Ethylbenzene dehydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention discloses an ethylbenzene dehydrogenation catalyst as well as a preparation method and application thereof. The catalyst is prepared from Fe2O3, K2O, CeO2, WO3, Co3O4 and TiO2; the catalyst is characterized in that a peak appears at a position of 500-560 DEG C in an O2 temperature programmed desorption spectrum O2-TPD of the catalyst. The catalyst is used in a reaction for preparing styrene through ethylbenzene dehydrogenation, and has remarkably high catalytic activity and selectivity.

Description

Technical Field

[0001] This invention belongs to the field of ethylbenzene dehydrogenation catalysts, specifically relating to a catalyst for the dehydrogenation of ethylbenzene to styrene with a low water ratio, its preparation method, and its application. Background Technology

[0002] Styrene is a crucial raw material for the synthetic rubber and plastics industries, primarily used as a monomer in the production of materials such as expandable polystyrene, polystyrene, and ABS (acrylonitrile-butadiene-styrene). Due to its wide range of applications, styrene production capacity has grown rapidly. The main production methods for styrene are the ethylbenzene catalytic dehydrogenation process and the styrene-propylene oxide co-production process. The ethylbenzene catalytic dehydrogenation process, using ethylbenzene as a raw material, catalytically dehydrogenates styrene in the presence of steam, accounting for approximately 80% of styrene production capacity.

[0003] With the release of styrene production capacity and changes in supply and demand, the styrene production process urgently needs further improvement in economic efficiency. Current styrene production technology is developing towards larger-scale plants and more comprehensive energy utilization. The styrene production process consumes a large amount of superheated steam as a dehydrogenation medium, resulting in high energy consumption, large product condensation volume, high process equipment costs, and high production costs. Styrene plants urgently need to further reduce energy and material consumption, and develop highly active ethylbenzene dehydrogenation catalysts suitable for low water ratio conditions, thereby achieving energy conservation, consumption reduction, and lower production costs in styrene plants.

[0004] In the important petrochemical catalytic process of ethylbenzene dehydrogenation to styrene, the catalyst plays a crucial role in styrene production. Most existing ethylbenzene dehydrogenation catalysts are based on the Fe-K-Ce series, with Fe-K oxides as the main catalyst and Ce as the main promoter. They also contain structural stabilizers and electronic aids such as oxides of Mg, Mo, W, and Ca. CN101279269A discloses a catalyst with bismuth oxide and beryllium oxide added to an iron-potassium-cerium-tungsten-calcium catalytic system, which improves the stability and activity of the ethylbenzene dehydrogenation catalyst under low water ratio conditions. CN115957775A discloses a Fe-K-Ce-Mo-Ca catalyst, in which the exposed crystal surface area of ​​CeO2(100) accounts for more than 60% of the total exposed crystal surface area of ​​CeO2, improving the activity of the ethylbenzene dehydrogenation catalyst under low water ratio conditions. However, the existing catalysts still suffer from insufficient activity and selectivity under low water ratios in the ethylbenzene dehydrogenation reaction, leading to reduced economic benefits. Summary of the Invention

[0005] To address the problem of low catalyst activity under low water ratio conditions in existing ethylbenzene dehydrogenation technologies, this invention provides an ethylbenzene dehydrogenation catalyst, its preparation method, and its application. This catalyst, when used in the dehydrogenation of ethylbenzene to styrene, exhibits significantly higher catalytic activity and selectivity, particularly under low water ratio conditions.

[0006] The first aspect of this invention provides an ethylbenzene dehydrogenation catalyst. The catalyst comprises Fe2O3, K2O, CeO2, WO3, Co3O4, and TiO2; the O2-TPD spectrum of the catalyst, obtained through temperature-programmed dehydrogenation, shows a peak at 500–560 °C.

[0007] According to the present invention, the O2-TPD spectrum of the catalyst also shows a peak at 580-640℃.

[0008] According to the present invention, preferably, the O2-TPD spectrum of the catalyst has a peak intensity of 20% to 120% of the peak intensity at 580 to 640°C at 500 to 560°C, more preferably 50% to 100%.

[0009] According to the present invention, the total amount of O2 desorbed in the O2-TPD test of the catalyst is 4 to 10 mmol / g.

