JP7254453B2 - Alkane dehydrogenation catalyst structure, method for producing the same, and alkene production apparatus having the dehydrogenation catalyst structure - Google Patents

Description

The present invention relates to an alkane, especially propane dehydrogenation catalyst structure, a method for producing the same, and an alkene production apparatus, particularly a propylene production apparatus, having the dehydrogenation catalyst structure.

In recent years, the demand for alkenes, which are industrially useful raw materials such as propylene and isobutylene, is increasing. In particular, since propylene is used as a raw material in the production of gasoline and in the production of various chemical materials, methods for producing propylene are likely to become even more important in the future.

Methods for producing alkenes by dehydrogenating alkanes such as _C3 and _C4 groups in the presence of a catalyst have been extensively studied. A supported catalyst is used in which an active substance such as a metal or metal oxide is supported on a carrier. For example, in a method for dehydrogenating propane to propylene, known as the Lummus Catofin method, a catalyst (Cr ₂ O ₃ /Al ₂ O ₃ ) is used.

For example, Patent Document 1 describes a method of dehydrogenating propane to produce propylene. By the way, since the dehydrogenation reaction is an endothermic reaction, the reaction is generally carried out at a high temperature. tend to decline. In such cases, the deposited coke must be burnt off and reactivated to maintain catalyst activity.

However, when burning and removing coke, the catalyst particles (metal oxide fine particles) move within the carrier due to the influence of heat, and aggregation (sintering) of the metal oxide fine particles easily occurs. The effective surface area of the dehydrogenation catalyst is expected to decrease significantly, leading to a decrease in the catalytic activity of the dehydrogenation catalyst. Due to the deterioration of the catalyst function, the life of the catalyst itself becomes shorter than usual, so the catalyst itself must be replaced and regenerated in a short period of time. There's a problem.

In addition, steam is generated by combustion of coke during the coke removal process. When a carrier such as alumina is heated in the presence of steam, Al elements (active sites) in the skeleton are desorbed, which may cause permanent deterioration of the catalyst.

US Pat. No. 6,200,000 discloses the complete hydrogenation of highly unsaturated components (acetylenes, diolefins) present in hydrocarbon streams of feed alkanes and recycle alkanes that contribute to coke formation, but metal oxides Aggregation of fine particles and elimination of active sites are not mentioned.

Japanese Patent Publication No. 2008-520603

An object of the present invention is to prevent agglomeration of metal oxide fine particles, suppress a decrease in catalytic activity, realize a long service life, and save resources without requiring complicated replacement work. It is an object of the present invention to provide an alkane dehydrogenation catalyst structure capable of producing a dehydrogenation catalyst structure, a method for producing the same, and an alkene production apparatus having the dehydrogenation catalyst structure.

The present inventors have made intensive studies to achieve the above object, and as a result, have found that a carrier having a porous structure composed of a zeolite-type compound and at least one metal oxide fine particle contained in the carrier are provided. , the carrier has passages that communicate with each other, and the metal oxide fine particles are present at least in the passages, thereby preventing aggregation of the metal oxide fine particles and suppressing a decrease in catalytic activity; The present inventors have found that an alkane dehydrogenation catalyst structure capable of achieving a longer life can be obtained, and have completed the present invention based on such findings.

That is, the gist and configuration of the present invention are as follows.
[1] a carrier having a porous structure composed of a zeolite-type compound;
at least one metal oxide fine particle inherent in the carrier;
with
the carrier has passages that communicate with each other;
An alkane dehydrogenation catalyst structure, wherein the metal oxide fine particles are present at least in the passage.
[2] The passage is defined by the framework structure of the zeolite-type compound, and any of the one-dimensional, two-dimensional, and three-dimensional pores, and the one-dimensional, two-dimensional, and three-dimensional pores. The alkane dehydrogenation catalyst according to [1] above, characterized in that it has an enlarged diameter portion different from any of the above, and the metal oxide fine particles are present at least in the enlarged diameter portion. Structure.
[3] The alkane according to [2] above, wherein the enlarged diameter portion communicates with a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. Dehydrogenation catalyst structure.
[4] The above-mentioned [2] or [3], wherein the average particle size of the metal oxide fine particles is larger than the average inner diameter of the passage and equal to or smaller than the inner diameter of the expanded diameter portion. Alkane dehydrogenation catalyst structure.
[5] The above [1], wherein the metal element (M) of the metal oxide fine particles is contained in an amount of 0.5 to 2.5% by mass with respect to the dehydrogenation catalyst structure. The alkane dehydrogenation catalyst structure according to any one of [4].
[6] The alkane dehydrogenation catalyst structure according to any one of [1] to [5] above, wherein the metal oxide fine particles have an average particle size of 0.1 nm to 50 nm. body.
[7] The alkane dehydrogenation catalyst structure according to [6] above, wherein the metal oxide fine particles have an average particle size of 0.5 nm to 14.0 nm.
[8] Any one of [1] to [7] above, wherein the ratio of the average particle size of the metal oxide fine particles to the average inner diameter of the passage is 0.06 to 500. alkane dehydrogenation catalyst structure.
[9] The alkane dehydrogenation catalyst structure according to [8] above, wherein the ratio of the average particle diameter of the metal oxide fine particles to the average inner diameter of the passage is 0.1 to 45. .
[10] The alkane dehydrogenation catalyst according to [9] above, wherein the ratio of the average particle diameter of the metal oxide fine particles to the average inner diameter of the passage is 1.7 to 4.5. Structure.
[11] The passage is any one of a one-dimensional pore, a two-dimensional pore, and a three-dimensional pore defined by the framework structure of the zeolite-type compound, and the one-dimensional pore, the two-dimensional pore, and the three-dimensional pore. and an enlarged diameter portion different from any of the
The average inner diameter of the passage is 0.1 nm to 1.5 nm,
The alkane dehydrogenation catalyst structure according to any one of [1] to [10] above, wherein the inner diameter of the enlarged diameter portion is 0.5 nm to 50 nm.
[12] Dehydrogenation of alkane according to any one of [1] to [11] above, further comprising at least one other metal oxide fine particle held on the outer surface of the support. catalyst structure.
[13] The content of the at least one metal oxide fine particle inherent in the carrier is higher than the content of the at least one other metal oxide fine particle retained on the outer surface of the carrier. The alkane dehydrogenation catalyst structure according to [12] above.
[14] The alkane dehydrogenation catalyst structure according to any one of [1] to [13] above, wherein the zeolite-type compound is a silicate compound.
[15] An alkene production apparatus comprising the alkane dehydrogenation catalyst structure according to any one of [1] to [14] above.
[16] A calcination step of calcining the precursor material (A) impregnated with a metal-containing solution to obtain a porous structure carrier composed of a zeolite-type compound;
a hydrothermal treatment step of hydrothermally treating the precursor material (C) obtained by firing the precursor material (B);
A method for producing an alkane dehydrogenation catalyst structure, comprising:
[17] The alkane according to [16] above, characterized in that 50 to 500% by mass of a nonionic surfactant is added to the precursor material (A) before the firing step. A method for producing a dehydrogenation catalyst structure.
[18] impregnating the precursor material (A) with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in a plurality of times before the firing step; A method for producing an alkane dehydrogenation catalyst structure according to the above [16] or [17].
[19] When the precursor material (A) is impregnated with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is In terms of the ratio (atomic ratio Si/M) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to (A), The method for producing an alkane dehydrogenation catalyst structure according to any one of [16] to [18] above, wherein the adjustment is made so that the value is 10 to 1000.
[20] The method for producing an alkane dehydrogenation catalyst structure according to [16] above, wherein the precursor material (C) and a structure-directing agent are mixed in the hydrothermal treatment step.
[21] The method for producing an alkane dehydrogenation catalyst structure according to [16] above, wherein the hydrothermal treatment step is performed in a basic atmosphere.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to prevent the agglomeration of the metal oxide fine particles, suppress the deterioration of the catalytic activity, realize a long service life, and save resources without requiring complicated replacement work. It is possible to provide an alkane dehydrogenation catalyst structure, a method for producing the same, and an alkene production apparatus having the dehydrogenation catalyst structure.

