Composite hydroalkylation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of chemical technology catalyst preparation, in particular to a composite hydroalkylation catalyst as well as a preparation method and application thereof, and the composite hydroalkylation catalyst comprises a first component and a second component, the first component has a chemical composition as shown in a formula 'A.BOx', A is selected from at least one of precious metal elements, BOx is a metal oxide, and B is selected from one or more of rare earth metal, IIIA group metal and IVA group metal; the second component is selected from H-type molecular sieves; based on the total mass of the catalyst, in the catalyst, the content of A is 0.1-2.0 wt%; the content of BOx is 5 to 50 weight percent; the mass ratio of the second component to the first component is 0.5-20. According to the composite hydroalkylation catalyst disclosed by the invention, the problem of selectivity bottleneck of a hydroalkylation reaction can be further solved by a method for adjusting the metal catalytic performance through metal-metal oxide interface interaction.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation in chemical technology, specifically to a composite hydrogenation alkylation catalyst, its preparation method, and its application. Background Technology

[0002] Phenol is an important precursor for the preparation of chemical products such as bisphenol A and phenolic resins. Traditional phenol production uses a co-production route of phenol-acetone, starting with benzene and propane, followed by further oxidation and hydrolysis of cumene intermediate. However, the current market faces the problem of low acetone prices and low economic added value. Therefore, the route of co-producing phenol-cyclohexanone from benzene via cyclohexylbenzene intermediate has attracted increasing attention. Its advantage lies in the fact that cyclohexanone is more economically competitive than acetone as a precursor for the preparation of caprolactam and nylon 6. However, on the other hand, the production of cyclohexylbenzene remains one of the difficulties restricting the large-scale industrialization of this route.

[0003] Depending on the reactants, the main methods for preparing cyclohexylbenzene include: alkylation of benzene with cyclohexene and hydrogenation of benzene. The basic principle of hydrogenation of benzene is as follows: using benzene and hydrogen as raw materials, some benzene is hydrogenated at the metal active site to obtain a 6-membered cyclic olefin structure (such as cyclohexene), which further undergoes alkylation with benzene at the acidic active site to obtain the cyclohexylbenzene product. Therefore, bifunctional catalysts with both hydrogenation and alkylation active sites can be used in the production process of cyclohexylbenzene.

[0004] Research on the hydrogenation alkylation of benzene to cyclohexylbenzene began in the 1980s. Currently, most developed catalysts suffer from slow catalytic efficiency and difficulty in improving selectivity. For example, catalysts based on MCM-22 series molecular sieves (US2011 / 0015457A1, CN104105679A) exhibit slow catalytic rates and high selectivity for the byproduct cyclohexane. Other catalysts, such as those using Ni-rare earth treated HY molecular sieves as supports (US4219689), suffer from low benzene conversion and low cyclohexylbenzene yield. A subsequent report (Molecular Catalysis 2017, 442, 27-38) utilized Pd / HY supported molecular sieves as catalysts, employing low silica-to-alumina ratio (high acidity) molecular sieves as substrates for one-step catalytic hydrogenation alkylation of benzene to cyclohexylbenzene. The cyclohexylbenzene selectivity was maintained at approximately 72%, while the selectivity for the over-alkylation byproduct dicyclohexylbenzene reached approximately 20%.

[0005] However, previous studies have shown that most optimization schemes focus on adjusting the composition, topology, and spatial relationships of the molecular sieve, with limited methods for adjusting the metal center. In fact, supported metals, due to their small size (generally no more than 5 nm), are difficult to adjust for hydrogenation through alloying or other methods, thus limiting further improvements in the selectivity of the main product, cyclohexylbenzene. Summary of the Invention

[0006] To overcome the problem that existing technologies for alkylation production lack sufficient methods to adjust metal activity and thus cannot further improve the selectivity of the target compound, this invention provides a composite hydrogenation alkylation catalyst, its preparation method, and its application. The composite hydrogenation alkylation catalyst of this invention, through the method of adjusting the metal catalytic performance by the interaction of the metal-metal oxide interface, can further break through the selectivity bottleneck of the hydrogenation alkylation reaction.

