated as SiO2) to water during crystallization is 1:4.5. Then, crystallize at 170 °C in a crystallization kettle for 15 days. After taking out the product, wash it 3 times with deionized water, dry it, and calcine it at 550 °C for 6 h to obtain the required sample B.

[0094] Take 4 mL of a ruthenium chloride solution with a concentration of 3.2 g / L and drop it onto 1 g of sample B. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C and a hydrogen gas flow rate of 10 mL / min for 3 h to prepare the required catalyst.

[0095] The XRD spectrum data of the catalyst is shown in Table I-3. The XRD spectrum is similar to Figure 1 that. Among them, the composition is n(SiO2):n(Al2O3) = 10, the Ru mass fraction is 0.3%, that is, x / y = 0.0021, and y / z = 10.

[0096] The SEM of the catalyst is similar to Figure 3 that. In the catalyst, the crystal has a long strip-like morphology, the average length of the crystal is 0.4 - 2.0 μm, and the aspect ratio is 2 - 15.

[0097] Table I-4

[0098]

[0099]

[0100] Example 5

[0101] 1. Catalyst preparation:

[0102] Mix 4 g of deionized water, 1.5 g of 4-pyrrolidinopyridine, 0.42 g of aluminum isopropoxide, 1.5 g of silica sol, and 1 g of hydrofluoric acid uniformly to obtain a composition of 1SiO2:0.1Al2O3:2F - :30H2O:1OSDA. Subsequently, perform an open heating pretreatment at 80 °C to obtain a massive mixture. After the raw material mixture undergoes the heating pretreatment, the molar ratio of the silicon source (calculated as SiO2) to water during crystallization is 1:4.5. Then, crystallize at 170 °C in a crystallization kettle for 15 days. After taking out the product, wash it 3 times with deionized water, dry it, and calcine it at 550 °C for 6 h to obtain the required sample B.

[0103] 4 mL of 3.2 g / L ruthenium chloride solution was added dropwise to 1 g of sample B. After drying at 80°C for 2 h, the solution was reduced in a fixed bed reactor at 350°C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the desired catalyst.

[0104] The XRD spectrum data of the catalyst are shown in Table I-3. Figure 1 The composition is n(SiO2):n(Al2O3)=10, and the mass fraction of Ru is 0.3%, that is, x / y=0.0021, y / z=10.

[0105] SEM and Figure 3 Similarly, in the catalyst, the crystals have an elongated strip shape, the average length of the crystals is 0.5 to 2.5 μm, and the aspect ratio is 3 to 20.

[0106] Table I-5

[0107]

[0108] Example 6

[0109] 1. Catalyst preparation:

[0110] 4 g of deionized water, 0.75 g of 4-pyrrolidinopyridine, 0.42 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.5 g of hydrofluoric acid were mixed to obtain a composition of 1SiO2:0.1Al2O3:1F - :29H2O:0.5OSDA, then heat pretreatment at 80℃ to obtain a block mixture. After the raw material mixture is pretreated by heating, the molar ratio of silicon source (in terms of SiO2) to water during crystallization is 1:5, and then crystallization is carried out at 170℃ in a crystallization kettle for 15 days. After taking out the product, it is washed with deionized water 3 times, dried, and calcined at 550℃ for 6h to obtain the desired sample B.

[0111] Take 4 mL of 2.7 g / L palladium chloride solution and add it dropwise onto 1 g of sample B. After drying at 80°C for 2 h, reduce it in a fixed bed reactor at 350°C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the desired catalyst.

[0112] The XRD spectrum data of the catalyst are shown in Table I-5. Figure 1 The composition is n(SiO2):n(Al2O3)=10, the mass fraction of Pd is 0.3%, that is, x / y=0.0021, y / z=10.

[0113] SEM and Figure 3Similarly, in the catalyst, the crystals have an elongated strip shape, the average length of the crystals is 0.4-1.5 μm, and the aspect ratio is 2-10.

[0114] Table I-6

[0115]

[0116] Example 7

[0117] 1. Catalyst preparation:

[0118] 4 g of deionized water, 0.75 g of 4-pyrrolidinopyridine, 0.21 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.5 g of hydrofluoric acid were mixed to obtain a composition of 1SiO2:0.05Al2O3:1F - :29H2O:0.5OSDA, then heat pretreatment at 80℃ to obtain a block mixture. After the raw material mixture is pretreated by heating, the molar ratio of silicon source (in terms of SiO2) to water during crystallization is 1:5. Then crystallize at 170℃ in a crystallization kettle for 15 days. After taking out the product, wash it with deionized water 3 times, dry it, and roast it at 550℃ for 6h to obtain the desired sample B.