FIG. 1 schematically shows the internal structure of an alkane dehydrogenation catalyst structure according to an embodiment of the present invention, and FIG. ), and FIG. 1(b) is a partially enlarged sectional view. FIG. 2 is a partially enlarged cross-sectional view for explaining an example of the function of the alkane dehydrogenation catalyst structure of FIG. 1, FIG. 2(a) explaining the sieve function, and FIG. It is a figure to do. FIG. 3 is a flow chart showing an example of a method for producing the alkane dehydrogenation catalyst structure of FIG. FIG. 4 is a schematic diagram showing a modification of the alkane dehydrogenation catalyst structure of FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of dehydrogenation catalyst structure]
FIG. 1 is a diagram schematically showing the configuration of an alkane dehydrogenation catalyst structure (hereinafter also simply referred to as “catalyst structure”) according to an embodiment of the present invention, and (a) is a perspective view (one ), and (b) is a partially enlarged cross-sectional view. Note that the catalyst structure in FIG. 1 shows an example thereof, and the shape, dimensions, etc. of each component according to the present invention are not limited to those in FIG.

As shown in FIG. 1(a), the catalyst structure 1 comprises a porous carrier 10 made of a zeolite compound and at least one metal oxide fine particle 20 present in the carrier 10. .

In the catalyst structure 1, the plurality of metal oxide fine particles 20, 20, . . . The metal oxide fine particles 20 are catalytic substances having catalytic ability (catalytic activity). Details of the metal oxide fine particles will be described later. Also, the metal oxide fine particles 20 may be particles containing a metal oxide, a metal alloy, or a composite material thereof.

The carrier 10 has a porous structure and, as shown in FIG. 1(b), preferably has passages 11 communicating with each other by forming a plurality of holes 11a, 11a, . Here, the metal oxide fine particles 20 are present in at least the passages 11 of the carrier 10 and preferably held in at least the passages 11 of the carrier 10 .

With such a configuration, movement of the metal oxide fine particles 20 within the carrier 10 is regulated, and aggregation of the metal oxide fine particles 20, 20 is effectively prevented. As a result, the reduction in the effective surface area of the metal oxide fine particles 20 can be effectively suppressed, and the catalytic activity of the metal oxide fine particles 20 can be maintained over a long period of time. That is, according to the catalyst structure 1, deterioration of catalytic activity due to aggregation of the metal oxide fine particles 20 can be suppressed, and the service life of the catalyst structure 1 can be extended. In addition, by extending the life of the catalyst structure 1, the frequency of replacement of the catalyst structure 1 can be reduced, the amount of waste of the used catalyst structure 1 can be greatly reduced, and resource saving can be achieved. .

Normally, when a catalyst structure is used in a fluid (for example, heavy oil, reformed gas such as NOx, etc.), it may receive an external force from the fluid. In this case, if the metal oxide fine particles are only held in an adhered state on the outer surface of the carrier 10, there is a problem that they tend to separate from the outer surface of the carrier 10 under the influence of the external force from the fluid. On the other hand, in the catalyst structure 1, the metal oxide fine particles 20 are present at least in the passages 11 of the carrier 10, so even if the metal oxide fine particles 20 are affected by the external force of the fluid, the metal oxide fine particles 20 are separated from the carrier 10. hard to do. That is, when the catalyst structure 1 is in the fluid, the fluid flows from the holes 11a of the carrier 10 into the passages 11. Therefore, the speed of the fluid flowing in the passages 11 is It is considered to be slower than the speed of the fluid flowing on the outer surface of the carrier 10 . Due to the influence of such flow path resistance, the pressure exerted by the fluid on the metal oxide fine particles 20 held in the passage 11 is lower than the pressure exerted by the fluid on the metal oxide fine particles outside the carrier 10 . Therefore, separation of the metal oxide fine particles 20 inherent in the carrier 10 can be effectively suppressed, and the catalytic activity of the metal oxide fine particles 20 can be stably maintained for a long period of time. It is believed that the flow path resistance as described above increases as the passage 11 of the carrier 10 has a plurality of bends and branches and the inside of the carrier 10 has a more complicated three-dimensional three-dimensional structure. .

In addition, the passage 11 is defined by the framework structure of the zeolite-type compound, and any of the one-dimensional, two-dimensional, and three-dimensional pores, and the one-dimensional, two-dimensional, and three-dimensional pores It is preferable to have an enlarged diameter portion 12 different from any of them, and at this time, it is preferable that the metal oxide fine particles 20 are present at least in the enlarged diameter portion 12 and are enclosed by at least the enlarged diameter portion 12. more preferably. The one-dimensional pore here means a tunnel-shaped or cage-shaped pore that forms a one-dimensional channel, or a plurality of tunnel-shaped or cage-shaped pores that form a plurality of one-dimensional channels (a plurality of one-dimensional pores). channel). A two-dimensional pore refers to a two-dimensional channel in which a plurality of one-dimensional channels are two-dimensionally connected, and a three-dimensional pore refers to a three-dimensional channel in which a plurality of one-dimensional channels are three-dimensionally connected. Point. As a result, movement of the metal oxide fine particles 20 within the carrier 10 is further regulated, and detachment of the metal oxide fine particles 20 and aggregation of the metal oxide fine particles 20, 20 can be more effectively prevented. The inclusion refers to a state in which the metal oxide fine particles 20 are included in the carrier 10 . At this time, the metal oxide fine particles 20 and the carrier 10 do not necessarily have to be in direct contact with each other. The metal oxide fine particles 20 may be indirectly held by the carrier 10 with the intervening.

