JP7635943B2 - Functional structure and method for producing the functional structure - Google Patents

Description

The present invention relates to a functional structure having a porous skeleton and a functional substance, and a method for manufacturing the functional structure.

At petroleum complexes, refineries 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 and various fuels, as well as various impurities, a process is required to distill and separate the various components contained in the crude oil.

In the oil refining process, the difference in boiling points of each component is utilized to heat the crude oil on the trays in the tower of the atmospheric distillation unit to separate it into its components, and each separated substance is concentrated. As a result, low boiling point substances such as LPG and naphtha are extracted on 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 each separated and concentrated substance to secondary processing such as desulfurization.

In general, oil reforming catalysts are used in the above-mentioned oil refining process to efficiently reform naphtha and other low-boiling naphtha to produce gasoline with a high octane number. The naphtha fraction in crude oil has a low octane number as is and is unsuitable for use as gasoline to run vehicles. Therefore, the low-octane paraffin and naphthene fractions in the naphtha fraction are reformed using oil reforming catalysts to convert them into aromatic compounds with a high octane number, producing reformed gasoline with properties suitable for use as vehicle fuel.

In addition, as crude oil becomes heavier, hydrocracking is being carried out to further decompose the desulfurized heavy oil and desulfurized heavy light oil obtained by hydrodesulfurizing heavy oil in a hydrodesulfurization unit such as a direct desulfurization unit or an intermediate desulfurization unit, thereby increasing the production of desulfurized naphtha, desulfurized kerosene, desulfurized light oil, etc. For example, by hydrocracking atmospheric distillation residual oil, the yield of desulfurized light oil fraction and desulfurized naphtha fraction is increased and the desulfurized heavy oil is reduced, and the desulfurized heavy oil is produced in a catalytic cracking unit to produce an LPG fraction, an FCC gasoline fraction, and an LCO fraction, thereby reducing the residual oil and increasing the light oil fraction. At this time, catalysts made of a crystalline aluminosilicate carrier, which is a typical zeolite, and hydrocracking catalysts containing zeolite and porous inorganic oxide in a specific ratio have been proposed.

For example, a catalyst has been disclosed as a hydrocracking catalyst 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).

In the automotive field, a ceramic catalyst body has been proposed as a catalyst structure for exhaust gas from vehicles equipped with diesel engines, in which a ceramic carrier is placed on the surface of a substrate ceramic and both a main catalyst component and a promoter catalyst component are supported 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 components consisting of Ce-Zr, Pt, etc. are supported directly near the surface of the ceramic carrier (Patent Document 2).

US Patent Application Publication No. 2016/0030934 US Patent Application Publication No. 2003/0109383

However, in the above-mentioned catalyst structure, since the catalyst particles are supported on the surface or near the surface of the carrier, the catalyst particles move within the carrier due to the influence of the force and heat from the fluid such as the reformed substance during the reforming process, and the catalyst particles are likely to aggregate (sinter). When the catalyst particles aggregate, the effective surface area of the catalyst decreases, and the catalytic activity decreases, so the life becomes shorter than usual. Therefore, the catalyst structure itself must be replaced and regenerated in a short period of time, which makes the replacement work complicated and prevents resource saving. In addition, since the oil reforming catalyst is usually connected to the downstream side of the atmospheric distillation unit and used continuously in the oil refining process, it is difficult to apply catalyst reactivation technology, and even if reactivation technology can be applied, the work is very complicated. In addition, suppressing or preventing such deterioration of function over time is cited as an issue not only in the field of catalysts but also in various technical fields, and a solution is desired to maintain the function for a long time.

The object of the present invention is to provide a functional structure and a method for manufacturing the functional structure that can suppress the functional deterioration of functional materials, realize a long life, do not require complicated replacement work, and can conserve resources.

As a result of intensive research conducted by the inventors in order to achieve the above object, they discovered that a functional structure can be obtained that is capable of suppressing functional deterioration of the functional substance and realizing a long life by comprising a porous skeleton composed of a zeolite-type compound and at least one functional substance present in the skeleton, the skeleton having passages that communicate with each other, and the functional substance being present in at least the passages of the skeleton, and this finding led to the completion of the present invention.

