Dehydrogenation catalyst and preparation method, and application of the dehydrogenation catalyst in synthesis of opp from cyclohexanone dimer
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI ZHONGHUA TECH CO LTD
- Filing Date
- 2023-12-18
- Publication Date
- 2026-07-24
Smart Images
Figure CN117816156B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a dehydrogenation catalyst and its preparation method, and its application in the synthesis of o-phenylphenol (OPP) from cyclohexanone dimers. Background Technology
[0002] The dehydrogenation of cyclohexanone dimer to o-phenylphenol (OPP) is a dehydrogenation aromatization reaction. Based on domestic and international research, the cyclohexanone dimer dehydrogenation catalysts currently used can be classified into the following types:
[0003] (1) A series of copper-nickel-aluminum-chromium alloy catalysts, which contain at least one metal sulfate or carbonate as an auxiliary agent. Chinese patent CN1371897A discloses a copper-zinc-aluminum and nickel-zinc-copper metal catalyst. Although the initial conversion rate of the dimer is 100% and the selectivity of o-phenylphenol can reach more than 95%, the dehydrogenation conversion rate of the copper-zinc-aluminum catalyst drops from the initial 96% to 62% after 6 hours when reacting at 360℃, indicating poor activity.
[0004] (2) Dehydrogenation catalysts with metals supported on activated carbon. For example, Chinese patent CN1490293A discloses a method for preparing o-phenylphenol by condensation dehydrogenation of cyclohexanone. It uses metals Pt and Pd supported on activated carbon as dimer dehydrogenation catalysts. The selectivity of o-phenylphenol is below 90%, and the activity decreases rapidly, resulting in high cost.
[0005] (3) Catalysts supported on metals using Al2O3 as the catalyst support. On the one hand, such catalyst supports have strong surface acidity, which easily leads to catalytic side reactions, resulting in carbon deposition. Furthermore, the long diffusion path exacerbates coking and carbon buildup on the catalyst. On the other hand, the agglomeration and sintering of active components during the reaction process is also a significant cause of catalyst deactivation. Carbon deposition and sintering deactivation of such catalysts affect catalytic activity, necessitating frequent high-temperature regeneration and increasing energy costs. Currently, these issues are often addressed by adding anti-carbon deposition additives. Most anti-carbon deposition additives are added via solution impregnation: for example, CN106179338B involves first impregnating the alumina support with a noble metal solution, followed by a second impregnation with potassium sulfate, an anti-carbon deposition additive, to obtain a dehydrogenation catalyst with a certain degree of anti-carbon deposition capability; similarly, CN105268459B involves first impregnating the alumina support with the active metal component, followed by impregnation with various carbon deposition additives to obtain a dehydrogenation catalyst. The entire process involves two impregnations, making the preparation process cumbersome. Another approach involves introducing relevant additives during the support preparation process. For example, in CN201711075070.3, magnesium-modified alumina is synthesized by co-precipitating magnesium nitrate and aluminum nitrate in a certain ratio. This magnesium-modified alumina is then further loaded with active components to obtain a dehydrogenation catalyst. However, this method also suffers from a cumbersome preparation process. As with the existing technologies described above, in addition to the cumbersome preparation process, the resulting catalysts still exhibit drawbacks such as poor resistance to carbon deposition and low stability. Summary of the Invention
[0006] This invention overcomes the shortcomings of existing technologies in the dehydrogenation of cyclohexanone dimers to prepare o-phenylphenol (OPP) due to poor catalyst stability and weak resistance to carbon deposition. It provides a dehydrogenation catalyst, its preparation method, and its application in the synthesis of o-phenylphenol (OPP) from cyclohexanone dimers. This dehydrogenation catalyst exhibits advantages such as strong resistance to carbon deposition, excellent stability, and high catalytic activity. Its preparation method is simple and eliminates the need for secondary impregnation aids.
[0007] To achieve the above objectives, the technical solution adopted by this invention is as follows:
[0008] This invention provides a method for preparing a dehydrogenation catalyst, comprising the following steps:
[0009] S1 contains a mixture of alumina source, additives and binder, which is extruded, dried and calcined to obtain an alumina carrier;
[0010] The alumina source comprises macroporous boehmite and microporous boehmite; the macroporous boehmite has a pore volume greater than 0.7 cm³. 3 / g; the pore volume of the microporous pseudoboehmite is less than 0.6 cm³. 3 / g; the adjuvant contains potassium salt;
[0011] S2 The alumina support is impregnated in a solution containing a noble metal salt, the resulting impregnated material is dried and calcined to obtain a dehydrogenation catalyst.
[0012] Wherein, the impregnation conditions satisfy at least one of the following conditions:
[0013] The impregnation temperature described in condition (1) is 40℃-90℃;
[0014] The impregnation pressure described in condition (2) is -1 to 0 MPa and does not include 0 MPa.
[0015] In S1, the pore volume of the macroporous pseudoboehmite can be 0.9-1.1 cm. 3 / g.
[0016] In S1, the pore volume of the microporous pseudoboehmite can be 0.4-0.5 cm. 3 / g.
[0017] In S1, the amount of macroporous pseudoboehmite can be 10wt%-90wt% of the alumina source, preferably 50wt%-80wt%, for example 55wt%, 60wt%, 65wt%, 70wt% or 75wt%.
[0018] In S1, the amount of the microporous pseudoboehmite can be 10wt%-90wt% of the alumina source, preferably 20wt%-50wt%, for example 25wt%, 30wt%, 35wt%, 40wt% or 45wt%.
[0019] In S1, the ratio of macroporous pseudoboehmite to microporous pseudoboehmite can be (20-80):(80-20), preferably (50-80):(50-20), for example 50:50, 55:45, 60:40, 65:35, 70:30 or 75:25.
[0020] In S1, the auxiliary agent may be a conventional potassium salt in the art, such as one or more selected from potassium sulfate, potassium nitrate, potassium carbonate, potassium hydroxide and potassium bicarbonate.