Although FIG. 1(b) shows the case where the metal oxide fine particles 20 are enclosed in the expanded diameter portion 12, the configuration is not limited to this, and the metal oxide fine particles 20 are partially expanded. It may be held in the passage 11 in a state of protruding outside the diameter portion 12 . Moreover, the metal oxide fine particles 20 may be partially embedded in a portion of the passage 11 other than the enlarged diameter portion 12 (for example, an inner wall portion of the passage 11), or may be held by adhesion or the like. Moreover, it is preferable that the diameter-enlarging portion 12 communicates with a plurality of holes 11a, 11a forming any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. As a result, separate passages different from the one-dimensional, two-dimensional, or three-dimensional holes are provided inside the carrier 10, so that the catalytic function of the metal oxide fine particles 20 can be exhibited more effectively.

Further, the passage 11 is formed three-dimensionally inside the carrier 10 including a branching portion or a merging portion, and the enlarged diameter portion 12 is preferably provided at the branching portion or the merging portion of the passage 11. .

The average inner diameter D _F of the passages 11 formed in the carrier 10 is calculated from the average value of the short diameter and long diameter of the holes 11a constituting any one of the one-dimensional, two-dimensional and three-dimensional holes. It is 0.1 nm to 1.5 nm, preferably 0.5 nm to 0.8 nm. Further, the inner diameter D _E of the expanded diameter portion 12 is, for example, 0.5 nm to 50 nm, preferably 1.1 nm to 40 nm, more preferably 1.1 nm to 3.3 nm. The inner diameter D _E of the expanded diameter portion 12 depends, for example, on the pore diameter of the precursor material (A) described later and the average particle diameter D _C of the enclosed metal oxide fine particles 20 . The inner diameter D _E of the expanded diameter portion 12 is large enough to enclose the metal oxide fine particles 20 .

Carrier 10 is composed of a zeolite-type compound. Zeolite type compounds include, for example, zeolite (aluminosilicate), cation-exchanged zeolite, silicate compounds such as silicalite, zeolite analogues such as aluminoborates, aluminoarsenates, and germanates, molybdenum phosphate, and the like. phosphate-based zeolite-like substances, and the like. Among them, the zeolite-type compound is preferably a silicate compound.

The skeleton structure of the zeolite type compound is FAU type (Y type or X type), MTW type, MFI type (ZSM-5), FER type (ferrierite), LTA type (A type), MWW type (MCM-22). , MOR type (mordenite), LTL type (L type), BEA type (beta type), etc., preferably MFI type, more preferably ZSM-5. A zeolite-type compound is formed with a plurality of pores having a pore size corresponding to each skeleton structure. be.

The metal oxide fine particles 20 _may be primary particles or may be secondary particles formed by agglomeration of primary particles. It is larger than the average inner diameter D _F and equal to or less than the inner diameter D _E of the enlarged diameter portion 12 ( _DF <D _C ≤ D _E ). Such metal oxide fine particles 20 preferably exist in the enlarged diameter portion 12 within the passage 11 , and the movement of the metal oxide fine particles 20 within the carrier 10 is restricted. Therefore, even when the metal oxide fine particles 20 receive an external force from the fluid, the movement of the metal oxide fine particles 20 within the carrier 10 is suppressed, and the expanded diameter portions 12 dispersedly arranged in the passages 11 of the carrier 10 , 12, . . . can be effectively prevented from coming into contact with each other.

In addition, the average particle diameter D _C of the metal oxide fine particles 20 is preferably 0.1 nm to 50 nm, more preferably 0.1 nm or more and less than 30 nm, in both primary particles and secondary particles. It is preferably 0.5 nm to 14.0 nm, particularly preferably 1.0 nm to 3.3 nm. In addition, the ratio of the average particle diameter D _C of the metal oxide fine particles 20 to the average inner diameter D _F of the passage 11 (D _C /D _F ) is preferably 0.06 to 500, more preferably 0.1 to 45. , more preferably 1.1 to 45, and particularly preferably 1.7 to 4.5. Further, the metal element (M) of the metal oxide fine particles 20 is preferably contained in an amount of 0.5 to 2.5% by mass with respect to the catalyst structure 1, and is 0.5% with respect to the catalyst structure 1. More preferably, it is contained in an amount of up to 1.5% by mass. For example, when the metal element (M) is Cr, the Co element content (% by mass) is represented by {(mass of Cr element)/(mass of all elements in catalyst structure 1)}×100. .

The metal oxide fine particles may be composed of a metal oxide, for example, may be composed of a single metal oxide, or may be composed of a mixture of two or more metal oxides. good. In this specification, the “metal oxide” (as a material) constituting the metal oxide fine particles means an oxide containing one kind of metal element (M) and two or more kinds of metal elements (M). It is a generic term for oxides containing one or more metal elements (M).

Examples of such metal oxides include cobalt oxide (CoO _x ), nickel oxide (NiO _{x ), iron oxide (FeO x )} , copper oxide (CuO _x ), zirconium oxide (ZrO _x ), cerium oxide (CeO _{x )} , ), aluminum oxide (AlO _x ), niobium oxide (NbO _x ), titanium oxide (TiO _x ), bismuth oxide (BiO _x ), molybdenum oxide (MoO _x ), vanadium oxide (VO _x ), chromium oxide (CrO _x ) , gallium oxide (GaO _x ), manganese oxide (MnO _x ), etc., and it is preferable to use at least one of the above as a main component.

Further, the ratio of silicon (Si) constituting the carrier 10 to the metal element (M) constituting the metal oxide fine particles 20 (atomic ratio Si/M) is preferably 10 to 1000, more preferably 50 to 200. is more preferable. If the above ratio is more than 1000, there is a possibility that the activity of the metal oxide fine particles as a catalyst substance may not be sufficiently obtained, such as low activity. On the other hand, when the ratio is less than 10, the ratio of the metal oxide fine particles 20 becomes too large, and the strength of the carrier 10 tends to decrease. The metal oxide fine particles 20 referred to here refer to fine particles held or supported inside the carrier 10 and do not include metal oxide fine particles adhering to the outer surface of the carrier 10 .

[Function of Dehydrogenation Catalyst Structure]
As described above, the catalyst structure 1 includes a carrier 10 having a porous structure and at least one metal oxide fine particle 20 present in the carrier. The catalyst structure 1 exhibits the catalytic ability of the metal oxide fine particles 20 when the metal oxide fine particles 20 inherent in the carrier come into contact with the fluid. Specifically, the fluid in contact with the outer surface 10a of the catalyst structure 1 flows into the carrier 10 through the holes 11a formed in the outer surface 10a, is guided into the passage 11, and moves through the passage 11. , exits the catalyst structure 1 through another hole 11a. When the fluid comes into contact with the metal oxide fine particles 20 present in the passage 11 on the path along which the fluid moves through the passage 11 , a catalytic reaction is caused by the metal oxide fine particles 20 . In addition, the catalyst structure 1 has a molecular sieving ability due to the porous structure of the carrier.