[0007] To achieve the above objectives, a first aspect of the present invention provides a composite hydrogenation alkylation catalyst, which comprises: a first component and a second component;

[0008] The first component has the following formula: "A·BO" x The chemical composition shown is given, wherein A is selected from at least one of the noble metal elements, and B0... x B is a metal oxide, and B is selected from one or more of rare earth metals, Group IIIA metals other than Al, and Group IVA metals.

[0009] The second component is selected from H-type molecular sieves;

[0010] Based on the total mass of the catalyst, the content of A in the catalyst is 0.1-2.0 wt%; BO x The content is 5-50 wt%;

[0011] The mass ratio of the second component to the first component is 0.5-20.

[0012] A second aspect of the present invention provides a method for preparing the composite hydrogenation alkylation catalyst of the present invention, the method comprising:

[0013] (1) Mix the solution containing metal ions A with BO x Contact, remove solvent, and reduce to obtain the precursor;

[0014] (2) The H-type molecular sieve and the precursor are mixed to obtain the product.

[0015] A third aspect of the present invention provides the application of the composite hydrogenation alkylation catalyst described herein in the hydrogenation alkylation of aromatics, preferably in the one-step preparation of cyclohexylbenzene by hydrogenation of benzene.

[0016] Through the above technical solution, the composite hydrogenation alkylation catalyst of the present invention has a metal-metal support structure, achieving the effect of regulating the metal catalytic activity at a small-sized metal level. Furthermore, the composite hydrogenation alkylation catalyst of the present invention has the advantage of a spatial distance of 50-300 nm between the first and second components.

[0017] The catalyst provided by this invention has dual functions of hydrogenation and solid acid, and is used for alkylation, especially the hydrogenation alkylation of benzene to produce cyclohexylbenzene. It can achieve the advantages of very high selectivity of target product under mild reaction conditions and good stability of reaction system. Attached Figure Description

[0018] Figure 1 This is a SEM image of the catalyst prepared in Example 1. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] The first aspect of the present invention provides a composite hydrogenation alkylation catalyst, the composite hydrogenation alkylation catalyst comprising: a first component and a second component;

[0021] The first component has the following formula: "A·BO" x The chemical composition shown is given, wherein A is selected from at least one of the noble metal elements, and B0... x B is a metal oxide, and B is selected from one or more of rare earth metals, Group IIIA metals other than Al, and Group IVA metals.

[0022] The second component is selected from H-type molecular sieves;

[0023] Based on the total mass of the catalyst, the content of A in the catalyst is 0.1-2.0 wt%; BO x The content is 5-50 wt%;

[0024] The mass ratio of the second component to the first component is 0.5-20. The composite hydrogenation alkylation catalyst of this invention achieves the effect of regulating metal catalytic activity at a small-scale metal level by adjusting the metal catalytic performance through metal-metal oxide interface interactions. Furthermore, the catalyst provided by this invention has dual functions of hydrogenation and solid acid production. When used for alkylation, particularly the hydrogenation alkylation of benzene to cyclohexylbenzene, it achieves very high selectivity for the target product under mild reaction conditions, and the reaction system exhibits excellent stability.

[0025] In this invention, the mass ratio of the second component to the first component can be selected within a wide range. According to a preferred embodiment of this invention, the mass ratio of the second component to the first component is 1-20, preferably 1-8.

[0026] In this invention, the mass content of A in the catalyst can be selected within a wide range. According to a preferred embodiment of the invention, the mass content of A is 0.1-2.0 wt%, preferably 0.1%-1.5 wt%, more preferably 0.1%-0.8 wt%, such as, but not limited to, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, etc.