[0010] According to the present invention, the catalyst, based on the total mass of the catalyst and calculated as oxides, comprises:

[0011] (a) 60%–86% Fe2O3;

[0012] (b) 8%–14% K₂O;

[0013] (c) 4%–14% CeO2;

[0014] (d) 0.5%–5% WO3;

[0015] (e) 0.2%–5% Co3O4;

[0016] (f) 0.1% to 2% TiO2.

[0017] A second aspect of the present invention provides a method for preparing the above-mentioned ethylbenzene dehydrogenation catalyst. The method includes:

[0018] The Fe source, K source, Ce source, W source, Co source and Ti source, along with an optional pore-forming agent, are mixed, then shaped, calcined and pre-reduced to obtain the ethylbenzene dehydrogenation catalyst.

[0019] According to the present invention, drying can also be performed before calcination. The drying conditions are: temperature 10-90°C; time 0.5-10 hours.

[0020] According to the present invention, the calcination conditions are: calcination temperature of 700-1000℃; calcination time of 0.5-20h.

[0021] According to the present invention, an appropriate amount of water may be added as needed during the molding process. There is no particular limitation on the amount of water added; it is a conventional amount added in the art. Preferably, the amount of water added accounts for 10% to 30% of the total weight of the catalyst raw materials.

[0022] According to the present invention, the pre-reduction conditions are as follows: the pre-reduction temperature is 500–800°C; the pre-reduction time is 0.1–10 h. The pre-reduction atmosphere is a reducing gas atmosphere. Preferably, the reducing gas atmosphere is N2 and at least one selected from NH3 and H2. More preferably, in the reducing gas atmosphere, the volume fraction of at least one selected from NH3 and H2 in N2 is 0.1 vol%–10 vol%.

[0023] According to the present invention, the Fe source is selected from Fe oxides, preferably iron oxide red and / or iron oxide yellow. The K source is selected from potassium salts, preferably one or more of potassium carbonate, potassium nitrate, and potassium bicarbonate. The Ce source is selected from cerium salts, preferably one or more of cerium nitrate, cerium oxalate, and cerium carbonate. The W source is selected from tungsten salts and / or tungsten oxides, preferably one or more of ammonium tungstate and tungsten oxide. The Co source is selected from one or more of cobalt nitrate and cobalt oxide. The Ti source is selected from titanium salts and / or oxides, preferably TiO2. The pore-forming agent is selected from at least one of activated carbon, graphite, sodium carboxymethyl cellulose, and polystyrene microspheres; preferably, the amount of the pore-forming agent added is 0.01 wt% to 5 wt% of the mass of the metal source. The metal source is calculated as an oxide.

[0024] The third aspect of this invention provides the application of the above-mentioned ethylbenzene dehydrogenation catalyst in the preparation of styrene from ethylbenzene dehydrogenation.

[0025] According to the present invention, the application includes: a dehydrogenation reaction of an ethylbenzene-containing feedstock with the catalyst in the presence of water vapor to obtain a styrene-containing product.

[0026] According to the present invention, in the application described, the weight ratio of water to ethylbenzene is 0.8 to 2.0.

[0027] According to the present invention, preferably, the application is suitable for ethylbenzene dehydrogenation at a low water ratio, wherein the water ratio is 1.3 or less, preferably 0.85 to 1.2. The water ratio is the weight ratio of water to ethylbenzene.

[0028] According to the present invention, water is preheated into steam and fully mixed with the feed gas before entering the reactor.

[0029] According to the present invention, the temperature of the dehydrogenation reaction is 550–640°C. The pressure of the dehydrogenation reaction is an absolute pressure of 20–100 kPa. The mass hourly space velocity (HSV) of ethylbenzene is 0.2–2.0 h⁻¹. -1 .

[0030] Compared with the prior art, the present invention has significant advantages and outstanding effects, as follows:

