Dehydrogenation catalyst, preparation method and application thereof, and method for dehydrogenation of oxidized alkylbenzene

Abstract

The invention relates to the technical field of dehydrogenation catalysis, in particular to a dehydrogenation catalyst, a preparation method and application of the dehydrogenation catalyst and an alkylbenzene oxide dehydrogenation method. Based on the total weight of the catalyst, the dehydrogenation catalyst comprises Fe2O3, K2O, CeO2, Co3O4, VIB group metal element oxide, MnO2 and IVB group metal element oxide, the oxygen desorption amount of the dehydrogenation catalyst in an O2-TPD test is greater than 8.2 mmol / g. The surface of the catalyst has rich oxygen vacancies (the oxygen desorption amount in an O2-TPD test is greater than 8.2 mmol / g), and the migration ability of active species on the surface of the catalyst is obviously enhanced. The dehydrogenation catalyst is applied to a reaction for preparing alkenyl arene (such as styrene) by dehydrogenating oxidized alkyl arene (such as ethylbenzene), and has the characteristics of high catalytic activity and good stability.

Description

Technical Field

[0001] The present invention relates to the technical field of dehydrogenation catalysis, and specifically relates to a dehydrogenation catalyst, a preparation method and application thereof, and a method for dehydrogenating alkylbenzene by oxidation. Background Art

[0002] Styrene is an important basic organic raw material, mainly used in the manufacture of materials such as polystyrene resin, unsaturated polyester resin, ion exchange resin, synthetic resin coatings, and insulators. These materials have very important uses in industrial sectors such as automobile manufacturing, household appliances, textiles, building materials, light industry, and toys. So far, the ethylbenzene catalytic dehydrogenation method has always been the main technical route for producing styrene at home and abroad, and its production capacity accounts for about 85% of the total styrene production capacity. To improve the production efficiency of ethylbenzene dehydrogenation, a large amount of high-temperature steam is usually introduced in industry. Steam plays various important roles in the reaction, such as providing the heat required for the reaction, promoting the chemical equilibrium to shift towards styrene, eliminating carbon deposition on the catalyst surface through the water-gas shift reaction, and oxidizing the catalyst surface to maintain the catalyst activity, etc.

[0003] Generally speaking, hydrocarbon dehydrogenation can be divided into two reaction types: oxidative dehydrogenation and direct dehydrogenation. For the reaction of dehydrogenating ethylbenzene to styrene, non-oxidative direct dehydrogenation catalysis has been widely industrialized, but it has disadvantages such as thermodynamic equilibrium limitation, large steam consumption, high energy consumption, and easy deactivation of the catalyst. In the oxidative dehydrogenation catalysis process, oxides of iron or vanadium are mostly used as catalysts, and ethylbenzene is oxidized and dehydrogenated in an atmosphere such as air, oxygen, or CO 2 etc., which can break through the limitation of the thermodynamic equilibrium. And the most important core technology in this method is the research and development of a high-performance catalyst for oxidatively dehydrogenating ethylbenzene to styrene. CN112844362B discloses a method for improving the activity of metal oxide catalysts in oxidation and oxidative dehydrogenation reactions. By utilizing the property that metal oxides can dissolve and deposit in acidic or alkaline solutions, the metal oxide catalyst is treated in an acidic or alkaline solution, and the catalyst is reconstructed, and the uniformity and activity of its active components are significantly improved, thereby significantly improving its catalytic reaction performance. CN106000409B discloses an iron-based composite oxide catalyst for oxidatively dehydrogenating ethylbenzene to styrene. The active component of this catalyst is FeO x and the promoter is any one of TiO 2 , PdO, ZnO, V 2 O 5 , and the carrier is γ-Al 2 O 3 , and it is prepared by atomic layer deposition. The dispersion degree of the active components of the catalyst is relatively high, showing good performance in oxidatively dehydrogenating ethylbenzene.

[0004] However, in the catalytic reaction technology for dehydrogenating ethylbenzene to styrene, the catalyst preparation methods so far have not shown obvious benefits, and the performance of the catalyst, such as catalytic activity and stability, cannot fully meet the requirements in the actual application of the ethylbenzene dehydrogenation to styrene catalyst. Summary of the Invention

[0005] Aiming at the problems of low activity and poor stability of the ethylbenzene dehydrogenation to styrene catalyst in the prior art, as well as the problems of large consumption of water vapor, high energy consumption, and easy deactivation of the catalyst during the dehydrogenation process, the present invention provides a dehydrogenation catalyst, its preparation method and application, and a method for dehydrogenating alkylbenzene by oxidation. This dehydrogenation catalyst is applied to the reaction of dehydrogenating alkyl aromatic hydrocarbons (such as ethylbenzene) to vinyl aromatic hydrocarbons (such as styrene), and has the characteristics of high catalytic activity and good stability.

[0006] To achieve the above object, in the first aspect of the present invention, a dehydrogenation catalyst is provided. Based on the total weight of the catalyst, the dehydrogenation catalyst includes: Fe 2 O 3 , K 2 O, CeO 2 , Co 3 O 4 , an oxide of a Group VIB metal element, MnO 2 and an oxide of a Group IVB metal element; the oxygen desorption amount of the dehydrogenation catalyst in the O 2 -TPD test is greater than 8.2 mmol / g.

