JP7635945B2 - Functional structure and method for producing same - Google Patents

Description

The present invention relates to a functional structure and a method for manufacturing the same.

As a method for producing hydrocarbon compounds used as raw materials for liquid fuel products such as synthetic oils and synthetic fuels, which are alternative fuels to petroleum, the Fischer-Tropsch synthesis reaction (hereinafter sometimes referred to as the "FT synthesis reaction") is known, which uses a catalytic reaction to synthesize hydrocarbons, particularly liquid hydrocarbons, from a synthesis gas mainly composed of carbon monoxide gas (CO) and hydrogen gas ( _H2 ). As a catalyst used in this FT synthesis reaction, for example, Patent Document 1 discloses a catalyst in which an active metal such as cobalt or iron is supported on a support such as silica or alumina, and Patent Document 2 discloses a catalyst containing cobalt, zirconium or titanium, and silica.

The catalyst used in the FT synthesis reaction can be obtained as a catalyst (unreduced catalyst) carrying cobalt oxide and/or ruthenium oxide by impregnating a carrier such as silica or alumina with a cobalt salt, a ruthenium salt, or the like, and then calcining the resultant. In order for the catalyst obtained in this way to exhibit sufficient activity in the FT synthesis reaction, as disclosed in Patent Document 3, the catalyst must be brought into contact with a reducing gas such as hydrogen gas for reduction treatment, and the active metals cobalt and/or ruthenium must be converted from the oxide state to the metal state.

As disclosed in Patent Document 4, the FT synthesis reaction generates a large amount of heat, and locally overheated areas on the catalyst surface become hot spots. It is known that the progression of side reactions (such as carbonaceous precipitation) on the catalyst surface due to these hot spots reduces activity. In order to prevent the formation of such hot spots, it is necessary to disperse active points without agglomerating the fine particles of active metal species (metal fine particles), which are functional substances that act as catalysts. In order to prevent the agglomeration of fine particles of active metal species, it is possible to use a carrier that has a strong interaction with the active metal species, so that the metal fine particles cannot easily agglomerate with each other.

One example of this method is the sol-gel method, which supports metal particles in a highly dispersed state. In the sol-gel method, active metal species are introduced uniformly at the atomic level during the synthesis of the metal oxide that serves as the support. The active metal species of the supported metal catalyst are highly dispersed within the lattice of the metal oxide that serves as the support, so they do not easily aggregate during various treatments or reactions. However, because the active metal species are strongly bound to the support, it is difficult to activate the catalyst prior to the reaction, and there is a problem that sufficient catalytic activity cannot be obtained.

In addition, when the metal microparticles aggregate, the effective surface area of the catalyst decreases, causing a decrease in catalytic activity, and the lifespan of the catalyst itself becomes shorter than usual. This means that the catalyst itself must be replaced and regenerated in a short period of time, which not only makes the replacement process complicated but also makes it difficult to conserve resources. In addition, there is a demand for the catalyst to maintain its activity for a long period of time.

This problem of reduced activity due to aggregation of fine particles is not limited to metal fine particles used as catalysts in FT synthesis reactions, but is also evident in fine particles of other functional substances. Therefore, there is a demand for functional structures that can hold fine particles of functional substances without causing them to aggregate.

Japanese Unexamined Patent Publication No. 4-227847 Japanese Unexamined Patent Publication No. 59-102440 International Publication No. 2015/072573 JP 2000-70720 A

The object of the present invention is to provide a functional structure and a method for producing the same that can prevent aggregation of fine particles of functional substances and suppress a decrease in activity to achieve a long life.

As a result of intensive research conducted by the inventors in order to achieve the above object, they discovered that a functional structure is obtained that comprises a carrier having a porous structure composed of a zeolite-type compound and at least one functional substance present in the carrier, the carrier having passages communicating with each other, the carrier containing aluminum and silicon, the Si/Al atomic ratio value contained in the carrier being 2.0 or more, and the functional substance being present at least in the passages of the carrier, which prevents aggregation of fine particles of the functional substance, suppresses a decrease in activity, and can achieve a long life, and the present invention was completed based on this finding.

That is, the gist of the present invention is as follows.
[1] A porous support composed of a zeolite-type compound, and at least one functional substance present in the support;
Equipped with
The support contains aluminum (Al) and silicon (Si);
The atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) contained in the carrier is 2.0 or more;
The carrier has passages communicating with each other,
A functional structure, characterized in that the functional substance is present at least in the passages of the carrier.
[2] The functional structure described in [1] above, characterized in that the passage has any one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the framework structure of the zeolite-type compound, and an expanded diameter portion different from any of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores, and the functional substance is present at least in the expanded diameter portion.
[3] The functional structure described in [2] above, wherein the enlarged diameter portion connects a plurality of holes that constitute any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole.
[4] The functional structure according to the above [2] or [3], characterized in that the average particle size of the functional substance is larger than the average inner diameter of the passage and is equal to or smaller than the inner diameter of the expanded portion.
[5] The functional structure according to any one of [1] to [4] above, characterized in that the metal element (M) of the functional substance is contained in an amount of 0.5 to 2.5 mass% relative to the functional structure.
[6] The functional structure according to any one of the above [1] to [5], wherein the functional substance is metal oxide fine particles.
[7] The functional structure according to any one of [1] to [5] above, wherein the functional substance is a metal fine particle.
[8] The functional structure described in [7] above, characterized in that the metal microparticles contain one or more metals or alloys selected from the group consisting of cobalt (Co), iron (Fe), nickel (Ni) or ruthenium (Ru).
[9] The functional structure according to any one of the above [1] to [8], characterized in that the average particle size of the functional substance is 0.08 nm to 30 nm.
[10] The functional structure according to any one of [1] to [9] above, characterized in that the ratio of the average particle size of the functional material to the average inner diameter of the passage is 0.05 to 300.
[11] The functional structure according to any one of the above [1] to [10], characterized in that the average inner diameter of the passage is 0.1 nm to 1.5 nm.
[12] The functional structure according to any one of [2] to [11] above, characterized in that the inner diameter of the expanded portion is 0.5 nm to 50 nm.
[13] The functional structure according to any one of [1] to [12] above, further comprising at least one other functional substance held on the outer surface of the carrier.
[14] The functional structure described in [13] above, characterized in that the content of the at least one functional substance contained within the carrier is greater than the content of the at least one other functional substance held on the outer surface of the carrier.
[15] The functional structure according to any one of the above [1] to [14], characterized in that the zeolite type compound is a silicate compound.
[16] A hydrocarbon production device having the functional structure according to any one of [1] to [15] above.
[17] A calcination step of calcining a precursor material (B) obtained by impregnating a precursor material (A) with a metal-containing solution to obtain a porous support composed of a zeolite-type compound;
a hydrothermal treatment step of subjecting the precursor material (C) obtained by calcining the precursor material (B) to a hydrothermal treatment;
A method for producing a functional structure comprising the steps of:
The precursor material (A) contains aluminum (Al) and silicon (Si),
A method for producing a functional structure, comprising preparing the precursor material (A) so that the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) is 2.0 or more.
[18] The method for producing a functional structure according to the above [17], characterized in that a nonionic surfactant is added in an amount of 50 to 500 mass % based on the precursor material (A) prior to the firing step.
[19] The method for producing a functional structure according to the above [17] or [18], characterized in that the metal-containing solution is added to the precursor material (A) in multiple batches prior to the firing step, thereby impregnating the precursor material (A) with the metal-containing solution.
[20] The method for producing a functional structure according to any one of the above [17] to [19], characterized in that, when impregnating the precursor material (A) with the metal-containing solution before the firing step, an amount of the metal-containing solution added to the precursor material (A) is adjusted so that an atomic ratio Si/M of silicon (Si) constituting the precursor material (A) to a metal element (M) contained in the metal-containing solution added to the precursor material (A) is 10 to 1000.
[21] The method for producing a functional structure according to any one of [17] to [20] above, characterized in that in the hydrothermal treatment step, the precursor material (C) is mixed with a structure-directing agent.
[22] The method for producing a functional structure according to any one of [17] to [21] above, characterized in that the hydrothermal treatment step is carried out under a basic atmosphere.
[23] The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of [17] to [22] above, further comprising a step of subjecting the hydrothermally treated precursor material (C) to a reduction treatment.