[0031] 1. The inventors discovered that oxygen vacancies in the catalyst play a crucial role in the catalytic process of ethylbenzene dehydrogenation, significantly improving catalytic activity and selectivity, and increasing the styrene formation rate. This invention utilizes a combination of Fe, Ce, W, Co, and Ti in the catalyst, which is easily partially reduced in a specific reducing atmosphere, resulting in a change in the metal oxidation state and generating a high concentration of oxygen vacancies. Further research revealed that the characteristics of this component combination are highly favorable for ethylbenzene dehydrogenation under low water ratio conditions, exhibiting high catalytic activity and high styrene selectivity. Pre-reduction of the catalyst ensures sufficient oxygen vacancies during ethylbenzene dehydrogenation, significantly improving catalytic performance. Further research showed that pre-reduction promotes the full formation of oxygen vacancies in the catalyst, resulting in an O2 temperature-programmed desorption (O2-TPD) peak at 500–560 °C. The resulting catalyst exhibits high activity, particularly high activity under low water ratio conditions. For the Fe-K-Ce ethylbenzene dehydrogenation catalyst, the ethylbenzene dehydrogenation reaction itself produces H2, and the catalyst is partially reduced during the reaction. However, due to the oxidizing effect of water vapor under high-temperature reaction conditions, which can replenish oxygen vacancies generated during the reaction process, the pre-reduction effect of the catalyst cannot be controlled. The pre-reduction method adopted in this invention can promote the full formation of oxygen vacancies in the catalyst, resulting in an optimal range of oxygen vacancy concentrations before use. This leads to better catalytic activity of the catalyst compared to conventional preparation and application methods, which involve reduction during the reaction induction period. Therefore, the preparation method and catalyst components of this invention are mutually influential. The combination of catalyst components and preparation method produces important characteristics in the catalyst's O2-TPD spectrum, such as a peak intensity of 20% to 120% of the peak intensity at 580 to 640℃ compared to 500–560℃, and a total O2 desorption amount of 4–10 mmol / g in the O2-TPD test, significantly improving the catalyst's low water ratio performance.

[0032] 2. The catalyst of this invention has a simple preparation process and is used in the dehydrogenation reaction of ethylbenzene to styrene. It exhibits high activity, high selectivity and high stability at low to high water ratios, especially at low water ratios, and has achieved good technical results.

[0033] Using the technical solution of this invention, the catalyst of this invention was evaluated for activity in a negative pressure isothermal fixed bed at 50 kPa (absolute pressure) and ethylbenzene mass hourly space velocity (MHSV) of 1.0 h⁻¹.-1 The conversion rate reached over 79% under the conditions of 620℃ and a water ratio reduced from the usual 2.0 (by weight) to 1.0 (by weight). This demonstrates that the catalyst of this invention exhibits high activity, especially under low water ratio conditions, in the dehydrogenation reaction of ethylbenzene to styrene, achieving good technical results. Attached Figure Description

[0034] Figure 1 The image shows the O2-TPR diagrams of the catalysts in Example 1 and Comparative Example 1. Detailed Implementation

[0035] The present invention will be further illustrated by the following embodiments, but the scope of protection of the present invention is not limited by the embodiments.

[0036] In this invention, the O2-TPD test was performed using an AutoChem II 2920 temperature-programmed chemisorption analyzer from Micromeritics. For each experiment, approximately 100 mg of sample was packed into a quartz tube, and the sample was heated at a rate of 10 °C / min under a high-purity He atmosphere, followed by pretreatment at 300 °C for 30 min. After pretreatment, the sample was allowed to cool to room temperature, and then 5 vol% O2 / He was introduced for adsorption for 1 h. After adsorption was complete, He gas was purged for 30 min to remove physically weakly adsorbed O2. Once the baseline flattened, the temperature was increased at a rate of 10 °C / min, and the desorption curve was recorded.

[0037] In this invention, the performance of the catalyst for the ethylbenzene dehydrogenation reaction is evaluated in an isothermal fixed bed. The process is briefly described below:

[0038] The reactor is a 1-inch inner diameter stainless steel tube filled with 50–150 ml of catalyst with a diameter of 3–10 mm. Deionized water and ethylbenzene are separately metered into a preheating mixer, preheated and mixed into a gaseous state before entering the reactor, which is heated by an electric heating wire to reach a predetermined temperature. The reactants flowing out of the reactor are condensed in water and their composition is analyzed by gas chromatography.

[0039] Ethylbenzene conversion and styrene selectivity are calculated using the following formulas:

[0040]

[0041]

Example 1

[0042] By weight, the following amounts were weighed: 70.0 parts of iron oxide red (Fe₂O₃), 12.5 parts of potassium carbonate (K₂O), 10.3 parts of cerium carbonate (CeO₂), 2.8 parts of ammonium tungstate (WO₃), 3.6 parts of cobalt nitrate (Co₃O₄), 0.8 parts of TiO₂, and 2.0 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% (by weight) of deionized water was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 850°C for 4 hours. Finally, they were pre-reduced in N₂ containing 1.0 vol% NH₃ at 650°C for 1 hour to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0043] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0044]