[0007] In the second aspect of the present invention, a preparation method of the dehydrogenation catalyst of the present invention is provided, and the method includes:

[0008] (1) Mix an Fe source, a K source, an Mn source, and a Group IVB metal source, and then perform the first drying and the first calcination;

[0009] (2) Mix a Ce source, a Co source, and a Group VIB metal source, then perform the second drying and the second calcination to obtain a calcined product. The calcined product is mixed with a solution containing a polyol and an alkali, and a solvothermal reduction reaction is carried out, followed by alcohol washing and drying under vacuum or in an inert gas atmosphere;

[0010] (3) Mix the products obtained in steps (1) and (2) and form them;

[0011] The mass ratio of the calcined product, the polyol, and the alkali is 1:(35.8 - 44.2):(1.06 - 1.75).

[0012] In the third aspect of the present invention, an application of the dehydrogenation catalyst of the present invention in dehydrogenating alkyl aromatic hydrocarbons to prepare vinyl aromatic hydrocarbons is provided.

[0013] In the fourth aspect of the present invention, a method for dehydrogenating alkylbenzene by oxidation is provided, and the method includes:

[0014] In the presence of a catalyst and oxygen, an alkylbenzene is contacted with water to carry out a dehydrogenation reaction to prepare a vinylbenzene;

[0015] The catalyst includes the dehydrogenation catalyst described in the present invention.

[0016] By the above technical solution, compared with the prior art, the advantages of the present invention are as follows:

[0017] (1) The surface of the catalyst described in the present invention has abundant oxygen vacancies (the oxygen desorption amount in the O 2 -TPD test is greater than 8.2 mmol / g), and the migration ability of the active species on the catalyst surface will be significantly enhanced.

[0018] (2) By adjusting the preparation method of the present invention, a method of segmentally synthesizing different active components is combined with a solvothermal reduction reaction to introduce abundant oxygen vacancies into the catalyst.

[0019] (3) The dehydrogenation catalyst described in the present invention can be used for dehydrogenating an alkylaromatic hydrocarbon (such as ethylbenzene) to prepare a vinylaromatic hydrocarbon (such as styrene). Introducing oxygen into the reaction process of directly dehydrogenating an alkylaromatic hydrocarbon (such as ethylbenzene) can break the thermodynamic equilibrium limitation of the reaction and promote the positive shift of the chemical equilibrium towards the direction of dehydrogenating to prepare a vinylaromatic hydrocarbon (such as styrene), significantly increasing the conversion rate of the alkylaromatic hydrocarbon (such as ethylbenzene) in the reaction. The surface of the catalyst has abundant oxygen vacancies, and the migration ability of the active species on the catalyst surface will be significantly enhanced, which can significantly reduce the generation of carbon deposition, thereby improving the stability of the catalyst. Description of the Drawings

[0020] Figure 1 O 2 -TPD characterization test results of the catalysts obtained in Example 1 and Comparative Example 1 of the present invention. Detailed Embodiments

[0021] The endpoints and any values disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values and individual point values of each range, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0022] In the present invention, O 2- The TPD test was carried out using an AutoChem II 2920 temperature-programmed chemisorption instrument from Micromeritics. In each experiment, about 100 mg of the sample was loaded into a quartz tube and heated at a heating rate of 10 °C / min under a high-purity He atmosphere, and pretreated at 300 °C for 30 min. After pretreatment, after the sample temperature cooled to room temperature, 5% O 2 / He was introduced for adsorption for 1 h. After the adsorption was completed, He gas was introduced for purging for 30 min to remove physically weakly adsorbed O 2 . After the baseline became flat, the temperature was increased at a heating rate of 10 °C / min and the desorption curve was recorded.

[0023] In the first aspect of the present invention, a dehydrogenation catalyst is provided. Based on the total weight of the catalyst, the dehydrogenation catalyst includes: Fe 2 O 3 , K 2 O, CeO 2 , Co 3 O 4 , an oxide of a Group VIB metal element, MnO 2 and an oxide of a Group IVB metal element; the oxygen desorption amount of the dehydrogenation catalyst in the O 2 -TPD test is greater than 8.2 mmol / g. The surface of the catalyst of the present invention has abundant oxygen vacancies (the oxygen desorption amount in the O 2 -TPD test is greater than 8.2 mmol / g), and the migration ability of the active species on the catalyst surface will be significantly enhanced.

[0024] According to a preferred embodiment of the present invention, the content of Fe 2 O 3 is 56 wt% - 74 wt%.

[0025] According to a preferred embodiment of the present invention, the content of K 2 O is 5 wt% - 11 wt%.

[0026] According to a preferred embodiment of the present invention, the content of CeO 2 is 8 wt% - 13 wt%.

[0027] According to a preferred embodiment of the present invention, the content of the oxide of the Group VIB metal element is 4 wt% - 8.5 wt%.

[0028] According to a preferred embodiment of the present invention, the content of Co 3 O 4 is 3 wt% - 7.5 wt%.

[0029] According to a preferred embodiment of the present invention, the content of MnO 2The content is 2.1 wt% - 5.7 wt%.

[0030] According to a preferred embodiment of the present invention, the content of the Group IVB metal element oxide is 0.3 wt% - 1.5 wt%.

[0031] According to a preferred embodiment of the present invention, the Group VIB metal element oxide is WO 3 and / or MoO 3 , preferably WO 3 ;

[0032] According to a preferred embodiment of the present invention, the Group IVB metal element oxide is TiO 2 and / or ZrO 2 , preferably TiO 3 .

