CN115090280A - Supported cluster molybdenum oxide catalyst, preparation method thereof and application thereof in propane dehydrogenation - Google Patents
Supported cluster molybdenum oxide catalyst, preparation method thereof and application thereof in propane dehydrogenation Download PDFInfo
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- 238000011161 development Methods 0.000 description 4
- 230000018109 developmental process Effects 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
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- RIOQSEWOXXDEQQ-UHFFFAOYSA-N triphenylphosphine Chemical compound C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 RIOQSEWOXXDEQQ-UHFFFAOYSA-N 0.000 description 2
- 239000002841 Lewis acid Substances 0.000 description 1
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/24—Chromium, molybdenum or tungsten
- B01J23/28—Molybdenum
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
- B01J35/391—Physical properties of the active metal ingredient
- B01J35/393—Metal or metal oxide crystallite size
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
- B01J37/086—Decomposition of an organometallic compound, a metal complex or a metal salt of a carboxylic acid
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
- C07C5/32—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
- C07C5/327—Formation of non-aromatic carbon-to-carbon double bonds only
- C07C5/333—Catalytic processes
- C07C5/3332—Catalytic processes with metal oxides or metal sulfides
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Abstract
The invention discloses a supported cluster molybdenum oxide catalyst, the chemical formula of which is X-MoO x ZT, wherein MoO x Is an active component, ZT is a carrier, X is expressed as the theoretical loading capacity of the active component, wherein the theoretical loading capacity of the active component is 1-15%, and the active component MoO x Has an average particle diameter of 0.8 to 1.5 nm. The invention also discloses a preparation method of the supported cluster molybdenum oxide catalyst and application of the supported cluster molybdenum oxide catalyst in propane dehydrogenation. The invention can effectively avoid the growth and agglomeration of active component particles in the heat treatment and reaction processes of the catalyst; the loading amount of the active component is adjustable within the range of 1-15 percent, and the size of the active component nano-particles can be controlled within 0.8-Within 1.5 nm; the catalyst shows excellent dehydrogenation activity, olefin selectivity and catalyst regeneration stability in the propane dehydrogenation reaction, and the initial conversion rate of the catalyst is reduced by only 0.8 percent after the cluster molybdenum oxide catalyst is repeatedly reacted and regenerated for 4 times.
Description
Technical Field
The invention relates to the field of catalysts and preparation thereof, in particular to a supported cluster molybdenum oxide catalyst, a preparation method thereof and application thereof in propane dehydrogenation.
Background
Propylene is an extremely important basic chemical in the chemical industry and is one of the basic raw materials for the production of plastics, rubbers and fibers. The demand of the rapid development of economy in China on propylene is increased year by year. In recent years, the direct dehydrogenation of propane to produce olefin is distinguished from a plurality of propylene production processes and becomes an important channel for increasing the yield of propylene in China by virtue of the strong downstream demand of propylene and the wide application of natural gas and shale gas in the world. Propane dehydrogenation is a thermodynamically controlled, strongly endothermic reaction, with reaction temperatures typically between 550 ℃ and 620 ℃. In the prior art, although the Cr oxide catalyst used in industry can obtain higher propylene yield, Cr element has great pollution to the environment, and the application prospect is greatly limited. Therefore, the development of an environmentally friendly oxide catalyst with both high selectivity and stability under the condition of appreciable propane conversion rate is an important direction for the development of industrial catalysts for propane dehydrogenation. Among them, the supported Mo-based oxide catalyst has a potential industrial application value due to its advantages of stable structure, difficult reduction, low cost, environmental protection, etc., and is widely studied.
