Functional structure and method for manufacturing the functional structure

Abstract

To provide a functional structure that can realize a long life time by suppressing a decline in functions and that can save resources without requiring a complicated replacement operation, and to provide a method for producing the functional structure.SOLUTION: A functional structure includes a skeletal body of a porous structure composed of a zeolite-type compound, and at least one kind of metal microparticles present in the skeletal body, wherein the skeletal body has channels in communication with each other, and the metal microparticles are present at least in the channels of the skeletal body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a functional structure including a skeleton with a porous structure and metal fine particles, and a method for producing the functional structure. [Background technology]

[0002] Refineries at petroleum complexes produce a petrochemical raw material called naphtha, as well as various fuels such as heavy oil, diesel, kerosene, gasoline, and LPG from crude oil. Because crude oil is a mixture of the above petrochemical raw materials, various fuels, and various impurities, a process is required to distill and separate the various components contained in the crude oil.

[0003] In the petroleum refining process, the difference in boiling points of each component is utilized to heat crude oil on the trays in the tower of an atmospheric distillation unit to separate each component, and then each separated substance is concentrated. As a result, low-boiling-point substances such as LPG and naphtha are extracted from the upper trays of the atmospheric distillation unit, while high-boiling-point substances such as heavy oil are extracted from the bottom of the atmospheric distillation unit. Various fuel products are then produced by subjecting the separated and concentrated substances to secondary treatment such as desulfurization.

[0004] In general, petroleum reforming catalysts are used in the petroleum refining process to efficiently reform low-boiling naphtha, etc., to produce high-octane gasoline, etc. The naphtha fraction in crude oil has a low octane number as is and is unsuitable as gasoline for running vehicles, so the low-octane paraffin and naphthene components in the naphtha fraction are reformed using petroleum reforming catalysts to convert them into high-octane aromatic components, thereby producing reformed gasoline with properties suitable for vehicle fuel.

[0005] Furthermore, with the increasing heaviness of crude oil, hydrocracking is being carried out to further crack the desulfurized heavy oil and desulfurized heavy light oil obtained by hydrodesulfurization of heavy oil in hydrodesulfurization units such as direct desulfurization units and indirect desulfurization units, thereby increasing the production of desulfurized naphtha, desulfurized kerosene, desulfurized light oil, etc. For example, by hydrocracking atmospheric distillation residue, the yield of desulfurized light oil fraction and desulfurized naphtha fraction is increased, thereby reducing the desulfurized heavy oil. Furthermore, by using the desulfurized heavy oil in a catalytic cracking unit to produce LPG fraction, FCC gasoline fraction, and LCO fraction, the residual oil is reduced and the light oil fraction is increased. For this purpose, catalysts made of a crystalline aluminosilicate support, a typical example of zeolite, and hydrocracking catalysts containing zeolite and porous inorganic oxide in specific ratios have been proposed.

[0006] For example, a hydrocracking catalyst has been disclosed in which a metal selected from Pd, Pt, Co, Fe, Cr, Mo, W, and mixtures thereof is deposited on the surface of a carrier made of Y-type zeolite (Patent Document 1).

[0007] In the automotive field, a ceramic catalyst body has been proposed as a catalyst structure for exhaust gas from vehicles equipped with diesel engines. The ceramic catalyst body is made by disposing a ceramic carrier on the surface of a substrate ceramic and supporting both a main catalyst component and a promoter catalyst component on the ceramic carrier. In this ceramic catalyst body, a large number of pores consisting of lattice defects in the crystal lattice are formed on the surface of the ceramic carrier made of γ-alumina, and the main catalyst component made of Ce—Zr, Pt, etc. is directly supported near the surface of the ceramic carrier (Patent Document 2). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US Patent Application Publication No. 2016 / 0030934 [Patent Document 2] US Patent Application Publication No. 2003 / 0109383 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the above-described catalyst structure, because the catalyst particles are supported on or near the surface of the support, they tend to move within the support due to the influence of forces and heat from the fluid, such as the reforming material, during the reforming process, which can easily cause agglomeration (sintering) of catalyst particles. When catalyst particles agglomerate, the effective surface area of ​​the catalyst decreases, which reduces catalytic activity and shortens the catalyst's lifespan. Therefore, the catalyst structure itself must be replaced or regenerated frequently, which is both cumbersome and prevents resource conservation. Furthermore, because petroleum reforming catalysts are typically connected downstream of atmospheric distillation units and used continuously in the petroleum refining process, it is difficult to apply catalyst reactivation techniques. Even if reactivation techniques could be applied, the work would be extremely cumbersome.

[0010] The object of the present invention is to provide a functional structure and a method for manufacturing a functional structure that can suppress functional degradation, achieve a long life, do not require complicated replacement work, and can save resources. [Means for solving the problem]

[0011] As a result of extensive research to achieve the above-mentioned object, the inventors have discovered that a functional structure can be obtained that is capable of suppressing functional deterioration of the metal microparticles and achieving a longer lifespan, by comprising a porous skeleton composed of a zeolite-type compound and at least one metal microparticle contained within the skeleton, wherein the skeleton has passages that communicate with each other and the metal microparticles are held in at least the passages of the skeleton, and based on this finding, has completed the present invention.

[0012] That is, the gist of the present invention is as follows. [1] A porous framework composed of zeolite-type compounds; At least one metal fine particle present inside the framework; Equipped with the framework has passages that communicate with each other, A functional structure characterized in that the metal fine particles are present at least in the passages of the skeleton. [2] The passages have 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 portion different from any of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores; and The functional structure according to [1] above, wherein the metal fine particles are present at least in the expanded diameter portion. [3] The functional structure according to [2] above, wherein the enlarged diameter portion connects a plurality of pores that constitute any one of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores. [4] The metal fine particles are a catalytic material, The functional structure according to any one of the above [1] to [3], wherein the framework is a support that supports at least one of the catalyst substances. [5] The functional structure according to any one of [1] to [4] above, characterized in that the average particle size of the metal microparticles is larger than the average inner diameter of the passage and is equal to or smaller than the inner diameter of the expanded portion. [6] The functional structure according to any one of [1] to [5] above, characterized in that the metal element (M) of the metal fine particles is contained in an amount of 0.5 to 2.5 mass % relative to the functional structure. [7] The functional structure according to any one of the above [1] to [6], wherein the metal fine particles have an average particle size of 0.08 nm to 30 nm. [8] The functional structure according to [7] above, wherein the metal fine particles have an average particle size of 0.4 nm to 11.0 nm. [9] The functional structure according to any one of the above [1] to [8], characterized in that the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the passages is 0.05 to 300.