[0021] In S1, the amount of the additive, based on the total weight of the alumina source, can be 0-30 wt%, and is not 0, preferably 0.01 wt%-20 wt%, more preferably 0.1 wt%-15 wt%, and even more preferably 5 wt%-15 wt%, for example 5.7 wt%, 6.3 wt%, 7.1 wt%, 9.3 wt%, 11 wt%, or 12.5 wt%.
[0022] In some embodiments, the auxiliary agent is potassium sulfate; the amount of potassium sulfate used is 1 wt% to 15 wt% based on the total weight of the alumina source, preferably 5 wt% to 15 wt%, for example 6.3 wt%, 9.3 wt%, or 12.5 wt%.
[0023] In S1, the binder may be selected from one or more of nitric acid, acetic acid, citric acid and oxalic acid, preferably acetic acid and / or nitric acid.
[0024] In S1, the amount of binder is preferably 1wt%-2wt% based on the total weight of the alumina source, more preferably 1.17wt%-1.95wt%, for example 1.17wt%, 1.27wt%, 1.3wt%, 1.46wt%, 1.66wt%, 1.76wt%, or 1.95wt%.
[0025] In S1, the preparation method of the mixture may include the following steps: mixing the alumina source and the additive, and then adding a solution of binder and water for mixing; or, dissolving the additive in the solution of binder and water, and then adding the alumina source for secondary mixing; preferably, dissolving the additive in the solution of binder and water, and then adding the alumina source for secondary mixing.
[0026] In some preferred embodiments, the preparation of the mixture includes: dissolving the additive in a solution of the binder and water, and then adding the alumina source for secondary mixing; the amount of the additive is 2wt%-5wt% and the amount of the binder is 1wt%-2wt% based on the total weight of the alumina source.
[0027] In S1, the extrusion molding step can be conventional in the art, generally including extruding into strips, followed by pelletizing and rounding.
[0028] The extrusion into strips can be performed using an extruder. The extrusion pressure is, for example, below 100 N. The extrusion temperature is, for example, room temperature (25°C). The extrusion speed is, for example, 10 Hz.
[0029] The number of times the extrusion into strips is preferably 3, 4, 5 or 6.
[0030] The pelletizing and rounding can be carried out using a shaping machine, such as the E50 product from Chongqing Chengmingtong Machinery Equipment Co., Ltd.
[0031] In step S1, the drying temperature can be between 30℃ and 200℃, for example, 110℃. The drying time is, for example, 2 hours. Drying removes free water, preventing it from being introduced into the muffle furnace later and increasing the energy consumption of the muffle furnace.
[0032] In S1, the calcination temperature can be 450℃-800℃, for example, 500℃. The calcination time can be 3-10h, for example, 3h. By calcining and activating at a specific temperature, alumina with a specific crystal form, namely γ-Al2O3, can be obtained.
[0033] In S1, the mixture may further include an extrusion aid; the extrusion aid is preferably selected from carbon-containing materials, and more preferably from one or more of starch, guar gum, carboxymethyl cellulose, and polyethylene glycol. The carbon-containing material oxidizes during calcination, generating and escaping gas, which can form certain channels in the alumina carrier.
[0034] The amount of the extrusion aid can be 1wt%-10wt%, for example, 2.5wt%, based on the total weight of the alumina source.
[0035] In S1, when the raw material of the alumina support also includes an extrusion aid, the preparation method of the mixture preferably includes the following steps:
[0036] The alumina source, extrusion aid, and additives are mixed, and then a solution of binder and water is added for further mixing; or, the alumina source and extrusion aid are mixed first, the additives are dissolved in the solution of binder and water, and then added for secondary mixing; more preferably, the alumina source and extrusion aid are mixed first, the additives are dissolved in the solution of binder and water, and then added for secondary mixing.
[0037] In S1, the alumina support is a potassium-modified γ-Al2O3 support. Preferably, the alumina support contains 80wt%-90wt% Al2O3 and 3wt%-7wt% potassium, and the specific surface area of the alumina support is not less than 200m². 2 / g, the pore volume of the alumina carrier is 0.1-0.9 cm³. 3 / g.
[0038] Preferably, the Al2O3 content in the alumina support is 84wt%-90wt%, for example 85.38wt%, 87.22wt%, 87.23wt%, 87.35wt%, or 89.32wt%.
[0039] Preferably, the potassium content in the alumina support is 4.5 wt% to 5.5 wt%, for example, 5.00 wt%, 5.02 wt%, 5.10 wt%, or 5.12 wt%.
[0040] Preferably, the specific surface area of the alumina carrier is 200-250 m². 2 / g.
[0041] Preferably, the pore volume of the alumina carrier is 0.4-0.8 cm³. 3 / g.
[0042] In S2, the noble metal salt may include platinum salts and / or palladium salts, such as chloroplatinic acid and / or palladium chloride.
[0043] For the purposes of this invention, it is only necessary to ensure that the noble metal loading in the final alumina carrier is 0.3wt%-1wt%. Those skilled in the art can adjust the ion concentration in the solution containing noble metal salts as needed.
[0044] In a preferred embodiment, in S2, the concentration of noble metal ions in the noble metal salt solution can be 0.1wt%-10wt%, more preferably 0.5wt%-5wt%, for example 1wt%.
[0045] In step S2, the alumina carrier is generally vacuumed before impregnation. Preferably, the vacuuming conditions are the same as the impregnation conditions.
[0046] In S2, the impregnation can be an equal-volume impregnation. The number of impregnation cycles can be once.
[0047] In S2, in condition (1), the immersion temperature is preferably 50°C-80°C, for example 60°C or 70°C.
[0048] In S2, when the impregnation conditions meet the temperature in condition (1), the impregnation pressure can be any pressure, preferably -1 to 0 MPa, for example -0.1 MPa, -0.05 MPa or 0 MPa.