[0027] In this invention, BO x The mass content of the catalyst can be selected within a wide range. According to a preferred embodiment of the present invention, BO x The mass content is 8-50 wt%, for example, but not limited to 10 wt%, 20 wt%, 30 wt%, 40 wt%, etc., preferably 20.0-50.0 wt%.

[0028] In this invention, any type of element A that meets the aforementioned requirements can achieve the purpose of this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, A is selected from one or more of ruthenium, platinum and palladium. By adjusting the metal catalytic activity at a small metal level, a very high selectivity of the main product of the hydrogenation alkylation reaction is achieved under mild reaction conditions.

[0029] In this invention, BO x It is a metal oxide with a support function, where x is the total number of oxygen atoms satisfying the oxidation states of all elements in the catalyst; BO satisfies the aforementioned requirements. x All types can achieve the purpose of this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, BO xIt is selected from one or more of cerium oxide, gallium oxide and germanium oxide; by adjusting the metal catalytic activity at a small metal level, it is achieved that benzene undergoes a hydrogenation alkylation reaction to produce cyclohexylbenzene under mild reaction conditions, with very high selectivity for the main product cyclohexylbenzene.

[0030] In this invention, the acid content of the catalyst can be selected from a wide range. According to a preferred embodiment of this invention, the acid content of the catalyst is 100-2000 μmol·g. -1 More preferably, the acidity is 200-1800 μmol·g -1 More preferably, the acid content is 600-1000 μmol·g. -1 .

[0031] In this invention, the range of molecular sieves that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the molecular sieve is selected from one or more of MWW, FAU, BEA and MOR, whose structural unit has a 12-membered ring channel structure.

[0032] In this invention, the silicon-to-aluminum ratio of the molecular sieve can be selected within a wide range. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the silicon-to-aluminum molar ratio of the molecular sieve is 3-25.

[0033] In this invention, according to a preferred embodiment, the spatial distance between the first component and the second component is 50-300nm, for example, it can be 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 150nm, 180nm, 200nm, 220nm, 250nm, 280nm, 300nm, preferably 190nm-260nm.

[0034] Any composite catalyst possessing the aforementioned characteristics of this invention can be prepared; the preparation method of the composite catalyst is not particularly required. This is an illustrative example and does not limit the scope of this invention. According to a preferred embodiment of this invention, a method for preparing the composite hydrogenation alkylation catalyst of this invention is provided, the method comprising:

[0035] (1) Mix the solution containing metal ions A with BO x Contact, remove solvent, and reduce to obtain the precursor;

[0036] (2) The H-type molecular sieve and the precursor are mixed to obtain the composite hydrogenation alkylation catalyst. The composite hydrogenation alkylation catalyst prepared by the above technical solution provides a method to adjust the metal catalytic performance through the interaction of the metal-metal oxide interface, realizing the effect of adjusting the metal catalytic activity at the small-sized metal level, and achieving the advantages of very high selectivity of the target product under mild reaction conditions and good stability of the reaction system.

[0037] In this invention, the method of removing the solvent in step (1) is not particularly limited, and any conventional technical means in the art are acceptable, such as removing the solvent by evaporation; according to a preferred embodiment of the present invention, in step (1), the solution containing metal ions A is reacted with BO x Contacting and removing the solvent within 5 minutes ensures that the solution-state metal ions are loaded onto the support surface within no more than 5 minutes, which is beneficial to improving the catalytic activity of the catalyst.

[0038] In this invention, there is no particular limitation on the method of removing the solvent within 5 minutes. The solvent is removed by rapid concentration, such as freeze-drying or high-power infrared thermal irradiation. Taking freeze-drying as an example, the homogeneous mixture is sealed and placed in liquid nitrogen. After 1-5 minutes, it is quickly removed to obtain a solid mixture.

[0039] In this invention, the concentration of metal ions A in the solution can be selected from a wide range. According to a preferred embodiment of this invention, the concentration of metal ions A is 0.2-50 g / L, for example, it can be 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, or 4.5 g / L.