The unsaturated coordinated Mo-O bonds in the molybdenum oxide species are generally believed to act as Lewis acid sites to activate the C-H bonds in the propane molecule. Therefore, the preparation of the small-size molybdenum oxide can fully expose the reactive active sites and improve the atom economy, and is an important means for improving the performance of the supported molybdenum oxide catalyst. The active component nano-particles of the supported catalyst prepared by the existing impregnation method are large, and are easy to aggregate and grow under the reaction condition to cause the catalyst deactivation. Thus, the controlled preparation of supported cluster molybdenum oxide catalysts is a major challenge currently encountered. In recent years, methods for producing supported cluster catalysts have been reported. Article (Chinese character)The Chang Zhipeng, Song Zhen, Liu gan, Rodriguez Jos A, Hrbek Jan, Surface Science,2002,512,353 use Au (111) as substrate and Mo (CO) under ultra-high vacuum condition 6 The supported molybdenum oxide cluster catalyst is prepared by an atomic layer deposition method as a precursor, and the size of molybdenum oxide can be regulated and controlled by changing the deposition condition and coverage. The Au is prepared by liquid phase synthesis in a system with surfactant in the presence of a stabilizer triphenyl phosphine in the documents of Zhang Haifeng, Stender Matthias, Zhang Rui, Wang Chongmin, Li Jun, Wang Laisheng, J.Phys.chem.B. 2004,108,12259 20 And (4) clustering. Both the vapor phase chemical deposition technology and the liquid phase synthesis technology have the problems of complicated preparation method, high cost, poor material structure stability, difficulty in realizing large-scale preparation of the solid catalyst and the like. Therefore, the development of a synthetic method of the supported cluster catalyst which can be simply prepared in a large scale is a hotspot and difficulty of research in the field of catalyst materials.
In conclusion, the supported cluster molybdenum oxide catalyst has higher research value in the propane dehydrogenation reaction due to the unique structural characteristics and excellent catalytic properties, but the structural preparation methods reported in the existing documents have the defects of complex reaction conditions, difficulty in operation, high preparation cost, poor material practicability, incapability of large-scale preparation and the like. Therefore, the controllable preparation of the supported molybdenum oxide cluster catalyst and the research on the application of the catalyst in the important petrochemical process need to be further developed.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a supported cluster molybdenum oxide catalyst, the loading amount of an active component is adjustable within the range of 1-15%, and the average particle size of active component nanoparticles is less than 1.5 nm.
The second purpose of the invention is to provide a preparation method of the supported cluster molybdenum oxide catalyst.
The third purpose of the invention is to provide the application of the supported cluster molybdenum oxide catalyst in propane dehydrogenation.
To achieve the above object, the present invention adopts a technique for solving the above problemsThe technical scheme is as follows: a supported cluster molybdenum oxide catalyst has a chemical formula of X-MoO x ZT, wherein MoO x Is an active component, ZT is a carrier, X is expressed as the theoretical loading capacity of the active component, wherein the theoretical loading capacity of the active component is 1-15%, and the active component MoO x Has an average particle diameter of 0.8 to 1.5 nm.
The preparation method of the supported cluster molybdenum oxide catalyst comprises the following steps:
(1) dissolving Mo salt and a complexing agent in water to prepare a mixed salt solution; wherein the concentration of Mo ions in the mixed salt solution is 1-200 mmol/L; the mol ratio of the complexing agent to Mo ions is 5-20: 1;
(2) transferring the mixed salt solution into a reaction kettle, sealing, heating to 140-200 ℃ for reaction for 3-8h, dropwise adding the reacted solution into carrier precursor sol, and drying the slurry at 60-120 ℃ to obtain X-MoO x a/ZT catalyst precursor;
(3) mixing X-MoO x The ZT catalyst precursor is placed in a muffle furnace to be roasted for 1-10h at the temperature of 400-plus-one-900 ℃, the roasted solid powder is placed in a tube furnace to be reduced for 2-8h at the temperature of 500-plus-one-1000 ℃, and the X-MoO is prepared x a/ZT catalyst.
The Mo salt may be ammonium molybdate.
The complexing agent is one or the combination of two of acetonitrile, glucose, ethylenediamine, citric acid, isopropylamine or ascorbic acid.
The carrier precursor sol is one of silica sol and aluminum sol, and the solid content is 5-20%.
In the step (2), the solution is kept in a stirring state in the process of being dropwise added to the carrier precursor sol so as to ensure uniform mixing, preferably by magnetic stirring, and the stirring speed range is 300-.
In the step (3), the temperature rise range of the roasting is 10 ℃/min.