The present invention provides a functional structure and a method for producing the same that can prevent aggregation of fine particles of functional substances and suppress a decrease in activity to achieve a long life.

FIG. 1 is a schematic diagram showing the internal structure of a functional structure according to an embodiment of the present invention, in which FIG. 1(a) is a perspective view (partially shown in cross section), and FIG. 1(b) is a partially enlarged cross-sectional view. 2A and 2B are enlarged partial cross-sectional views for explaining a catalytic function, which is an example of the function of the functional structure of FIG. 1, in which FIG. 2A illustrates a sieving function and FIG. 2B illustrates a catalytic ability. FIG. 3 is a flowchart showing an example of a method for manufacturing the functional structure of FIG. FIG. 4 is a schematic diagram showing a modified example of the functional structure of FIG.

The following describes an embodiment of the present invention in detail with reference to the drawings.

[Configuration of functional structure]
Fig. 1 is a diagram showing a schematic configuration of a functional structure according to an embodiment of the present invention, in which (a) is a perspective view (partially shown in cross section) and (b) is a partially enlarged cross-sectional view. Note that the functional structure in Fig. 1 shows one example, and the shape, dimensions, etc. of each component according to the present invention are not limited to those in Fig. 1.

As shown in FIG. 1(a), the functional structure 1 comprises a porous support 10 composed of a zeolite-type compound and at least one functional substance 20 present within the support 10.

The functional structure 1 is a material that exerts one or more functions, at least when in use, either alone or in cooperation with the carrier 10 or the like. Specific examples of the above functions include a catalytic function, a light emitting (or fluorescent) function, a light absorbing function, and a recognition function. The functional structure 1 is preferably, for example, a catalytic material having a catalytic function. When the functional structure 1 is a catalytic material, the carrier 10 is a carrier that supports the catalytic material.

In the functional structure 1, multiple functional substances 20, 20, ... are encapsulated inside the porous structure of the carrier 10. The functional substances 20 are substances that have functionality (e.g., catalytic activity when used as a catalyst) and have the form of fine particles. The functional substances will be described in detail later. The functional substances 20 may also be particles that contain metals, metal oxides, metal alloys, or composite materials thereof.

The carrier 10 has a porous structure, and preferably has a plurality of holes 11a, 11a, ... formed therein, thereby providing passages 11 that communicate with each other, as shown in FIG. 1(b). Here, the functional substance 20 is present in at least the passages 11 of the carrier 10, and is preferably held in at least the passages 11 of the carrier 10.

This configuration restricts the movement of the functional material 20 within the carrier 10, and effectively prevents the functional materials 20 from agglomerating with each other. As a result, the reduction in the effective surface area of the functional material 20 can be effectively suppressed, and the activity of the functional material 20 is maintained for a long period of time. In other words, the functional structure 1 can suppress the decrease in catalytic activity due to the agglomeration of the functional material 20, and the functional structure 1 can be extended in life. Furthermore, the extended life of the functional structure 1 can reduce the frequency of replacement of the functional structure 1, and the amount of waste of used functional structures 1 can be significantly reduced, thereby saving resources.

Normally, when a functional structure is used in a fluid (e.g., heavy oil or reformed gas such as NOx), it may be subjected to an external force from the fluid. In this case, if the functional substance is only held in an attached state on the outer surface of the carrier 10, there is a problem that it is easily detached from the outer surface of the carrier 10 due to the influence of an external force from the fluid. In contrast, in the functional structure 1, the functional substance 20 is present at least in the passage 11 of the carrier 10, so that even if it is affected by an external force from the fluid, the functional substance 20 is unlikely to be detached from the carrier 10. That is, when the functional structure 1 is in a fluid, the fluid flows into the passage 11 from the hole 11a of the carrier 10, so that the speed of the fluid flowing in the passage 11 is considered to be slower than the speed of the fluid flowing on the outer surface of the carrier 10 due to the flow resistance (friction force). Due to the influence of such flow resistance, the pressure that the functional substance 20 held in the passage 11 receives from the fluid is lower than the pressure that the functional substance receives from the fluid outside the carrier 10. Therefore, it is possible to effectively prevent the functional substance 20 contained within the carrier 10 from being released, and it is possible to stably maintain the activity of the functional substance 20 for a long period of time. It is considered that the above-mentioned flow path resistance increases as the passage 11 of the carrier 10 has multiple bends and branches and the interior of the carrier 10 has a more complex, three-dimensional structure.

The carrier 10 is a zeolite-type compound containing aluminum (Al) and silicon (Si), and the atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) contained in the carrier 10 is 2.0 or more. By using a zeolite-type compound with a high proportion of silicon (Si) as the carrier 10, the generation of zeolite-type crystals in the functional structure is increased, making it possible to generate a stronger zeolite-type compound, and therefore a more durable functional structure can be obtained. From this perspective, the value of the Si/Al ratio in the carrier 10 is preferably 5.0 or more, more preferably 8.0 or more. On the other hand, the upper limit of the Si/Al ratio in the carrier 10 may be infinity (i.e., containing a trace amount of aluminum (Al).), but for example, from the viewpoint of production efficiency, the upper limit may be 10 ⁹ , and from the viewpoint of exerting the action of aluminum (Al) as a solid acid, the upper limit may be 10 ⁶ , and from the viewpoint of increasing the selectivity of the product, the Si/Al ratio is preferably less than 50.

In addition, the passage 11 preferably has one of one-dimensional, two-dimensional and three-dimensional holes defined by the skeletal structure of the zeolite-type compound, and an expanded diameter portion 12 different from any of the one-dimensional, two-dimensional and three-dimensional holes. In this case, the functional material 20 is preferably present at least in the expanded diameter portion 12, and more preferably is included in at least the expanded diameter portion 12. In addition, the expanded diameter portion 12 preferably connects multiple holes 11a, 11a constituting any of the one-dimensional, two-dimensional and three-dimensional holes. As a result, a separate passage different from the one-dimensional, two-dimensional or three-dimensional holes is provided inside the carrier 10, so that the function of the functional material 20 can be more effectively exhibited. The one-dimensional hole referred to here refers to a tunnel-type or cage-type hole forming a one-dimensional channel, or multiple tunnel-type or cage-type holes (multiple one-dimensional channels) forming multiple one-dimensional channels. In addition, the two-dimensional pore refers to a two-dimensional channel in which multiple one-dimensional channels are two-dimensionally connected, and the three-dimensional pore refers to a three-dimensional channel in which multiple one-dimensional channels are three-dimensionally connected. This further restricts the movement of the functional substance 20 within the carrier 10, and more effectively prevents the functional substance 20 from leaving and the functional substances 20, 20 from aggregating with each other. Inclusion refers to a state in which the functional substance 20 is encapsulated in the carrier 10. In this case, the functional substance 20 and the carrier 10 do not necessarily need to be in direct contact with each other, and the functional substance 20 may be indirectly held by the carrier 10 with another substance (e.g., a surfactant, etc.) intervening between the functional substance 20 and the carrier 10.