[0040] In this invention, there are no particular limitations on the reduction conditions; conventional conditions in the art are sufficient. This is an illustrative example and does not limit the scope of the invention. According to one embodiment of the invention, the reduction is carried out in a hydrogen-containing atmosphere, and the reduction conditions include: a temperature of 300-450°C; a reduction time that can be determined according to actual needs, preferably 3-6 hours; and a hydrogen volume hourly space velocity of 100-1000 h⁻¹. -1 .

[0041] In this invention, the source of metal ions A is a soluble salt of A. The range of soluble salts of A is relatively wide. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, it is preferably one or more of nitrates and chlorides of A. Taking ruthenium as an example, the ruthenium salt can be, for example, ruthenium nitrate and / or ruthenium chloride.

[0042] In this invention, the contact conditions in step (1) are not particularly limited. According to one embodiment of the invention, the solution containing metal ions A is added to the precursor by dropwise addition. There are no particular limitations on the dropwise addition conditions. For example, it can be added at room temperature and then mixed for 1-10 hours.

[0043] In this invention, in step (1), there is no particular limitation on the method of removing solvent, such as freeze drying, drying, infrared thermal irradiation, etc. The drying conditions are not particularly limited, and conventional conditions in the art are acceptable. This is an illustrative example, but it does not limit the scope of this invention. According to one embodiment of this invention, the drying conditions include: a temperature of 40-90°C; and a drying time that can be determined according to actual needs. Preferably, the time is 4-12 hours.

[0044] In this invention, after removing the solvent in step (1), the product can be calcined into an oxide and then reduced, or it can be directly reduced. In this invention, there are no particular limitations on the calcination conditions; conventional conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of this invention. According to one embodiment of this invention, the calcination conditions include: a temperature of 300-550°C; and a calcination time that can be determined according to actual needs. Preferably, the time is 3-8 hours.

[0045] According to a preferred embodiment of the present invention, in step (2), the H-type molecular sieve, the precursor and the low-boiling-point polar solvent are mixed and the low-boiling-point polar solvent is removed to obtain the catalyst, which is beneficial to improving the catalytic activity of the catalyst.

[0046] In this invention, controlling the spatial distance between the first component and the second component (H-type molecular sieve) to be 50-300 nm is beneficial to improving the catalytic activity of the catalyst; the preparation method of the composite catalyst with the aforementioned characteristics includes:

[0047] (1) Mix the solution containing metal ions A with BO x Contact, remove solvent, and reduce to obtain the precursor; remove solvent within 5 min when loading metal ions A;

[0048] (2) Mix the H-type molecular sieve, the precursor, and the low-boiling-point polar solvent, and then remove the low-boiling-point polar solvent. When loading metal ions A, remove the solvent within 5 minutes to ensure that the metal ions in solution are loaded onto the support surface within no more than 5 minutes; and mix the H-type molecular sieve, the precursor, and the low-boiling-point polar solvent, and then remove the low-boiling-point polar solvent to prepare the catalyst. This can control the spatial distance between the first component and the second component (H-type molecular sieve) to 50-300 nm, which is beneficial to improving the catalytic activity of the catalyst.

[0049] According to a preferred embodiment of the present invention, the solvent is removed within 1-5 minutes.

[0050] In this invention, the low-boiling-point polar solvent is a polar solvent with a boiling point not exceeding 75°C. According to a preferred embodiment of this invention, the low-boiling-point polar solvent is selected from one or more of methanol, acetone, and ethanol; more preferably, it is acetone or an acetone-ethanol mixture; more preferably, it is an acetone-ethanol mixture, wherein the volume ratio of acetone to ethanol is 0.1-10, which is beneficial to improving the catalytic activity of the catalyst.

[0051] In this invention, the amount of low-boiling-point polar solvent can be selected from a wide range. According to a preferred embodiment of this invention, the amount of low-boiling-point polar solvent is 10-50 based on the liquid-to-solid mass ratio, preferably 20-30.