In the step (3), mixed gas is introduced into the tube furnace to form an atmosphere with hydrogen, the mixed gas consists of hydrogen and argon, and the volume fraction of the hydrogen is 10% H 2 /Ar。
The invention has the beneficial effects that: metal ion complexing coordination assembly is adopted to uniformly inlay molybdenum ions in a supermolecule network framework generated by organic micromolecule coordination, and then a carrier is adopted to encapsulate and synthesize the supported cluster molybdenum oxide catalyst, so that the method can effectively avoid the growth and agglomeration of active component particles in the catalyst heat treatment and reaction processes; the loading capacity of the active component is adjustable within the range of 1-15%, and the size of the active component nano-particles can be controlled within the range of 0.8-1.5 nm; the regulation and control of the size of the molybdenum oxide particles can be realized by fine adjustment of the proportion of the small complexing molecules to the metal ions; the obtained supported molybdenum oxide cluster catalyst shows excellent dehydrogenation activity, olefin selectivity and catalyst regeneration stability in the propane dehydrogenation reaction, and the initial conversion rate of the catalyst is reduced by only 0.8% after the cluster molybdenum oxide catalyst is repeatedly reacted and regenerated for 4 times; the preparation method has strong universality and is green and environment-friendly, and the performance of the catalyst is greatly improved by regulating and controlling the size of the active component on the basis of not changing the composition of the catalyst.
Drawings
FIG. 1 shows 5-MoO in example 1 x /Al 2 O 3 XRD spectrum of (1);
FIG. 2 shows 5-MoO in example 1 x /Al 2 O 3 HRTEM of (g);
FIG. 3 shows 2-MoO in example 2 x /SiO 2 A TEM photograph of;
FIG. 4 shows 10-MoO in example 3 x /Al 2 O 3 The electron microscope photograph of (1);
FIG. 5 shows 2-MoO in example 2 x /SiO 2 The time-dependent change curve of the conversion rate and the selectivity of the catalyst in the reaction of preparing propylene by propane dehydrogenation;
FIG. 6 shows 10-MoO in the preparation of example 3 x /Al 2 O 3 The regeneration data of the catalyst in the reaction of propane dehydrogenation to propylene.
Detailed Description
The present invention is further illustrated by the following specific examples, which should not be construed as limiting the scope of the invention as claimed.
Example 1
A preparation method of a supported cluster molybdenum oxide catalyst comprises the following steps: adding 1.0g of ammonium molybdate and 10g of glucose into 100mL of deionized water, and stirring until the ammonium molybdate and the glucose are completely dissolved to obtain a mixed salt solution; transferring the mixed salt solution into a 150mL hydrothermal reaction kettle, sealing, and placing in an oven for reaction at 160 ℃ for 5 h; after the hydrothermal reaction kettle is cooled, taking out the hydrothermal reaction kettle, dropwise adding the solution into a beaker containing 100g of aluminum sol, wherein the solid content of the aluminum sol is 10%, and continuously stirring the solution during the period to ensure that the reaction solution and the aluminum sol are uniformly mixed; pouring the slurry into a watch glass after the dropwise addition is finished, transferring the slurry into a drying oven with the temperature of 100 ℃, and dehydrating and drying to obtain the X-MoO x a/ZT catalyst precursor; then drying the solid X-MoO x Placing the ZT catalyst precursor in a crucible, placing in a muffle furnace, roasting, heating to 700 ℃ at a heating range of 10 ℃/min, and keeping the temperature for 3 h; the calcined sample was then transferred to a tube furnace and 10% H was passed 2 Heating the mixed gas/Ar at the flow rate of 50mL/min to 600 ℃, and preserving the heat for 3 h; after the temperature of the tube furnace is reduced, 5-MoO with 5 percent of load capacity is prepared x /Al 2 O 3 A catalyst.
5-MoO obtained in this example x /Al 2 O 3 The carrier of the catalyst is Al 2 O 3 Active ingredient MoO x The loading amount is 5 percent, and the average grain diameter of the active component is less than 1.5 nm. As shown in fig. 1, it can be seen that the carrier is mainly gamma-crystalline after roasting reduction, no peak of active component is observed, which indicates that Mo species is highly dispersed on the alumina carrier, and no large particles exist. As shown in FIG. 2, the MoO as the active component can be found by taking out the lattice fringes in the HRTEM photograph 2 The species is dispersed on an alumina support.