Although FIG. 1(b) shows a case where the functional substance 20 is encapsulated in the enlarged diameter portion 12, the present invention is not limited to this configuration, and the functional substance 20 may be held in the passage 11 with a portion of the functional substance protruding outside the enlarged diameter portion 12. The functional substance 20 may also be partially embedded in a portion of the passage 11 other than the enlarged diameter portion 12 (e.g., an inner wall portion of the passage 11), or may be held by adhesion or the like.

The passage 11 is formed three-dimensionally inside the carrier 10, including a branching section or a junction section, and it is preferable that the enlarged diameter section 12 is provided at the branching section or the junction section 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 minor axis and major axis of the holes 11a constituting any one of the one-dimensional, two-dimensional, and three-dimensional holes, and is, for example, 0.1 nm to 1.5 nm, preferably 0.5 nm to 0.8 nm. 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, and more preferably 1.1 nm to 3.3 nm. The inner diameter D _E of the expanded diameter portion 12 depends on, for example, the pore diameter of the precursor material (A) described later and the average particle diameter D _C of the functional material 20 to be encapsulated. The inner diameter D _E of the expanded diameter portion 12 is a size that can encapsulate the functional material 20.

The carrier 10 is composed of a zeolite-type compound. Examples of zeolite-type compounds include silicate compounds such as zeolite (aluminosilicate), cation-exchanged zeolite, and silicalite, zeolite-related compounds such as aluminoborates, aluminoarsenates, and germanates, and phosphate-based zeolite-like substances such as molybdenum phosphate. Among these, the zeolite-type compound is preferably a silicate compound, and more specifically, it is preferably zeolite or silicalite.

The framework structure of the zeolite-type compound is selected from 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, MOR type, BEA type, more preferably MFI type. Zeolite-type compounds have multiple pores with pore sizes according to each framework structure, for example, the maximum pore size of MFI type is 0.636 nm (6.36 Å) and the average pore size is 0.560 nm (5.60 Å).

The functional material 20 has a form of fine particles, and may be a primary particle or a secondary particle formed by aggregation of the primary particles, but the average particle diameter D _C of the functional material 20 is preferably larger than the average inner diameter D _F of the passage 11 and is equal to or smaller than the inner diameter D _E of the expanded diameter portion 12 (D _F < D _C ≦ D _E ). Such a functional material 20 is preferably present in the expanded diameter portion 12 in the passage 11, and the movement of the functional material 20 in the carrier 10 is restricted. Therefore, even if the functional material 20 is subjected to an external force from the fluid, the movement of the functional material 20 in the carrier 10 is suppressed, and the functional materials 20, 20, ... present in the expanded diameter portions 12, 12, ... dispersed and arranged in the passage 11 of the carrier 10 can be effectively prevented from contacting each other.

The average particle diameter D _C of the fine particles of the functional material 20 is preferably 0.08 nm to 30 nm, more preferably 0.1 nm or more and less than 25 nm, even more preferably 0.4 nm to 11.0 nm, and particularly preferably 0.8 nm to 2.7 nm, in both cases of primary particles and secondary particles. The ratio (D _C /D _F ) of the average particle diameter D _C of the functional material 20 to the average inner diameter D F of _the passage 11 is preferably 0.05 to 300, more preferably 0.1 to 30, even more preferably 1.1 to 30, and particularly preferably 1.4 to 3.6. The metal element (M) of the functional material 20 is preferably contained in the functional structure 1 at 0.5 to 2.5 mass %, and more preferably 0.5 to 1.5 mass %. For example, when the metal element (M) is Co, the content (mass %) of the Co element is expressed as {(mass of the Co element)/(mass of all elements in the functional structure 1)}×100.

The functional material may include metals consisting of one metal element, mixtures of two or more metal elements, or metal particles in which at least a portion of these elements are alloyed. The functional material 20 may also include metal oxide particles consisting of oxides of one or more metal elements or composite materials thereof. In this specification, the "metal" (as a material) constituting the functional material includes simple metals containing one metal element (M) and metal alloys containing two or more metal elements (M), and is a general term for metals containing one or more metal elements.

Metal elements contained in metal microparticles and metal oxide microparticles include, for example, platinum (Pt), palladium (Pd), ruthenium (Ru), nickel (Ni), cobalt (Co), molybdenum (Mo), tungsten (W), iron (Fe), chromium (Cr), cerium (Ce), copper (Cu), magnesium (Mg), and aluminum (Al). It is preferable that one or more of the above are used as the main component, and it is more preferable that they are cobalt, iron, nickel, or ruthenium, and it is even more preferable that they are cobalt, iron, or nickel, and it is particularly preferable that they are cobalt. In particular, it is preferable that the metal microparticles contain one or more metals or alloys selected from the group consisting of cobalt, iron, nickel, and ruthenium. It is also preferable that the metal oxide microparticles contain one or more metal elements selected from the group consisting of cobalt, iron, and nickel.

The ratio of silicon (Si) constituting the carrier 10 to the total of the metal elements (M) constituting the functional material 20 (atomic ratio Si/M) is preferably 10 to 1000, and more preferably 50 to 200. If the ratio is greater than 1000, the activity may be low and the effect of the functional material may not be fully obtained. On the other hand, if the ratio is less than 10, the ratio of the functional material 20 becomes too large, and the strength of the carrier 10 tends to decrease. Note that the functional material 20 referred to here refers to fine particles held or supported inside the carrier 10, and does not include functional material attached to the outer surface of the carrier 10.

[Functions of functional structures]
As described above, the functional structure 1 includes a carrier 10 having a porous structure and at least one functional material 20 present in the carrier. The functional structure 1 exerts the functionality of the functional material 20 by contacting the functional material 20 present in the carrier with a fluid. For example, when the functional structure 1 is used as a catalyst, the fluid that contacts the outer surface 10a of the functional structure 1 flows into the carrier 10 through the holes 11a formed in the outer surface 10a, is guided into the passage 11, moves through the passage 11, and exits the functional structure 1 through another hole 11a. In the path in which the fluid moves through the passage 11, the fluid comes into contact with the functional material 20 present in the passage 11, causing a catalytic reaction by the functional material 20 having catalytic activity. In addition, the functional structure 1 has a molecular sieve function due to the carrier having a porous structure.