That is, the gist of the present invention is as follows.
[1] A porous framework composed of a zeolite-type compound;
At least one functional substance present within the scaffold;
Equipped with
The framework has passages communicating with each other,
A functional structure, characterized in that the functional substance is present in at least the passages of the framework, and the average particle size of the functional substance is less than 30 nm.
[2] The functional structure according to the above [1], characterized in that the average particle size of the functional substance is less than 5.0 nm.
[3] The functional structure according to the above [2], characterized in that the average particle size of the functional substance is less than 2.0 nm.
[4] The functional structure according to any one of the above [1] to [3], characterized in that the passage has any one of one-dimensional holes, two-dimensional holes, and three-dimensional holes defined by the framework structure of the zeolite-type compound, and an expanded diameter portion different from any one of the one-dimensional holes, the two-dimensional holes, and the three-dimensional holes, and the functional substance is present at least in the expanded diameter portion.
[5] The functional structure described in [4] 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.
[6] The functional material is a catalytic material,
The functional structure according to any one of the above [1] to [5], wherein the framework is a support that supports the at least one catalytic substance.
[7] The functional structure according to the above [5], characterized in that the catalytic substance is metal oxide fine particles.
[8] The functional structure according to the above [6], characterized in that the average particle size of the metal oxide fine particles is larger than the average inner diameter of the passages and is equal to or smaller than the inner diameter of the expanded portion.
[9] The functional structure according to [7] or [8] above, characterized in that the metal element (M) of the metal oxide fine particles is contained in an amount of 0.5 to 2.5 mass% relative to the functional structure.
[10] The functional structure according to any one of [6] to [9] above, characterized in that the ratio of the average particle diameter of the metal oxide microparticles to the average inner diameter of the passages is 0.06 to 500.
[11] The functional structure according to the above [10], characterized in that the ratio of the average particle diameter of the metal oxide fine particles to the average inner diameter of the passages is 0.1 to 45.
[12] The functional structure according to the above [11], characterized in that the ratio of the average particle diameter of the metal oxide fine particles to the average inner diameter of the passages is 1.3 to 3.5.
[13] The average inner diameter of the passages is 0.1 nm to 1.5 nm;
The functional structure according to any one of the above [4] to [12], characterized in that the inner diameter of the expanded diameter portion is 0.5 nm to 50 nm.
[14] The functional structure according to any one of [1] to [13] above, further comprising at least one functional substance held on the outer surface of the framework.
[15] The functional structure according to [14] above, characterized in that the content of the at least one functional substance present within the framework is greater than the content of the at least one functional substance retained on the outer surface of the framework.
[16] The functional structure according to any one of the above [1] to [15], characterized in that the zeolite type compound is a silicate compound.
[17] An impregnation step of adding a surfactant to a precursor material (A) for obtaining a porous structure framework composed of a zeolite-type compound, and then impregnating the precursor material with a metal-containing solution to obtain a precursor material (B);
A calcination step of calcining the precursor material (B) to obtain a precursor material (C);
an addition step of adding a structure-directing agent that defines the skeletal structure of the skeleton to the precursor material (C);
a hydrothermal treatment step of hydrothermally treating the precursor material (C) to which the structure-directing agent has been added;
A method for producing a functional structure, comprising:
[18] The method for producing a functional structure according to the above [17], characterized in that the molar ratio of silicon in the precursor material (A) to the surfactant is 25 or less.
[19] The method for producing a functional structure according to the above [18], characterized in that the molar ratio of silicon in the precursor material (A) to the surfactant is 5 or less.
[20] The method for producing a functional structure according to any one of [17] to [19] above, characterized in that in the impregnation step, the metal-containing solution is added to the precursor material (A) in a plurality of portions, thereby impregnating the precursor material (A) with the metal-containing solution.
[21] The method for producing a functional structure according to any one of the above [17] to [20], characterized in that when the precursor material (A) is impregnated with the metal-containing solution in the impregnation step, an 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.
[22] The method for producing a functional structure according to the above [17], characterized in that the hydrothermal treatment step is carried out under a basic atmosphere.