Example 2
A preparation method of a supported cluster molybdenum oxide catalyst comprises the following steps: adding 0.4g of ammonium molybdate, 1.6g of citric acid and 1.2g of isopropylamine into 100mL of deionized water, and stirring until the ammonium molybdate, the citric acid and the isopropylamine are completely dissolved to obtain a mixed salt solution; transferring the mixed salt solution into a 150mL hydrothermal reaction kettle, sealing, and placing in an oven to react for 3h at the temperature of 180 ℃; cooling the hydrothermal reaction kettle, taking out the solution, and dropwise adding the solution to the solution containing 5In a beaker containing 0g of silica sol, the solid content of the aluminum sol is 20%, and the reaction solution and the silica sol are uniformly mixed by continuously stirring in the beaker; pouring the slurry into a watch glass after the dropwise addition is finished, transferring the slurry into a drying oven with the temperature of 90 ℃, and dehydrating and drying to obtain the X-MoO x a/ZT catalyst precursor; then drying the solid X-MoO x Placing the ZT catalyst precursor in a crucible, placing in a muffle furnace, roasting, heating to 600 deg.C at a temperature rise rate of 10 deg.C/min, and keeping the temperature for 5 h; the calcined sample was then transferred to a tube furnace and 10% H was passed 2 Heating the mixed gas/Ar at the flow rate of 50mL/min to 700 ℃, and preserving the heat for 4 hours; after the temperature of the tube furnace is reduced, 2-MoO with 2 percent of load capacity is prepared x /SiO 2 A catalyst.
2-MoO obtained in this example x /SiO 2 The carrier of the catalyst is SiO 2 Active ingredient MoO x The loading amount is 2%, as shown in fig. 3, it can be seen that the active component nanoparticles in the catalyst are uniformly dispersed on the silica carrier, the particle size distribution is narrow, and the average particle size is 1.1 nm.
Example 3
A preparation method of a supported cluster molybdenum oxide catalyst comprises the following steps: adding 2.0g of ammonium molybdate, 2.0g of ascorbic acid and 0.5g of acetonitrile into 100mL of deionized water, and stirring until the ammonium molybdate, the ascorbic acid and the acetonitrile are completely dissolved to obtain a mixed salt solution; transferring the mixed salt solution into a 150mL hydrothermal reaction kettle, sealing, and placing in an oven for reaction at 160 ℃ for 3 h; after the hydrothermal reaction kettle is cooled, taking out the solution, dropwise adding the solution into a beaker containing 200g of aluminum sol, wherein the solid content of the aluminum sol is 5%, and continuously stirring the solution during the period to ensure that the reaction solution and the aluminum sol are uniformly mixed; pouring the slurry into a watch glass after the dropwise addition is finished, transferring the slurry into an oven with the temperature of 95 ℃, dehydrating and drying to obtain the X-MoO x a/ZT catalyst precursor; then drying the solid X-MoO x Placing the ZT catalyst precursor in a crucible, placing in a muffle furnace, roasting, heating to 500 ℃ at a heating range of 10 ℃/min, and keeping the temperature for 8 hours; the calcined sample was then transferred to a tube furnace and 10% H was passed 2 Heating the mixed gas/Ar at the flow rate of 50mL/min to 600 ℃, and preserving the heat for 5 hours; after the temperature of the tube furnace is reduced, 10-MoO with 10 percent of load capacity is prepared x /Al 2 O 3 A catalyst.
10-MoO obtained in this example x /Al 2 O 3 The carrier of the catalyst is Al 2 O 3 Active ingredient MoO x The loading amount was 10%, as shown in fig. 4, it can be seen that even though the loading amount of the active component was increased, the agglomeration and particle enlargement of the active component did not occur, and the average particle diameter of the active component nanoparticles was 1.4 nm.