First, the molecular sieving ability of the catalyst structure 1 will be described with reference to FIG. 2(a). As shown in FIG. 2( a ), molecules 15 a having a size equal to or less than the pore diameter of the pore 11 a , in other words, the inner diameter of the passage 11 or less can enter the carrier 10 . On the other hand, molecules 15b having a size exceeding the pore diameter of pore 11a cannot penetrate into carrier 10 . In this way, when the fluid contains multiple types of compounds, the reaction of the compounds that cannot penetrate into the carrier 10 is regulated, and the compounds that can penetrate into the carrier 10 can react.

Among the compounds produced in the carrier 10 by the reaction, only compounds composed of molecules having a size equal to or smaller than the pore diameter of the pores 11a can exit the carrier 10 through the pores 11a and are obtained as reaction products. On the other hand, compounds that cannot exit the carrier 10 through the pores 11a can be expelled from the carrier 10 by converting them into compounds composed of molecules having a size that allows them to exit the carrier 10. . Thus, by using the catalyst structure 1, a specific reaction product can be selectively obtained.

In the catalyst structure 1, as shown in FIG. 2(b), the metal oxide fine particles 20 are enclosed in the expanded diameter portion 12 of the passage 11. As shown in FIG. When the average particle diameter D _C of the metal oxide fine particles is larger than the average inner diameter D _F of the passage 11 and smaller than the inner diameter D _E of the expanded diameter portion 12 (D _F <D _C <D _E ), metal oxidation A small passage 13 is formed between the particle and the enlarged diameter portion 12 . Therefore, as indicated by the arrows in FIG. 2(b), the fluid that has entered the small passage 13 comes into contact with the metal oxide fine particles. Since each metal oxide fine particle is surrounded by the diameter-enlarged portion 12 , movement within the carrier 10 is restricted. This prevents aggregation of the metal oxide fine particles in the carrier 10 . As a result, a large contact area between the metal oxide fine particles and the fluid can be stably maintained.

Specifically, when the molecules that have entered the passage 11 come into contact with the metal oxide fine particles 20, the molecules (substance to be reformed) are reformed by the dehydrogenation reaction of alkane. In the present invention, by using the catalyst structure 1, for example, propane can be dehydrogenated to produce propylene. This dehydrogenation reaction is performed at a high temperature of, for example, around 600° C., but since the metal oxide fine particles 20 are present in the carrier 10, they are not easily affected by heating. Since the metal oxide fine particles 20 are present in the passage 11, particularly in the enlarged diameter portion 12, the movement of the metal oxide fine particles 20 within the carrier 10 is restricted, and aggregation of the metal oxide fine particles 20 occurs (sintering). is suppressed. As a result, a decrease in catalytic activity is suppressed, and a longer life of the catalyst structure 1 can be achieved.

[Method for producing dehydrogenation catalyst structure]
FIG. 3 is a flow chart showing a method for manufacturing the catalyst structure 1 of FIG.

(Step S1: preparation process)
As shown in FIG. 3, first, a precursor material (A) for obtaining a carrier having a porous structure composed of a zeolite-type compound is prepared. The precursor material (A) is preferably a regular mesoporous material, and can be appropriately selected according to the type (composition) of the zeolite compound that constitutes the carrier of the catalyst structure.

Here, when the zeolite-type compound constituting the carrier of the catalyst structure is a silicate compound, the ordered mesoporous material has pores with a pore diameter of 1 to 50 nm in one, two, or three dimensions. It is preferably a compound composed of a Si—O skeleton having a uniform size and regularly developed. Such regular mesoporous materials can be obtained as various synthetic products depending on the synthesis conditions. 16, MCM-41 and the like, among which MCM-41 is preferred. The pore diameter of SBA-1 is 10 to 30 nm, the pore diameter of SBA-15 is 6 to 10 nm, the pore diameter of SBA-16 is 6 nm, the pore diameter of KIT-6 is 9 nm, and the pore diameter of FSM-16 is 3 nm. ˜5 nm, and the pore size of MCM-41 is 1-10 nm. Examples of such ordered mesoporous materials include mesoporous silica, mesoporous aluminosilicate, mesoporous metallosilicate, and the like.

Precursor material (A) may be either commercially available or synthetic. Synthesis of the precursor material (A) can be carried out by a known method for synthesizing ordered mesoporous materials. For example, a mixed solution containing raw materials containing constituent elements of the precursor material (A) and a templating agent for defining the structure of the precursor material (A) is prepared, and the pH is adjusted as necessary. , perform hydrothermal treatment (hydrothermal synthesis). After that, the precipitate (product) obtained by the hydrothermal treatment is recovered (for example, filtered), washed and dried as necessary, and further calcined to obtain a powdery ordered mesoporous material. A precursor material (A) is obtained. Here, as the solvent of the mixed solution, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. The raw material is selected according to the type of carrier, and examples thereof include silica agents such as tetraethoxysilane (TEOS), fumed silica, and quartz sand. As the templating agent, various surfactants, block copolymers, and the like can be used, and it is preferable to select them according to the type of synthesis of the ordered mesoporous material. For example, when producing MCM-41 is preferably a surfactant such as hexadecyltrimethylammonium bromide. The hydrothermal treatment can be carried out, for example, in a closed vessel under conditions of 80 to 800° C., 5 hours to 240 hours, and 0 to 2000 kPa. The calcination treatment can be performed, for example, in the air at 350 to 850° C. for 2 to 30 hours.

(Step S2: impregnation step)
Next, the prepared precursor material (A) is impregnated with a metal-containing solution to obtain a precursor material (B).

The metal-containing solution may be any solution as long as it contains a metal component (for example, metal ions) corresponding to the metal element (M) that constitutes the metal oxide fine particles of the catalyst structure. ) can be prepared by dissolving a metal salt containing Examples of such metal salts include metal salts such as chlorides, hydroxides, oxides, sulfates and nitrates, with nitrates being preferred. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used.

The method for impregnating the precursor material (A) with the metal-containing solution is not particularly limited. For example, while stirring the powdery precursor material (A), the precursor material (A ), the metal-containing solution is preferably added little by little in multiple batches. In addition, from the viewpoint of making it easier for the metal-containing solution to penetrate into the pores of the precursor material (A), a surfactant is added as an additive to the precursor material (A) in advance before adding the metal-containing solution. It is preferable to add. Such an additive has the function of coating the outer surface of the precursor material (A), suppresses the metal-containing solution added thereafter from adhering to the outer surface of the precursor material (A), It is believed that the contained solution is more likely to penetrate into the pores of the precursor material (A).