[10] The functional structure according to the above [9], wherein the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the passages is 0.1 to 30.

[11] The functional structure according to the above

[10] , wherein the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the passages is 1.4 to 3.6.

[12] The average inner diameter of the passage is 0.1 nm to 1.5 nm; The functional structure according to any one of the above [2] to

[11] , wherein the inner diameter of the enlarged diameter portion is 0.5 nm to 50 nm.

[13] The functional structure according to any one of the above [1] to

[12] , further comprising at least one metal fine particle held on the outer surface of the framework.

[14] The functional structure according to

[13] above, characterized in that the content of the at least one metal microparticle present within the framework is greater than the content of the at least one metal microparticle held on the outer surface of the framework.

[15] The functional structure according to any one of the above [1] to

[14] , wherein the zeolite type compound is a silicate compound.

[16] 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 framework composed of a zeolite-type compound; a hydrothermal treatment step of hydrothermally treating a precursor material (C) obtained by calcining the precursor material (B); a step of subjecting the hydrothermally treated precursor material (C) to a reduction treatment; A method for producing a functional structure, comprising:

[17] The method for producing a functional structure according to

[16] above, characterized in that a nonionic surfactant is added in an amount of 50 to 500 mass % based on the precursor material (A) before the firing step.

[18] The method for producing a functional structure according to the above

[16] or

[17] , characterized in that, before the firing step, the metal-containing solution is added to the precursor material (A) in multiple batches, thereby impregnating the precursor material (A) with the metal-containing solution.

[19] The method for producing a functional structure according to any one of the above items

[16] to

[18] , characterized in that, when impregnating the precursor material (A) with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is adjusted so that 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 number ratio Si / M) is 10 to 1000.

[20] The method for producing a functional structure according to the above

[16] , characterized in that in the hydrothermal treatment step, the precursor material (C) is mixed with a structure-directing agent.

[21] The method for producing a functional structure according to

[16] above, wherein the hydrothermal treatment step is carried out in a basic atmosphere. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a functional structure that can suppress functional degradation, achieve a long life, do not require complicated replacement work, and can achieve resource conservation. [Brief explanation of the drawings]

[0014] [Figure 1] 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. [Figure 2] 2A and 2B are enlarged partial cross-sectional views for explaining an example of the function of the functional structure of FIG. 1, where FIG. 2A illustrates the sieving function and FIG. 2B illustrates the catalytic function. [Figure 3] FIG. 3 is a flowchart showing an example of a method for manufacturing the functional structure of FIG. [Figure 4] FIG. 4 is a schematic diagram showing a modified example of the functional structure of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0016] [Configuration of functional structures] 1A and 1B are diagrams schematically illustrating the 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 is merely an example, and the shape, dimensions, etc. of each component according to the present invention are not limited to those in Fig. 1.

[0017] As shown in FIG. 1( a ), the functional structure 1 comprises a porous skeleton 10 made of a zeolite-type compound, and at least one metal microparticle 20 present within the skeleton 10 .

[0018] The metal microparticles 20 are substances that exert one or more functions, either alone or in cooperation with the framework 10. Specific examples of the functions include a catalytic function, a light-emitting (or fluorescent) function, a light-absorbing function, and an identification function. The metal microparticles 20 are preferably, for example, a catalytic substance having a catalytic function. When the metal microparticles 20 are a catalytic substance, the framework 10 is a carrier that supports the catalytic substance.

[0019] In the functional structure 1, a plurality of metal microparticles 20, 20, ... are encapsulated within the porous structure of the skeleton 10. The catalyst substance, which is an example of the metal microparticles 20, is preferably metal microparticles. Metal microparticles will be described in detail later. The metal microparticles 20 may also be particles containing a metal oxide, a metal alloy, or a composite material thereof.

[0020] The skeleton 10 has a porous structure, and as shown in Fig. 1(b), preferably has a plurality of pores 11a, 11a, ... formed therein to form interconnected passages 11. Here, the metal microparticles 20 are present in at least the passages 11 of the skeleton 10, and are preferably held in at least the passages 11 of the skeleton 10.

[0021] With this configuration, the movement of the metal microparticles 20 within the framework 10 is restricted, and the aggregation of the metal microparticles 20 is effectively prevented. As a result, the reduction in the effective surface area of ​​the metal microparticles 20 can be effectively suppressed, and the function of the metal microparticles 20 is maintained for a long period of time. In other words, the functional structure 1 can suppress the deterioration of the function of the metal microparticles 20 due to aggregation, and the life of the functional structure 1 can be extended. Furthermore, the extended life of the functional structure 1 can reduce the frequency of replacement of the functional structure 1, significantly reducing the amount of used functional structure 1 that is discarded, thereby conserving resources.

[0022] Typically, when a functional structure is used in a fluid (e.g., heavy oil, reformed gas such as NOx, etc.), it may be subjected to an external force from the fluid. In this case, if the metal microparticles are merely held in an adhered state on the outer surface of the skeleton 10, there is a problem that they are easily detached from the outer surface of the skeleton 10 due to the influence of the external force from the fluid. In contrast, in the functional structure 1, the metal microparticles 20 are held at least in the passages 11 of the skeleton 10, and therefore the metal microparticles 20 are unlikely to detach from the skeleton 10 even when they are affected by the external force from the fluid. That is, when the functional structure 1 is in a fluid, the fluid flows into the passages 11 through the pores 11a of the skeleton 10, and therefore the speed of the fluid flowing through the passages 11 is thought to be slower than the speed of the fluid flowing along the outer surface of the skeleton 10 due to flow path resistance (frictional force). Due to the influence of such flow path resistance, the pressure that the metal microparticles 20 held in the passages 11 receive from the fluid is lower than the pressure that the metal microparticles receive from the fluid outside the skeleton 10. Therefore, it is possible to effectively prevent the metal microparticles 20 present in the skeleton 11 from being detached, and to stably maintain the function of the metal microparticles 20 for a long period of time. Note that the above-mentioned flow path resistance is considered to increase as the passages 11 of the skeleton 10 have multiple bends and branches and the interior of the skeleton 10 has a more complex, three-dimensional structure.