The present invention provides a functional structure that can suppress the functional deterioration of functional materials, achieve a long life, do not require complicated replacement work, and conserve resources.

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 partially enlarged cross-sectional views for explaining an example of the function of the functional structure of FIG. 1, in which FIG. 2A illustrates the sieving function and FIG. 2B illustrates the catalytic function. 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 framework 10 made of a zeolite-type compound, and at least one functional substance 20 present within the framework 10.

The functional material 20 is a material that exerts one or more functions, either alone or in cooperation with the framework 10. Specific examples of the above functions include a catalytic function, a light emitting (or fluorescent) function, a light absorbing function, and an identification function. The functional material 20 is preferably a catalytic material having a catalytic function. When the functional material 20 is a catalytic material, the framework 10 is a carrier that supports the catalytic material.

In the functional structure 1, multiple functional substances 20, 20, ... are encapsulated in a highly dispersed state inside the porous structure of the framework 10. The catalytic substance, which is an example of the functional substance 20, is preferably at least one of metal oxide fine particles and metal fine particles. Metal oxide fine particles and metal fine particles will be described in detail later. The functional substance 20 may also be particles containing a metal oxide or metal alloy, or a composite material thereof.

The skeleton 10 has a porous structure, and preferably has a plurality of holes 11a, 11a, ... formed therein, which are interconnected passages 11, as shown in FIG. 1(b). Here, the functional substance 20 is present in at least the passages 11 of the skeleton 10, and is preferably held in at least the passages 11 of the skeleton 10.

With this configuration, the movement of the functional material 20 within the framework 10 is restricted, and the aggregation of the functional materials 20 is effectively prevented, so that the highly dispersed state of the functional material 20 is maintained for a long period of time. As a result, the reduction in the effective surface area of the functional material 20 can be effectively suppressed, and the function of the functional material 20 is maintained for a long period of time. In other words, according to the functional structure 1, the deterioration of the function of the functional material 20 due to aggregation can be suppressed, 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, and the amount of waste of used functional structures 1 can be significantly reduced, resulting in resource conservation.

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 skeleton 10, there is a problem that it is easily detached from the outer surface of the skeleton 10 due to the influence of an external force from the fluid. In contrast, in the functional structure 1, the functional substance 20 is held at least in the passage 11 of the skeleton 10, so that the functional substance 20 is unlikely to be detached from the skeleton 10 even if it is affected by an external force from the fluid. That is, when the functional structure 1 is in a fluid, the fluid flows into the passage 11 from the hole 11a of the skeleton 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 skeleton 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 skeleton 10. Therefore, it is possible to effectively prevent the functional material 20 contained within the skeleton 11 from being released, and it is possible to stably maintain the function of the functional material 20 for a long period of time. It is considered that the above-mentioned flow path resistance increases as the passage 11 of the skeleton 10 has multiple bends and branches and the interior of the skeleton 10 has a more complex, three-dimensional structure.

In addition, the passage 11 preferably has one of one-dimensional, two-dimensional and three-dimensional pores defined by the framework structure of the zeolite-type compound, and an expanded diameter portion 12 different from any of the one-dimensional, two-dimensional and three-dimensional pores. 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. The one-dimensional pore here refers to a tunnel-type or cage-type pore forming a one-dimensional channel, or a plurality of tunnel-type or cage-type pores (a plurality of one-dimensional channels) forming a plurality of one-dimensional channels. The two-dimensional pore refers to a two-dimensional channel in which a plurality of one-dimensional channels are two-dimensionally connected, and the three-dimensional pore refers to a three-dimensional channel in which a plurality of one-dimensional channels are three-dimensionally connected.
This further restricts the movement of the functional substance 20 within the framework 10, and more effectively prevents the functional substance 20 from being separated or the functional substances 20, 20 from aggregating together. Inclusion refers to a state in which the functional substance 20 is encapsulated in the framework 10. In this case, the functional substance 20 and the framework 10 do not necessarily need to be in direct contact with each other, and the functional substance 20 may be indirectly held in the framework 10 with another substance (e.g., a surfactant, etc.) intervening between the functional substance 20 and the framework 10.