[0033] The second aspect of the present invention provides a preparation method of the dehydrogenation catalyst described in the present invention, and the method includes:

[0034] (1) Mix the Fe source, K source, Mn source, and Group IVB metal source, and then perform the first drying and the first calcination;

[0035] (2) Mix the Ce source, Co source, and Group VIB metal source, and then perform the second drying and the second calcination to obtain a calcined product. Mix the calcined product with a solution containing polyol and alkali, perform a solvothermal reduction reaction, then wash with alcohol, and dry in a vacuum or in an inert gas atmosphere;

[0036] (3) Mix the products obtained in steps (1) and (2) and form them;

[0037] The mass ratio of the calcined product, polyol, and alkali is 1:(35.8 - 44.2):(1.06 - 1.75).

[0038] Through the regulation of the preparation method, the present invention adopts a method of segmentally synthesizing different active components combined with a solvothermal reduction reaction to introduce abundant oxygen vacancies into the catalyst, so as to effectively increase the content of active oxygen species in the dehydrogenation reaction of ethylbenzene to styrene, accelerate the catalytic reaction on the catalyst surface, and improve the catalyst activity.

[0039] In the present invention, steps (1) and (2) are only used to distinguish the preparation of different component intermediates, and the order of steps (1) and (2) is not required.

[0040] According to a preferred embodiment of the present invention, in step (2), the mass ratio of the calcined product, polyol, and alkali is 1:(37.2 - 42.6):(1.18 - 1.65).

[0041] According to a preferred embodiment of the present invention, the conditions for the solvothermal reduction reaction include: the temperature is 140-180 °C; the reaction time can be reasonably adjusted according to actual needs. Preferably, the reaction time is 10-15 h.

[0042] According to a preferred embodiment of the present invention, the heating rate is 10-15 °C / min.

[0043] In the present invention, in step (2), the types of the polyols have a relatively wide selection range. According to a preferred embodiment of the present invention, the polyol is selected from C2-C5 polyols, preferably at least one of diethylene glycol, triethylene glycol, ethylene glycol and propylene glycol, and preferably diethylene glycol.

[0044] According to a preferred embodiment of the present invention, the base is selected from at least one of alkali metal hydroxides and ammonia water, such as at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and ammonia water, and preferably sodium hydroxide.

[0045] In the present invention, the types of the Fe source, K source, Ce source, Group VIB metal source, Mn source, Co source and Group IVB metal source have a relatively wide selection range. According to a preferred embodiment of the present invention, the Fe source, K source, Ce source, Group VIB metal source, Mn source, Co source and Group IVB metal source are each an oxide of each element and / or a salt of each element; taking the Fe source as an example, the Fe source is selected from one or more of Fe oxides and soluble salts of Fe.

[0046] According to a preferred embodiment of the present invention, the Fe source includes one or more of iron(III) oxide, iron(III) chloride, iron(III) acetate, iron(III) nitrate and iron(III) sulfate.

[0047] According to a preferred embodiment of the present invention, the K source includes one or more of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium chloride and potassium sulfate.

[0048] According to a preferred embodiment of the present invention, the Ce source includes one or more of cerium carbonate, cerium oxalate, cerium nitrate, cerium acetate, cerium chloride and cerium sulfate.

[0049] According to a preferred embodiment of the present invention, the Group IVB metal source is one or more of ammonium molybdate, ammonium metatungstate, phosphomolybdic acid, ammonium tungstate, ammonium metatungstate and phosphotungstic acid.

[0050] According to a preferred embodiment of the present invention, the Co source includes one or more of cobalt nitrate, cobalt acetate, cobalt chloride, cobalt sulfate and cobalt acetylacetonate.

[0051] According to a preferred embodiment of the present invention, the Mn source includes one or more of manganese dioxide, manganese chloride, manganese acetate, manganese nitrate and manganese sulfate.

[0052] According to a preferred embodiment of the present invention, the Group IVB metal source includes one or more of titanium dioxide, titanium tetrachloride, titanium sulfate, zirconium dioxide, zirconium tetrachloride, and zirconium sulfate.

[0053] In the present invention, there are no particular limitations on the conditions of the first drying and the second drying, as long as the moisture can be removed. According to a preferred embodiment of the present invention, the conditions of the first drying and the second drying include: oven drying, with a drying temperature of 60 - 80 °C and a drying time of 20 - 40 min.

[0054] In the present invention, there are no particular limitations on the vacuum drying conditions, as long as the moisture can be removed. Preferably, the drying conditions include: vacuum oven drying, with a drying temperature of 75 - 85 °C and a drying time of 9 - 12 h.

[0055] In step (3), there are no particular limitations on the shaping process, as long as the products obtained in step (1) and step (2) are mixed evenly.

[0056] For example, the products obtained in step (1) and step (2) can be stirred in a mixing container until evenly mixed and an appropriate amount of water is added, followed by extrusion, pelletizing, shaping, and then drying to obtain an integral structured finished catalyst.

[0057] In the present invention, there are no particular limitations on the shape of the finished catalyst, which can be adjusted according to actual needs.

[0058] The third aspect of the present invention provides an application of the dehydrogenation catalyst described in the present invention in the dehydrogenation of alkylaromatics to prepare alkenylaromatics by oxidation.