[0023] Furthermore, the passages 11 preferably have 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 12 that is different from any of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores. In this case, the metal microparticles 20 are preferably present at least in the expanded diameter portion 12, and more preferably are included in at least the expanded diameter portion 12. The one-dimensional pores referred to here refer to tunnel-type or cage-type pores that form a one-dimensional channel, or multiple tunnel-type or cage-type pores (multiple one-dimensional channels) that form multiple one-dimensional channels. The two-dimensional pores refer to two-dimensional channels in which multiple one-dimensional channels are connected two-dimensionally, and the three-dimensional pores refer to three-dimensional channels in which multiple one-dimensional channels are connected three-dimensionally. This further restricts the movement of the metal microparticles 20 within the skeleton 10, making it possible to more effectively prevent the metal microparticles 20 from detaching and the metal microparticles 20 from aggregating with each other. Inclusion refers to a state in which the metal microparticles 20 are encapsulated in the skeleton 10. In this case, the metal microparticles 20 and the skeleton 10 do not necessarily need to be in direct contact with each other, and the metal microparticles 20 may be indirectly held by the skeleton 10 with another substance (for example, a surfactant) interposed between the metal microparticles 20 and the skeleton 10.

[0024] 1(b) shows a case where the metal microparticles 20 are enclosed in the expanded diameter portion 12, but this configuration is not limited thereto, and the metal microparticles 20 may be present in the passage 11 with a portion of them protruding outside the expanded diameter portion 12. Furthermore, the metal microparticles 20 may be partially embedded in a portion of the passage 11 other than the expanded diameter portion 12 (for example, the inner wall portion of the passage 11), or may be held by adhesion or the like. Furthermore, it is preferable that the expanded diameter portion 12 connects the plurality of holes 11a, 11a constituting any one of the one-dimensional holes, the two-dimensional holes, and the three-dimensional holes, with each other, thereby providing a separate passage different from the one-dimensional holes, the two-dimensional holes, or the three-dimensional holes inside the skeleton 10, thereby enabling the metal microparticles 20 to exhibit their functions more effectively.

[0025] Furthermore, the passage 11 is formed three-dimensionally inside the framework 10, including a branching portion or a junction portion, and the enlarged diameter portion 12 is preferably provided at the branching portion or the junction portion of the passage 11.

[0026] The average inner diameter D of the passage 11 formed in the skeleton 10 F is calculated from the average value of the minor axis and the major axis of the pores 11a constituting any one of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores, and is, for example, 0.1 nm to 1.5 nm, preferably 0.5 nm to 0.8 nm. E The inner diameter D 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. E is, for example, the pore diameter of the precursor material (A) described later and the average particle diameter D of the metal fine particles 20 to be enclosed. C The inner diameter D of the expanded diameter portion 12 depends on E is a size that can encapsulate the metal fine particles 20.

[0027] The framework 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, silicate compounds are preferred as the zeolite-type compounds.

[0028] The framework structure of the zeolite 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., with MFI type being preferred, and ZSM-5 being more preferred. Zeolite compounds have multiple pores with pore sizes corresponding to their framework structures; 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).

[0029] The case where the metal microparticles 20 are metal microparticles will be described in detail below.

[0030] The metal particles 20 may be primary particles or secondary particles formed by aggregation of primary particles. C is preferably the average inner diameter D of the passage 11 F and the inner diameter D of the expanded diameter portion 12 is larger than E The following is true (D F <D C ≦D E ). Such metal microparticles 20 are preferably enclosed in the enlarged diameter portions 12 within the passages 11, and movement of the metal microparticles 20 within the skeleton 10 is restricted. Therefore, even when the metal microparticles 20 are subjected to an external force from the fluid, movement of the metal microparticles 20 within the skeleton 10 is restricted, and contact between the metal microparticles 20 enclosed in the enlarged diameter portions 12, 12, ... dispersed and arranged in the passages 11 of the skeleton 10 can be effectively prevented.

[0031] In addition, the average particle diameter D of the metal fine particles 20 C In both the primary particles and secondary particles, the average inner diameter D of the passages 11 is preferably 0.08 nm to 30 nm, more preferably 0.08 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. F Average particle size D of metal particles 20 C The ratio (D C / D F ) 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. Furthermore, when the functional substance 20 is a metal microparticle, the metal element (M) of the metal microparticle is preferably contained in an amount of 0.5 to 2.5 mass % relative to the functional structure 1, and more preferably 0.5 to 1.5 mass % relative to the functional structure 1. For example, when the metal element (M) is Co, the content (mass %) of the Co element is expressed as {(mass of Co element) / (mass of all elements in the functional structure 1)}×100.

[0032] The metal microparticles may be composed of any non-oxidized metal, and may be composed of, for example, a single metal or a mixture of two or more metals. In this specification, the term "metal" (as a material) constituting the metal microparticles means both a simple metal containing one metal element (M) and a metal alloy containing two or more metal elements (M), and is a general term for metals containing one or more metal elements.

[0033] Examples of such metals include 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), and it is preferable to use one or more of the above as the main component.

[0034] Furthermore, the ratio of silicon (Si) constituting the skeleton 10 to the metal element (M) constituting the metal microparticles 20 (atomic ratio Si / M) is preferably 10 to 1000, more preferably 50 to 200. If the ratio is greater than 1000, the activity may be low and the effect of the metal microparticles may not be fully achieved. On the other hand, if the ratio is less than 10, the proportion of the metal microparticles 20 becomes too large, and the strength of the skeleton 10 tends to decrease. Note that the metal microparticles 20 referred to here refer to microparticles present inside or supported on the skeleton 10, and do not include metal microparticles attached to the outer surface of the skeleton 10.

[0035] [Functions of functional structures] As described above, the functional structure 1 includes a porous skeleton 10 and at least one metal microparticle 20 contained within the skeleton. When the metal microparticle 20 contained within the skeleton comes into contact with a fluid, the functional structure 1 exhibits a function corresponding to the function of the metal microparticle 20. Specifically, a fluid that comes into contact with the outer surface 10a of the functional structure 1 flows into the skeleton 10 through the pores 11a formed in the outer surface 10a, is guided into the passages 11, travels through the passages 11, and exits the functional structure 1 through other pores 11a. As the fluid travels through the passages 11, it comes into contact with the metal microparticles 20 held in the passages 11, causing a reaction (e.g., a catalytic reaction) corresponding to the function of the metal microparticle 20. Furthermore, the functional structure 1 has a molecular sieving ability due to the porous structure of the skeleton.