1(b) shows a case where the functional substance 20 is encapsulated in the enlarged diameter portion 12, but the present invention is not limited to this configuration, and the functional substance 20 may be present in the passage 11 with a part of it protruding outside the enlarged diameter portion 12. The functional substance 20 may also be partially embedded in a part of the passage 11 other than the enlarged diameter portion 12 (for example, an inner wall part of the passage 11) or held by adhesion or the like.
In addition, it is preferable that the expanded diameter portion 12 communicates with the plurality of holes 11a, 11a constituting any one of the one-dimensional holes, the two-dimensional holes, and the three-dimensional holes, so that a separate passage different from the one-dimensional holes, the two-dimensional holes, or the three-dimensional holes is provided inside the framework 10, thereby enabling the function of the functional material 20 to be more effectively exhibited.

In addition, the passage 11 is formed three-dimensionally inside the framework 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 framework 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, and preferably 0.5 nm to 0.8 nm. The inner diameter D _E of the enlarged 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 enlarged 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 substance 20 to be encapsulated. The inner diameter D _E of the enlarged diameter portion 12 is a size that can encapsulate the functional substance 20.

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, it is preferable that the zeolite-type compound is a silicate compound.

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, more preferably ZSM-5. Zeolite-type compounds have multiple pores with pore sizes according to each framework structure. For example, the maximum pore size of the MFI type is 0.636 nm (6.36 Å), and the average pore size is 0.560 nm (5.60 Å).

The following provides a detailed explanation of the case where the functional material 20 is at least one of metal oxide microparticles and metal microparticles (hereinafter, collectively referred to as "microparticles").

When the functional material 20 is the above-mentioned fine particles, the fine particles 20 may be primary particles or secondary particles formed by aggregation of the primary particles, and the average particle diameter D _C of the fine particles 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 ). In the passage 11, such fine particles 20 are preferably included in the expanded diameter portion 12, and the movement of the fine particles 20 in the skeleton 10 is restricted. Therefore, even if the fine particles 20 are subjected to an external force from the fluid, the movement of the fine particles 20 in the skeleton 10 is suppressed, and the fine particles 20, 20, ... included in each of the expanded diameter portions 12, 12, ... dispersed and arranged in the passage 11 of the skeleton 10 can be effectively prevented from contacting each other.

Furthermore, when the functional material 20 is metal oxide fine particles, the dispersibility of the metal oxide fine particles 20 is such that the average particle size D _C is less than 30 nm, preferably less than 5.0 nm, more preferably 3.3 nm or less, and even more preferably less than 2.0 nm, in both the primary particles and the secondary particles. The lower limit of the average particle size D _C of the metal oxide fine particles 20 is not particularly limited, but is preferably 0.1 nm or more, and even more preferably 1.0 nm or more, in both the primary particles and the secondary particles. Furthermore, the ratio (D _C /D _F ) of the average particle size D _C of the metal oxide fine particles 20 to the average inner diameter D _F of the passage 11 is preferably 0.06 to 500, more preferably 0.1 to 45, even more preferably 1.1 to 45, and particularly preferably 1.3 to 3.5.
Furthermore, when the functional material 20 is metal oxide fine particles, the metal element (M) of the metal oxide fine particles 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.

The metal oxide microparticles may be composed of a metal oxide, for example, a single metal oxide or a mixture of two or more metal oxides. In this specification, the term "metal oxide" (as a material) constituting the metal oxide microparticles means an oxide containing one type of metal element (M) and a composite oxide containing two or more types of metal elements (M), and is a general term for oxides containing one or more metal elements (M).

Examples of such metal oxides include cobalt oxide (CoO _x ), nickel oxide (NiO _x ), iron oxide (FeO _x ), copper oxide (CuO _x ), zirconium oxide (ZrO _x ), cerium oxide (CeO _x ), aluminum oxide (AlO _x ), niobium oxide (NbO _x ), titanium oxide (TiO _x ), bismuth oxide (BiO _x ), molybdenum oxide (MoO _x ), vanadium oxide (VO _x ), and chromium oxide (CrO _x ). It is preferable to use one or more of the above as a main component.