[0059] The dehydrogenation catalyst described in the present invention can be used for the dehydrogenation of alkylaromatics (such as ethylbenzene) to prepare alkenylaromatics (such as styrene) by oxidation. Introducing oxygen in the reaction process of the direct dehydrogenation of alkylaromatics (such as ethylbenzene) can break the thermodynamic equilibrium limitation of the reaction, promote the positive shift of the chemical equilibrium towards the direction of dehydrogenating to prepare alkenylaromatics (such as styrene), and significantly improve the conversion rate of alkylaromatics (such as ethylbenzene) in the reaction. The catalyst surface has abundant oxygen vacancies, and the migration ability of the active species on the catalyst surface will be significantly enhanced, which can significantly reduce the generation of carbon deposition, thereby improving the stability of the catalyst.

[0060] The fourth aspect of the present invention provides a method for the dehydrogenation of alkylbenzene by oxidation, which includes:

[0061] Contacting an alkylbenzene with water in the presence of a catalyst and oxygen to carry out a dehydrogenation reaction to prepare an alkenylbenzene;

[0062] The catalyst includes the dehydrogenation catalyst described in the present invention.

[0063] According to a preferred embodiment of the present invention, the molar ratio of alkylbenzene to oxygen is 4 - 6.5:1.

[0064] According to a preferred embodiment of the present invention, the water ratio is 0.5 - 1.0 (wt).

[0065] According to a preferred embodiment of the present invention, the space velocity of alkylbenzene is 0.2 - 2.0 h -1 .

[0066] According to a preferred embodiment of the present invention, the dehydrogenation reaction conditions include: the temperature is 550 - 650 °C, and the absolute pressure is 20 - 100 kPa.

[0067] According to a preferred embodiment of the present invention, the alkylbenzene is ethylbenzene.

[0068] In order to further understand the present invention, the preferred embodiments of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0069] In order to more clearly illustrate the present invention, the following examples are listed, but the applicable situations of the present invention are not limited to the scope of the examples.

[0070] In the following examples, the activity of the catalyst was evaluated in an isothermal fixed bed. The ethylbenzene-containing raw material was dehydrogenated by contacting with a dehydrogenation catalyst in the presence of steam and O 2 The process for the activity evaluation of the ethylbenzene dehydrogenation to styrene catalyst is briefly described as follows:

[0071] Deionized water, ethylbenzene, and O 2 were respectively input into a preheating mixer through metering pumps or flow meters, preheated and mixed into a gas state, and then entered the reactor. The reactor was heated by an electric heating wire to reach the set temperature. The molar ratio of ethylbenzene to O 2 was 5:1, and the dehydrogenation reaction water-oil ratio was 0.8. The reactor was a stainless steel tube filled with 100 mL of catalyst. The reactants flowing out of the reactor were condensed with water and analyzed for their composition by a gas chromatograph.

[0072] The conversion rate of ethylbenzene and the selectivity of styrene were calculated according to the following formulas:

[0073]

[0074]

[0075] Example 1

[0076] (1) Weigh an amount equivalent to 65 parts of Fe 2 O 3Iron(III) oxide equivalent to 8.5 parts of K 2 Potassium carbonate equivalent to 3.1 parts of MnO 2 Manganese nitrate equivalent to 0.7 parts of TiO 2 Titanium dioxide, stirred in a mixing container until evenly mixed, after drying, placed in a muffle furnace, calcined at 800 °C for 5 h to obtain Product 1.

[0077] (2) Weigh cerium nitrate equivalent to 11.2 parts of CeO 2 Cobalt acetate equivalent to 6 parts of Co 3 O 4 Ammonium tungstate equivalent to 5.5 parts of WO 3 Stir in a mixing container until evenly mixed, after drying, placed in a muffle furnace, calcined at 800 °C for 5 h. Then take 3 g of the calcined sample and immerse it in a solution containing 120.74 g of diethylene glycol and 4.32 g of sodium hydroxide, react at 140 °C for 12 h, wash repeatedly with absolute ethanol, and then place in a vacuum oven and dry at 80 °C overnight to obtain Product 2.

[0078] (3) Stir Product 1 and Product 2 in a mixing container for 2 h until evenly mixed and add an appropriate amount of water. Then extrude and pelletize to obtain particles with a diameter of 3 mm and a length of 5 mm, place in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain an integral structured finished catalyst.

[0079] The oxygen desorption amount of the catalyst in the O 2 -TPD test is 11.8 mmol / g.

[0080] Load 100 mL of the catalyst into the reactor, under the conditions of 40 kPa (absolute pressure), ethylbenzene space velocity of 1.0 h -1 , temperature of 620 °C, water ratio of 0.8 (wt), and molar ratio of ethylbenzene to O 2 of 5:1 for performance evaluation. After reacting for 100 h, the conversion rate of ethylbenzene can reach 82.5%, and the selectivity of styrene is 94.2%.

[0081] Example 2

[0082] Weigh iron(III) oxide equivalent to 65 parts of Fe 2 O 3 Potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 Titanium dioxide equivalent to 0.7 parts of TiO 2 Stir in a mixing container until evenly mixed, after drying, placed in a muffle furnace, calcined at 800 °C for 5 h to obtain Product 1.