[0036] The functional structure 1 has a molecular sieving ability that allows specific molecules contained in heavy oils such as residual oil to pass through. Specifically, as shown in Fig. 2(a), molecules having a size equal to or smaller than the inner diameter of pores 11a formed in the outer surface 10a of the skeleton 10 can penetrate into the skeleton 10, while molecules having a size larger than the inner diameter of pores 11a are restricted from penetrating into the skeleton 10. This molecular sieving ability allows specific molecules that can enter pores 11a to react preferentially.

[0037] Furthermore, among the molecules produced in the pores 11a by the above reaction, only molecules that can escape from the pores 11a to the outside of the framework 10 can be obtained as products, and molecules that cannot escape from the pores 11a to the outside of the framework 10 are converted into molecules of a size that can escape from the pores 11a, and then escape from the pores 11a to the outside of the framework 10. This makes it possible to restrict the products obtained by the catalytic reaction to predetermined molecules.

[0038] In the functional structure 1, the metal particles 20 are preferably enclosed in the expanded diameter portion 12 of the passage 11. Therefore, the molecules that have entered the pores 11a, i.e., the passage 11, come into contact with the metal particles 20. In addition, the primary average particle diameter D C is the average inner diameter D of the passage 11. F The inner diameter D of the expanded diameter portion 12 is larger thanE If it is smaller than (D F <D C <D E ), small passages 13 are formed between the metal microparticles 20 and the expanded diameter portion 12 (FIG. 2(b)), and molecules that have entered the small passages 13 come into contact with the metal microparticles 20. At this time, the movement of the metal microparticles 20 is restricted by being enclosed by the expanded diameter portion 12, and the contact area with the fluid containing the molecules that have entered the passages 11 can be maintained.

[0039] When the molecules that have entered the passage 11 come into contact with the metal microparticles 20, the molecules (substances to be reformed) are reformed by an oxidative decomposition reaction caused by the metal microparticles 20. For example, when ruthenium contained in the metal microparticles 20 is used as a catalyst, ammonia is oxidatively decomposed to produce nitrogen and hydrogen. By performing oxidative decomposition treatment using a metal catalyst in this way, the hydrogen used in conventional hydrocracking treatments is no longer necessary, and heavy components that could not be fully utilized due to regional restrictions on hydrogen supply and cost considerations can be reformed into light oil. The substance to be treated is not limited to specific molecules contained in heavy oil, but may also be specific molecules contained in other feedstock oils such as naphtha, kerosene, and diesel.

[0040] Here, because the metal microparticles 20 are unoxidized metal, there is a concern that, when the fluid is hot, the metal microparticles 20 will diffuse due to the heat they receive from the fluid, turning into ultrafine metal particles and detaching from the expanded diameter section 12. However, the phenomenon in which small metal microparticles, for example, with a particle size of approximately 5 nm, diffuse into smaller metal microparticles is unstable, and high activation energy is required for diffusion to proceed, making this type of diffusion difficult to proceed. Furthermore, even if diffusion proceeds, the metal microparticles 20 will become ultrafine particles, so the effective surface area as a catalyst after diffusion will be larger than before diffusion. Furthermore, although the passages 11 are depicted in a simplified manner in FIG. 1(b), in reality, they have a complex three-dimensional structure due to the presence of the metal microparticles 20. This makes it possible to restrict the movement of metal atoms along the inner wall surface of the passages 11 to some extent, and it is presumed that aggregation (sintering) due to the movement of metal atoms can be suppressed. Furthermore, even if the metal particles 20 are detached from the expanded diameter portion 12, it is presumed that the above-described structure of the passages 11 prolongs the time that the ultrafine metal particles remain within the framework 10. Therefore, by encapsulating the metal particles 20 in the expanded diameter portion 12, it becomes possible to exert the catalytic function for a long period of time.

[0041] [Method of manufacturing functional structures] Fig. 3 is a flowchart showing a method for producing the functional structure 1 of Fig. 1. Hereinafter, an example of the method for producing the functional structure will be described, taking as an example the case where metal fine particles are present inside the framework.

[0042] (Step S1: Preparation process) First, a precursor material (A) for obtaining a porous structure framework composed of a zeolite-type compound is prepared, as shown in Figure 3. The precursor material (A) is preferably a regular mesoporous substance, and can be selected appropriately depending on the type (composition) of the zeolite-type compound that constitutes the framework of the functional structure.

[0043] When the zeolite-type compound constituting the framework of the functional structure is a silicate compound, the ordered mesoporous material is preferably a compound having an Si—O framework in which pores with diameters of 1 to 50 nm are uniformly sized and regularly developed in one, two, or three dimensions. Such ordered mesoporous materials can be obtained as various synthetic products depending on the synthesis conditions. Specific examples of synthetic products include SBA-1, SBA-15, SBA-16, KIT-6, FSM-16, and MCM-41, with MCM-41 being preferred. The pore diameters of SBA-1 are 10 to 30 nm, SBA-15 are 6 to 10 nm, SBA-16 are 6 nm, KIT-6 are 9 nm, FSM-16 are 3 to 5 nm, and MCM-41 are 1 to 10 nm. Examples of such regular mesoporous materials include mesoporous silica, mesoporous aluminosilicate, and mesoporous metallosilicate.

[0044] The precursor material (A) may be either a commercially available product or a synthetic product. The precursor material (A) can be synthesized using a known method for synthesizing ordered mesoporous materials. For example, a mixed solution containing raw materials containing the constituent elements of the precursor material (A) and a templating agent for defining the structure of the precursor material (A) is prepared, the pH is adjusted as necessary, and hydrothermal treatment (hydrothermal synthesis) is performed. The precipitate (product) obtained by the hydrothermal treatment is then recovered (e.g., filtered), washed and dried as necessary, and calcined to obtain the powdered ordered mesoporous material, precursor material (A). The solvent for the mixed solution can be, for example, water, an organic solvent such as alcohol, or a mixture thereof. The raw materials are selected depending on the type of framework, and examples include silica agents such as tetraethoxysilane (TEOS), fumed silica, and quartz sand. Furthermore, various surfactants, block copolymers, etc. can be used as templating agents, and it is preferable to select one depending on the type of ordered mesoporous material synthesized. 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 sealed container under 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 treatment conditions of 350 to 850°C, and 2 to 30 hours.

[0045] (Step S2: Impregnation process) Next, the prepared precursor material (A) is impregnated with a metal-containing solution to obtain precursor material (B).