[0049] In S2, in condition (2), the impregnation pressure is preferably -0.5-0 MPa, for example -0.05 MPa or -0.1 MPa.
[0050] In S2, when the impregnation conditions meet the pressure of condition (2), the impregnation temperature can be 20℃-90℃, for example 25℃, 50℃ or 70℃.
[0051] In step S2, the drying temperature can be 100-130℃, for example, 110℃. The drying time can be 2-12 hours, for example, 12 hours.
[0052] In step S2, the roasting temperature can be 300℃-600℃, preferably 300℃-500℃. The roasting time can be 2-5 hours.
[0053] The present invention also provides a dehydrogenation catalyst, which is prepared by the method for preparing a dehydrogenation catalyst as described above.
[0054] Preferably, the loading of noble metal in the dehydrogenation catalyst is 0.3wt%-1wt%, more preferably 0.4wt%-1wt%, for example 0.47wt%, 0.48wt%, 0.87wt%, 0.88wt%, 0.89wt% or 0.9wt%.
[0055] Preferably, the potassium content in the dehydrogenation catalyst is 2 wt%-7 wt%, more preferably 3.4-6.6 wt%, for example 4.91 wt%, 4.92 wt%, 4.93 wt%, 4.94 wt%, 4.95 wt%, 5.0 wt%, 5.05 wt%, 5.06 wt%, 5.07 wt%, 5.08 wt%, 5.09 wt%, or 5.1 wt%.
[0056] Preferably, the aluminum content in the dehydrogenation catalyst is 42wt%-48wt%, more preferably 44wt%-46wt%, for example 44.5wt%, 44.54wt%, 44.6wt%, 44.63wt%, 44.70wt%, 44.75wt%, 44.8wt%, 44.85wt%, 44.9wt%, 44.92wt%, 44.94wt%, or 45.01wt%.
[0057] Preferably, the dehydrogenation catalyst has a pore volume greater than 0.6 m³. 3 / g, more preferably 0.6-0.68m 3 / g, for example 0.61m 3 / g, 0.62m 3 / g, 0.63m 3 / g, 0.64m 3 / g, 0.65m 3 / g, 0.66m 3 / g or 0.67m 3 / g.
[0058] Preferably, the dehydrogenation catalyst has a pore size greater than 9 nm, more preferably 9-9.5 nm, such as 9.1 nm, 9.2 nm, 9.3 nm or 9.4 nm.
[0059] Preferably, the specific surface area of the dehydrogenation catalyst is greater than 200 m². 2 / g, more preferably 212-257m 2 / g, for example 215m 2 / g、219m 2 / g、221m 2 / g、222m 2 / g、235m 2 / g、236m 2 / g、237m 2 / g、238m 2 / g、239m 2 / g、241m 2 / g、242m 2 / g、243m 2 / g、244m 2 / g、245m 2 / g、246m 2 / g、253m 2 / g、254m 2 / g or 256m 2 / g.
[0060] The present invention also provides the application of the dehydrogenation catalyst as described above in a dehydrogenation reaction, wherein the dehydrogenation reaction is the dehydrogenation of cyclohexanone dimer to synthesize o-phenylphenol (OPP).
[0061] In this art, the dehydrogenation catalyst is typically used after reduction. For example, the dehydrogenation catalyst can be reduced under hydrogen gas.
[0062] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.
[0063] The reagents and raw materials used in this invention are all commercially available.
[0064] The positive and progressive effects of this invention are as follows:
[0065] This invention selects boehmite with a specific pore volume as the alumina source and adds additives before the carrier is formed. The resulting potassium salt modified alumina carrier (γ-Al2O3 carrier) has the advantages of large specific surface area and significantly enhanced anti-carbon deposition performance. Moreover, the forming process is simple, avoids secondary impregnation, reduces energy consumption, and simplifies the preparation process.
[0066] The dehydrogenation catalyst prepared using the γ-Al2O3 support in this invention exhibits good catalytic activity, selectivity, and anti-carbon deposition ability in the synthesis of o-phenylphenol from cyclohexanone dimer. Attached Figure Description
[0067] Figure 1 This is a mapping diagram of the K element in the Pt-K / γ-Al2O3 dehydrogenation catalyst obtained in Example 1. Detailed Implementation
[0068] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.
[0069] Unless otherwise specified, in the following examples and comparative examples, the boehmite is high-purity boehmite; among them, the macroporous boehmite is domestically produced high-purity boehmite, provided by Zibo Xuanzheng New Materials Co., Ltd.; and the microporous boehmite is imported commercial SB powder, provided by Sasol.
[0070] Unless otherwise specified, in the following examples and comparative examples, the extrusion conditions are as follows: at room temperature (25°C), at an extrusion speed of 10 Hz and an extrusion pressure of less than 100 N.
[0071] Example 1
[0072] The pore volume is 0.9cm 3 70g of macroporous pseudoboehmite with a pore volume of 0.5cm³ 3 30g of small-pore boehmite, 2.5g of extrusion aid guar gum powder, and 9.3g of K2SO4 powder were mixed evenly in a mixer. Then, 121g of acid solution (2.55g of 65% nitric acid solution, where the percentage refers to the mass concentration of nitric acid in the nitric acid solution) was added, and water was added to make up the difference to prepare 121g of acid solution. The mixture was then extruded multiple times instead of kneading, and extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was repeated three times. The strips were then placed in a shaping machine for pelletizing, rolled into balls, dried at 110℃ for 2 hours, and calcined at 500℃ for 3 hours to obtain spherical K / γ-Al2O3 carrier.
[0073] A Pt-K / γ-Al₂O₃ dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al₂O₃ support with an aqueous solution of noble metal chloroplatinic acid under vacuum (room temperature 25℃, gauge pressure -0.1 MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours. The concentration of the noble metal chloroplatinic acid aqueous solution was adjusted according to the adsorption capacity of the support to ensure a final platinum loading of 1 wt%.