Furthermore, when the functional material 20 is metal fine particles, the dispersibility of the metal fine particles 20 is such that the average particle size D _C is less than 30 nm, preferably less than 5.0 nm, and more preferably less than 2.0 nm, in both the primary particles and the secondary particles. The lower limit of the average particle size D _C of the metal fine particles 20 is not particularly limited, but is preferably 0.08 nm or more, and more preferably 0.8 nm or more, in both the primary particles and the secondary particles. Furthermore, the ratio (D _C /D _F ) of the average particle size D _C of the metal fine particles 20 to the average inner diameter D _F of the passages 11 is preferably 0.05 to 300, more preferably 0.1 to 30, even more preferably 1.1 to 30, and particularly preferably 1.3 to 3.5.
When the functional material 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 contained in an amount of 0.5 to 1.5 mass% relative to the functional structure 1.

The metal microparticles may be composed of a 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 "metal" (as a material) constituting the metal microparticles means 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.

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.

From the standpoint of durability, it is preferable that the functional material 20 be metal oxide microparticles.

The ratio of silicon (Si) constituting the framework 10 to the metal element (M) constituting the microparticles 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 as a functional material may not be fully obtained. On the other hand, if the ratio is less than 10, the proportion of the microparticles 20 becomes too large, and the strength of the framework 10 tends to decrease. Note that the microparticles 20 referred to here refer to microparticles present inside or supported by the framework 10, and do not include microparticles attached to the outer surface of the framework 10.

[Functions of functional structures]
As described above, the functional structure 1 includes a porous skeleton 10 and at least one functional material 20 present in the skeleton 10. The functional structure 1 exerts a function according to the functional material 20 by contacting the functional material 20 present in the skeleton 10 with a fluid. Specifically, the fluid that contacts the outer surface 10a of the functional structure 1 flows into the skeleton 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 held in the passage 11, causing a reaction (e.g., a catalytic reaction) according to the function of the functional material 20. In addition, the functional structure 1 has a molecular sieve function because the skeleton 10 has a porous structure.

First, the molecular sieving ability of the functional structure 1 will be described with reference to FIG. 2(a) using an example in which the fluid is a liquid containing benzene, propylene, and mesitylene. As shown in FIG. 2(a), compounds (e.g., benzene, propylene) composed of molecules 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 framework 10. On the other hand, compounds (e.g., mesitylene) composed of molecules having a size larger than the pore size of the hole 11a cannot penetrate into the framework 10. In this way, when the fluid contains multiple types of compounds, the reaction of the compounds that cannot penetrate into the framework 10 is restricted, and the compounds that can penetrate into the framework 10 can be reacted.

Of the compounds produced in the framework 10 by the reaction, only compounds composed of molecules having a size equal to or smaller than the diameter of the holes 11a can exit the framework 10 through the holes 11a and are obtained as reaction products. On the other hand, compounds that cannot exit the framework 10 through the holes 11a can be transferred to the framework 10 if they are converted into compounds composed of molecules of a size that allows them to exit the framework 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 preferably included in the expanded diameter portion 12 of the passage 11. When the functional material 20 is metal oxide fine particles, if the average particle diameter D _C of the metal oxide fine particles is larger than the average inner diameter D _F of the passage 11 and smaller than the inner diameter D _E of the expanded diameter portion 12 (D _F < D _C < D _E ), a small passage 13 is formed between the metal oxide fine particles 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 metal oxide fine particles. Since each metal oxide fine particle is included in the expanded diameter portion 12, the movement within the framework 10 is restricted. This prevents the metal oxide fine particles from coagulating with each other within the framework 10. As a result, a large contact area between the metal oxide fine particles and the fluid can be stably maintained. Furthermore, in the functional structure 1, the metal fine particles/metal oxide fine particles are maintained in a highly dispersed state with an average particle size D _C of less than 30 nm, so that high activity such as catalytic function can be maintained for a long period of time.