[0046] The metal-containing solution may be any solution containing a metal component (e.g., metal ion) corresponding to the metal element (M) constituting the metal microparticles of the functional structure, and can be prepared, for example, by dissolving a metal salt containing the metal element (M) in a solvent. Examples of such metal salts include chlorides, hydroxides, oxides, sulfates, and nitrates, with nitrates being preferred. The solvent may be, for example, water, an organic solvent such as alcohol, or a mixture thereof.

[0047] The method for 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 in small amounts in multiple batches while stirring the powdered precursor material (A) before the calcination step described below. Furthermore, 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. It is believed that such an additive serves to coat the outer surface of the precursor material (A), preventing the metal-containing solution added thereafter from adhering to the outer surface of the precursor material (A), thereby making it easier for the metal-containing solution to penetrate into the pores of the precursor material (A).

[0048] Examples of such additives include nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, and polyoxyethylene alkylphenyl ether. These surfactants have large molecular sizes and cannot penetrate the pores of the precursor material (A). Therefore, they do not adhere to the pores and do not prevent the metal-containing solution from penetrating the pores. A preferred method for adding the nonionic surfactant is to add 50 to 500% by mass of the nonionic surfactant to the precursor material (A) before the firing step described below. If the amount of the nonionic surfactant added to the precursor material (A) is less than 50% by mass, the suppression effect described above is not readily achieved. However, adding more than 500% by mass of the nonionic surfactant to the precursor material (A) is undesirable because the viscosity increases excessively. Therefore, the amount of the nonionic surfactant added to the precursor material (A) is set to a value within the above range.

[0049] Furthermore, the amount of metal-containing solution added to precursor material (A) is preferably adjusted appropriately, taking into consideration the amount of metal element (M) contained in the metal-containing solution impregnated into precursor material (A) (i.e., the amount of metal element (M) to be incorporated into precursor material (B)). For example, before the firing step described below, the amount of metal-containing solution added to precursor material (A) is preferably adjusted so that the ratio of silicon (Si) constituting precursor material (A) to the metal element (M) contained in the metal-containing solution added to precursor material (A) (atomic ratio Si / M) is 10 to 1000, and more preferably 50 to 200. For example, if a surfactant is added as an additive to precursor material (A) before the metal-containing solution is added to precursor material (A), the amount of metal-containing solution added to precursor material (A) is adjusted to an atomic ratio Si / M of 50 to 200, thereby allowing the metal element (M) of the metal fine particles to be contained in an amount of 0.5 to 2.5 mass% relative to the functional structure 1. The amount of metal element (M) present inside the pores of precursor material (B) is roughly proportional to the amount of metal-containing solution added to precursor material (A), provided that the metal concentration of the metal-containing solution, the presence or absence of the additive, and other conditions such as temperature and pressure are the same. Furthermore, the amount of metal element (M) present in precursor material (B) is proportional to the amount of metal element constituting the metal microparticles present in the framework of the functional structure. Therefore, by controlling the amount of metal-containing solution added to precursor material (A) within the above range, the metal-containing solution can be sufficiently impregnated into the pores of precursor material (A), and thus the amount of metal microparticles present in the framework of the functional structure can be adjusted.

[0050] After the precursor material (A) has been impregnated with the metal-containing solution, it may be washed if necessary. The washing solution may be water, an organic solvent such as alcohol, or a mixture of these. Furthermore, after the precursor material (A) has been impregnated with the metal-containing solution and washed if necessary, it is preferable to further perform a drying process. Examples of the drying process include natural drying overnight or high-temperature drying at 150°C or less. If the calcination process described below is performed while a large amount of water from the metal-containing solution or the washing solution remains in the precursor material (A), the framework structure of the ordered mesoporous material of the precursor material (A) may be destroyed, so thorough drying is preferable.

[0051] (Step S3: Firing process) Next, precursor material (A) for obtaining a porous framework composed of a zeolite-type compound is impregnated with a metal-containing solution to obtain precursor material (B), which is then calcined to obtain precursor material (C).

[0052] The calcination treatment is preferably carried out in air at 350 to 850°C for 2 to 30 hours, for example. Such calcination treatment causes crystal growth of the metal component impregnated in the pores of the ordered mesoporous material, forming metal fine particles in the pores.

[0053] (Step S4: Hydrothermal treatment process) Next, a mixed solution is prepared by mixing the precursor material (C) with a structure-directing agent, and the precursor material (B) is calcined to obtain the precursor material (C), which is then subjected to a hydrothermal treatment to obtain a functional structure.

[0054] The structure-directing agent is a templating agent for defining the skeletal structure of the skeleton of the functional structure, and for example, a surfactant can be used. The structure-directing agent is preferably selected depending on the skeletal structure of the skeleton of the functional structure, and suitable examples include surfactants such as tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), and tetrapropylammonium bromide (TPABr).

[0055] The precursor material (C) and the structure-directing agent may be mixed during the hydrothermal treatment step or before the hydrothermal treatment step. The method for preparing the mixed solution is not particularly limited. The precursor material (C), the structure-directing agent, and the solvent may be mixed simultaneously, or the precursor material (C) and the structure-directing agent may be dispersed in separate solutions in the solvent, and then the respective dispersion solutions may be mixed. Examples of the solvent that can be used include water, organic solvents such as alcohol, and mixtures of these. It is preferable to adjust the pH of the mixed solution using an acid or base before the hydrothermal treatment.

[0056] The hydrothermal treatment can be carried out by a known method, and is preferably carried out in a sealed container under treatment conditions of 80 to 800°C, 5 to 240 hours, and 0 to 2000 kPa. The hydrothermal treatment is also preferably carried out in a basic atmosphere. Although the reaction mechanism here is not entirely clear, by performing hydrothermal treatment using precursor material (C) as a raw material, the skeletal structure of precursor material (C) as a regular mesoporous substance gradually collapses, but the positions of the metal microparticles inside the pores of precursor material (C) are largely maintained, and a new skeletal structure (porous structure) is formed as the skeleton of the functional structure due to the action of the structure-directing agent. The functional structure obtained in this way comprises a porous skeleton and metal microparticles contained within the skeleton, and further, the skeleton has passages in which multiple pores are interconnected due to the porous structure, and at least a portion of the metal microparticles are present in the passages of the skeleton. Furthermore, in the present embodiment, in the hydrothermal treatment step, a mixed solution is prepared by mixing the precursor material (C) with a structure-directing agent, and the precursor material (C) is hydrothermally treated. However, this is not limiting, and the precursor material (C) may be hydrothermally treated without mixing the precursor material (C) with a structure-directing agent.