[0074] Example 2
[0075] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0076] The preparation process of the dehydrogenation catalyst is as follows:
[0077] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (room temperature 25℃, gauge pressure -0.05MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0078] Example 3
[0079] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0080] The preparation process of the dehydrogenation catalyst is as follows:
[0081] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (50℃, gauge pressure -0.1MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0082] Example 4
[0083] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0084] The preparation process of the dehydrogenation catalyst is as follows:
[0085] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (50℃, gauge pressure -0.05MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0086] Example 5
[0087] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0088] The preparation process of the dehydrogenation catalyst is as follows:
[0089] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (70℃, gauge pressure -0.1MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0090] Example 6
[0091] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0092] The preparation process of the dehydrogenation catalyst is as follows:
[0093] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (70℃, gauge pressure -0.05MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0094] Example 7
[0095] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0096] The preparation process of the dehydrogenation catalyst is as follows:
[0097] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (50℃, gauge pressure 0 MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0098] Example 8
[0099] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0100] The preparation process of the dehydrogenation catalyst is as follows:
[0101] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (70℃, gauge pressure 0 MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0102] Example 9
[0103] The pore volume is 1.1cm 3 70g of macroporous pseudoboehmite with a pore volume of 0.5cm³ 3 30g of small-pore boehmite and 2.5g of extrusion aid guar gum powder were mixed evenly in a mixer to obtain a premix. Then, 121g of acid solution (2.55g of 65% nitric acid solution (the percentage here means the mass concentration of nitric acid in the nitric acid solution), 9.3g of K2SO4 auxiliary agent, and water was added to make up the difference to prepare 121g of acid solution) were added to obtain a mixture. The mixture was then extruded multiple times instead of kneading. It was extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was carried out three times in total. The strips were then put into a shaping machine for pelletizing, rolled into balls, dried at 110℃ for 2 hours, and calcined at 500℃ for 3 hours to obtain spherical K / γ-Al2O3 carrier.
[0104] The preparation process of the dehydrogenation catalyst is as follows:
[0105] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (50℃, gauge pressure 0 MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0106] Example 10
[0107] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0108] The preparation process of the dehydrogenation catalyst is as follows:
[0109] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (70℃, gauge pressure 0 MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0110] Example 11
[0111] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0112] The preparation process of the dehydrogenation catalyst is as follows:
[0113] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (50℃, gauge pressure -0.1MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0114] Example 12
[0115] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0116] The preparation process of the dehydrogenation catalyst is as follows:
[0117] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (70℃, gauge pressure -0.1MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0118] Example 13
[0119] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0120] The preparation process of the dehydrogenation catalyst is as follows:
[0121] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (50℃, gauge pressure -0.05MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0122] Example 14
[0123] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0124] The preparation process of the dehydrogenation catalyst is as follows:
[0125] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (70℃, gauge pressure -0.05MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0126] Example 15
[0127] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0128] The preparation process of the dehydrogenation catalyst is as follows:
[0129] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid (25℃, gauge pressure -0.1MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0130] Example 16
[0131] The preparation of the K / γ-Al2O3 support was the same as in Example 9.
[0132] The preparation process of the dehydrogenation catalyst is as follows:
[0133] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (25℃, gauge pressure -0.05MPa), drying at 110℃ for 12 hours, and calcining at 500℃ for 3 hours.
[0134] Example 17
[0135] The pore volume is 0.9cm 3 70g of macroporous pseudoboehmite with a pore volume of 0.5cm³ 3 30g of small-pore boehmite and 2.5g of extrusion aid guar gum powder were placed in a mixer and mixed evenly. Then, 121g of acid solution (2.55g of 65% nitric acid solution (the percentage here means the mass concentration of nitric acid in the nitric acid solution), 9.3g of K2SO4 additive, and water was added to make up the amount to prepare 121g of acid solution) were added to obtain a mixture. The mixture was then extruded multiple times instead of kneading. It was extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was carried out three times in total. The strips were then put into a shaping machine for pelletizing. After being rounded into balls, they were dried at 110℃ for 2 hours and calcined at 500℃ for 3 hours to obtain spherical K / γ-Al2O3 carrier.
[0136] A spherical K / γ-Al₂O₃ support was impregnated with noble metal chloroplatinic acid (room temperature 25℃, gauge pressure -0.1 MPa) by vacuum immersion in an aqueous solution of chloroplatinic acid with a specific ion concentration (0.1 wt% - 10 wt%). The catalyst was then dried at 110℃ for 12 h and calcined at 500℃ for 3 h to obtain a Pt-K / γ-Al₂O₃ dehydrogenation catalyst containing 1 wt% platinum. The concentration of the noble metal chloroplatinic acid aqueous solution can be adjusted according to the adsorption capacity of the support to ultimately ensure a platinum loading of 1 wt%.
[0137] Comparative Example 1
[0138] The pore volume is 0.9cm 3 100g of macroporous pseudoboehmite and 2.5g of extrusion aid guar gum powder were placed in a mixer and mixed evenly. Then, 130g of acid solution (3g of 65% nitric acid solution (the percentage here means the mass concentration of nitric acid in the nitric acid solution), and water was added to make up the difference to prepare 130g of acid solution) was added. The mixture was extruded multiple times instead of kneading. The mixture was extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was repeated three times. The strips were then placed in a shaping machine for pelletizing. After being rounded into balls, the balls were dried at 110℃ for 2 hours and calcined at 500℃ for 3 hours to obtain spherical γ-Al2O3 carrier.
[0139] A Pt / γ-Al2O3 catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an equal volume of noble metal chloroplatinic acid aqueous solution (room temperature 25℃, gauge pressure -0.1MPa) and drying it at 110℃ for 12 hours.