[0052] In this invention, the H-type molecular sieve and the precursor are mixed evenly. There is no particular limitation on the mixing method, and conventional techniques in the art are acceptable, such as stirring, ultrasound, and vibration. According to one embodiment of this invention, ultrasonic vibration is used to make the mixture evenly.

[0053] In this invention, there is no particular limitation on the method for removing low-boiling-point polar solvents. For example, low-boiling-point polar solvents can be removed by centrifugation, drying, filtration, etc. In the implementation of this invention, drying at 80°C for 4 hours to remove low-boiling-point solvents is used as an example, but this does not limit the scope of the invention.

[0054] In this invention, there is no particular limitation on the preparation method of the H-type molecular sieve; conventional techniques in the art are sufficient. According to one embodiment of the invention, the preparation method includes: subjecting the molecular sieve to ammonium ion exchange and calcination.

[0055] In this invention, the ammonium ion exchange is performed by exchanging Na in the alkaline metal molecular sieve. + K + Alkali metal or alkaline earth metal cations exchange to NH4 + .

[0056] In this invention, the conditions for ammonium ion exchange are not particularly limited; conventional conditions in the art are acceptable. This is an illustrative example, but it does not limit the scope of the invention. According to one embodiment of the invention, the ammonium ion exchange conditions include: a temperature of 20-60°C; an ammonium ion exchange time that can be determined according to actual needs, preferably 0.5-4 hours; and no limit on the number of ammonium ion exchanges, which can be performed once or multiple times.

[0057] In this invention, the ammonium ions in the ammonium ion exchange are sourced from ammonium salts. The range of sources of ammonium salts is quite wide. This is an illustrative example, but it does not limit the scope of this invention. According to one embodiment of this invention, the ammonium salt is selected from one or more of ammonia, ammonium chloride, ammonium nitrate, and ammonium carbonate.

[0058] In this invention, the concentration of ammonium salt can be selected from a wide range. This is an illustrative example, but it does not limit the scope of the invention. According to one embodiment of the invention, the concentration of ammonium salt is 0.1 mol / L-1.0 mol / L.

[0059] In this invention, after ammonium ion exchange, drying is required. There are no particular limitations on the drying conditions; conventional conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to one embodiment of the invention, the drying conditions include: a temperature of 60-120°C; and a drying time that can be determined according to actual needs. Preferably, the time is 4-24 hours.

[0060] In this invention, the calcination conditions for the preparation of the H-type molecular sieve are not particularly limited; conventional conditions in the art are sufficient. This is an illustrative example, but does not limit the scope of the invention. According to one embodiment of the invention, the calcination conditions include: a temperature of 400-650°C; a calcination time that can be determined according to actual needs, preferably 1-12 hours; and a calcination atmosphere of oxygen or air.

[0061] The third aspect of this invention provides an application of the composite hydrogenation alkylation catalyst described herein in the hydrogenation alkylation of aromatics, preferably in the one-step preparation of cyclohexylbenzene by benzene hydrogenation; it has the advantages of achieving very high selectivity of the target product under mild reaction conditions and good stability of the reaction system.

[0062] In this invention, the method for preparing cyclohexylbenzene by benzene hydrogenation in one step includes: contacting benzene with hydrogen in the presence of a catalyst to obtain cyclohexylbenzene; the catalyst includes the composite hydrogenation alkylation catalyst described in this invention.

[0063] In this invention, the mass ratio of the raw material benzene to the catalyst can be selected within a wide range. According to one embodiment of this invention, the mass ratio of the raw material benzene to the catalyst is 8-40:1, preferably 10-40:1.

[0064] In this invention, the molar ratio of hydrogen to benzene can be selected from a wide range. According to one embodiment of this invention, the molar ratio of hydrogen to benzene is 0.3-1:1.

[0065] In this invention, there are no particular limitations on the reaction conditions; conventional conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to one embodiment of the invention, the reaction temperature is 130-220°C and the reaction time is 2-8 hours.