[0057] The precipitate (functional structure) obtained after the hydrothermal treatment is preferably recovered (e.g., filtered) and then washed, dried, and calcined as necessary. Examples of washing solutions include water, organic solvents such as alcohol, or a mixture of these. Examples of drying treatments include natural drying overnight or high-temperature drying at 150°C or lower. If the precipitate is calcined while a large amount of moisture remains, the skeleton structure of the functional structure may be destroyed, so thorough drying is preferred. Calcination can be performed, for example, in air at 350 to 850°C for 2 to 30 hours. Such calcination burns off the structure-directing agent attached to the functional structure. Depending on the intended use, the recovered precipitate can be used as is without calcination. For example, if the functional structure is used in a high-temperature, oxidizing environment, exposing the functional structure to the environment for a certain period of time burns off the structure-directing agent, resulting in a functional structure similar to that obtained after calcination, allowing it to be used as is.

[0058] The above-described manufacturing method is an example in which the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) is a metal species that is difficult to oxidize (for example, a noble metal).

[0059] When the metal element (M) contained in the metal-containing solution to be impregnated into the precursor material (A) is a metal species that is easily oxidized (e.g., Fe, Co, Cu, etc.), 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 and S4) subsequent to the impregnation treatment (step S2). Therefore, metal oxide microparticles will be present in the framework formed in the hydrothermal treatment step (step S4). Therefore, to obtain a functional structure in which metal microparticles are present in the framework, it is preferable to calcinate the recovered precipitate after the hydrothermal treatment and further perform a reduction treatment in an atmosphere of a reducing gas such as hydrogen gas (step S5: reduction treatment step). The reduction treatment reduces the metal oxide microparticles present in the framework, forming metal microparticles corresponding to the metal element (M) constituting the metal oxide microparticles. As a result, a functional structure in which metal microparticles are present in the framework is obtained. Such reduction treatment may be carried out as needed. For example, if the environment in which the functional structure is used is a reducing atmosphere, the metal oxide microparticles will be reduced by exposing the functional structure to the environment for a certain period of time, and a functional structure similar to that obtained after reduction treatment will be obtained, making it possible to use the structure as is with the oxide microparticles present within the framework.

[0060] [Modification of Functional Structure 1] FIG. 4 is a schematic diagram showing a modified example of the functional structure 1 of FIG. The functional structure 1 in Figure 1 is shown as comprising a skeleton 10 and metal microparticles 20 contained within the skeleton 10, but is not limited to this configuration.For example, as shown in Figure 4, the functional structure 2 may further comprise at least one metal microparticle 30 held on the outer surface 10a of the skeleton 10.

[0061] The metal microparticles 30 are substances that exhibit one or more functions. The functions possessed by the metal microparticles 30 may be the same as or different from the functions possessed by the metal microparticles 20. Specific examples of the functions possessed by the metal microparticles 30 are the same as those described for the metal microparticles 20, and among them, it is preferable that the metal microparticles 30 have a catalytic function, in which case the metal microparticles 30 are catalytic substances. Furthermore, when both the metal microparticles 20 and 30 are substances that have the same function, the material of the other metal microparticle 30 may be the same as or different from the material of the metal microparticle 20. According to this configuration, the content of the metal microparticles held in the functional structure 2 can be increased, and the function of the metal microparticles can be further promoted.

[0062] In this case, it is preferable that the content of the metal microparticles 20 present inside the skeleton 10 is greater than the content of the other metal microparticles 30 held on the outer surface 10a of the skeleton 10. This allows the function of the metal microparticles 20 held inside the skeleton 10 to become dominant, and the function of the metal microparticles is stably exerted.

[0063] Although the functional structure according to the embodiment of the present invention has been described above, 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. [Example]

[0064] (Examples 1 to 384) [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. The pH was adjusted appropriately, and the solution was subjected to hydrothermal treatment in a sealed container at 80 to 350°C for 100 hours. The resulting precipitate was then filtered, washed with water and ethanol, and calcined in air at 600°C for 24 hours to obtain precursor materials (A) with the types and pore sizes shown in Tables 1 to 8. The following surfactants were used depending on the type of precursor material (A) ("Type of precursor material (A): Surfactant"). MCM-41: Hexadecyltrimethylammonium bromide (CTAB) (Wako Pure Chemical Industries, Ltd.) SBA-1: Pluronic P123 (BASF)

[0065] [Preparation of precursor materials (B) and (C)] Next, metal-containing aqueous solutions were prepared by dissolving metal salts containing the metal elements (M) constituting the metal microparticles of the types shown in Tables 1 to 8 in water. The metal salts used were as follows, depending on the type of metal microparticles ("metal microparticles: metal salts"). Co: Cobalt(II) nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) Ni: Nickel(II) nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) ·Fe: Iron(III) nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) Cu: Copper(II) nitrate trihydrate (Wako Pure Chemical Industries, Ltd.)

[0066] Next, the metal-containing aqueous solution was added in small amounts in multiple batches to the powdered precursor material (A), and the mixture was dried at room temperature (20°C ± 10°C) for 12 hours or more to obtain the precursor material (B).

[0067] In addition, when the condition for the presence or absence of additives shown in Tables 1 to 8 is "Yes," a pretreatment was performed by adding an aqueous solution of polyoxyethylene (15) oleyl ether (NIKKOL BO-15V, manufactured by Nikko Chemicals Co., Ltd.) as an additive to the precursor material (A) before adding the metal-containing aqueous solution, and then the metal-containing aqueous solution was added as described above. In addition, when the condition for the presence or absence of additives is "No," the pretreatment with the additives as described above was not performed.

[0068] In addition, 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 number ratio Si / M) would be one of the values ​​shown in Tables 1 to 8.

[0069] 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 a precursor material (C).

[0070] The precursor material (C) obtained as described above was mixed with a structure-directing agent shown in Tables 1 to 8 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 to 8. The resulting precipitate was then filtered, washed with water, dried at 100°C for 12 hours or more, and then calcined in air at 600°C for 24 hours. The calcined product was then recovered and reduced in a flow of hydrogen gas at 400°C for 350 minutes to obtain functional structures having a framework and metal fine particles shown in Tables 1 to 8 (Examples 1 to 384).