Next, a case where the functional material 20 has a catalytic function will be described. Specifically, a case where the functional material 20 is iron oxide (FeO _x ) fine particles, and dodecylbenzene, which is a heavy oil, is infiltrated into the framework 10 of the functional structure 1 will be described as an example. When dodecylbenzene infiltrates into the framework 10, as shown below, dodecylbenzene is decomposed into various alcohols and ketones by an oxidative decomposition reaction. Furthermore, benzene, which is a light oil, is generated from ketone (acetophenone in this case), which is one of the decomposition products. This means that the functional material 20 functions as a catalyst in the oxidative decomposition reaction. In this way, heavy oil can be converted into light oil by using the functional structure 1. Conventionally, in order to convert heavy oil into light oil, hydrocracking treatment using hydrogen has been performed. In contrast, if the functional structure 1 is used, hydrogen is not required. Therefore, it can be used to convert heavy oil into light oil even in areas where it is difficult to supply hydrogen. In addition, by eliminating the need for hydrogen, it is possible to realize low costs, and it is expected that the use of heavy oil, which has not been fully utilized until now, will be promoted.

[Method of manufacturing a functional structure]
Fig. 3 is a flow chart 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 a case where the functional substance present in the framework is metal oxide fine particles.

(Step S1: Preparation process)
As shown in Fig. 3, first, a precursor material (A) for obtaining a porous structure framework 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 that constitutes the framework of the functional structure.

Here, when the zeolite-type compound constituting the framework of the functional structure is a silicate compound, the ordered mesoporous material is preferably a compound consisting of a 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 ordered mesoporous materials 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 preferred. The pore diameter of SBA-1 is 10 to 30 nm, the pore diameter of SBA-15 is 6 to 10 nm, the pore diameter of SBA-16 is 6 nm, the pore diameter of KIT-6 is 9 nm, 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 the framework, and examples thereof include silica agents such as tetraethoxysilane (TEOS), fumed silica, and quartz sand. 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 to obtain a precursor material (B).

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 oxide microparticles 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, with nitrates being preferred among them. 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 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 (O-15), 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 considered not to prevent the metal-containing solution from penetrating into the pores. It is preferable to appropriately adjust the amount of the additive added to the precursor material (A) in consideration of the dispersibility of the metal element (M) contained in the metal-containing solution to be impregnated into the precursor material (A). For example, the molar ratio (Si/additive) of silicon (Si) constituting the precursor material (A) to the additive (surfactant) added to the precursor material (A) is preferably 25 or less in terms of obtaining dispersibility, more preferably 10 or less in terms of obtaining higher dispersibility, and particularly preferably 5 or less.

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) of the metal oxide fine particles can be contained in an amount of 0.5 to 2.5% by 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 metal oxide fine particles present in the framework 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 into the pores of precursor material (A), and thus the amount of metal oxide fine particles present in the framework 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, precursor material (A) for obtaining a porous structure 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).

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 metal oxide fine particles in the pores.

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

The structure-directing agent is a template 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 according to the skeletal structure of the skeleton of the functional structure, and surfactants such as tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), and tetrapropylammonium bromide (TPABr) are suitable.

The precursor material (C) and the structure-directing agent may be mixed during the hydrothermal treatment process or 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, and the solvent may be mixed at the same time, or the precursor material (C) and the structure-directing agent 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 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 positions of the metal oxide particles inside the pores of the precursor material (C) are generally maintained, and a new skeletal structure (porous structure) is formed as the skeleton of the functional structure by the action of the structure-directing agent. The functional structure thus obtained comprises a skeleton of a porous structure and metal oxide particles contained in the skeleton, and the skeleton further has a passage in which a plurality of pores are connected to each other due to the porous structure, and at least a portion of the metal oxide particles are present in the passage of the skeleton.