The composition analysis of the supported molybdenum oxide cluster catalysts prepared in examples 1 to 3 above, from the ICP-AES analysis results, are shown in the following table:
| sample (I) | 5-MoO x /Al 2 O 3 | 2-MoO x /SiO 2 | 10-MoO x /Al 2 O 3 |
| Theoretical load (%) | 5.0 | 2.0 | 10.0 |
| Actual load amount (%) | 4.9 | 2.0 | 9.8 |
It can be seen that the actual Mo loading and the theoretical loading of the catalyst are essentially the same, and that no active component is lost during the catalyst preparation process.
Example 4
A preparation method of a supported cluster molybdenum oxide catalyst comprises the following steps: adding 0.2g of ammonium molybdate, 1.0g of citric acid and 0.8g of ethylenediamine into 100mL of deionized water, and stirring until the ammonium molybdate, the citric acid and the ethylenediamine are completely dissolved to obtain a mixed salt solution; transferring the mixed salt solution into a 150mL hydrothermal reaction kettle, sealing, and placing in an oven for reaction at 160 ℃ for 6 h; and (3) taking out the solution after the hydrothermal reaction kettle is cooled, dropwise adding the solution into a beaker containing 100g of silica sol, wherein the solid content of the alumina sol is 10%, and continuously stirring the solution during the period to ensure that the reaction solution and the silica sol are uniformly mixed. After the dropwise addition is finished, pouring the slurry into a watch glass, transferring the watch glass to a 110 ℃ drying oven for dehydration and drying to obtain X-MoO x a/ZT catalyst precursor; then drying the solid X-MoO x Placing the ZT catalyst precursor in a crucible, placing in a muffle furnace, roasting, heating to 650 ℃ at a heating range of 10 ℃/min, and keeping the temperature for 3 h; the calcined sample was then transferred to a tube furnace and 10% H was passed 2 Heating the mixed gas/Ar at the flow rate of 50mL/min to 600 ℃, and preserving the heat for 4 hours; after the temperature of the tube furnace is reduced, 1-MoO with 1 percent of load capacity is prepared x /SiO 2 A catalyst.
1-MoO obtained in this example x /SiO 2 The carrier of the catalyst is SiO 2 Active ingredient MoO x The loading amount is 1 percent, and the average grain diameter of the active component is 0.9 nm.
Example 5
A preparation method of a supported cluster molybdenum oxide catalyst comprises the following steps: adding 3.1g of ammonium molybdate, 3.5g of glucose and 1.5g of isopropylamine into 100mL of deionized water, and stirring until the ammonium molybdate, the glucose and the isopropylamine are completely dissolved to obtain a mixed salt solution; transferring the mixed salt solution into a 150mL hydrothermal reaction kettle, sealing, and placing in an oven for reaction at the temperature of 170 ℃ for 4 hours; after the hydrothermal reaction kettle is cooled, taking out the solution, dropwise adding the solution into a beaker containing 100g of aluminum sol, wherein the solid content of the aluminum sol is 10%, and continuously stirring the solution in the beaker to ensure that the reaction solution and the silica sol are uniformly mixed; pouring the slurry into a watch glass after the dropwise addition is finished, transferring the slurry into a 90 ℃ oven for dehydration and drying to obtain the X-MoO x Catalyst precursor/ZT catalyst precursorA body; then drying the solid X-MoO x Placing the ZT catalyst precursor in a crucible, placing in a muffle furnace, roasting, heating to 750 ℃ at a heating range of 10 ℃/min, and keeping the temperature for 4 h; the calcined sample was then transferred to a tube furnace and 10% H was passed 2 Heating the mixed gas/Ar at the flow rate of 50mL/min to 600 ℃, and preserving the heat for 6 hours; after the temperature of the tube furnace is reduced, 15-MoO with 15 percent of load capacity is prepared x /Al 2 O 3 A catalyst.
15-MoO prepared in this example x /Al 2 O 3 The carrier of the catalyst is Al 2 O 3 Active ingredient MoO x The loading amount is 15%, and the average particle size of the active component is 1.5 nm.