[0119] 4 mL of 3.2 g / L ruthenium chloride solution was added dropwise to 1 g of sample B. After drying at 80°C for 2 h, the solution was reduced in a fixed bed reactor at 350°C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the desired catalyst.

[0120] The XRD spectrum data of the catalyst are shown in Table I-6. Figure 1 The composition is n(SiO2):n(Al2O3)=20, and the mass fraction of Ru is 0.3%, that is, x / y=0.0021, y / z=20.

[0121] SEM and Figure 3 Similarly, in the catalyst, the crystals have an elongated strip shape, the average length of the crystals is 0.4-1.5 μm, and the aspect ratio is 2-12.

[0122] Table I-7

[0123]

[0124] Example 8

[0125] 1. Catalyst preparation:

[0126] 4 g of deionized water, 0.75 g of 4-pyrrolidinopyridine, 0.08 g of aluminum isopropoxide, 1.5 g of silica sol, and 0.5 g of hydrofluoric acid were mixed to obtain a composition of 1SiO2:0.02Al2O3:1F -:29H2O:0.5OSDA, then heat pretreatment at 80℃ to obtain a block mixture. After the raw material mixture is pretreated by heating, the molar ratio of silicon source (in terms of SiO2) to water during crystallization is 1:5. Then crystallize at 170℃ in a crystallization kettle for 15 days. After taking out the product, wash it with deionized water 3 times, dry it, and roast it at 550℃ for 6h to obtain the desired sample B.

[0127] 4 mL of 3.2 g / L ruthenium chloride solution was added dropwise to 1 g of sample B. After drying at 80°C for 2 h, the solution was reduced in a fixed bed reactor at 350°C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the desired catalyst.

[0128] The XRD spectrum data of the catalyst are shown in Table I-7. Figure 1 The composition is n(SiO2):n(Al2O3)=50, and the mass fraction of Ru is 0.3%, that is, x / y=0.0021, y / z=50.

[0129] SEM and Figure 3 Similarly, in the catalyst, the crystals have an elongated strip shape, the average length of the crystals is 0.4-1.5 μm, and the aspect ratio is 2-12.

[0130] Table I-8

[0131]

[0132] Example 9

[0133] 0.25 g of the catalyst synthesized in Example 1 was added to a high-pressure reactor, and then 8 g of benzene was added to the reactor, and hydrogen was introduced to make the system pressure reach 1.2 MPa. The system was then heated to 150° C. and the reaction was terminated after 4 hours.

[0134] For comparison purposes, the evaluation data are summarized in Table 2.

[0135] Example 10

[0136] 0.25 g of the catalyst synthesized in Example 1 was added to a high-pressure reactor, and then 8 g of benzene was added to the reactor, and hydrogen was introduced to make the system pressure reach 1.6 MPa. The system was then heated to 150° C. and the reaction was terminated after 4 hours.

[0137] For ease of comparison, the evaluation data are summarized in Table 2.

[0138] Embodiment 11

[0139] Take 0.25 g of the catalyst synthesized in Example 1 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 2.0 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0140] For easy comparison, the evaluation data are summarized in Table 2.

[0141] Example 12

[0142] Take 0.25 g of the catalyst synthesized in Example 1 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 180 °C and end the reaction after 4 h.

[0143] For easy comparison, the evaluation data are summarized in Table 2.

[0144] Example 13

[0145] Take 0.25 g of the catalyst synthesized in Example 1 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 200 °C and end the reaction after 4 h.

[0146] For easy comparison, the evaluation data are summarized in Table 2.

[0147] Example 14

[0148] Take 0.25 g of the catalyst synthesized in Example 2 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0149] For easy comparison, the evaluation data are summarized in Table 2.

[0150] Example 15

[0151] Take 0.25 g of the catalyst synthesized in Example 3 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0152] For easy comparison, the evaluation data are summarized in Table 2.

[0153] Example 16

[0154] Take 0.25 g of the catalyst synthesized in Example 4 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0155] For easy comparison, the evaluation data are summarized in Table 2.

[0156] Example 17

[0157] Take 0.25 g of the catalyst synthesized in Example 5 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0158] For easy comparison, the evaluation data are summarized in Table 2.