First, the molecular sieving function of the functional structure 1 will be described with reference to FIG. 2(a). As shown in FIG. 2(a), molecules 15a having a size equal to or smaller than the pore size of the hole 11a, in other words, equal to or smaller than the inner diameter of the passage 11, can penetrate into the carrier 10. On the other hand, molecules 15b having a size larger than the pore size of the hole 11a cannot penetrate into the 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 restricted, and the compounds that can penetrate into the carrier 10 can be reacted.

Of the compounds produced in the carrier 10 by the reaction, only those composed of molecules having a size equal to or smaller than the pore size 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 transferred to the outside of the carrier 10 if they are converted into compounds composed of molecules of a size that allows them to exit the carrier 10. In this way, by using the functional structure 1, a specific reaction product can be selectively obtained.

In the functional structure 1, as shown in FIG. 2(b), the functional material 20 is encapsulated in the expanded diameter portion 12 of the passage 11. When the average particle size D _C of the functional material 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 ), a small passage 13 is formed between the functional material and the expanded diameter portion 12. Then, as shown by the arrow in FIG. 2(b), the fluid that has entered the small passage 13 comes into contact with the functional material. Since each functional material is encapsulated in the expanded diameter portion 12, the movement of the functional material within the carrier 10 is restricted. This prevents the functional materials from coagulating with each other within the carrier 10. As a result, a large contact area between the functional material and the fluid can be stably maintained.

In particular, by making the atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) in the carrier 10 2.0 or more, the production of zeolite-type crystals in the functional structure increases, making it possible to produce stronger zeolite-type compounds, thereby further increasing the durability of the functional structure.

For example, when the functional structure 1 is used as a catalyst, when a molecule that has entered the passage 11 comes into contact with the functional material 20 having catalytic activity, the molecule (substance to be reformed) is reformed by a catalytic reaction. In the present invention, by using the functional structure 1 as a catalyst, for example, a mixed gas mainly composed of hydrogen and carbon monoxide can be used as a raw material to produce hydrocarbons (excluding _CH4 ), preferably hydrocarbons having 2 to 20 carbon atoms, more preferably olefins having 2 to 20 carbon atoms or aromatic hydrocarbons having 6 to 20 carbon atoms. According to the functional structure 1 of the present invention, it is possible to produce hydrocarbons containing particularly low-grade ( _C2 to _C4 ) hydrocarbons, and it is also possible to produce hydrocarbons containing more olefins than paraffins. This catalytic reaction is carried out at high temperatures, for example, 180°C to 350°C, but since the functional material 20 is contained within the carrier 10, it is not easily affected by heating.

In particular, since the functional material 20 is present in the expanded diameter section 12, the movement of the functional material 20 within the carrier 10 is further restricted, and aggregation (sintering) of the functional materials 20 is further suppressed. As a result, the decrease in activity is further suppressed, and the life span of the functional structure 1 can be further extended.

[Method of manufacturing a functional structure]
FIG. 3 is a flowchart showing a method for manufacturing the functional structure 1 of FIG.

(Step S1: Preparation process)
As shown in Fig. 3, first, a precursor material (A) for obtaining a support having a porous structure composed of a zeolite-type compound is prepared. The precursor material (A) is preferably a regular mesoporous substance, and can be appropriately selected depending on the type (composition) of the zeolite-type compound constituting the support of the functional structure.

Here, when the zeolite-type compound constituting the support of the functional structure is a silicate compound, the regular mesoporous substance is preferably a compound consisting of an Si-O framework in which pores with a pore diameter of 1 to 50 nm are uniform in size and regularly developed in one, two or three dimensions. Such regular mesoporous substances can be obtained as various synthetic products depending on the synthesis conditions, and specific examples of synthetic products include SBA-1, SBA-15, SBA-16, KIT-6, FSM-16, MCM-41, etc., and among them, MCM-41 is preferable. 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, the pore diameter of FSM-16 is 3 to 5 nm, and the pore diameter of MCM-41 is 1 to 10 nm. Examples of such regular mesoporous materials include mesoporous silica, mesoporous aluminosilicate, and mesoporous metallosilicate.

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

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

The metal-containing solution may be any solution containing a metal component (e.g., a metal ion) corresponding to the metal element (M) constituting the functional material of the functional structure, and may be prepared, for example, by dissolving a metal salt containing the metal element (M) in a solvent. Examples of such metal salts include metal salts such as chlorides, hydroxides, oxides, sulfates, and nitrates, and among these, nitrates are preferred. Examples of the solvent that can be used include water, organic solvents such as alcohol, and mixtures of these.

The method of impregnating the precursor material (A) with the metal-containing solution is not particularly limited. For example, it is preferable to add the metal-containing solution to the precursor material (A) in small amounts in multiple batches while stirring the powdered precursor material (A) before the firing step described below. In addition, from the viewpoint of making it easier for the metal-containing solution to penetrate into the pores of the precursor material (A), it is preferable to add a surfactant as an additive to the precursor material (A) before adding the metal-containing solution. Such an additive has the function of coating the outer surface of the precursor material (A), and is thought to suppress the adhesion of the metal-containing solution added thereafter to the outer surface of the precursor material (A), making it easier for the metal-containing solution 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 alkyl phenyl ether. These surfactants have a large molecular size and cannot penetrate into the pores of the precursor material (A), so they do not adhere to the inside of the pores and are thought to not hinder the metal-containing solution from penetrating into the pores. As a method for adding the nonionic surfactant, for example, it is preferable to add 50 to 500 mass% of the nonionic surfactant to the precursor material (A) before the firing process described below. If the amount of the nonionic surfactant added to the precursor material (A) is less than 50 mass%, the above-mentioned suppression effect is difficult to manifest, and if the nonionic surfactant is added to the precursor material (A) in excess of 500 mass%, the viscosity increases too much, which is not preferable. Therefore, the amount of the nonionic surfactant added to the precursor material (A) is set to a value within the above range.

In addition, it is preferable to appropriately adjust the amount of the metal-containing solution added to the precursor material (A) in consideration of the amount of the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) (i.e., the amount of the metal element (M) to be contained in the precursor material (B)). For example, before the firing step described below, it is preferable to adjust the amount of the metal-containing solution added to the precursor material (A) to be 10 to 1000, and more preferably 50 to 200, in terms of the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to the precursor material (A) (atomic ratio Si/M). For example, when a surfactant is added as an additive to the precursor material (A) before adding the metal-containing solution to the precursor material (A), the amount of the metal-containing solution added to the precursor material (A) can be adjusted to be 50 to 200 in terms of the atomic ratio Si/M, so that the metal element (M) contained in the functional material can be contained in an amount of 0.5 to 2.5 mass% relative to the functional structure. In the state of precursor material (B), the amount of metal element (M) present inside the pores is roughly proportional to the amount of metal-containing solution added to precursor material (A) if the metal concentration of the metal-containing solution, the presence or absence of the above-mentioned additive, and other conditions such as temperature and pressure are the same. In addition, the amount of metal element (M) present in precursor material (B) is proportional to the amount of metal element constituting the functional substance present in the support of the functional structure. Therefore, by controlling the amount of metal-containing solution added to precursor material (A) to be within the above range, the metal-containing solution can be sufficiently impregnated inside the pores of precursor material (A), and thus the amount of functional substance present in the support of the functional structure can be adjusted.