Examples of such additives include nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether. Since these surfactants have a large molecular size and cannot penetrate inside the pores of the precursor material (A), they do not adhere to the inside of the pores and prevent the metal-containing solution from entering inside the pores. not considered to be a hindrance. As a method for adding the nonionic surfactant, for example, it is preferable to add 50 to 500% by mass of the nonionic surfactant with respect to the precursor material (A) before the firing step described later. If the amount of the nonionic surfactant added to the precursor material (A) is less than 50% by mass, the above suppressing effect is difficult to develop, and the nonionic surfactant is added to the precursor material (A) in an amount of 500% by mass. Adding more than % by mass is not preferable because the viscosity increases too much. Therefore, the amount of the nonionic surfactant added to the precursor material (A) is set within the above range.

In addition, the amount of the metal-containing solution added to the precursor material (A) is the amount of the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) (that is, the amount of the precursor material (B ) is preferably adjusted as appropriate in consideration of the amount of the metal element (M) to be incorporated in ). For example, before the firing step to be described later, the addition amount of the metal-containing solution added to the precursor material (A) is set to In terms of the ratio of silicon (Si) constituting the precursor material (A) (atomic ratio Si/M), it is preferably adjusted to be 10 to 1000, and adjusted to be 50 to 200. is more preferable. For example, if a surfactant is added as an additive to the precursor material (A) before adding the metal-containing solution to the precursor material (A), the addition of the metal-containing solution to the precursor material (A) By setting the amount to 50 to 200 in terms of the atomic ratio Si/M, the metal element (M) of the metal oxide fine particles is contained at 0.5 to 2.5% by mass with respect to the catalyst structure. can be made In the state of the precursor material (B), the amount of the metal element (M) present inside the pores is the same under conditions such as the metal concentration of the metal-containing solution, the presence or absence of the above additives, and other conditions such as temperature and pressure. If so, it is roughly proportional to the amount of the metal-containing solution added to the precursor material (A). Moreover, the amount of the metal element (M) inherent in the precursor material (B) is in a proportional relationship with the amount of the metal element constituting the metal oxide fine particles inherent in the carrier of the catalyst structure. Therefore, by controlling the addition amount of the metal-containing solution to be added to the precursor material (A) within the above range, the inside of the pores of the precursor material (A) can be sufficiently impregnated with the metal-containing solution. , the amount of the metal oxide fine particles to be incorporated in the carrier of the catalyst structure can be adjusted.

After impregnating the precursor material (A) with the metal-containing solution, a washing treatment may be performed as necessary. As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Moreover, it is preferable that the precursor material (A) is impregnated with the metal-containing solution, washed as necessary, and then dried. Drying treatments include natural drying for about one night and high-temperature drying at 150° C. or less. In addition, when the precursor material (A) is subjected to the firing treatment described later in a state in which a large amount of water contained in the metal-containing solution or the washing solution remains in the precursor material (A), regular mesopores of the precursor material (A) Sufficient drying is preferable because the skeleton structure of the substance may be destroyed.

(Step S3: Firing step)
Next, the precursor material (B) obtained by impregnating the precursor material (A) with the metal-containing solution for obtaining a carrier having a porous structure composed of a zeolite-type compound is calcined to obtain the precursor material (C). get

The calcination treatment is preferably carried out, for example, in the air at 350 to 850° C. for 2 to 30 hours. By such a calcination treatment, the metal component impregnated in the pores of the ordered mesoporous material undergoes crystal growth to form metal oxide fine particles in the pores.

(Step S4: hydrothermal treatment step)
Next, a mixed solution is prepared by mixing the precursor material (C) and a structure-directing agent, and the precursor material (C) obtained by calcining the precursor material (B) is hydrothermally treated to obtain a catalyst structure. get a body

The structure-directing agent is a templating agent for defining the skeleton structure of the carrier of the catalyst structure, and for example, a surfactant can be used. The structure-directing agent is preferably selected according to the skeleton structure of the carrier of the catalyst structure. is preferred.

Mixing of the precursor material (C) and the structure-directing agent may be performed during the main hydrothermal treatment step or before the hydrothermal treatment step. The method for preparing the mixed solution is not particularly limited, and the precursor material (C), the structure-directing agent, and the solvent may be mixed at the same time, or the precursor material (C) and the structure-directing agent may be mixed together in the solvent. Each dispersion solution may be mixed after dispersing each of the agents into individual solutions. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. Moreover, it is preferable that the mixed solution is adjusted in pH with an acid or a base before the hydrothermal treatment.

The hydrothermal treatment can be carried out by a known method, and is preferably carried out in a closed vessel under treatment conditions of 80 to 800° C., 5 hours to 240 hours, and 0 to 2000 kPa. Also, the hydrothermal treatment is preferably performed in a basic atmosphere. Although the reaction mechanism here is not necessarily clear, by performing hydrothermal treatment using the precursor material (C) as a raw material, the skeletal structure of the precursor material (C) as an ordered mesoporous substance gradually collapses. While the position of the metal oxide fine particles inside the pores of the precursor material (C) is generally maintained, a new skeleton structure (porous structure) is formed as a support for the catalyst structure by the action of the structure-directing agent. be done. The catalyst structure obtained in this manner comprises a carrier having a porous structure and metal oxide fine particles contained in the carrier, and the carrier has passages in which a plurality of pores communicate with each other due to the porous structure of the carrier, At least part of the metal oxide fine particles exists in the passages of the carrier. In the present embodiment, in the hydrothermal treatment step, a mixed solution is prepared by mixing the precursor material (C) and the structure-directing agent, and the precursor material (C) is hydrothermally treated, but the present invention is not limited to this. Alternatively, the precursor material (C) may be hydrothermally treated without mixing the precursor material (C) and the structure-directing agent.

The precipitate (catalyst structure) obtained after the hydrothermal treatment is preferably collected (for example, separated by filtration) and then washed, dried and calcined as necessary. As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Drying treatments include natural drying for about one night and high-temperature drying at 150° C. or less. It should be noted that if the calcination treatment is performed in a state in which a large amount of water remains in the precipitate, there is a risk that the skeletal structure as a carrier of the catalyst structure may be broken, so it is preferable to dry the precipitate sufficiently. Further, the calcination treatment can be performed, for example, in the air under the treatment conditions of 350 to 850° C. for 2 to 30 hours. The structure-directing agent adhering to the catalyst structure is burned off by such a calcination treatment. In addition, the catalyst structure can be used as it is without calcining the collected precipitate depending on the purpose of use. For example, when the environment in which the catalyst structure is used is a high-temperature environment in an oxidizing atmosphere, the structure-directing agent is burned off by exposing it to the use environment for a certain period of time, and the same catalyst structure as in the case of calcining is obtained. Since it is obtained, it becomes possible to use it as it is.