[0159] Example 18

[0160] Take 0.25 g of the catalyst synthesized in Example 6 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0161] For easy comparison, the evaluation data are summarized in Table 2.

[0162] Example 19

[0163] Take 0.25 g of the catalyst synthesized in Example 7 and add it to a high-pressure reactor. Subsequently, add 8 g of benzene into the reactor and fill it with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0164] For easy comparison, the evaluation data are summarized in Table 2.

[0165] Table 1 Catalyst properties of each example

[0166]

[0167] Table 2 Catalytic performance of each example

[0168]

[0169] Example 21

[0170] The catalyst prepared in Example 1 was washed and dried and then put into the next reaction, and the reaction was cycled 6 times in total. Among them, the reaction conditions in Example 8 were retained for catalyst evaluation, that is, 8 g of benzene was added into the high-pressure reactor and filled with hydrogen to make the system pressure reach 1.2 MPa. Then heat the system to 150 °C and end the reaction after 4 h.

[0171] Table 2

[0172] Number of cyclic applications Yield of cyclohexylbenzene (%) Selectivity of cyclohexylbenzene (%) 1 61 97.6 2 60 96.8 3 61 96.6 4 61 97.4 5 60 96.9 6 61 97.4

[0173] Comparative Example 1

[0174] 1. Catalyst preparation:

[0175] The preparation method refers to Example 1, only changing sample B to a hydrogen-form Y zeolite molecular sieve with n(Si):n(Al)=10.

[0176] Take 20 mL of a 3.2 g / L ruthenium chloride solution and drop it onto 10 g of the above-mentioned Y zeolite molecular sieve. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the required catalyst.

[0177] 2. Catalyst evaluation:

[0178] The catalyst evaluation method is shown in Example 9.

[0179] For easy comparison, the compositions and evaluation results of the catalysts are listed in Table 3.

[0180] Comparative Example 2

[0181] 1. Catalyst preparation:

[0182] The preparation method refers to Example 1, only changing sample B to a hydrogen-form Y zeolite molecular sieve with n(Si):n(Al)=20.

[0183] Take 20 mL of a 3.2 g / L ruthenium chloride solution and drop it onto 10 g of the above-mentioned Y zeolite molecular sieve. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the required catalyst.

[0184] 2. Catalyst evaluation:

[0185] The catalyst evaluation method is shown in Example 9.

[0186] For easy comparison, the compositions and evaluation results of the catalysts are listed in Table 3.

[0187] Comparative Example 3

[0188] 1. Catalyst preparation:

[0189] The preparation method refers to Example 8, only changing sample B to an MCM-22 zeolite molecular sieve with n(Si):n(Al)=20.

[0190] Take 20 mL of a 3.2 g / L ruthenium chloride solution and drop it onto 10 g of the above-mentioned MCM-22 zeolite molecular sieve. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the required catalyst.

[0191] 2. Catalyst evaluation:

[0192] The catalyst evaluation method is shown in Example 9.

[0193] The composition and evaluation results of the catalysts are listed in Table 3 for easy comparison.

[0194] Comparative Example 4

[0195] 1. Catalyst preparation:

[0196] The preparation method refers to Example 1, only changing sample B to MCM-22 zeolite molecular sieve with n(Si):n(Al)=30.

[0197] Take 20 mL of ruthenium chloride solution at 3.2 g / L and drop it onto 10 g of the above MCM-22 zeolite molecular sieve. After drying at 80 °C for 2 h, reduce it in a fixed-bed reactor at 350 °C and a hydrogen flow rate of 10 mL / min for 3 h to obtain the required catalyst.

[0198] 2. Catalyst evaluation:

[0199] The catalyst evaluation method is shown in Example 9.

[0200] The composition and evaluation results of the catalysts are listed in Table 3 for easy comparison.

[0201] Table 3

[0202] Comparative example Type of molecular sieve n(Si):n(Al) Yield of cyclohexylbenzene (%) Selectivity of cyclohexylbenzene (%) 1 Y 10 54 87.5 2 Y 20 53 83.8 3 MCM-22 20 57 87.7 4 MCM-22 30 55 84.8

[0203] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. Modifications can be made to the present invention within the scope of the claims of the present invention, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A catalyst for the production of cyclohexylbenzene, the catalyst having a schematic chemical composition as shown by the formula "xM•ySiO2•zAl2O3"; Among them, M is a metal element selected from one or more of ruthenium, platinum, palladium, copper and nickel metals; Wherein, in the chemical composition, 0.001 ≤ x / y ≤ 0.02, 8 ≤ y / z ≤ 80; The total acid amount of the catalyst is 500 - 1500 µmol•g -1 , and the acid amount ratio of B acid to L acid is 3 - 10; In the catalyst, the crystal has a long strip or rod-like morphology, the average length of the crystal is 0.3 - 3 μm, and the aspect ratio is 2 - 20; The catalyst has an X-ray diffraction pattern as shown in Table A-1 below, Table A-1 (a) = ±0.3°, (b) varies with 2θ.