Example 2

[0045] By weight, the following amounts were weighed: 62.0 parts of iron oxide red (Fe₂O₃), 13.5 parts of potassium carbonate (K₂O), 13.8 parts of cerium carbonate (CeO₂), 4.5 parts of ammonium tungstate (WO₃), 4.6 parts of cobalt nitrate (Co₃O₄), 1.6 parts of TiO₂, and 0.2 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% (by weight) of deionized water was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 850°C for 4 hours. Finally, they were pre-reduced in N₂ containing 1.0 vol% NH₃ at 650°C for 1 hour to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0046] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0047]

Example 3

[0048] By weight, the following amounts were weighed: 82.1 parts of iron oxide red (Fe₂O₃), 8.6 parts of potassium carbonate (K₂O), 6.2 parts of cerium carbonate (CeO₂), 1.2 parts of ammonium tungstate (WO₃), 1.3 parts of cobalt nitrate (Co₃O₄), 0.6 parts of TiO₂, and 4.0 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% (by weight) of deionized water was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 700°C for 15 hours. Finally, they were pre-reduced in N₂ containing 10 vol% NH₃ at 650°C for 9 hours to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0049] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0050]

Example 4

[0051] By weight, the following amounts were weighed: 70.0 parts of iron oxide red (Fe₂O₃), 12.5 parts of potassium carbonate (K₂O), 10.3 parts of cerium carbonate (CeO₂), 2.8 parts of ammonium tungstate (WO₃), 3.6 parts of cobalt nitrate (Co₃O₄), 0.8 parts of TiO₂, and 2.0 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% (by weight) of deionized water was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 850°C for 4 hours. Finally, they were pre-reduced in N₂ containing 0.5 vol% NH₃ at 700°C for 4 hours to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0052] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0053]

Example 5

[0054] By weight, the following amounts were weighed: 70.0 parts of iron oxide red (Fe₂O₃), 12.5 parts of potassium carbonate (K₂O), 10.3 parts of cerium carbonate (CeO₂), 2.8 parts of ammonium tungstate (WO₃), 3.6 parts of cobalt nitrate (Co₃O₄), 0.8 parts of TiO₂, and 2.0 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% (by weight) of deionized water was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 850°C for 4 hours. Finally, they were pre-reduced in N₂ containing 3.0 vol% NH₃ at 600°C for 0.5 hours to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0055] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0056]

Example 6

[0057] By weight, 70.0 parts of iron oxide yellow (Fe2O3), 12.5 parts of potassium bicarbonate (K2O), 10.3 parts of cerium oxalate (CeO2), 2.8 parts of WO3, 3.6 parts of Co3O4, 0.8 parts of TiO2, and 2.0 parts of graphite were weighed and added to a mixer and stirred for 2 hours until homogeneous. Then, 20% of the total weight of the catalyst raw materials (deionized water) was added and mixed for 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 850°C for 4 hours. Finally, they were pre-reduced in N2 containing 1.0 vol% H2 at 650°C for 1 hour to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O2-TPD test results are listed in Tables 1 and 2.

[0058] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0059] Comparative Example 1

[0060] By weight, the following amounts were weighed: 70.0 parts of iron oxide red (Fe₂O₃), 12.5 parts of potassium carbonate (K₂O), 10.3 parts of cerium carbonate (CeO₂), 2.8 parts of ammonium tungstate (WO₃), 3.6 parts of cobalt nitrate (Co₃O₄), 0.8 parts of TiO₂, and 2.0 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% of the total weight of the catalyst raw materials (deionized water) was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours and then calcined in a muffle furnace at 850°C for 4 hours to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0061] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0062] Comparative Example 2

[0063] By weight, the following amounts were weighed: 75.2 parts of iron oxide red (Fe₂O₃), 12.5 parts of potassium carbonate (K₂O), 10.3 parts of cerium carbonate (CeO₂), 0.8 parts of ammonium molybdate (MoO₃), 0.6 parts of cobalt nitrate (Co₃O₄), 0.6 parts of TiO₂, and 2.0 parts of sodium carboxymethyl cellulose. These were added to a mixer and stirred for 2 hours until homogeneous. Then, 20% (by weight) of deionized water was added and mixed for another 2 hours. The mixture was then extruded and granulated to obtain particles with a diameter of 3 mm and a length of 6 mm. These particles were dried at 80°C for 5 hours, then calcined in a muffle furnace at 850°C for 4 hours. Finally, they were pre-reduced in N₂ containing 1.0 vol% NH₃ at 650°C for 1 hour to obtain the ethylbenzene dehydrogenation catalyst. The catalyst composition and O₂-TPD test results are listed in Tables 1 and 2.