[0066] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0067] In the context of this specification, including in the following examples and comparative examples, the scanning electron microscope (SEM) used for the samples is an S-4800II field emission scanning electron microscope. The method for measuring the average distance between the first and second components in the sample is as follows: using the scanning electron microscope at a magnification of 10,000x, observe the molecular sieve; randomly select an observation field; calculate the average sum of the distances between all the first and second components in that observation field; repeat this operation a total of 10 times. The average of the sum of the 10 averages is taken as the average distance between the first and second components.

[0068] In the context of this specification, including in the following examples and comparative examples, the inductively coupled plasma atomic emission spectrometer (ICP) used is a Varian 725-ES, and the elemental content, in molar terms, is determined by dissolving the analytical sample in hydrofluoric acid, including the determination of the total content of metal A and B in the sample. x The total content (quantified by metal content) and the silicon and aluminum content.

[0069] The reaction product, cyclohexylbenzene, was qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the yield of cyclohexylbenzene and the conversion of the reaction substrate, benzene, were analyzed by gas chromatography (GC). The GC-MS system was an Agilent 7890A from Agilent Technologies, USA, with an HP-5 nonpolar capillary column (30 m, 0.53 mm). The gas chromatograph was an Agilent 7890B, with a flame ionization detector (FID) and an SE-54 capillary column (30 m, 0.53 mm).

[0070] The formulas for calculating the yield and selectivity of the product cyclohexylbenzene are as follows:

[0071] The yield % of the product cyclohexylbenzene = (molar amount of cyclohexylbenzene produced in the reaction * 2) / (molar amount of the substrate benzene) × 100%.

[0072] The selectivity % of the product cyclohexylbenzene = (molar amount of cyclohexylbenzene produced in the reaction * 2) / (molar amount of benzene reacted) × 100%.

[0073] Example 1

[0074] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0075] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of cerium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0076] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0077] The obtained catalyst SEM image is as follows Figure 1 As shown, the sheet-like structure is an H-type molecular sieve, and the clusters are metal oxide supports; the spatial distance between the first and second components was measured to be 240 nm according to SEM results.

[0078] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0079] Example 2

[0080] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0081] (2) Add 18 mL of ruthenium chloride solution (2 g / L) dropwise to 2 g of cerium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0082] (3) Take 1.5g of H-type molecular sieve and 0.5g of precursor, add 50mL of acetone and sonicate until homogeneous, then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0083] The spatial distance between the first and second components, as measured by SEM, is 190 nm.

[0084] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0085] Example 3

[0086] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0087] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of gallium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0088] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0089] The spatial distance between the first and second components, as measured by SEM, is 260 nm.

[0090] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0091] Example 4

[0092] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0093] (2) Add 9 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of gallium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0094] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0095] The spatial distance between the first and second components, as measured by SEM, is 250 nm.

[0096] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0097] Example 5

[0098] (1) Na-type FAU molecular sieve (silicon-aluminum molar ratio of 4:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0099] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of cerium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0100] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0101] The spatial distance between the first and second components, as measured by SEM, is 210 nm.

[0102] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0103] Example 6

[0104] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 15:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0105] (2) Add 10 mL of palladium chloride solution (1 g / L) dropwise to 2 g of cerium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0106] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0107] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0108] Example 7

[0109] (1) Na-type BEA molecular sieve (silicon-aluminum molar ratio of 15:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0110] (2) Add 12 mL of ruthenium chloride solution (2 g / L) dropwise to 2 g of germanium oxide, mix well, place in 200 mL of liquid nitrogen for 5 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0111] (3) Take 1.6g of H-type molecular sieve and 0.2g of precursor, add 80mL of ethanol, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain the catalyst.

[0112] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0113] Example 8

[0114] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0115] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of cerium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0116] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone-ethanol mixed solution with a volume ratio of 1:1, and then sonicate to homogenize. After centrifugation and drying at 80℃ for 4h, the catalyst is obtained.