After the precursor material (A) is impregnated with the metal-containing solution, a washing process may be performed as necessary. As the washing solution, water, an organic solvent such as alcohol, or a mixture of these can be used. In addition, after the precursor material (A) is impregnated with the metal-containing solution and washed as necessary, it is preferable to further perform a drying process. Examples of the drying process include natural drying for about one night, and high-temperature drying at 150°C or less. Note that if the calcination process described below is performed while a large amount of moisture contained in the metal-containing solution or the moisture of the washing solution remains in the precursor material (A), the skeletal structure of the precursor material (A) as a regular mesoporous material may be destroyed, so it is preferable to dry it thoroughly.

(Step S3: Firing process)
Next, a precursor material (B) in which a precursor material (A) for obtaining a carrier having a porous structure composed of a zeolite type compound is impregnated with a metal-containing solution is calcined to obtain a precursor material (C).

The calcination process is preferably carried out in air at 350 to 850°C for 2 to 30 hours. This calcination process causes crystal growth of the metal components impregnated in the pores of the ordered mesoporous material, forming a functional material in the pores.

(Step S4: Hydrothermal treatment step)
Next, a mixed solution is prepared by mixing the precursor material (C), a structure directing agent, and an aluminum source, and the precursor material (C) obtained by calcining the precursor material (B) is subjected to a hydrothermal treatment to obtain a functional structure.

The structure directing agent is a template agent for directing the skeletal structure of the skeleton (support) of the functional structure, and at least one of organic structure directing agents (usually written as "organic structure directing agents" or "OSDA") and inorganic structure directing agents having ^OH- can be used. Among these, as the organic structure directing agent, for example, a surfactant can be used. The organic structure directing agent is preferably selected according to the skeleton structure of the support of the functional structure, and for example, surfactants such as tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), tetrapropylammonium bromide (TPABr), and tetraethylammonium hydroxide (TEAOH) are suitable. Representative examples of inorganic structure-directing agents include hydroxides of alkali metals and alkaline earth metals, such as lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (Rb(OH)), calcium hydroxide (Ca(OH) ₂ ), and strontium hydroxide (Sr(OH) ₂ ).

The aluminum source is a raw material for supplying aluminum contained in the support of the functional structure, and dissolves in water to supply Al ions. For example, _NaAlO2 or Al(OH) ₃ is preferable.

The precursor material (C), the structure-directing agent, and the aluminum source may be mixed during the hydrothermal treatment process, or may be mixed before the hydrothermal treatment process. The method for preparing the mixed solution is not particularly limited, and the precursor material (C), the structure-directing agent, the aluminum source, and the solvent may be mixed at the same time, or the precursor material (C), the structure-directing agent, and the aluminum source may be dispersed in a solvent in their respective solutions, and then the respective dispersion solutions may be mixed. As the solvent, for example, water, an organic solvent such as alcohol, or a mixture of these may be used. It is also preferable to adjust the pH of the mixed solution using an acid or a base before performing the hydrothermal treatment.

The hydrothermal treatment can be carried out by a known method, and is preferably carried out, for example, in a sealed container at 80 to 800°C, for 5 to 240 hours, and under conditions of 0 to 2000 kPa. The hydrothermal treatment is also preferably carried out in a basic atmosphere. Although the reaction mechanism here is not necessarily clear, by carrying out hydrothermal treatment using precursor material (C) as a raw material, the skeletal structure of the precursor material (C) as a regular mesoporous substance gradually collapses, but the position of the functional substance inside the pores of precursor material (C) is roughly maintained, and a new skeletal structure (porous structure) is formed as a skeleton (carrier) of the functional structure due to the action of the structure-directing agent. At this time, aluminum is incorporated into the new skeletal structure. The functional structure thus obtained comprises a carrier having a porous structure and a functional substance (e.g., metal oxide fine particles) present in the carrier, and the carrier has a passage in which a plurality of pores are interconnected due to its porous structure, the atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) contained in the carrier 10 is 2.0 or more, and at least a portion of the functional substance is retained in the passage of the carrier. In addition, in the above-mentioned hydrothermal treatment step, in this embodiment, a mixed solution is prepared by mixing the precursor material (C), the structure-directing agent, and the aluminum source, and the precursor material (C) is hydrothermally treated, but this is not limited thereto, and the precursor material (C) may be mixed with only the aluminum source without mixing the structure-directing agent, and the precursor material (C) may be hydrothermally treated.

The precipitate (functional structure) obtained after the hydrothermal treatment is preferably washed, dried and calcined as necessary after recovery (e.g., filtration). As the washing solution, water, an organic solvent such as alcohol, or a mixture of these can be used. Examples of the drying treatment include natural drying for about one night, and high-temperature drying at 150°C or less. If the precipitate is calcined while a large amount of moisture remains, the skeletal structure as a support for the functional structure may be destroyed, so it is preferable to dry it thoroughly. The calcination treatment can be performed, for example, in air at 350 to 850°C for 2 to 30 hours. Such a calcination treatment burns off the structure-directing agent attached to the functional structure. Depending on the purpose of use, the precipitate after recovery can be used as it is without calcining. For example, if the environment in which the functional structure is used is a high-temperature environment with an oxidizing atmosphere, the structure-directing agent is burned off by exposing it to the usage environment for a certain period of time, and the functional structure can be obtained in the same manner as when it is calcined, so it can be used as it is.

The manufacturing method described above is an example in which the metal element (M) contained in the metal-containing solution to be impregnated into the precursor material (A) is a metal species that is difficult to oxidize (e.g., the noble metal Ru).

(Step S5: Reduction process)
On the other hand, when the metal element (M) contained in the metal-containing solution to be impregnated into the precursor material (A) contains a metal species (e.g., Fe, Co, Cu, etc.) that is easily oxidized, and metal fine particles made of these metal species are used as the functional substance, it is preferable to perform a reduction treatment on the hydrothermally treated precursor material (C) after the hydrothermal treatment step. If the metal element (M) contained in the metal-containing solution is a metal species that is easily oxidized, the metal component will be oxidized by the heat treatment in the steps (steps S3 to S4) after the impregnation treatment (step S2). Therefore, the support formed in the hydrothermal treatment step (step S4) will contain metal oxide fine particles as a functional substance. Therefore, in order to obtain a functional structure in which a functional substance is contained in the support, it is desirable to perform a reduction treatment under a reducing gas atmosphere such as hydrogen gas after performing a calcination treatment on the precipitate recovered as necessary after the hydrothermal treatment. By performing the reduction treatment, the metal oxide fine particles contained in the support are reduced, and a functional substance consisting of metal fine particles corresponding to the metal elements constituting the metal oxide fine particles is formed. As a result, a functional structure having metal fine particles present as a functional substance in the carrier is obtained. At this time, the functionality provided by the functional substance can be adjusted by adjusting the degree of reduction in the reduction step. Such reduction treatment may be performed as necessary. For example, when the environment in which the functional structure is used can be at least temporarily a reducing atmosphere, the metal oxide fine particles are reduced by exposing the functional structure to a use environment including a reducing atmosphere for a certain period of time, and thus a functional structure similar to that obtained by reduction treatment is obtained, and it becomes possible to use the functional structure with the oxide fine particles present in the carrier as it is.