[0064] 100 mL of catalyst was loaded into the reactor and incubated at 50 kPa (absolute pressure) and a mass hourly space velocity (WHSV) of 1.0 h⁻¹ for ethylbenzene. -1 The performance was evaluated at a temperature of 620℃ and a water ratio of 1.0 (wt). The test results after 100 h of reaction are listed in Table 2.

[0065] Table 1 Catalyst composition of the examples and comparative examples

[0066]

[0067] Table 2. Catalyst properties and evaluation results for the examples and comparative examples.

[0068]

[0069]

[0070] Note: *Ethylbenzene conversion and styrene selectivity after 100 h of reaction at a water ratio of 1.0.

[0071] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An ethylbenzene dehydrogenation catalyst, characterized in that, The catalyst includes Fe2O3, K2O, CeO2, WO3, Co3O4, and TiO2; the O2 temperature-programmed desorption spectroscopy (TPD) of the catalyst shows a peak at 500–560 °C.

2. The catalyst according to claim 1, characterized in that, The O2-TPD spectrum of the catalyst also shows peaks at 580–640 °C.

3. The catalyst according to claim 2, characterized in that, The O2-TPD spectrum of the catalyst has a peak intensity of 20% to 120% of the peak intensity at 580 to 640°C at 500 to 560°C, preferably 50% to 100%. And / or, the total O2 desorption in the O2-TPD test of the catalyst is 4 to 10 mmol / g.

4. The catalyst according to claim 1, characterized in that, Based on the total mass of the catalyst, and calculated as oxides, the catalyst comprises: (a) 60%–86% Fe2O3; (b) 8%–14% K₂O; (c) 4%–14% CeO2; (d) 0.5%–5% WO3; (e) 0.2%–5% Co3O4; (f) 0.1% to 2% TiO2.

5. A method for preparing the catalyst according to any one of claims 1 to 4, comprising: The Fe source, K source, Ce source, W source, Co source and Ti source, as well as an optional pore-forming agent, are mixed, then shaped, calcined and pre-reduced to obtain the ethylbenzene dehydrogenation catalyst.

6. The method according to claim 5, characterized in that, The calcination conditions are as follows: calcination temperature is 700–1000℃; calcination time is 0.5–20h.

7. The method according to claim 5, characterized in that, The pre-reduction conditions are: the pre-reduction temperature is 500-800℃; the pre-reduction time is 0.1-10h.

8. The method according to claim 5, characterized in that, The Fe source is selected from Fe oxides, preferably iron oxide red and / or iron oxide yellow; And / or, the K source is selected from potassium salts, preferably one or more of potassium carbonate, potassium nitrate, and potassium bicarbonate; And / or, the Ce source is selected from cerium salts, preferably one or more of cerium nitrate, cerium oxalate, and cerium carbonate; And / or, the W source is selected from tungsten salts and / or tungsten oxides, preferably one or more of ammonium tungstate and tungsten oxide; And / or, the Co source is selected from one or more of cobalt nitrate and cobalt oxide; And / or, the Ti source is selected from titanium salts and / or oxides, preferably TiO2; And / or, the pore-forming agent is selected from at least one of activated carbon, graphite, sodium carboxymethyl cellulose and polystyrene microspheres; preferably, the amount of the pore-forming agent added is 0.01 wt% to 5 wt% of the metal source mass; wherein the metal source is calculated as an oxide.

9. The use of the catalyst according to any one of claims 1 to 4 or the catalyst prepared by any one of claims 5 to 8 in the dehydrogenation of ethylbenzene to styrene.

10. The application according to claim 9, characterized in that, The dehydrogenation reaction is carried out at a temperature of 550–640 °C; and / or at an absolute pressure of 20–100 kPa; and / or at a mass hourly space velocity (HSV) of ethylbenzene of 0.2–2.0 h⁻¹. -1 ; And / or, in the aforementioned applications, the weight ratio of water to ethylbenzene is 0.8 to 2.0; Preferably, the application is suitable for ethylbenzene dehydrogenation at low water ratios, with a water ratio of 1.3 or less, preferably 0.85 to 1.2; wherein the water ratio is the weight ratio of water to ethylbenzene.

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