[0117] The spatial distance between the first and second components, as measured by SEM, is 220 nm.

[0118] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0119] Example 9

[0120] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0121] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of cerium oxide, mix well, dry at 80 °C for 4 h, and then place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0122] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0123] The spatial distance between the first and second components was measured to be 670 nm according to the SEM results.

[0124] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0125] Example 10

[0126] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0127] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of cerium oxide, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0128] (3) Take 1g of H-type molecular sieve and 1g of precursor, grind and mix them evenly to obtain the catalyst.

[0129] The spatial distance between the first and second components, as measured by SEM, is 420 nm.

[0130] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0131] Comparative Example 1

[0132] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0133] (2) Add 4.5 mL of ruthenium chloride solution (1 g / L) dropwise to 2 g of the above H-type MWW molecular sieve, mix well, dry at 80 °C for 2 h, and then place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The catalyst was obtained by reduction under the specified conditions for 3 hours.

[0134] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0135] Comparative Example 2

[0136] (1) Na-type FAU molecular sieve (silicon-aluminum molar ratio of 4:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0137] (2) Add 4.5 mL of ruthenium chloride solution (1 g / L) dropwise to 2 g of the above H-type MWW molecular sieve, mix well, dry at 80 °C for 2 h, and then place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The catalyst was obtained by reduction under the specified conditions for 3 hours.

[0138] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0139] Comparative Example 3

[0140] (1) Na-type MWW molecular sieve (silicon-aluminum molar ratio of 12:1) was subjected to ammonium ion exchange with NH4NO3 solution (0.5mol / L) at a mass ratio of 1:20 for 2 hours at 60℃. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain H-type molecular sieve.

[0141] (2) Add 6 mL of ruthenium chloride solution (2 g / L) dropwise onto 2 g of porous alumina support, mix well, place in 200 mL of liquid nitrogen for 3 minutes, then remove and place in a fixed-bed reactor at 450 °C and a hydrogen volume hourly space velocity of 50 h⁻¹. -1 The precursor was obtained by reducing it for 1 hour under the specified conditions.

[0142] (3) Take 1g of H-type molecular sieve and precursor, add 50mL of acetone, and sonicate until homogeneous. Then centrifuge and dry at 80℃ for 4h to obtain catalyst.

[0143] The metal content, support content, molecular sieve mass content, and acid content of the catalyst are shown in Table 1.

[0144] Table 1

[0145]

[0146] Example 11

[0147] Take 0.5g of the catalyst synthesized in Example 1 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0148] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0149] Example 12

[0150] Take 0.5g of the catalyst synthesized in Example 1 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 180°C and let it react for 6 hours.

[0151] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0152] Example 13

[0153] Take 0.5g of the catalyst synthesized in Example 1 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.08mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0154] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0155] Example 14

[0156] Take 0.5g of the catalyst synthesized in Example 2 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0157] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0158] Example 15

[0159] Take 0.5g of the catalyst synthesized in Example 3 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0160] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0161] Example 16

[0162] Take 0.5g of the catalyst synthesized in Example 4 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0163] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0164] Example 17

[0165] Take 0.5g of the catalyst synthesized in Example 5 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0166] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0167] Example 18

[0168] Take 0.5g of the catalyst synthesized in Example 6 and add it to a high-pressure reactor. Add 0.1mol of benzene and 0.05mol of hydrogen gas into the reactor. Heat the system to 150°C and react for 6 hours.

[0169] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0170] Examples 19-22

[0171] The implementation process is the same as in Example 11, except that the catalyst is replaced with the catalyst prepared in Examples 7-10.

[0172] The selectivity and yield of cyclohexylbenzene are shown in Table 2.

[0173] Comparative Example 4

[0174] The implementation process is the same as in Example 11, except that the catalyst is replaced with the catalyst prepared in Comparative Example 1.