[0083] Weigh cerium nitrate equivalent to 11.2 parts of CeO 2 and cobalt acetate equivalent to 6 parts of Co 3 O 4 and ammonium tungstate equivalent to 5.5 parts of WO 3 Stir them in a mixing container until evenly mixed. After drying, place them in a muffle furnace and calcine at 800 °C for 5 h. Then take 3 g of the calcined sample and immerse it in a solution containing 111.9 g of diethylene glycol and 4.32 g of sodium hydroxide, react at 140 °C for 12 h, wash it with absolute ethanol multiple times, and then place it in a vacuum oven and dry at 80 °C overnight to obtain Product 2.

[0084] Stir Product 1 and Product 2 in a mixing container for 2 h until evenly mixed and add an appropriate amount of water. Then perform extrusion and granulation to obtain particles with a diameter of 3 mm and a length of 5 mm. Place them in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0085] The oxygen desorption amount of the catalyst in the O 2 -TPD test is 10.4 mmol / g.

[0086] Load 100 mL of the catalyst into the reactor and evaluate its performance under the conditions of 40 kPa (absolute pressure), ethylbenzene space velocity of 1.0 h -1 , temperature of 620 °C, water ratio of 0.8 (wt), and molar ratio of ethylbenzene to O 2 of 5:1. After reacting for 100 h, the conversion rate of ethylbenzene can reach 81.6% and the selectivity of styrene is 93.7%.

[0087] Example 3

[0088] (1) Weigh iron oxide equivalent to 74 parts of Fe 2 O 3 and potassium carbonate equivalent to 6 parts of K 2 O, manganese nitrate equivalent to 2.5 parts of MnO 2 and titanium dioxide equivalent to 0.3 parts of TiO 2 Stir them in a mixing container until evenly mixed. After drying, place them in a muffle furnace and calcine at 800 °C for 5 h to obtain Product 1.

[0089] (2) Weigh cerium nitrate equivalent to 9 parts of CeO 2 and cobalt acetate equivalent to 4.2 parts of Co 3 O 4 and ammonium tungstate equivalent to 4 parts of WO 3Ammonium tungstate was stirred in a mixing container until evenly mixed. After drying, it was placed in a muffle furnace and calcined at 800 °C for 5 h. Then, 3 g of the calcined sample was immersed in a solution containing 111.6 g of propylene glycol and 4.95 g of sodium hydroxide, and reacted at 160 °C for 15 h. After being washed repeatedly with absolute ethanol, it was then placed in a vacuum oven and dried at 80 °C overnight to obtain Product 2.

[0090] (3) Product 1 and Product 2 were stirred in a mixing container for 2 h until evenly mixed and an appropriate amount of water was added. Subsequently, it was extruded and pelletized to obtain particles with a diameter of 3 mm and a length of 5 mm, which were placed in an oven and dried at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0091] The oxygen desorption amount of the catalyst in the O 2 -TPD test was 9.6 mmol / g.

[0092] 100 mL of the catalyst was loaded into a reactor, and under the conditions of 40 kPa (absolute pressure), an ethylbenzene space velocity of 1.0 h -1 , a temperature of 620 °C, a water ratio of 0.8 (wt), and a molar ratio of ethylbenzene to O 2 of 5:1, a performance evaluation was carried out. After reacting for 100 h, the conversion rate of ethylbenzene could reach 80.7%, and the selectivity of styrene was 93.3%.

[0093] Example 4

[0094] (1) Weigh iron(III) oxide equivalent to 56 parts of Fe 2 O 3 , potassium carbonate equivalent to 10.5 parts of K 2 O, manganese nitrate equivalent to 5 parts of MnO 2 , titanium dioxide equivalent to 1.5 parts of TiO 2 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h to obtain Product 1.

[0095] (2) Weigh cerium nitrate equivalent to 12 parts of CeO 2 , cobalt acetate equivalent to 8 parts of Co 3 O 4 , ammonium tungstate equivalent to 7 parts of WO 3 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h. Then, take 3 g of the calcined sample and immerse it in a solution containing 127.8 g of triethylene glycol and 3.54 g of sodium hydroxide, react at 180 °C for 10 h, wash it repeatedly with absolute ethanol, and then place it in a vacuum oven and dry at 80 °C overnight to obtain Product 2.

[0096] (3) Stir Product 1 and Product 2 in a mixing container for 2 h until they are evenly mixed, and add an appropriate amount of water. Then, perform extrusion and granulation to obtain particles with a diameter of 3 mm and a length of 5 mm. Place them in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0097] The amount of oxygen desorbed by the catalyst in the O 2 -TPD test is 9.7 mmol / g.

[0098] Load 100 mL of the catalyst into the reactor, and under the conditions of 40 kPa (absolute pressure), an ethylbenzene space velocity of 1.0 h -1 , a temperature of 620 °C, a water ratio of 0.8 (wt), and a molar ratio of ethylbenzene to O 2 of 5:1, conduct performance evaluation. After reacting for 100 h, the conversion rate of ethylbenzene can reach 80.9%, and the selectivity of styrene is 93.4%.

[0099] Example 5

[0100] (1) Weigh ferric oxide equivalent to 65 parts of Fe 2 O 3 , potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 , and titanium dioxide equivalent to 0.7 parts of TiO 2 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h to obtain Product 1.

[0101] (2) Weigh cerium nitrate equivalent to 11.2 parts of CeO 2 , cobalt acetate equivalent to 6 parts of Co 3 O 4 , and ammonium tungstate equivalent to 5.5 parts of WO 3 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h. Then, take 3 g of the calcined sample and immerse it in a solution containing 120.74 g of diethylene glycol and 3.54 g of sodium hydroxide, react at 140 °C for 12 h, wash it repeatedly with absolute ethanol, and then place it in a vacuum oven and dry at 80 °C overnight to obtain Product 2.