[0071] (Comparative Example 1) In Comparative Example 1, MFI-type silicalite was mixed with cobalt oxide powder (II, III) (manufactured by Sigma-Aldrich Japan LLC) having an average particle size of 50 nm or less, and hydrogen reduction treatment was carried out in the same manner as in Examples 1 and 2 to obtain a functional structure in which cobalt fine particles were attached as a functional material to the outer surface of the silicalite as a framework. The MFI-type silicalite was synthesized in the same manner as in Examples 52 to 57, except for the step of adding the metal.

[0072] (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 adhering cobalt fine particles was omitted.

[0073] [evaluation] The functional structures of the above examples and the silicalite of the comparative examples were subjected to various property evaluations under the conditions shown below.

[0074] [A] Cross-sectional observation Observation samples were prepared by a pulverization method for the functional structures of the above-mentioned Examples and the silicalite of the Comparative Examples, and cross-sections were observed using a transmission electron microscope (TEM) (TITAN G2, manufactured by FEI). As a result, it was confirmed that in the functional structures of the above Examples, metal particles were present and held inside the framework made of silicalite or zeolite, whereas in the silicalite of Comparative Example 1, metal particles were only attached to the outer surface of the framework and were not present inside the framework. Furthermore, for the functional structures in the above examples in which the metal was iron fine particles (Fe), cross sections were cut out by FIB (focused ion beam) processing, and cross-sectional elemental analysis was performed using an SEM (SU8020, manufactured by Hitachi High-Technologies Corporation) and an EDX (X-Max, manufactured by Horiba, Ltd.) As a result, Fe elements were detected from inside the framework. The results of the cross-sectional observations using TEM and SEM / EDX confirmed the presence of iron particles inside the framework.

[0075] [B] Average inner diameter of the pathways in the skeleton and average particle size of the metal particles In the TEM image taken by the cross-sectional observation performed in the above evaluation [A], 500 passages of the skeleton were randomly selected, and the long and short diameters of each were measured. The inner diameter of each was calculated from the average value (N=500). The average inner diameter was then calculated to obtain the average inner diameter D of the passages of the skeleton. F Similarly, for metal microparticles, 500 metal microparticles were randomly selected from the TEM image, and the particle diameters of each were measured (N=500), and the average value was calculated to obtain the average particle diameter D of the metal microparticles. C The results are shown in Tables 1 to 8. In addition, SAXS (small-angle X-ray scattering) was used to analyze the average particle size and dispersion state of the functional material. SAXS measurements were performed using the beamline BL19B2 at Spring-8. The obtained SAXS data was fitted to a spherical model using the Guinier approximation method to calculate the particle size. The particle size was measured for a functional structure in which the metal was iron fine particles. For comparison, commercially available iron fine particles (manufactured by Wako) were also observed and measured using an SEM. As a result, while the commercially available product contained 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, which had an average particle size of 1.2 nm to 2.0 nm determined from TEM images, also detected scattering peaks of particle sizes of 10 nm or less in the SAXS measurement results. The SAXS measurement results and the cross-sectional measurement results using SEM / EDX revealed that functional substances of particle sizes of 10 nm or less were present within the framework in a uniform and highly dispersed state.

[0076] [C] Relationship between the amount of metal-containing solution added and the amount of metal encapsulated within the framework Functional structures were prepared by encapsulating metal particles within the framework with the addition amounts of Si / M=50, 100, 200, and 1000 (M=Co, Ni, Fe, and Cu), and then the amounts of metal (mass%) encapsulated within the framework of the functional structures prepared with the above addition amounts were measured. Note that in this measurement, the functional structures with Si / M=100, 200, and 1000 atomic ratios were prepared by adjusting the amount of metal-containing solution added in the same manner as the functional structures with Si / M=100, 200, and 1000 atomic ratios in Examples 1 to 384, respectively, and the functional structures with Si / M=50 atomic ratios were prepared in the same manner as the functional structures with Si / M=100, 200, and 1000 atomic ratios, except that the amount of metal-containing solution added was different. Metal content was determined using either 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 in a vacuum atmosphere at an accelerating 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 fluorescence intensity, and quantitative values ​​(in mass %) cannot be calculated using XRF alone. Therefore, the amount of metal in functional structures to which metal was added at Si / M = 100 was quantified using ICP analysis, and the amount of metal in functional structures to which metal was added at Si / M = 50 and less than 100 was calculated based on the results of XRF and ICP measurements. As a result, it was confirmed that, at least within the atomic ratio Si / M range of 50 to 1000, the amount of metal encapsulated in the functional structure increased as the amount of metal-containing solution added increased.

[0077] [D] Performance evaluation The catalytic ability (performance) of the metal fine particles (catalytic substance) was evaluated for the functional structures of the above examples and the silicalite of the comparative example. The results are shown in Tables 1 to 8.

[0078] (1)Catalytic activity The catalytic activity was evaluated under the following conditions. First, 0.2 g of the functional structure was loaded into a normal pressure flow reactor, and a decomposition reaction of butylbenzene (a model substance of heavy oil) was carried out at 400°C for 2 hours using nitrogen gas (N2) as the carrier gas (5 ml / min). After the reaction was completed, the recovered product gas and liquid were analyzed for their components by gas chromatography-mass spectrometry (GC / MS). The product gas was analyzed using a TRACE 1310GC (manufactured by Thermo Fisher Scientific, Inc., detector: thermal conductivity detector), and the product liquid was analyzed using a TRACE DSQ (manufactured by Thermo Fisher Scientific, Inc., detector: mass detector, ionization method: EI (ion source temperature: 250°C, MS transfer line temperature: 320°C, detector: thermal conductivity detector)). Furthermore, based on the results of the above component analysis, the yield (mol%) of compounds having a molecular weight smaller than that of butylbenzene (specifically, benzene, toluene, ethylbenzene, styrene, cumene, methane, ethane, ethylene, propane, propylene, butane, butene, etc.) was determined. The yield of the above compounds was calculated as the percentage (mol%) of the total amount (mol) of compounds having a molecular weight smaller than that of butylbenzene contained in the product solution relative to the amount (mol) of butylbenzene before the start of the reaction. In this example, when the yield of compounds having a smaller molecular weight than butylbenzene contained in the product liquid was 40 mol% or more, the catalytic activity (resolution ability) was judged to be excellent and marked with a "◎", when it was 25 mol% or more but less than 40 mol%, the catalytic activity was judged to be good and marked with a "○", when it was 10 mol% or more but less than 25 mol%, the catalytic activity was judged to be not good but at an acceptable level (passable) and marked with a "△", and when it was less than 10 mol%, the catalytic activity was judged to be poor (unacceptable) and marked with an "×".