Application example 1
The supported cluster molybdenum oxide catalysts prepared in examples 1 to 5 were applied to the reaction of propane dehydrogenation to produce propylene, and an activity selectivity evaluation experiment was performed: propane dehydrogenation reaction in P of Kyoto Kaimeno science and technology Limited&The ID-A type micro-reaction is carried out on a fixed bed, the reaction temperature range is 560-600 ℃, the reaction raw material is propane, the reaction mass space velocity is 1.2h -1 . Tabletting the catalyst powder, and screening out particles of 20-40 meshes for reaction evaluation. For different catalyst samples, 0.1g to 1.5g of catalyst particles are weighed and mixed with quartz sand to 2mL in order to ensure consistent content of filled Mo, and the mixed particles are filled in a quartz reaction tube. The concentrations of the reactants and products were analyzed by on-line gas chromatography with a hydrogen flame detector and data processing by normalization, the statistics obtained are shown in the following table:
| catalyst sample | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 |
| Temperature (. degree.C.) | 580 | 600 | 580 | 600 | 600 |
| Propane conversion (%) | 32.6 | 38.9 | 42.2 | 27.8 | 34.2 |
| Propylene selectivity (%) | 89.6 | 91.9 | 92.2 | 89.8 | 90.6 |
In addition, as shown in FIG. 5, 2-MoO prepared in example 2 x /SiO 2 The conversion rate and the selectivity of the catalyst in the reaction of preparing propylene by propane dehydrogenation change with time, and it can be seen that the activity and the propylene selectivity of the catalyst are not obviously reduced in the reaction process of 200 min.
As shown in FIG. 6, 10-MoO prepared in example 3 x /Al 2 O 3 Catalyst in propane removalRegeneration data in the hydrogen to propylene reaction it can be seen that the catalyst undergoes 4 regenerations without a significant drop in initial conversion and selectivity.
Although the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
Claims (9)
1. A supported cluster molybdenum oxide catalyst, characterized in that: the chemical formula is X-MoO x ZT, wherein MoO x Is an active component, ZT is a carrier, X is expressed as the theoretical loading capacity of the active component, wherein the theoretical loading capacity of the active component is 1-15%, and the active component MoO x Has an average particle diameter of 0.8 to 1.5 nm.
2. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 1, wherein: comprises the following steps:
(1) dissolving Mo salt and a complexing agent in water to prepare a mixed salt solution; wherein the concentration of Mo ions in the mixed salt solution is 1-200 mmol/L; the mol ratio of the complexing agent to Mo ions is 5-20: 1;
(2) transferring the mixed salt solution into a reaction kettle, sealing, heating to 140-200 ℃ for reaction for 3-8h, dropwise adding the reacted solution into the carrier precursor sol, and drying the slurry at 60-120 ℃ to obtain the X-MoO x a/ZT catalyst precursor;
(3) mixing X-MoO x The ZT catalyst precursor is placed in a muffle furnace and roasted for 1-10h at the temperature of 400-900 ℃, and the roasted solid powder is placed in a tube furnace and reduced for 2-8h at the temperature of 500-1000 ℃.
3. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 2, wherein: the Mo salt is ammonium molybdate.
4. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 2, wherein: the complexing agent is one or the combination of two of acetonitrile, glucose, ethylenediamine, citric acid, isopropylamine or ascorbic acid.
5. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 2, wherein: the carrier precursor sol is one of silica sol and aluminum sol, and the solid content is 5-20%.
6. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 2, wherein: and (2) in the process of dropwise adding the solution into the carrier precursor sol, keeping the stirring state.
7. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 2, wherein the supported cluster molybdenum oxide catalyst comprises the following components in percentage by weight: in the step (3), the temperature rise range of the roasting is 10 ℃/min.
8. The method for preparing a supported cluster molybdenum oxide catalyst according to claim 2, wherein the supported cluster molybdenum oxide catalyst comprises the following components in percentage by weight: and in the step (3), introducing mixed gas into the tubular furnace to form an atmosphere with hydrogen, wherein the mixed gas consists of hydrogen and argon, and the volume fraction of the hydrogen is 10%.
9. Use of a supported cluster molybdenum oxide catalyst according to claim 1 in the dehydrogenation of propane.
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