[0175] Comparative Example 5

[0176] The implementation process is the same as in Example 11, except that the catalyst is replaced with the catalyst prepared in Comparative Example 2.

[0177] Comparative Example 6

[0178] The implementation process is the same as in Example 11, except that the catalyst is replaced with the catalyst prepared in Comparative Example 3.

[0179] Table 2

[0180]

[0181]

[0182] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite hydroalkylation catalyst characterized in that, The composite hydroalkylation catalyst comprises a first component and a second component; The first component has a chemical composition as indicated in formula "A-BO x ", wherein A is selected from at least one of the noble metal elements, BO x is a metal oxide, B is selected from one or more of the rare earth metals, the group IIIA metals, except Al, and the group IVA metals; The second component is selected from H-type molecular sieves; The content of A in the catalyst is 0.1-2.0 wt% based on the total mass of the catalyst; the content of BO x is 5-50 wt%. The mass ratio of the second component to the first component is 0.5-20.

2. The catalyst according to claim 1, wherein, The mass ratio of the second component to the first component is 1-8; and / or In the catalyst, The content of A is 0.1-1.5 wt%; and / or BO x in an amount of 8 to 50 wt%.

3. The catalyst according to claim 1 or 2, wherein, A is selected from one or more of ruthenium, platinum and palladium; and / or BO x is one or more of cerium oxide, gallium oxide and germanium oxide; and / or The catalyst acid amount is 100-2000 μmol-g -1 , preferably 200-1800 μmol-g -1 ; Preferably, the molecular sieve is selected from molecular sieves having a 12-membered ring pore structure, preferably selected from one or more of MWW, FAU, BEA and MOR; more preferably the molar ratio of silicon to aluminum of the molecular sieve is 3-25.

4. The catalyst according to any one of claims 1-3, wherein, The spatial distance between the first component and the second component is 50-300 nm, preferably 190-260 nm.

5. The process for preparing the composite hydroalkylation catalyst as claimed in any one of claims 1 to 4, characterized in that, The method comprises: (1) contacting a solution containing A metal ions with BO x and removing the solvent to obtain a precursor after reduction; (2) mixing the H-type molecular sieve and the precursor to obtain the catalyst.

6. The production method according to claim 5, wherein In step (1), The concentration of the solution containing A metal ions is 0.2-50 g / L; and / or The reduction conditions include a temperature of 300-450°C and a time of 3-6 h; Preferably, the solution containing the A metal ions is contacted with BO x and the solvent is removed within 5 min; more preferably, the solvent is removed by lyophilization or by infrared heat radiation.

7. The production method according to claim 5 or 6, wherein In step (2), The H-type molecular sieve, the precursor and the low-boiling polar solvent are mixed, and the low-boiling polar solvent is removed to obtain the catalyst; Preferably, The low-boiling polar solvent has a boiling point of not more than 75°C; more preferably, it is selected from one or more of methanol, acetone and ethanol; and / or The amount of the low-boiling polar solvent is 10-50, preferably 20-30, based on the mass ratio of liquid to solid.

8. The preparation method according to claim 7, wherein, The low-boiling polar solvent is acetone or an acetone-ethanol mixed solution.

9. Use of the composite hydroalkylation catalyst according to any one of claims 1-4 in the hydroalkylation of aromatic hydrocarbons, preferably in the one-step preparation of cyclohexylbenzene from benzene.

10. Use according to claim 9, wherein, The method for preparing cyclohexylbenzene from benzene by one-step hydrogenation comprises: Benzene is contacted with hydrogen in the presence of a catalyst to obtain cyclohexylbenzene; the catalyst comprises the composite hydroalkylation catalyst according to any one of claims 1-4; Preferably, the mass ratio of benzene to catalyst is 8-40:1; and / or The molar ratio of hydrogen to benzene is 0.3-1:1; and / or The reaction conditions include a temperature of 130-220°C and a time of 2-8 h.

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