[0140] After vacuuming, the spherical Pt / γ-Al2O3 support was impregnated with K2SO4 (K content 5wt%) (room temperature 25℃, gauge pressure 0MPa), dried at 110℃ for 12 hours, and calcined at 500℃ for 3 hours to obtain the Pt-K / γ-Al2O3 catalyst.
[0141] Comparative Example 2
[0142] 100g of small-pore boehmite with a pore volume of 0.5cm³ / g and 2.5g of extrusion aid guar gum powder were mixed evenly in a mixer. Then, 100g of acid solution (1.5g of 65% nitric acid solution (the percentage here refers to the mass concentration of nitric acid in the nitric acid solution), made up with water to prepare 100g of acid solution) was added. The mixture was extruded multiple times instead of kneading. The mixture was extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was repeated three times. The strips were then placed in a shaping machine for pelletizing. After being rounded into balls, the balls were dried at 110℃ for 2 hours and calcined at 500℃ for 3 hours to obtain spherical γ-Al₂O₃ carrier.
[0143] A spherical γ-Al2O3 support was impregnated with an equal volume of a noble metal chloroplatinic acid aqueous solution after vacuuming (room temperature 25℃, gauge pressure -0.1MPa), and dried at 110℃ for 12 hours to obtain a Pt / γ-Al2O3 catalyst containing 1wt% platinum.
[0144] After vacuuming, the spherical Pt / γ-Al2O3 support was impregnated with K2SO4 (K content 5wt%), dried at 110℃ for 12 hours (room temperature 25℃, gauge pressure 0MPa), and calcined at 500℃ for 3 hours to obtain the Pt-K / γ-Al2O3 catalyst.
[0145] Comparative Example 3
[0146] The pore volume is 0.9cm 3 70g of macroporous pseudoboehmite with a pore volume of 0.5cm³ 3 30g of small-pore boehmite and 2.5g of extrusion aid guar gum powder were placed in a mixer and mixed evenly. Then, 121g of acid solution (2.55g of 65% nitric acid solution (the percentage here means the mass concentration of nitric acid in the nitric acid solution) was added, and water was added to make up the difference to prepare 121g of acid solution). The mixture was extruded multiple times instead of kneading. The mixture was extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was repeated three times. The strips were then placed in a shaping machine for pelletizing. After being rounded into balls, the balls were dried at 110℃ for 2 hours and calcined at 500℃ for 3 hours to obtain spherical γ-Al2O3 carrier.
[0147] A spherical γ-Al2O3 support was impregnated with an equal volume of a noble metal chloroplatinic acid aqueous solution after vacuuming (room temperature 25℃, gauge pressure 0MPa), and dried at 110℃ for 12 hours to obtain a Pt / γ-Al2O3 catalyst containing 1wt% platinum.
[0148] After vacuuming, the spherical Pt / γ-Al2O3 support was impregnated with K2SO4 (K content 5wt%) (room temperature 25℃, gauge pressure 0MPa), dried at 110℃ for 12 hours, and calcined at 500℃ for 3 hours to obtain the Pt-K / γ-Al2O3 catalyst.
[0149] Comparative Example 4
[0150] The support preparation process was the same as in Comparative Example 3, with the same precious metal impregnation method. However, the precious metal platinum chloride was replaced with palladium chloride, the palladium loading was 0.5 wt%, and the calcination temperature was reduced to 350℃ to obtain the Pd-K / γ-Al2O3 dehydrogenation catalyst.
[0151] Comparative Example 5
[0152] The pore volume is 0.9cm 3100g of macroporous pseudoboehmite and 2.5g of extrusion aid guar gum powder were mixed evenly in a mixer. 9.3g of K2SO4 additive was dissolved in 130g of acid solution (3g of 65% nitric acid solution (the percentage here refers to the mass concentration of nitric acid in the nitric acid solution), and water was added to make up the difference to prepare 130g of acid solution). The mixture was extruded multiple times instead of kneading, and extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was repeated three times. The strips were then placed in a shaping machine for pelletizing, rolled into balls, dried at 110℃ for 2 hours, and calcined at 500℃ for 3 hours to obtain spherical γ-Al2O3 carrier.
[0153] A spherical γ-Al₂O₃ support was impregnated with an equal volume of a noble metal chloroplatinic acid aqueous solution under vacuum (room temperature 25℃, gauge pressure 0 MPa), and dried at 110℃ for 12 hours to obtain a Pt / γ-Al₂O₃ catalyst containing 1 wt% platinum. Then, it was calcined at 500℃ for 3 hours to obtain a Pt-K / γ-Al₂O₃ catalyst.
[0154] Comparative Example 6
[0155] The pore volume is 0.5cm 3 100g of small-pore boehmite and 2.5g of extrusion aid guar gum powder were mixed evenly in a mixer. 9.3g of K2SO4 additive was dissolved in 101g of acid solution (1.5g of 65% nitric acid solution (the percentage here refers to the mass concentration of nitric acid in the nitric acid solution), and water was added to make up the difference to prepare 101g of acid solution). The mixture was extruded multiple times instead of kneading, and extruded into cylindrical strips under an extrusion pressure of less than 100N. The extrusion was repeated three times. The strips were then placed in a shaping machine for pelletizing, rolled into balls, dried at 110℃ for 2 hours, and calcined at 500℃ for 3 hours to obtain spherical γ-Al2O3 carrier.
[0156] A spherical γ-Al₂O₃ support was impregnated with an equal volume of a noble metal chloroplatinic acid aqueous solution under vacuum (room temperature 25℃, gauge pressure 0 MPa), and dried at 110℃ for 12 hours to obtain a Pt / γ-Al₂O₃ catalyst containing 1 wt% platinum. Then, it was calcined at 500℃ for 3 hours to obtain a Pt-K / γ-Al₂O₃ catalyst.