[Modified Example of Dehydrogenation Catalyst Structure]
FIG. 4 is a schematic diagram showing a modification of the catalyst structure 1 of FIG. Although the catalyst structure 1 in FIG. 1 includes the carrier 10 and the metal oxide fine particles 20 present in the carrier 10, it is not limited to this configuration. For example, as shown in FIG. , the catalyst structure 2 may further comprise other metal oxide fine particles 30 held on the outer surface 10 a of the carrier 10 .

The metal oxide fine particles 30 are catalytic substances that exhibit one or more catalytic functions. The catalytic ability of the other metal oxide fine particles 30 may be the same as or different from the catalytic ability of the metal oxide fine particles 20 . Further, when both of the metal oxide fine particles 20 and 30 are catalyst substances having the same catalytic ability, the material of the other metal oxide fine particles 30 may be the same as the material of the metal oxide fine particles 20. , can be different. According to this configuration, the content of the metal oxide fine particles held in the catalyst structure 2 can be increased, and the catalytic activity of the metal oxide fine particles can be further promoted.

In this case, the content of the metal oxide fine particles 20 inherent in the carrier 10 is preferably higher than the content of the other metal oxide fine particles 30 retained on the outer surface 10a of the carrier 10 . As a result, the catalytic ability of the metal oxide fine particles 20 held inside the carrier 10 becomes dominant, and the catalytic ability of the metal oxide fine particles is stably exhibited.

The alkane used as a raw material is not particularly limited as long as it can be decomposed into an alkene and hydrogen by a dehydrogenation reaction, but alkanes having 2 to 5 carbon atoms are generally used. Examples of such alkanes include ethane, propane, n-butane, isobutane, n-pentane, 2-methylbutane (isopentane), and the like. Then, these are subjected to a dehydrogenation reaction in the presence of the catalyst structure according to the present invention to give ethylene, propylene (propene), 1-butene, 2-butene, isobutene (isobutylene), 1-pentene, 2 -pentene, 2-methyl-1-butene, 2-methyl-2-butene, and the like. Among them, the dehydrogenation reaction of propane is particularly preferable from the viewpoint of usefulness.

Moreover, the dehydrogenation reaction of alkane can be performed by a known process. Furthermore, highly unsaturated components (eg acetylenes, diolefins) produced as by-products by dehydrogenation reactions of alkanes, especially propane, can be converted to propane or propylene by selective hydrogenation. Thus, by dehydrogenating alkanes, especially propane, and selectively hydrogenating the highly unsaturated components produced, propylene can be produced more efficiently.

The present invention also provides an alkene production apparatus, particularly a propylene production apparatus, having the above catalyst structure. Such a production apparatus is not particularly limited as long as it can dehydrogenate alkane using the catalyst structure, and for example, a commonly used production apparatus such as a dehydrogenation reactor is used. can do. By using the catalyst structure according to the present invention in such a production apparatus, the production apparatus can also achieve the same effects as described above.

Although the catalyst structures according to the embodiments of the present invention have been described above, the present invention is not limited to the described embodiments, and various modifications and changes are possible based on the technical idea of the present invention.

(Examples 1 to 384)
[Synthesis of precursor material (A)]
A mixed aqueous solution is prepared by mixing a silica agent (tetraethoxysilane (TEOS), manufactured by Wako Pure Chemical Industries, Ltd.) and a surfactant as a template agent, and the pH is adjusted as appropriate. Hydrothermal treatment was performed at 350° C. for 100 hours. After that, the produced precipitate is filtered off, washed with water and ethanol, and further calcined in the air at 600° C. for 24 hours to obtain the precursor material (A) having the types and pore sizes shown in Tables 1 to 8. Obtained. The following surfactants were used according to the type of the precursor material (A) (“type of precursor material (A): surfactant”).
・ MCM-41: hexadecyltrimethylammonium bromide (CTAB) (manufactured by Wako Pure Chemical Industries, Ltd.)
・ SBA-1: Pluronic P123 (manufactured by BASF)

[Production of precursor materials (B) and (C)]
Next, according to the metal element (M) constituting the metal oxide fine particles of the types shown in Tables 1 to 8, a metal salt containing the metal element (M) is dissolved in water to obtain a metal-containing aqueous solution. was prepared. The following metal salts were used according to the type of metal oxide fine particles (“metal oxide fine particles: metal salt”).
・CrO _x : chromium (III) nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product name “chromium (III) nitrate nonahydrate, 98.5%”)
・ GaO _x : Gallium nitrate hydrate (manufactured by Wako Pure Chemical Industries, Ltd., product name “Gallium (III) nitrate n-hydrate”)
・ AlO _x : aluminum nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product name “aluminum nitrate nonahydrate”)
・ MnO _x : manganese (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product name “aluminum nitrate nonahydrate”)

Next, the metal-containing aqueous solution is added to the powdery precursor material (A) little by little in multiple portions, dried at room temperature (20° C.±10° C.) for 12 hours or more, and precursor material (B) is obtained. got

In addition, when the condition of the presence or absence of additives shown in Tables 1 to 8 is "Yes", polyoxyethylene (15) as an additive is added to the precursor material (A) before adding the metal-containing aqueous solution. Pretreatment was performed by adding an aqueous solution of oleyl ether (NIKKOL BO-15V, manufactured by Nikko Chemicals Co., Ltd.), and then a metal-containing aqueous solution was added as described above. In addition, in the case of "absent" in the condition of the presence or absence of additives, pretreatment with additives as described above was not performed.

The amount of the metal-containing aqueous solution added to the precursor material (A) is determined by the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing aqueous solution ( Numerical values when converted to the atomic number ratio (Si/M) were adjusted to the values shown in Tables 1-8.

Next, the precursor material (B) impregnated with the metal-containing aqueous solution obtained as described above was calcined in the air at 600° C. for 24 hours to obtain the precursor material (C).

The precursor material (C) obtained as described above was mixed with the structure-directing agents shown in Tables 1 to 8 to prepare a mixed aqueous solution, which was heated in a sealed container at 80 to 350 ° C. in Tables 1 to 8. Hydrothermal treatment was performed under the pH and time conditions shown in . After that, the produced precipitate was filtered off, washed with water, dried at 100° C. for 12 hours or more, and further calcined in the air at 600° C. for 24 hours. In this way, catalyst structures having carriers shown in Tables 1 to 8 and metal oxide fine particles as catalytic substances were obtained (Examples 1 to 384).

(Comparative example 1)
In Comparative Example 1, MFI-type silicalite was added with chromium (III) nitrate nonahydrate and copper nitrate trihydrate (manufactured by Wako Pure Chemical Industries, Ltd., product name "chromium (III) nitrate nonahydrate, 98. 5% copper (II) nitrate trihydrate, 99.9%”) was added dropwise and calcined under the same conditions as the CrO _x clathrate zeolite, and on the outer surface of silicalite as a support, CrO _x particles as a catalyst substance was attached to obtain a catalyst structure. MFI-type silicalite was synthesized in the same manner as in Examples 52 to 57, except for the step of adding metal.