2. The catalyst according to claim 1, characterized in that, In the catalyst, based on the mass of the catalyst, the mass content of metal M is 0.2% - 2%.

3. The catalyst according to claim 1, wherein The catalyst also includes an X-ray diffraction pattern as shown in Table A-2 below, Table A-2 (a) = ±0.3°, (b) varies with 2θ.

4. The catalyst according to claim 1, characterized in that, The total acid amount of the catalyst is 800~1500 µmol•g -1 , and the acid amount ratio of B acid to L acid is 5~7.

5. The catalyst according to claim 1, wherein The specific surface area of the catalyst is 200 to 600 m 2 / g; the micropore volume of the catalyst is 0.05 to 0.30 cm 3 / g.

6. The catalyst according to claim 1, characterized in that, The specific surface area of the catalyst is 250 to 500 m 2 / g; the micropore volume of the catalyst is 0.10 to 0.25 cm 3 / g.

7. A method for preparing the catalyst for the production of cyclohexylbenzene according to any one of claims 1 - 6, comprising the following steps: (1) Mix a silicon source, an aluminum source, a fluorine source, an organic structure-directing agent and water, after heating and pretreatment, then carry out crystallization treatment and calcination to obtain sample B; (2) Add a solution containing metal M to sample B in step (1), and obtain the catalyst through drying and reduction.

8. The preparation method according to claim 7, characterized in that, In step (1), the molar ratio of the silicon source calculated as SiO2, the aluminum source calculated as Al2O3, the fluorine source calculated as F - , the organic structure-directing agent a and water is 1: (0.02~0.2):(0.5~2): (0.25~1.5): (3~15).

9. The preparation method according to claim 7, wherein In step (1), the molar ratio of the silicon source calculated as SiO2, the aluminum source calculated as Al2O3, the fluorine source calculated as F - , the organic structure-directing agent a and water is 1: (0.05~0.15):(0.5~1): (0.5~1): (5~10).

10. The preparation method according to claim 7 or 8, characterized in that, In step (1), the silicon source is selected from at least one of silicic acid, silica gel, silica sol, tetraethyl orthosilicate, and water glass; the aluminum source is selected from at least one of pseudo-boehmite and aluminum isopropoxide; in step (1), the fluorine source is selected as hydrofluoric acid; the organic structure-directing agent is selected from 4-pyrrolidinylpyridine.

11. The preparation method according to claim 7 or 8, characterized in that, In step (1), after the raw material mixture is heated and pretreated, the molar ratio of the silicon source calculated as SiO2 to water during crystallization is 1: (1 - 10).

12. The preparation method according to claim 7 or 8, characterized in that, In step (1), after the raw material mixture is heated and pretreated, the molar ratio of the silicon source calculated as SiO2 to water during crystallization is 1: (1.5 - 6.5).

13. The preparation method according to claim 7 or 8, characterized in that, In step (1), the crystallization conditions are: temperature is 120 - 200 °C, and time is 7 - 21 days.

14. The preparation method according to claim 7 or 8, characterized in that, In step (1), the crystallization conditions are: temperature is 150 - 200 °C, and time is 7 - 15 days.

15. The preparation method according to claim 7 or 8, characterized in that, In step (2), the concentration of the solution containing metal M is 2 - 50 g / L.

16. A method for preparing cyclohexylbenzene by one-step hydrogenation of benzene using the catalyst according to any one of claims 1 - 6.

17. The method according to claim 16, characterized in that, The method includes contacting the raw material benzene with the catalyst for reaction, and using hydrogen as the hydrogen source to produce cyclohexylbenzene; wherein, the mass ratio of the raw material benzene to the catalyst is 8 - 40; the reaction temperature is 100 - 220 °C, the reaction time is 2 - 8 hours, and the reaction hydrogen pressure is 0.8 - 2.5 MPa.

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