[0157] Comparative Example 7
[0158] The preparation of the K / γ-Al2O3 support was the same as in Example 1.
[0159] The preparation process of the dehydrogenation catalyst is as follows:
[0160] A Pt-K / γ-Al2O3 dehydrogenation catalyst containing 1 wt% platinum was obtained by impregnating a spherical K / γ-Al2O3 support with an aqueous solution of noble metal chloroplatinic acid under vacuum (25°C, gauge pressure 0 MPa), drying at 110°C for 12 hours, and calcining at 500°C for 3 hours.
[0161] Example 1
[0162] The alumina supports and dehydrogenation catalysts obtained in Examples 1-17 and Comparative Examples 1-6 were characterized according to the relevant descriptions in Table 1.
[0163] The contents of K, Pt, Pd or Al in the support and dehydrogenation catalyst are obtained by ICP testing, specifically by using an Agilent 5110 inductively coupled plasma emission source, taking an appropriate amount of sample, microwave digesting it into a clear solution, and then measuring the volume.
[0164] The contents of K2O and Al2O3 in the support and dehydrogenation catalyst were determined by XRF testing. Specifically, the XRF was performed using a Panaco Zetium X-ray fluorescence spectrometer with an end-window Rh target tube and a power of 4000W. After the sample and binder were ground and mixed evenly, they were pressed into tablets using a tablet press, and the elements were tested using a full elemental scanning method.
[0165] Pore volume, pore size, and specific surface area were determined using the BET characterization method. The BET was performed using a Micromeritics ASAP2460 pore size and specific surface area analyzer. A certain mass of sample was weighed using a balance with a sensitivity of 0.0001 g and placed in a sample tube. The sample was then treated under vacuum at 300°C for a period of time to remove the original adsorbates on the solid surface. The treated sample was then placed in a cold trap, and N2 was used as the adsorbate for testing. The pore size distribution curve and average pore size of the sample were calculated using the BJH model desorption curve, and the specific surface area of the sample was calculated using the BET equation.
[0166] The alumina supports obtained in Examples 1-17 of this invention are all potassium-modified γ-Al₂O₃ supports; wherein the alumina support contains 80wt%-90wt% γ-Al₂O₃ and 2wt%-7wt% potassium, and has a specific surface area of not less than 200m². 2 / g, pore volume 0.1-0.9cm 3 / g; the prepared catalyst contains 2wt%-7wt% potassium, 44wt%-45wt% Al, 80wt%-90wt% γ-Al2O3, and a Pd / Pt content of 0.3-1wt%, with a specific surface area of 230-245m². 2 / g, pore volume 0.65-0.67m 3 / g, with a pore size of 9-9.5nm. Specific results are shown in Table 1.
[0167] The results are shown in Table 1. All percentages in the table are by mass, and pore size is the average pore size. In Comparative Example 4, the precious metal is Pd, and the others are Pt. The K and K₂O in the carrier originate from trace potassium impurities in the raw materials.
[0168] Table 1. Relevant structural characterization parameters of the alumina support and dehydrogenation catalysts obtained in the examples and comparative examples.
[0169]
[0170]
[0171] Example 2
[0172] The platinum-containing dehydrogenation catalysts obtained in Examples 1-17 and Comparative Examples 1-6 were used for the dehydrogenation reaction of cyclohexanone dimers. The catalysts were reduced before use.
[0173] Specifically, the dimer dehydrogenation reaction was carried out in a fixed-bed microreactor under atmospheric pressure, using an electric heating mantle as the experimental equipment. The reactor inner diameter was φ = 13 mm. 5 ml of catalyst of a certain mesh size was loaded into the reaction tube, and the catalyst bed was placed in the constant temperature section of the heating furnace. The reactor temperature was 300 °C. Nitrogen was first purged for 30 min at a flow rate of 60 ml / min. Reduction was carried out under pure hydrogen for 3 h at a flow rate of 60 ml / min.
[0174] After reduction, the reactor temperature is lowered to 300℃-400℃, and the hydrogen flow rate is reduced to 2.8 ml / min. A plunger pump introduces the dimer feedstock from the top, with a liquid feed rate of 0.02 ml / min-0.06 ml / min. Gas and liquid feeds occur simultaneously. After passing through the preheating section of the reactor, the dimer enters the catalyst bed. The hydrogen flow rate can be fine-tuned to control the residence time of the reaction liquid in the catalyst bed. At the reactor outlet, the receiving bottle is kept at 65℃ and a separate gas path is used for tail gas treatment. An electric heating tape is wrapped around the discharge end to prevent OPP precipitation and to block the discharge line. After one hour of normal reaction, the sample in the receiving bottle is dissolved in methanol, and a single emission test is performed (sampling is done every hour). The weight of the methanol solution is weighed, and samples are taken for chromatographic analysis. The weights of OPP, dimer, and other byproducts are calculated, and then converted into product selectivity and feedstock conversion rates. After 500 hours of reaction, the catalyst was removed for TGA analysis (TGA was performed using a Netzsch TG 209F3 thermal analyzer to analyze the amount of carbon deposit on the catalyst. The test was conducted in an air atmosphere, with a temperature range of 40℃-800℃ and a heating rate of 10℃ / min). The amount of carbon deposit on the catalyst after 500 hours was measured.
[0175] Table 2 shows the sampling and testing results of the dehydrogenation catalysts obtained in Examples 1-17 and Comparative Examples 1-6 in the dehydrogenation of cyclohexanone dimer to prepare o-phenylphenol (OPP) at 300℃-400℃ for 48 hours after reaction and 500 hours after the reaction endpoint.