[0102] (3) Stir Product 1 and Product 2 in a mixing container for 2 h until they are evenly mixed, and add an appropriate amount of water. Then, perform extrusion and granulation to obtain particles with a diameter of 3 mm and a length of 5 mm. Place them in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0103] The catalyst in O 2- The oxygen desorption amount in the TPD test is 10.9 mmol / g.

[0104] Load 100 mL of the catalyst into the reactor. At 40 kPa (absolute pressure), the ethylbenzene space velocity is 1.0 h -1 , the temperature is 620 °C, the water ratio is 0.8 (wt), and the molar ratio of ethylbenzene to O 2 is 5:1 for performance evaluation. After reacting for 100 h, the conversion rate of ethylbenzene can reach 82.0%, and the selectivity of styrene is 93.9%.

[0105] Example 6

[0106] (1) Weigh ferric oxide equivalent to 65 parts of Fe 2 O 3 , potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 , titanium dioxide equivalent to 0.7 parts of TiO 2 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h to obtain Product 1.

[0107] (2) Weigh cerium nitrate equivalent to 11.2 parts of CeO 2 , cobalt acetate equivalent to 6 parts of Co 3 O 4 , ammonium tungstate equivalent to 5.5 parts of WO 3 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h. Then take 3 g of the calcined sample and immerse it in a solution containing 120.74 g of diethylene glycol and 3.18 g of sodium hydroxide. React at 140 °C for 12 h, wash it repeatedly with absolute ethanol, and then place it in a vacuum oven and dry at 80 °C overnight to obtain Product 2.

[0108] (3) Stir Product 1 and Product 2 in a mixing container for 2 h until evenly mixed and add an appropriate amount of water. Then perform extrusion and pelletizing to obtain particles with a diameter of 3 mm and a length of 5 mm. Place them in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0109] The oxygen desorption amount of the said catalyst in the O 2 -TPD test is 8.8 mmol / g.

[0110] Load 100 mL of the catalyst into the reactor. At 40 kPa (absolute pressure), the ethylbenzene space velocity is 1.0 h -1 , the temperature is 620 °C, the water ratio is 0.8 (wt), and the molar ratio of ethylbenzene to O 2Performance evaluation was carried out under the condition of a molar ratio of 5:1. After 100 h of reaction, the conversion rate of ethylbenzene could reach 80.1%, and the selectivity of styrene was 92.8%.

[0111] Example 7

[0112] (1) Weigh iron oxide equivalent to 65 parts of Fe 2 O 3 , potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 , titanium dioxide equivalent to 0.7 parts of TiO 2 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h to obtain Product 1.

[0113] (2) Weigh cerium nitrate equivalent to 11.2 parts of CeO 2 , cobalt acetate equivalent to 6 parts of Co 3 O 4 , ammonium tungstate equivalent to 5.5 parts of WO 3 . Stir in a mixing container until evenly mixed. After drying, place it in a muffle furnace and calcine at 800 °C for 5 h. Then take 3 g of the calcined sample and immerse it in a solution containing 107.4 g of diethylene glycol and 4.32 g of sodium hydroxide, react at 140 °C for 12 h, wash it with absolute ethanol multiple times, and then place it in a vacuum oven and dry at 80 °C overnight to obtain Product 2.

[0114] (3) Stir Product 1 and Product 2 in a mixing container for 2 h until evenly mixed and add an appropriate amount of water. Then extrude and cut into particles with a diameter of 3 mm and a length of 5 mm, place them in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0115] The oxygen desorption amount of the catalyst in the O 2 -TPD test is 8.6 mmol / g.

[0116] Load 100 mL of the catalyst into the reactor, and carry out performance evaluation under the conditions of 40 kPa (absolute pressure), an ethylbenzene space velocity of 1.0 h -1 , a temperature of 620 °C, a water ratio of 0.8 (wt), and a molar ratio of ethylbenzene to O 2 of 5:1. After 100 h of reaction, the conversion rate of ethylbenzene can reach 79.8%, and the selectivity of styrene is 92.7%.

[0117] Example 8

[0118] (1) Weigh iron equivalent to 66 parts of Fe 2 O 3Iron(III) oxide equivalent to 9.5 parts of K 2 Potassium carbonate equivalent to 4.1 parts of MnO 2 Manganese nitrate equivalent to 0.7 parts of TiO 2 Titanium dioxide, stirred in a mixing container until evenly mixed, dried, placed in a muffle furnace, calcined at 800 °C for 5 h to obtain Product 1.

[0119] (2) Weigh cerium nitrate equivalent to 10.2 parts of CeO 2 Cobalt acetate equivalent to 5 parts of Co 3 O 4 Ammonium tungstate equivalent to 4.5 parts of WO 3 , stirred in a mixing container until evenly mixed, dried, placed in a muffle furnace, calcined at 800 °C for 5 h. Then, 3 g of the calcined sample was immersed in a solution containing 120.74 g of diethylene glycol and 4.32 g of sodium hydroxide, reacted at 140 °C for 12 h, washed repeatedly with absolute ethanol, and then placed in a vacuum oven and dried at 80 °C overnight to obtain Product 2.