[Modification of functional structure]
Fig. 4 is a schematic diagram showing a modified example of the functional structure 1 in Fig. 1. The functional structure 1 in Fig. 1 shows a case in which the functional structure 1 includes a carrier 10 and a functional substance 20 present in the carrier 10, but is not limited to this configuration, and for example, as shown in Fig. 4, the functional structure 2 may further include another functional substance 30 held on the outer surface 10a of the carrier 10.

This functional material 30 is a material that exhibits one or more functionalities at least during use. The functionality possessed by the other functional material 30 may be the same as or different from the functionality possessed by the functional material 20. Furthermore, when both functional materials 20 and 30 are materials having the same functionality, the material of the other functional material 30 may be the same as or different from the material of the functional material 20. According to this configuration, the content of the functional material held in the functional structure 2 can be increased, and the activity of the functional material can be further promoted.

In this case, it is preferable that the content of the functional material 20 present in the carrier 10 is greater than the content of the other functional material 30 held on the outer surface 10a of the carrier 10. This allows the functionality of the functional material 20 held inside the carrier 10 to predominate, and the functionality of the functional material is stably exhibited.

[Application examples of functional structure 1]
The functional structure 1 of the present invention can be used as a catalytic substance having a catalytic function, for example. In this case, a method for producing hydrocarbons in which hydrocarbons are synthesized from carbon monoxide and hydrogen using the functional structure 1 as a catalyst may be provided. Such a catalyst includes a carrier 10 having a porous structure composed of a zeolite-type compound and at least one functional substance 20 present in the carrier 10, the carrier 10 having passages 11 communicating with each other, the atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) contained in the carrier 10 being 2.0 or more, and the functional substance 20 including the functional structure 1 present at least in the expanded diameter portion 12 of the passage 11 of the carrier 10. That is, in the present invention, a method for producing liquid hydrocarbons in which liquid hydrocarbons are synthesized from carbon monoxide and hydrogen using the above-mentioned functional structure is provided. Furthermore, as described above, olefins can be preferentially produced by the FT synthesis reaction using this functional structure 1.

The raw material for carrying out such a method for producing hydrocarbons using the Fischer-Tropsch synthesis reaction is not particularly limited as long as it is a synthesis gas mainly composed of molecular hydrogen and carbon monoxide, but a synthesis gas having a hydrogen/carbon monoxide molar ratio of 1.5 to 2.5 is preferable, and a synthesis gas having such a molar ratio of 1.8 to 2.2 is more preferable. There are also no particular limitations on the reaction conditions for the FT synthesis reaction, and the reaction can be carried out under known conditions. For example, the reaction temperature is preferably 200 to 500°C, and the pressure is preferably 0.1 to 3.0 MPa (absolute pressure).

The Fischer-Tropsch synthesis reaction can be carried out in a process known as a Fischer-Tropsch synthesis reaction process, such as a fixed bed, a supercritical fixed bed, a slurry bed, or a fluidized bed. Preferred processes include a fixed bed, a supercritical fixed bed, and a slurry bed.

In addition, in the present invention, a hydrocarbon production apparatus having the above-mentioned functional structure may be provided. Such a hydrocarbon production apparatus is not particularly limited as long as it can carry out a chemical reaction using the above-mentioned functional structure as a catalyst, and for example, a commonly used production apparatus such as an FT synthesis reaction apparatus or an FT synthesis reaction column can be used. By using the functional structure according to the present invention in such a hydrocarbon production apparatus, the production apparatus can also achieve the same effects as those described above.

The functional structure according to the embodiment of the present invention, its manufacturing method, a method for manufacturing hydrocarbons using the functional structure, and a hydrocarbon manufacturing apparatus having the functional structure have been described above, but the present invention is not limited to the above embodiment, and various modifications and changes are possible based on the technical concept of the present invention.

(Examples 1 to 40)
[Synthesis of precursor material (A)]
A mixed aqueous solution was prepared by mixing a silica agent (tetraethoxysilane (TEOS), manufactured by Wako Pure Chemical Industries, Ltd.) with a surfactant as a template agent, and the pH was appropriately adjusted. The solution was subjected to hydrothermal treatment at 80 to 350°C for 100 hours in a sealed container. Thereafter, the resulting precipitate was filtered off, washed with water and ethanol, and further calcined in air at 600°C for 24 hours to obtain powdered precursor material (A) with the type and pore size shown in Tables 1 and 3. The following surfactants were used according to the type of precursor material (A) ("Type of precursor material (A): Surfactant").
MCM-41: Hexadecyltrimethylammonium bromide (CTAB) (manufactured by Wako Pure Chemical Industries, Ltd.)

[Preparation of Precursor Materials (B) and (C)]
Next, metal salts containing metal elements (M) constituting the types of functional substances shown in Tables 2 and 4 were dissolved in water to prepare metal-containing aqueous solutions. The metal salts used were as follows, depending on the types of metal fine particles that are functional substances ("metal fine particles: metal salts").
Co: Cobalt (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
Ni: Nickel (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・Fe: Iron (III) nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
Ru: Ruthenium (III) chloride anhydrous (Tokyo Chemical Industry Co., Ltd.)

This precursor material (A) was pretreated by adding an aqueous solution of polyoxyethylene (15) oleyl ether (NIKKOL BO-15V, manufactured by Nikko Chemicals Co., Ltd.) as an additive (nonionic surfactant), and then a metal-containing aqueous solution was added in small amounts in multiple batches to the precursor material (A), followed by drying at room temperature (20°C ± 10°C) for 12 hours or more to obtain precursor material (B).

The amount of metal-containing aqueous solution added to the precursor material (A) was adjusted so that the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing aqueous solution (atomic ratio Si/M) would be the value shown in Tables 1 and 3.

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

The precursor material (C) obtained as described above was mixed with aluminum hydroxide (Al(OH) ₃ , manufactured by Sigma Aldrich) as an aluminum source, and a structure-directing agent shown in Tables 1 and 3 to prepare a mixed aqueous solution, which was then subjected to hydrothermal treatment in a sealed container at 80 to 350°C under the conditions of pH and time shown in Tables 1 and 3. The resulting precipitate was then filtered, washed with water, dried at 100°C for 12 hours or more, and calcined in air at 600°C for 24 hours. The calcined product was then collected and reduced at 500°C for 60 minutes under a flow of hydrogen gas to obtain a functional structure having a support and metal fine particles shown in Tables 1 and 3 (Examples 1 to 40).

(Comparative Examples 1 to 3)
In Comparative Examples 1 to 3, functional structures were obtained in the same manner as in Examples 1, 5, and 8, respectively, except that the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) was set to 1.8.

(Comparative Example 4)
In Comparative Example 4, cobalt oxide powder (II, III) (manufactured by Sigma-Aldrich Japan LLC) having an average particle size of 50 nm or less was mixed with MFI-type silicalite, and hydrogen reduction treatment was carried out in the same manner as in Example 1 to obtain a functional structure in which cobalt fine particles were attached to the outer surface of the silicalite as a carrier. The MFI-type silicalite was synthesized in the same manner as in Example 1, except for the step of adding metal.

(Comparative Example 5)
In Comparative Example 5, MFI-type silicalite was synthesized in the same manner as in Comparative Example 4, except that the step of adhering cobalt fine particles was omitted.

[evaluation]
Various characteristics of the functional structures of the above examples and the silicalite of the comparative example were evaluated under the conditions shown below.