(Comparative example 2)
In Comparative Example 2, MFI-type silicalite was synthesized in the same manner as in Comparative Example 1, except that the step of attaching _CrOx particles was omitted.

[evaluation]
Various characteristic evaluations were performed on the catalyst structures of the above examples and the silicalite of the comparative examples under the following conditions.

[A] Cross-sectional observation For the catalyst structures of the above examples and the silicalite of the comparative examples, observation samples were prepared by a pulverization method, and cross-sectional observations were performed using a transmission electron microscope (TEM) (TITAN G2, manufactured by FEI). did As a result, it was confirmed that in the catalyst structures of the above examples, the metal oxide fine particles were inherently present and held inside the carrier made of silicalite or zeolite. On the other hand, in the silicalite of Comparative Example 1, the metal oxide fine particles adhered only to the outer surface of the carrier and were not present inside the carrier.

In the above examples, the catalyst structures in which the metal oxide was Al ₂ O ₃ fine particles (AlO _x fine particles) were cut out by FIB (focused ion beam) processing and subjected to SEM (SU8020, Hitachi High-Technologies Corporation). (manufactured by Horiba, Ltd.) and EDX (X-Max, manufactured by Horiba, Ltd.) were used to perform cross-sectional elemental analysis. As a result, Al element was detected from inside the carrier. From the results of cross-sectional observation by TEM and SEM/EDX, it was confirmed that Al ₂ O ₃ fine particles were present inside the carrier.

[B] The average inner diameter of the carrier passage and the average particle diameter of the catalyst material. The minor diameters _were measured, and the average inner diameter was calculated (N=500). In the same manner, 500 catalyst substances were arbitrarily selected from the TEM image, the particle size of each was measured (N = 500), and the average value was obtained. The particle size was defined as D _C. The results are shown in Tables 1-8.

In addition, in order to confirm the average particle diameter and dispersion state of the catalyst substance, analysis was performed using SAXS (small angle X-ray scattering). Measurements by SAXS were performed using Spring-8 beamline BL19B2. The obtained SAXS data was fitted with a spherical model by the Guinier approximation method to calculate the particle size. The particle size was measured for a catalyst structure in which the metal oxide was fine Al ₂ O ₃ particles. As a comparative object, commercial Al ₂ O ₃ fine particles (manufactured by EM Japan Co., Ltd.) were observed and measured by SEM.

As a result, in the commercial product, Al ₂ O ₃ fine particles of various sizes with a particle size range of about 10 nm to 100 nm are randomly present, whereas the average particle size obtained from the TEM image is 1.2 nm to 2.0 nm. In the catalyst structure of each example having a particle size of 0 nm, a scattering peak with a particle size of 10 nm or less was detected in the SAXS measurement results. From the SAXS measurement results and SEM/EDX cross-sectional measurement results, it was found that catalytic substances with particle sizes of 10 nm or less were present inside the carrier in a highly dispersed state with a uniform particle size.

[C] Relationship between the amount of the metal-containing solution added and the amount of the metal clathrated inside the support Addition amount of atomic number ratio Si/M = 50, 100, 200, 1000 (M = Cr, Ga, Al, Mn) , a catalyst structure in which metal oxide fine particles were included inside the carrier was produced, and then the amount (mass%) of the metal enclosed inside the carrier of the catalyst structure produced with the above addition amount was measured. . In this measurement, the catalyst structures with atomic ratios Si/M = 100, 200, and 1000 are the same as the catalyst structures with atomic ratios Si/M = 100, 200, and 1000 in Examples 1 to 384, respectively. The catalyst structure with the atomic ratio Si/M = 50 was prepared by adjusting the amount of the metal-containing solution added by the method of No., except that the amount of the metal-containing solution added was changed. = 100, 200 and 1000 catalyst structures.

The amount of metal was quantified by ICP (high frequency inductively coupled plasma) alone or by combining ICP and XRF (X-ray fluorescence analysis). XRF (energy dispersive X-ray fluorescence spectrometer "SEA1200VX", manufactured by SSI Nanotechnology Co., Ltd.) was performed under the conditions of a vacuum atmosphere and an acceleration voltage of 15 kV (using a Cr filter) or an accelerating voltage of 50 kV (using a Pb filter). . XRF is a method of calculating the amount of metal present based on fluorescence intensity, and a quantitative value (in terms of mass %) cannot be calculated using XRF alone. Therefore, the metal content of the catalyst structure to which the metal was added at Si/M = 100 was quantified by ICP analysis, and the metal content of the catalyst structure to which the metal was added at Si/M = 50 and less than 100 was the result of XRF measurement. and calculated based on the ICP measurement results.

As a result, it was confirmed that at least within the range of the atomic number ratio Si/M of 50 to 1000, the amount of the metal clathrated in the catalyst structure increased as the amount of the metal-containing solution added increased. rice field.

[C] Performance Evaluation The catalyst structures of the above examples and the silicalite of the comparative example were evaluated for their catalytic ability. The results are shown in Tables 1-8.

(1) Catalytic activity Catalytic activity was evaluated under the following conditions.

First, 0.2 g of the obtained catalyst structure was charged into a normal pressure flow reactor, and a mixed gas of propane and carbon dioxide (mixing ratio by volume: 1:7) was supplied at a flow rate of 5 cc/min. Dehydrogenation of propane was carried out at 0° C. for 2 hours.

After completion of the dehydrogenation reaction, the components of the recovered product gas were analyzed by gas chromatography/mass spectrometry (GC/MS). A TRACE 1310GC (manufactured by Thermo Fisher Scientific Co., Ltd., detector: thermal conductivity detector) was used as a generated gas analyzer.

Furthermore, the conversion rate of propane was calculated based on the results of the above component analysis. In this example, when the conversion rate of propane is 30% or more, the catalyst activity is particularly good "⊚", when it is 20% or more and less than 30%, the catalyst activity is good "○", and when it is 10% or more and less than 20% The case where the catalyst activity was slightly poor was evaluated as "Δ", and the case where the catalyst activity was less than 10% was evaluated as "poor".

(2) Durability (service life)
Durability was evaluated under the following conditions.

First, the catalyst structure used in the above evaluation (1) was collected and heated at 650° C. for 12 hours to prepare a heated catalyst structure. The heated catalyst structure was then cooled to room temperature and left for 30 minutes. After repeating this operation 10 times, the propane was dehydrogenated, and the components of the produced gas were analyzed in the same manner as in the above evaluation (1).

Based on the obtained analysis results, the conversion of propane was calculated in the same manner as in the above evaluation (1). In this example, when the conversion rate of propane by the catalyst structure after heating is 30% or more, the catalyst durability is particularly good. , 10% or more and less than 20%, the catalyst durability is slightly poor "Δ", and less than 10%, the catalyst durability is poor "x".