[0079] (2) Durability (lifespan) Durability was evaluated under the following conditions. First, the functional structure used in the above evaluation (1) was recovered and heated at 650°C for 12 hours to produce a heated functional structure. Next, using the obtained heated functional structure, a decomposition reaction of butylbenzene (a model substance of heavy oil) was carried out in the same manner as in the above evaluation (1), and further, the components of the produced gas and the produced liquid were analyzed in the same manner as in the above evaluation (1). Based on the obtained analytical results, the yield (mol%) of compounds having a molecular weight smaller than that of butylbenzene was determined using the same method as in Evaluation (1) above. Furthermore, the degree to which the yield of the compound obtained by the functional structure after heating was maintained was compared with the yield of the compound obtained by the functional structure before heating (the yield obtained in Evaluation (1) above). Specifically, the percentage (%) of the yield of the compound obtained by the functional structure after heating (the yield obtained in Evaluation (2)) relative to the yield of the compound obtained by the functional structure before heating (the yield obtained in Evaluation (1) above) was calculated. In this example, when the yield of the above compound from the functional structure after heating (the yield determined in this evaluation (2)) was maintained at 80% or more compared to the yield of the above compound from the functional structure before heating (the yield determined in the above evaluation (1)), the durability (heat resistance) was judged to be excellent and marked with "◎", when the yield was maintained at 60% or more but less than 80%, the durability (heat resistance) was judged to be good and marked with "○", when the yield was maintained at 40% or more but less than 60%, the durability (heat resistance) was judged to be not good but to be at an acceptable level (passable) and marked with "△", and when the yield dropped to less than 40%, the durability (heat resistance) was judged to be poor (unacceptable) and marked with "×".

[0080] For Comparative Examples 1 and 2, the same performance evaluations as in the above evaluations (1) and (2) were carried out. Note that Comparative Example 2 is the skeleton itself and does not contain any functional substance. Therefore, in the above performance evaluation, only the skeleton of Comparative Example 2 was filled in place of the functional structure. The results are shown in Table 8.

[0081] [Table 1]

[0082] [Table 2]

[0083] [Table 3]

[0084] [Table 4]

[0085] [Table 5]

[0086] [Table 6]

[0087] [Table 7]

[0088] [Table 8]

[0089] As is clear from Tables 1 to 8, the functional structures (Examples 1 to 384) in which it was confirmed by cross-sectional observation that metal microparticles were retained inside the skeleton exhibited superior catalytic activity in the decomposition reaction of butylbenzene and also had superior durability as a catalyst, compared to a functional structure in which metal microparticles were simply attached to the outer surface of the skeleton (Comparative Example 1) or the skeleton itself without any functional substance (Comparative Example 2).

[0090] The relationship between the amount of metal (mass%) encapsulated within the framework of the functional structure measured in the above evaluation [C] and the yield (mol%) determined in the above evaluation (1) was evaluated. The evaluation method was the same as that used in "(1) Catalytic activity" in the above [D] "Performance evaluation." As a result, in each example, it was found that when the amount of metal-containing solution added to the precursor material (A) was 50 to 200 in terms of atomic ratio Si / M (the content of the metal element (M) of the metal microparticle relative to the functional structure was 0.5 to 2.5 mass%), the yield of compounds with a smaller molecular weight than butylbenzene contained in the product solution was 32 mol% or more, and the catalytic activity in the decomposition reaction of butylbenzene was particularly excellent.

[0091] On the other hand, the silicalite of Comparative Example 1, in which metal microparticles were attached only to the outer surface of the skeleton, had improved catalytic activity in the decomposition reaction of butylbenzene compared to the skeleton itself of Comparative Example 2, which did not have any metal microparticles, but its durability as a catalyst was inferior to that of the functional structures of Examples 1 to 384.

[0092] Furthermore, the framework of Comparative Example 2, which did not contain any functional material, showed almost no catalytic activity in the decomposition reaction of butylbenzene, and was inferior in both catalytic activity and durability compared to the functional structures of Examples 1 to 384. [Explanation of symbols]

[0093] 1 Functional structure 10 Skeleton 10a outer surface 11 Passage 11a hole 12 Expanded diameter part 20 Metal fine particles 30 Metal fine particles D C Average particle size D F Average inner diameter D E Inner diameter

Claims

1. a porous framework composed of zeolite-type compounds; At least one metal microparticle present within the framework; Equipped with The framework has passages that communicate with each other, the passages have one-dimensional pores, two-dimensional pores, or three-dimensional pores defined by the framework structure of the zeolite-type compound, and an expanded portion different from any of the one-dimensional pores, the two-dimensional pores, or the three-dimensional pores; the average particle diameter of the metal microparticles is larger than the average inner diameter of the passage and is equal to or smaller than the inner diameter of the expanded diameter portion, the average inner diameter of the passage is calculated from an average value of minor axes and major axes of pores constituting any one of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores; the metal fine particles are present in a state of being included in at least the expanded diameter portion of the framework, the metal microparticles are metal microparticles made of a single metal selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), and copper (Cu), A catalyst structure characterized in that the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the passages is 1.4 to 3.

6.

2. The catalyst structure according to claim 1 , wherein the expanded 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 metal fine particles are a catalytic material, 3. The catalyst structure according to claim 1, wherein the framework is a support that supports at least one of the catalyst substances.

4. 4. The catalyst structure according to claim 1, wherein the metal element (M) of the metal fine particles is contained in an amount of 0.5 to 2.5 mass % relative to the catalyst structure.

5. 5. The catalyst structure according to claim 1, wherein the metal fine particles have an average particle size of 0.08 nm to 2.7 nm.

6. 6. The catalyst structure according to claim 5, wherein the average particle size of the metal particles is 0.4 nm to 2.7 nm.

7. the average inner diameter of the passages is between 0.1 nm and 1.5 nm; 7. The catalyst structure according to claim 1, wherein the inner diameter of the expanded diameter portion is 0.5 nm to 50 nm.

8. 8. The catalyst structure according to claim 1, further comprising at least one metal fine particle held on the outer surface of the framework.

9. 9. The catalyst structure according to claim 8, wherein the content of the at least one metal microparticle present inside the framework is greater than the content of the at least one metal microparticle held on the outer surface of the framework.

10. 10. The catalyst structure according to claim 1, wherein the zeolite type compound is a silicate compound.

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