[0120] (3) Stir Product 1 and Product 2 in a mixing container for 2 h until evenly mixed and add an appropriate amount of water. Subsequently, extrusion molding and pelletizing were carried out to obtain particles with a diameter of 3 mm and a length of 5 mm, placed in an oven and dried at 80 °C for 4 h and at 120 °C for 10 h to obtain an integral regular finished catalyst.

[0121] The oxygen desorption amount of the catalyst in the O 2 -TPD test is 11.1 mmol / g.

[0122] Load 100 mL of the catalyst into the reactor, at 40 kPa (absolute pressure), ethylbenzene space velocity 1.0 h -1 , temperature 620 °C, water ratio 0.8 (wt), molar ratio of ethylbenzene and O 2 5:1 for performance evaluation. After reacting for 100 h, the ethylbenzene conversion rate can reach 82.1%, and the styrene selectivity is 94.0%.

[0123] Comparative Example 1

[0124] Weigh iron(III) oxide equivalent to 65 parts of Fe 2 O 3 Potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 Titanium dioxide equivalent to 0.7 parts of TiO 2 , stirred in a mixing container until evenly mixed, dried, placed in a muffle furnace, calcined at 800 °C for 5 h to obtain Product 1.

[0125] Weigh cerium nitrate equivalent to 11.2 parts of CeO 2 and cobalt acetate equivalent to 6 parts of Co 3 O 4 and ammonium tungstate equivalent to 5.5 parts of WO 3 Stir them in a mixing container until evenly mixed. After drying, place them in a muffle furnace and calcine at 800 °C for 5 h. Then, immerse 3 g of the calcined sample into a solution containing 88 mL of diethylene glycol and 4.32 g of sodium hydroxide, react at 140 °C for 12 h, wash with absolute ethanol multiple times, and then place it in a vacuum oven to dry overnight at 80 °C to obtain Product Two.

[0126] Stir Product One and Product Two in a mixing container for 2 h until evenly mixed and add an appropriate amount of water. Then, extrude and pelletize to obtain particles with a diameter of 3 mm and a length of 5 mm. Place them in an oven and dry at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0127] The oxygen desorption amount of the catalyst in the O 2 -TPD test is 6.5 mmol / g. Load 100 mL of the catalyst into a reactor and evaluate its performance under the conditions of 40 kPa (absolute pressure), ethylbenzene space velocity of 1.0 h -1 , temperature of 620 °C, water ratio of 0.8 (wt), and molar ratio of ethylbenzene to O 2 of 5:1. After reacting for 100 h, the conversion rate of ethylbenzene can reach 77.1% and the selectivity of styrene is 91.3%.

[0128] Comparative Example 2

[0129] Weigh iron(III) oxide equivalent to 65 parts of Fe 2 O 3 and potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 , titanium dioxide equivalent to 0.7 part of TiO 2 , cerium nitrate equivalent to 11.2 parts of CeO 2 , cobalt acetate equivalent to 6 parts of Co 3 O 4 and ammonium tungstate equivalent to 5.5 parts of WO 3 Stir them in a mixing container until evenly mixed. After drying, place them in a muffle furnace and calcine at 800 °C for 5 h.

[0130] Then, immerse 3 g of the calcined sample into a solution containing 120.74 g of diethylene glycol and 4.32 g of sodium hydroxide, react at 140 °C for 12 h, wash with absolute ethanol multiple times, and then place it in a vacuum oven to dry overnight at 80 °C.

[0131] The product dried in a vacuum oven was stirred in a mixing container for 2 h until evenly mixed, and an appropriate amount of water was added. Subsequently, it was extruded and pelletized to obtain pellets with a diameter of 3 mm and a length of 5 mm, which were placed in an oven and dried at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst.

[0132] The oxygen desorption amount of the catalyst in the O 2 -TPD test was 7.8 mmol / g.

[0133] 100 mL of the catalyst was loaded into a reactor, and at 40 kPa (absolute pressure), an ethylbenzene space velocity of 1.0 h -1 , a temperature of 620 °C, a water ratio of 0.8 (wt), and a molar ratio of ethylbenzene to O 2 of 5:1, the performance evaluation was carried out. After reacting for 100 h, the conversion rate of ethylbenzene could reach 78.2%, and the selectivity of styrene was 91.6%.

[0134] Comparative Example 3

[0135] Weighed iron(III) oxide equivalent to 65 parts of Fe 2 O 3 , potassium carbonate equivalent to 8.5 parts of K 2 O, manganese nitrate equivalent to 3.1 parts of MnO 2 , titanium dioxide equivalent to 0.7 parts of TiO 2 , and stirred in a mixing container until evenly mixed. After drying, it was placed in a muffle furnace and calcined at 800 °C for 5 h to obtain Product 1.

[0136] Weighed cerium nitrate equivalent to 11.2 parts of CeO 2 , cobalt acetate equivalent to 6 parts of Co 3 O 4 , ammonium tungstate equivalent to 5.5 parts of WO 3 , and stirred in a mixing container until evenly mixed. After drying, it was placed in a muffle furnace and calcined at 800 °C for 5 h. Then, 3 g of the calcined sample was immersed in water and reacted at 140 °C for 12 h, washed repeatedly with absolute ethanol, and then placed in a vacuum oven and dried overnight to obtain Product 2.