[A] Cross-sectional observation For the functional structure of the above-mentioned Example and the silicalite of the Comparative Example, observation samples were prepared by a pulverization method, and cross-sectional observation was performed using a transmission electron microscope (TEM) (TITAN G2, manufactured by FEI). As a result, it was confirmed that in the functional structure of the above-mentioned Example, metal fine particles of cobalt, iron, nickel or ruthenium are present and held inside the carrier made of silicalite or zeolite. On the other hand, in the silicalite of Comparative Example 4, metal fine particles of cobalt are only attached to the outer surface of the carrier, and are not present inside the carrier.

In addition, for the functional structures in the above examples in which the metal was iron (Fe) microparticles, cross sections were cut out by FIB (focused ion beam) processing, and cross-sectional elemental analysis was performed using an SEM (SU8020, Hitachi High-Technologies Corporation) and an EDX (X-Max, Horiba, Ltd.). As a result, Fe elements were detected from inside the carrier. The results of the cross-sectional observations using the above TEM and SEM/EDX confirmed the presence of Fe microparticles inside the carrier.

[B] Average inner diameter of the support passages and average particle size of metal microparticles From the TEM image taken by the cross-sectional observation performed in the above evaluation [A], 500 support passages were randomly selected, the long axis and short axis of each were measured, and the inner diameter of each was calculated from the average value (N = 500). Furthermore, the average value of the inner diameters was calculated, and this was designated as the average inner diameter D _F of the support passages.

In addition, analysis was performed using SAXS (small angle X-ray scattering) to confirm the average particle size and dispersion state of the metal microparticles. The SAXS measurements were performed using beamline BL19B2 at Spring-8. The obtained SAXS data was fitted with a spherical model using the Guinier approximation method to calculate the average particle size D _C of the metal microparticles. The particle size was measured for a functional structure having Fe microparticles as metal microparticles (functional substance). In addition, for comparison, commercially available Fe microparticles (manufactured by Wako) were observed and measured using a SEM. The results are shown in Tables 2 and 4.

As a result, while the commercially available product contains randomly-distributed iron particles of various sizes in the particle size range of approximately 50 nm to 400 nm, the functional structures of each example having metal particles with an average particle size of 1.5 nm to 1.6 nm showed that, in the SAXS measurement results, scattering peaks corresponding to the particle size values of each example listed in Tables 2 and 4 were detected within the particle size range of 10 nm or less. Furthermore, the SAXS measurement results and the cross-sectional measurement results by SEM/EDX showed that metal particles (Fe particles) with a particle size of 10 nm or less were present inside the carrier with a uniform particle size and in a highly dispersed state.

[C] Relationship between the amount of metal element (M) added to the precursor material (A) and the content of the metal element (M) encapsulated as a functional substance inside the carrier constituting the functional structure When the precursor material (A) was impregnated with a metal-containing solution, the amount of metal element (M) added in the precursor material (A) was an amount of addition such that the atomic ratio Si/M = 100, and a functional structure was produced in which metal fine particles were encapsulated as a functional substance inside the carrier. Thereafter, the amount of metal (mass%) encapsulated inside the carrier of each functional structure produced with the above amount of addition was measured.

The amount of metal was quantified using ICP (inductively coupled plasma) alone or a combination of ICP and XRF (X-ray fluorescence analysis). XRF (energy dispersive X-ray fluorescence analyzer "SEA1200VX", manufactured by SSI NanoTechnology) was performed under conditions of a vacuum atmosphere and an acceleration voltage of 15 kV (using a Cr filter) or 50 kV (using a Pb filter). XRF is a method for calculating the amount of metal present from the fluorescence intensity, and quantitative values (converted to mass %) cannot be calculated using XRF alone. Therefore, the content of metal elements (M) and Si atoms in the functional structure to which metal was added at Si/M = 100 was quantified using ICP analysis.

[D] Atomic ratio (Si/Al ratio) in the support The amount of aluminum (Al) and silicon (Si) contained in the support were quantified using ICP (inductively coupled plasma). The atomic ratio (Si/Al ratio) was calculated from the amount of aluminum (Al) and silicon (Si) measured.

[E] Performance Evaluation The performance of the metal fine particles was evaluated for the functional structures of the above examples and the silicalite of the comparative example. The results are shown in Tables 2 and 4.

(1) Catalytic Activity As an example of the performance of the metal fine particles encapsulated in the functional structure, the catalytic activity when the functional structure was used as a catalyst was evaluated under the following conditions.
First, 70 mg of the functional structure was loaded into an atmospheric pressure flow reactor, hydrogen (8 ml/min) and carbon monoxide (4 ml/min) were supplied, and the pressure inside the reactor was adjusted to 0.1 MPa. The temperature was raised at 20° C./min in the temperature range of 100 to 700° C., and then the temperature was maintained for 1 hour, thereby carrying out Fischer-Tropsch synthesis. Here, a single microreactor (Frontier Labs, Rx-3050SR) was used as the atmospheric pressure flow reactor.

After the reaction was completed, the recovered product gas and liquid were analyzed for components by gas chromatography mass spectrometry (GC/MS). The analyzer used for the product gas and liquid was a TRACE 1310GC (manufactured by Thermo Fisher Scientific, Inc., detector: thermal conductivity detector).

Furthermore, based on the results of the above component analysis, the products obtained by the FT synthesis reaction were confirmed. In this evaluation, the above operations were carried out at 250°C, 300°C, 350°C, and 400°C using the functional structures obtained in the examples and comparative examples, and the results were evaluated according to the following criteria.

Here, when the generation of hydrocarbons (excluding _CH4 , the same applies below) was confirmed at 250°C (i.e., when the reaction initiation temperature was 250°C or lower), the catalytic activity in the FT synthesis reaction was judged to be excellent and marked with "◎", when the generation of hydrocarbons was confirmed at 300°C (i.e., when the reaction initiation temperature was higher than 250°C and lower than 300°C), the catalytic activity was judged to be good and marked with "◯", when the generation of hydrocarbons was confirmed at 350°C (i.e., when the reaction initiation temperature was higher than 300°C and lower than 350°C), the catalytic activity was judged to be poor and marked with "△", and when the generation of hydrocarbons was confirmed at 400°C (i.e., when the reaction initiation temperature was higher than 350°C and lower than 400°C) or when the FT synthesis reaction did not occur, the catalytic activity was judged to be very poor (unacceptable) and marked with "X".

(2) Durability (lifespan)
The durability was evaluated under the following conditions.
First, the functional structure used in the above evaluation (1) was once collected and then heated at 650° C. for 12 hours to produce a functional structure after this heating. Next, the FT synthesis reaction was carried out using the functional structure after heating in the same manner as in the above evaluation (1), and the components of the generated gas and the generated liquid were analyzed in the same manner as in the above evaluation (1).

Based on the obtained analysis results, the amount of hydrocarbons produced was determined using the same method as in the above evaluation (1). Furthermore, the extent to which the yield of hydrocarbons produced by the functional structure after heating was maintained was compared with the amount of hydrocarbons produced by the functional structure before heating. Specifically, the percentage (%) of the amount of hydrocarbons produced by the functional structure after heating (the amount produced in this evaluation (2)) relative to the amount of hydrocarbons produced by the functional structure before heating (the amount produced in the above evaluation (1)) was calculated.