Performance evaluations similar to the above evaluations (1) and (2) were also performed for Comparative Examples 1 and 2. Comparative Example 2 is the carrier itself and does not have a catalyst substance. Therefore, in the above performance evaluation, only the carrier of Comparative Example 2 was filled instead of the catalyst structure. Table 8 shows the results.

As is clear from Tables 1 to 8, in the catalyst structures (Examples 1 to 384) in which it was confirmed that the catalyst substance was retained inside the carrier by cross-sectional observation, the catalyst substance was simply deposited on the outer surface of the carrier. Compared to the catalyst structure that is only attached (Comparative Example 1) and the support itself that does not have any catalytic substance (Comparative Example 2), it exhibits excellent catalytic activity in the dehydrogenation reaction of propane, and the catalyst It was also found to be excellent in durability as.

In addition, the relationship between the amount (% by mass) of the metal enclosed inside the carrier of the catalyst structure measured in the above evaluation [C], the catalytic activity in the above evaluation (1), and the durability (2) was evaluated. . The evaluation method was the same as the evaluation method for "(1) catalytic activity" and "(2) durability" in [D] "Performance evaluation". As a result, in each example, the amount of the metal-containing solution added to the precursor material (A) was 50 to 200 in terms of the atomic ratio Si/M (the metal element of the metal oxide fine particles to the catalyst structure When the content of (M) is 0.5 to 2.5% by mass), the evaluation of both (1) catalytic activity and (2) durability is “O” or more, and (1) catalytic activity The evaluation was "○" or higher and (2) the durability evaluation was "△" or higher, or (1) the catalytic activity evaluation was "△" or higher and (2) the durability evaluation was "○" or higher. . From this, by controlling the content of the metal element (M) in the metal oxide fine particles to 0.5 to 2.5% by mass with respect to the catalyst structure, the catalytic activity and durability in the alkane dehydrogenation reaction can be improved. It has been found that both or one can be enhanced.

On the other hand, the catalyst structure of Comparative Example 1, in which the catalyst substance was attached only to the outer surface of the carrier, was superior to the carrier itself of Comparative Example 2, which did not have any catalyst substance, in the dehydrogenation reaction of propane. Although the activity was improved, the durability as a catalyst was inferior to that of the catalyst structures of Examples 1-384.

From the above results, it can be inferred that the alkane dehydrogenation catalyst structure according to the present invention exhibits excellent catalytic activity in the alkane dehydrogenation reaction and has excellent durability as a catalyst.

Reference Signs List 1 alkane dehydrogenation catalyst structure 10 carrier 10a outer surface 11 passage 11a hole 12 expanded diameter portion 20 metal oxide fine particles 30 metal oxide fine particles D _C average particle size D _F average inner diameter D _E inner diameter

Claims (17)

a carrier having a porous structure composed of a zeolite-type compound;
at least one metal oxide fine particle inherent in the carrier;
with
the carrier has passages that communicate with each other;
the passages are any one-dimensional, two-dimensional, or three-dimensional pores defined by the framework structure of the zeolite-type compound; and any one-dimensional, two-dimensional, or three-dimensional pores. having a different enlarged diameter portion from each other,
the average particle diameter of the metal oxide fine particles is larger than the average inner diameter of the passage and equal to or smaller than the inner diameter of the expanded diameter portion;
the enlarged diameter portion communicates with a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole,
The average inner diameter of the passage is calculated from the average value of the short diameter and the long diameter of the holes that constitute any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole,
The metal oxide fine particles contain a metal oxide composed of at least one of cobalt oxide, aluminum oxide, gallium oxide and manganese oxide,
A catalyst structure for dehydrogenation of propane, wherein the metal oxide fine particles are included in at least the diameter-enlarged portion . The propane according to claim 1 , wherein the metal element (M) of the metal oxide fine particles is contained in an amount of 0.5 to 2.5% by mass with respect to the dehydrogenation catalyst structure. dehydrogenation catalyst structure. 3. The propane dehydrogenation catalyst structure according to claim 1 , wherein the metal oxide fine particles have an average particle size of 0.1 nm to 50 nm. 4. The propane dehydrogenation catalyst structure according to claim 3 , wherein the metal oxide fine particles have an average particle size of 0.5 nm to 14.0 nm. Propane dehydrogenation according to any one of claims 1 to 4 , wherein the ratio of the average particle size of the metal oxide fine particles to the average inner diameter of the passage is 0.06 to 500. catalyst structure. 6. The propane dehydrogenation catalyst structure according to claim 5 , wherein the ratio of the average particle size of the metal oxide fine particles to the average inner diameter of the passage is 0.1-45. 7. The propane dehydrogenation catalyst structure according to claim 6 , wherein the ratio of the average particle size of the metal oxide fine particles to the average inner diameter of the passage is 1.7 to 4.5. The average inner diameter of the passage is 0.1 nm to 1.5 nm,
The propane dehydrogenation catalyst structure according to any one of claims 1 to 7 , wherein the inner diameter of the enlarged diameter portion is 0.5 nm to 50 nm. The propane dehydrogenation catalyst structure according to any one of claims 1 to 8, further comprising at least one other metal oxide fine particle retained on the outer surface of said support. The content of the at least one metal oxide fine particle inherent in the carrier is higher than the content of the at least one other metal oxide fine particle retained on the outer surface of the carrier. 10. A propane dehydrogenation catalyst structure according to Item 9 . The propane dehydrogenation catalyst structure according to any one of claims 1 to 10 , wherein the zeolite type compound is a silicate compound. An alkene production apparatus comprising the propane dehydrogenation catalyst structure according to any one of claims 1 to 11 . Precursor material (A) impregnated with a metal-containing solution containing at least one metal selected from cobalt, aluminum, gallium and manganese for obtaining a carrier having a porous structure composed of a zeolite-type compound A firing step of firing the material (B);
a hydrothermal treatment step of mixing the precursor material (C) obtained by sintering the precursor material (B) with a structure-directing agent and performing hydrothermal treatment;
has
A method for producing a propane dehydrogenation catalyst structure, wherein the precursor material (A) is an ordered mesoporous material . 14. The propane dehydrogenation catalyst according to claim 13 , wherein a nonionic surfactant is added in an amount of 50 to 500% by mass with respect to the precursor material (A) before the calcination step. A method of manufacturing a structure. The precursor material (A) is impregnated with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in multiple batches before the firing step. 15. The method for producing a propane dehydrogenation catalyst structure according to claim 13 or 14 . When the precursor material (A) is impregnated with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is 10 to 1000 in terms of the ratio (atomic ratio Si/M) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to 16. The method for producing a propane dehydrogenation catalyst structure according to any one of claims 13 to 15 , characterized in that the structure is adjusted so that 14. The method for producing a propane dehydrogenation catalyst structure according to claim 13 , wherein the hydrothermal treatment step is performed under a basic atmosphere.

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