[0137] Product 1 and Product 2 were stirred in a mixing container for 2 h until evenly mixed, and an appropriate amount of water was added. Subsequently, it was extruded and pelletized to obtain pellets with a diameter of 3 mm and a length of 5 mm, which were placed in an oven and dried at 80 °C for 4 h and then at 120 °C for 10 h to obtain a monolithic regular finished catalyst. The oxygen desorption amount of the catalyst in the O 2 -TPD test was 5.1 mmol / g. 100 mL of the catalyst was loaded into a reactor, and at 40 kPa (absolute pressure), an ethylbenzene space velocity of 1.0 h -1, at a temperature of 620 °C, a water ratio of 0.8 (wt), and a molar ratio of ethylbenzene to O 2 Performance evaluation was carried out under the condition of 5:1. After 100 h of reaction, the conversion rate of ethylbenzene could reach 76.4%, and the selectivity of styrene was 90.5%.

[0138] 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 technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A dehydrogenation catalyst, characterized in that Based on the total weight of the catalyst, the dehydrogenation catalyst includes: Fe2O3, K2O, CeO2, Co3O4, VIB group metal element oxides, MnO2 and IVB group metal element oxides; the oxygen desorption amount of the dehydrogenation catalyst in the O2-TPD test is greater than 8.2 mmol / g.

2. The dehydrogenation catalyst according to claim 1, wherein Fe2O3 content of 56wt%-74wt%; and / or K2O content of 5wt%-11wt%; and / or CeO2 content is 8wt%-13wt%; and / or The content of oxide of VIB group metal element is 4wt%-8.5wt%; and / or Co3O4 content is 3wt%-7.5wt%; and / or MnO2 content is 2.1wt%-5.7wt%; and / or The content of oxide of IVB group metal elements is 0.3wt%-1.5wt%.

3. The dehydrogenation catalyst according to claim 1 or 2, wherein The VIB group metal element oxide is WO3 and / or MoO3, preferably WO3; The oxide of the Group IVB metal element is TiO2 and / or ZrO2, preferably TiO3.

4. The dehydrogenation catalyst according to any one of claims 1 to 3, characterized in that The method includes: (1) mixing an Fe source, a K source, a Mn source, and a Group IVB metal source, performing a first drying, and a first calcination; (2) After mixing the Ce source, the Co source, and the VIB group metal source, performing a second drying and a second calcination to obtain a calcined product, the calcined product is mixed with a solution containing a polyol and an alkali, subjected to a solvent thermal reduction reaction, then washed with alcohol, and dried in a vacuum or in an inert gas atmosphere; (3) mixing the products obtained in steps (1) and (2) and forming them; The mass ratio of the calcined product, the polyol and the alkali is 1:(35.8-44.2):(1.06-1.75).

5. The preparation method according to claim 4, wherein In step (2), the mass ratio of the calcined product to the polyol is 1:(37.2-42.6); and / or The mass ratio of the calcined product to the alkali is 1:(1.18-1.65); and / or The solvent thermal reduction reaction conditions include: a temperature of 140-180° C.; and / or a reaction time of 10-15 h; preferably, a heating rate of 10-15° C. / min.

6. The preparation method according to claim 4 or 5, wherein: In step (2), the polyol is selected from C2-C5 polyols, preferably at least one of diethylene glycol, triethylene glycol, ethylene glycol and propylene glycol, preferably diethylene glycol; The base is selected from at least one of alkali metal hydroxides and ammonia water, and is preferably sodium hydroxide.

7. The preparation method according to claim 4 or 5, wherein: The Fe source, K source, Ce source, VIB group metal source, Mn source, Co source, and IVB group metal source are each oxides and / or salts of the respective elements; Preferably, the Fe source includes one or more of ferric oxide, ferric chloride, ferric acetate, ferric nitrate, and ferric sulfate; and / or The K source includes one or more of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium chloride, and potassium sulfate; and / or The Ce source includes one or more of cerium carbonate, cerium oxalate, cerium nitrate, cerium acetate, cerium chloride, and cerium sulfate; and / or The IVB group metal source is one or more of ammonium molybdate, ammonium metamolybdate, phosphomolybdic acid, ammonium tungstate, ammonium metatungstate, and phosphotungstic acid; and / or The Co source includes one or more of cobalt nitrate, cobalt acetate, cobalt chloride, cobalt sulfate, and cobalt acetylacetonate; and / or The Mn source includes one or more of manganese dioxide, manganese chloride, manganese acetate, manganese nitrate, and manganese sulfate; and / or The Group IVB metal source includes one or more of titanium dioxide, titanium tetrachloride, titanium sulfate, zirconium dioxide, zirconium tetrachloride, and zirconium sulfate.

8. Use of the dehydrogenation catalyst according to any one of claims 1 to 3 in the preparation of alkenyl aromatics by dehydrogenation of alkyl aromatics.

9. A method for oxidative dehydrogenation of alkylbenzene, characterized in that: The method includes: In the presence of a catalyst and oxygen, alkylbenzene is contacted with water to carry out a dehydrogenation reaction to prepare alkenylbenzene; The catalyst comprises the dehydrogenation catalyst according to any one of claims 1 to 3.

10. The method according to claim 9, wherein: The molar ratio of alkylbenzene to oxygen is 4-6.5:1; and / or Water ratio 0.5-1.0 (wt); and / or The space velocity of alkylbenzene is 0.2-2.0h -1 ; and / or The dehydrogenation reaction conditions include: a temperature of 550-650°C and an absolute pressure of 20-100 kPa; Preferably, the alkylbenzene is ethylbenzene.

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