[0176] Table 2. Relevant performance of Pt-K / γ-Al2O3 dehydrogenation catalysts obtained in Examples 1-17 and Comparative Examples 1-6
[0177]
[0178]
[0179]
[0180] As shown in Table 2, for the examples: In Examples 1-8, during the catalyst preparation and application processes (at the same reaction temperature (e.g., 350°C), reaction time, and feed rate), when all other conditions are the same, at the same impregnation temperature, the higher the vacuum degree of the impregnation pressure, the better the catalytic performance. During the catalyst preparation process, when all other conditions are the same, at the same impregnation pressure, the higher the impregnation temperature, the better the catalytic performance. Examples 9-16 also conform to the above rules.
[0181] Compared with Example 1, Example 17 differs only in the mixing order (in Example 1, other components are mixed first and then mixed with the binder; in Example 17, the additives are dissolved in the binder and then mixed with boehmite). The anti-carbon deposit ability obtained in Example 17 is significantly better.
[0182] Compared with the comparative examples, the catalysts prepared in Examples 1-17 all exhibited superior catalytic performance. Specifically,
[0183] Compared with Comparative Examples 1-2, the catalyst prepared in Example 1 has significantly better dimer conversion, long-term OPP selectivity, and anti-carbon deposition ability than dehydrogenation catalysts prepared by using only macroporous pseudoboehmite or only microporous pseudoboehmite, as well as those prepared by loading noble metals and adding promoters (Comparative Examples 1-2).
[0184] Compared with Comparative Example 1, Comparative Example 3 had a lower impregnation pressure of 0 MPa, resulting in a catalyst with poorer catalytic activity.
[0185] Compared with Comparative Examples 1-2 and 5-6, the dehydrogenation catalyst (Comparative Example 1-2) prepared by loading noble metals and adding additives has significantly worse resistance to carbon deposition.
[0186] Compared with Example 1, Comparative Example 7, with the impregnation pressure set to atmospheric pressure, showed a decrease in the long-term OPP selectivity (reaction time 500h) and a significant reduction in the resistance to carbon deposition.
[0187] The TEM-mapping image of the K element in the Pt-K / γ-Al2O3 dehydrogenation catalyst obtained in Example 1 is shown below. Figure 1 As shown (TEM mapping was performed using a JEOL-2100 transmission electron microscope from Japan). (From...) Figure 1 The bright spots represent elements K. The distribution of elements K indicates that... Figure 1 The uniform distribution of potassium (K) in the catalyst effectively inhibits the formation of carbon deposits, making the catalyst performance more stable. Combined with the TGA (carbon deposit amount) analysis of the catalyst after a period of use, it can also be concluded that the effective dispersion of K effectively inhibits the amount of carbon deposits, prolongs the catalyst life, and improves the catalyst activity. In contrast, after a long period of reaction, the dehydrogenation catalyst with severe carbon deposits in Comparative Example 1 showed decreased stability and significantly reduced catalyst activity.
Claims
1. A method for preparing a dehydrogenation catalyst, characterized in that, It includes the following steps: S1 is an alumina carrier obtained by extruding a mixture containing an alumina source, additives and binders, drying and calcining. The alumina source comprises macroporous boehmite and microporous boehmite; the macroporous boehmite has a pore volume of 0.9-1.1 cm³. 3 / g; the pore volume of the microporous pseudoboehmite is 0.4-0.5 cm³. 3 / g; the additive contains a potassium salt, which is selected from one or more of potassium sulfate, potassium nitrate, potassium carbonate, potassium hydroxide, and potassium bicarbonate; the ratio of macroporous pseudoboehmite to microporous pseudoboehmite is (50-80):(50-20); the amount of the additive is 5wt%-15wt% based on the total weight of the alumina source; S2 The alumina support is impregnated in a solution containing a noble metal salt, the resulting impregnated material is dried and calcined to obtain a dehydrogenation catalyst. The impregnation conditions satisfy one of the following conditions: Condition (1) The impregnation temperature is 40℃-90℃, and the impregnation pressure is -1~-0.05MPa; The impregnation pressure in condition (2) is -1 to 0 MPa and does not include 0 MPa.
2. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that, The preparation method of the dehydrogenation catalyst satisfies one of the following conditions: (a) In condition (1), the immersion temperature is 50°C-80°C; (b) In condition (2), the impregnation pressure is -0.5 to 0 MPa and does not include 0 MPa.
3. The method for preparing the dehydrogenation catalyst according to claim 2, characterized in that, In condition (1), the immersion temperature is 60°C or 70°C.
4. The method for preparing the dehydrogenation catalyst according to claim 2, characterized in that, When the impregnation conditions meet the temperature in condition (1), the impregnation pressure is -0.1 MPa or -0.05 MPa.
5. The method for preparing the dehydrogenation catalyst according to claim 2, characterized in that, In condition (2), the impregnation pressure is -0.05 MPa or -0.1 MPa.
6. The method for preparing the dehydrogenation catalyst according to claim 2, characterized in that, When the impregnation conditions meet the pressure of condition (2), the impregnation temperature is 20℃-90℃.
7. The method for preparing the dehydrogenation catalyst according to claim 2, characterized in that, When the impregnation conditions meet the pressure of condition (2), the impregnation temperature is 25°C, 50°C or 70°C.
8. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that, The preparation method of the dehydrogenation catalyst satisfies one or more of the following conditions: (a) The solution containing the noble metal salt is a platinum salt and / or a palladium salt; (b) The impregnation is an equal-volume impregnation, and the impregnation is performed once; and, (c) The loading of noble metals in the dehydrogenation catalyst is 0.3wt%-1wt%.
9. The method for preparing the dehydrogenation catalyst according to claim 8, characterized in that, The solution containing the noble metal salt is chloroplatinic acid and / or palladium chloride; And / or, the loading of noble metals in the dehydrogenation catalyst is 0.4wt%-1wt%.
10. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that, The amount of macroporous pseudoboehmite used is 50wt%-80wt% of the alumina source; And / or, the amount of the small-pore boehmite used is 20wt%-50wt% of the alumina source.
11. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that, The preparation method of the alumina support satisfies one or more of the following conditions: (a) The adhesive is selected from one or more of nitric acid, acetic acid, citric acid and oxalic acid; (b) The amount of the binder is 1wt%-2wt% based on the total weight of the alumina source; and, (c) The preparation method of the mixture includes the following steps: mixing the alumina source and the additive, and then adding a solution of binder and water for mixing; or, dissolving the additive in the solution of binder and water, and then adding the alumina source for secondary mixing.
12. The method for preparing the dehydrogenation catalyst according to claim 11, characterized in that, The method for preparing the alumina support satisfies one or more of the following conditions: (a) The adhesive is acetic acid and / or nitric acid; (b) The amount of the binder is 1.17wt%-1.95wt% based on the total weight of the alumina source; (c) The preparation method of the mixture includes the following steps: dissolving the additive in a solution of the binder and water, and then adding the alumina source for secondary mixing.
13. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that, The method for preparing the alumina support satisfies one or more of the following conditions: (a) The extrusion molding includes extruding into strips, followed by pelletizing and rounding; wherein, (b) The calcination temperature is 450℃-800℃; (c) The roasting time is 3-10 hours; and, (d) The mixture also includes an extrusion aid.
14. The method for preparing the dehydrogenation catalyst according to claim 13, characterized in that, The method for preparing the alumina support satisfies one or more of the following conditions: (a) The number of times the extrusion into strips is 3, 4, 5 or 6; (b) The extrusion aid is selected from carbon-containing materials; (c) The amount of the extrusion aid is 1wt%-10wt% based on the total weight of the alumina source.
15. The method for preparing the dehydrogenation catalyst according to claim 13, characterized in that, The extrusion aid is selected from one or more of starch, guar gum, carboxymethyl cellulose, and polyethylene glycol.
16. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that, When the raw material for the alumina carrier also includes an extrusion aid, the preparation method of the mixture includes the following steps: The alumina source, extrusion aid, and additives are mixed, and then a solution of binder and water is added for further mixing; or, the alumina source and extrusion aid are mixed first, and the additives are dissolved in the solution of binder and water before being added for secondary mixing.
17. The method for preparing the dehydrogenation catalyst according to claim 16, characterized in that, When the raw material of the alumina carrier also includes an extrusion aid, the preparation method of the mixture includes the following steps: The alumina source and extrusion aid are first mixed, and the aid is dissolved in a solution of binder and water, and then added to the solution for a second mixing.
18. A dehydrogenation catalyst, characterized in that, It is prepared by the method for preparing the dehydrogenation catalyst as described in any one of claims 1-17.
19. The dehydrogenation catalyst according to claim 18, characterized in that, The dehydrogenation catalyst satisfies one or more of the following conditions: (a) The loading of noble metals in the dehydrogenation catalyst is 0.3wt%-1wt%; (b) The potassium content in the dehydrogenation catalyst is 2wt%-7wt%; (c) The aluminum content in the dehydrogenation catalyst is 42wt%-48wt%; (d) The pore volume of the dehydrogenation catalyst is greater than 0.6 m³. 3 / g; (e) The pore size of the dehydrogenation catalyst is greater than 9 nm; and, (f) The specific surface area of the dehydrogenation catalyst is greater than 200 m². 2 / g.
20. The dehydrogenation catalyst according to claim 19, characterized in that, The dehydrogenation catalyst satisfies one or more of the following conditions: (a) The loading of noble metals in the dehydrogenation catalyst is 0.4 wt%-1 wt%; (b) The potassium content in the dehydrogenation catalyst is 3.4-6.6 wt%; (c) The aluminum content in the dehydrogenation catalyst is 44wt%-46wt%; (d) The pore volume of the dehydrogenation catalyst is 0.6-0.68 m. 3 / g; (e) The dehydrogenation catalyst has a pore size of 9-9.5 nm; and, (f) The specific surface area of the dehydrogenation catalyst is 212-257 m². 2 / g.
21. The dehydrogenation catalyst according to claim 19, characterized in that, The dehydrogenation catalyst satisfies one or more of the following conditions: (a) The loading of noble metals in the dehydrogenation catalyst is 0.47 wt%, 0.48 wt%, 0.87 wt%, 0.88 wt%, 0.89 wt%, or 0.9 wt%; (b) The potassium content in the dehydrogenation catalyst is 4.91 wt%, 4.92 wt%, 4.93 wt%, 4.94 wt%, 4.95 wt%, 5.0 wt%, 5.05 wt%, 5.06 wt%, 5.07 wt%, 5.08 wt%, 5.09 wt%, or 5.1 wt%. (c) The aluminum content in the dehydrogenation catalyst is 44.5 wt%, 44.54 wt%, 44.6 wt%, 44.63 wt%, 44.70 wt%, 44.75 wt%, 44.8 wt%, 44.85 wt%, 44.9 wt%, 44.92 wt%, 44.94 wt%, or 45.01 wt%; (d) The pore volume of the dehydrogenation catalyst is 0.61 m³. 3 / g, 0.62m 3 / g, 0.63m 3 / g, 0.64m 3 / g, 0.65m 3 / g, 0.66m 3 / g or 0.67m 3 / g; (e) The dehydrogenation catalyst has a pore size of 9.1 nm, 9.2 nm, 9.3 nm, or 9.4 nm; and, (f) The specific surface area of the dehydrogenation catalyst is 215 m². 2 / g、219m 2 / g、221m 2 / g、222m 2 / g、235m 2 / g、237m 2 / g、238m 2 / g、239m 2 / g、241m 2 / g、242m 2 / g、244m 2 / g、245m 2 / g、246m 2 / g、253m 2 / g、254m 2 / g or 256m 2 / g.
22. The use of a dehydrogenation catalyst as described in any one of claims 18-21 in a dehydrogenation reaction, characterized in that, The dehydrogenation reaction is the dehydrogenation of cyclohexanone dimer to synthesize o-phenylphenol.