In this example, if the amount of hydrocarbons produced by the functional structure after heating (the amount of hydrocarbons produced as determined in this evaluation (2)) is maintained at 80% or more compared to the amount of hydrocarbons produced by the functional structure before heating (the amount of hydrocarbons produced as determined in the above evaluation (1)), the durability (heat resistance) is judged to be excellent and marked with a "◎", if the amount is maintained at 60% or more but less than 80%, the durability (heat resistance) is judged to be good and marked with a "○", and if the amount falls to less than 60%, the durability (heat resistance) is judged to be poor (unacceptable) and marked with a "×".

Similar performance evaluations were also carried out for Comparative Examples 1 to 5. Note that Comparative Example 5 is the carrier itself and does not contain metal microparticles. Therefore, in the above performance evaluation, only the carrier of Comparative Example 5 was filled in place of the functional structure. The results are shown in Tables 2 and 4.

As is clear from Tables 1 to 4, the functional structures (Examples 1 to 40) in which cross-sectional observation confirmed that metal microparticles, which are functional substances, were held inside the carrier, were found to exhibit excellent catalytic activity and also to have excellent durability, particularly when used as catalysts for the FT synthesis reaction. Therefore, it is presumed that the functional substances held inside the carrier are less likely to aggregate in the functional structures of Examples 1 to 40.

In addition, for the functional structures obtained in the above evaluation [C], the relationship between the amount of metal (mass%) encapsulated inside the carrier and the catalytic activity in the above evaluation (1) was evaluated. The evaluation method was the same as the evaluation method used in "(1) Catalytic activity" in the above [E] "Performance evaluation". As a result, it was found that in each example, when the amount of metal-containing solution added to the precursor material (A) was 100 in terms of the atomic ratio Si/M (the content of metal element (M) relative to the functional structure was 0.52 to 1.09 mass%), the catalytic activity improved when used as a catalyst for the FT synthesis reaction, and durability also tended to improve.

Furthermore, the catalyst structure of the present invention was separately evaluated for the relationship between the amount of metal (mass%) encapsulated inside the carrier and the catalytic activity in the above evaluation (1). The evaluation method was the same as the evaluation method used in "(1) Catalytic activity" in the above [D] "Performance evaluation". As a result, it was found that the catalytic activity in the FT synthesis reaction tends to improve when the amount of metal-containing solution added to the precursor material (A) is 10 to 1000, converted into an atomic ratio Si/M, and more preferably 50 to 200 (the content of metal element (M) relative to the catalyst structure is 0.5 to 2.5 mass%).

Furthermore, when the catalytic activity of a functional structure containing Co and a functional structure containing Fe, Ni or Ru was compared, the durability was evaluated as "◎" when the Si/Al ratio was 25 or more regardless of whether Co, Fe, Ni or Ru was included as the metal fine particles, and the durability was evaluated as "◎" even when the Si/Al ratio was 2 or more and less than 25, especially when Co was included as the metal fine particles. In contrast, when Fe, Ni or Ru was included as the metal fine particles, the durability was sometimes evaluated as "◯" when the Si/Al ratio was 2 or more and less than 15. In addition, the GC/MS area of hydrocarbons (C 2 -C 20 ) was compared between Example 1 (Co inclusion functional structure) and Examples 10, 17 and ₃₀ (Fe, Ni, Ru inclusion functional structures), which were good in _both activity and durability, as a representative. As a result, the Co inclusion functional structure had a peak area about 1.4 times that of the Fe, Ni, and Ru inclusion functional structures. From these results, it was found that Co is a more suitable inclusion metal species than Fe, Ni, and Ru.

On the other hand, in the functional structures of Comparative Examples 1 to 3, which had a small Si/Al ratio of 1.8, the zeolite-type compound did not crystallize, and the evaluation results for catalytic activity and durability were both "x". In addition, the functional structure of Comparative Example 4, in which metal fine particles were attached only to the outer surface of the carrier, had improved catalytic activity in the FT synthesis reaction compared to the carrier itself of Comparative Example 5, which did not have metal fine particles, but was inferior in both catalytic activity and durability to the functional structures of Examples 1 to 40.

From the above results, it can be inferred that the functional structures (Examples 1 to 40) exhibit excellent activity by suppressing the aggregation of functional substances such as metal microparticles, and also have excellent durability.

REFERENCE SIGNS LIST 1 functional structure 10 carrier 10a outer surface 11 passage 11a hole 12 enlarged diameter portion 20 functional material 30 functional material D _C average particle diameter D _F average inner diameter D _E inner diameter

Claims (10)

A porous support composed of a zeolite-type compound;
A plurality of functional substances present in the carrier;
Equipped with
the functional substance is a metal fine particle containing one or more metals or alloys selected from the group consisting of cobalt (Co), iron (Fe), nickel (Ni) and ruthenium (Ru);
The support contains aluminum (Al) and silicon (Si);
The atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) contained in the carrier is 2.0 or more;
the carrier has passages which communicate with each other, the passages having one of one-dimensional pores, two-dimensional pores and three-dimensional pores of the framework structure of the zeolite type compound, and an expanded portion different from any of the one-dimensional pores, the two-dimensional pores and the three-dimensional pores;
Among the plurality of functional substances,
At least one functional substance is present in an inclusion state in at least the expanded diameter portion of the carrier,
the average inner diameter of the passage is calculated from an average value of the minor axis and the major axis of the pores constituting any one of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores;
The average particle size of the functional substance is 0.08 nm to 30 nm;
A catalyst material for a Fischer-Tropsch synthesis , characterized in that the average particle size of the functional material is greater than the average inner diameter of the passages and is equal to or smaller than the inner diameter of the expanded portion. 2. The catalyst material for a Fischer-Tropsch synthesis according to claim 1, wherein the enlarged diameter portion connects a plurality of pores constituting any one of the one-dimensional pores, the two-dimensional pores and the three-dimensional pores. 3. The catalyst material for Fischer-Tropsch synthesis according to claim 1, wherein the metal element (M) of the functional material is contained in an amount of 0.5 to 2.5 mass % based on the catalyst material. 4. The catalyst material for Fischer-Tropsch synthesis according to claim 1, wherein the functional material is fine metal oxide particles. 5. The catalyst material for a Fischer-Tropsch synthesis according to claim 1 , wherein a ratio of an average particle size of said functional material to an average inner diameter of said passages is 1.1 to 300. The catalyst material for Fischer-Tropsch synthesis according to any one of claims 1 to 5 , characterized in that the average inner diameter of the channels is between 0.1 nm and 1.5 nm. The catalyst material for Fischer-Tropsch synthesis according to any one of claims 1 to 6 , further comprising at least one other functional material carried on the outer surface of the support. 8. The catalyst material for Fischer-Tropsch synthesis according to claim 7, characterized in that the content of the at least one functional material present within the support is greater than the content of the at least one other functional material carried on the outer surface of the support. The catalyst material for a Fischer-Tropsch synthesis according to any one of claims 1 to 8 , characterized in that the zeolite type compound is a silicate compound. A hydrocarbon production apparatus comprising the Fischer-Tropsch synthesis catalyst material according to any one of claims 1 to 9 .

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