The precipitate (functional structure) obtained after the hydrothermal treatment is preferably washed, dried and calcined as necessary after recovery (for example, filtration). As the washing solution, water, an organic solvent such as alcohol, or a mixture of these can be used. As the drying treatment, natural drying for about one night or high-temperature drying at 150°C or less can be used. If the precipitate is calcined while a large amount of moisture remains, the skeleton structure as the skeleton of the functional structure may be destroyed, so it is preferable to dry it thoroughly. In addition, the calcination treatment can be performed, for example, in air under treatment conditions of 350 to 850°C and 2 to 30 hours. By such a calcination treatment, the structure-directing agent attached to the functional structure is burned off. In addition, the functional structure can be used as it is without calcining the precipitate after recovery depending on the purpose of use. For example, when the environment in which the functional structure is used is a high-temperature environment in an oxidizing atmosphere, the structure-directing agent is burned off by exposing it to the use environment for a certain period of time, and the functional structure can be obtained similar to that obtained by calcination treatment, so that it can be used as it is.
In addition, in the present embodiment, in the above-mentioned hydrothermal treatment step, a mixed solution is prepared by mixing the precursor material (C) and the structure-directing agent, and the precursor material (C) is hydrothermally treated. However, this is not limited thereto, and the precursor material (C) may be hydrothermally treated without mixing the precursor material (C) with the structure-directing agent.

The above describes a method for producing a functional structure in which the functional substance is metal oxide microparticles, but a functional structure can be produced in the same manner as above when the functional substance is metal microparticles. For example, after obtaining a functional structure having metal oxide particles as described above, a reduction treatment is performed under a reducing gas atmosphere such as hydrogen gas to obtain a functional structure in which metal microparticles are present in the framework. In this case, the metal oxide microparticles present in the framework are reduced to form metal microparticles corresponding to the metal element (M) constituting the metal oxide microparticles. Alternatively, by using a metal element (M) contained in the metal-containing solution to be impregnated into the precursor material (A) as a metal species that is difficult to oxidize (e.g., a noble metal), the metal microparticles can be crystallized in the firing process (step S3), and then a hydrothermal treatment is performed to obtain a functional structure in which metal microparticles are present in the framework.

[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 to have a skeleton 10 and a functional substance 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 have at least one functional substance 30 held on the outer surface 10a of the skeleton 10.

The functional material 30 is a material that exerts one or more functions. The function possessed by the functional material 30 may be the same as or different from the function possessed by the functional material 20. Specific examples of the functions possessed by the functional material 30 are the same as those described for the functional material 20, and among them, it is preferable that the functional material 30 has a catalytic function, in which case the functional material 30 is a catalytic material. In addition, when both the functional materials 20 and 30 are materials having the same function, the material of the 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 exertion of the function 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 skeleton 10 is greater than the content of the functional material 30 held on the outer surface 10a of the skeleton 10. This allows the function of the functional material 20 held inside the skeleton 10 to predominate, and the function of the functional material is stably exerted.

The functional structure according to the embodiment of the present invention has 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 576)
[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. The resulting precipitate was then filtered off, washed with water and ethanol, and further calcined in air at 600°C for 24 hours to obtain precursor materials (A) of the types and pore sizes shown in Tables 1 to 16. 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.)
SBA-1: Pluronic P123 (manufactured by BASF)

[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 oxide microparticles of the types shown in Tables 1 to 16 in water. The following metal salts were used according to the type of metal oxide microparticles ("metal oxide microparticles: metal salts").
CoO _x : Cobalt (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・NiO _x : Nickel (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・FeO _x : Iron (III) nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
CuO _x : Copper (II) nitrate trihydrate (manufactured by Wako Pure Chemical Industries, Ltd.)

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).

When the additive condition shown in Tables 1 to 16 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.) (represented as "O-15" in Tables 1 to 16) 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. The ratio of silicon (Si) constituting the precursor material (A) to the amount of additive (O-15) added to the precursor material (A) (atomic ratio: Si/O-15) was adjusted so that it was the value shown in Tables 1 to 16. When the additive condition is "No", the pretreatment with the additive as described above was not performed.

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 one of the values shown in Tables 1 to 16.

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).

[Synthesis of functional structures]
The precursor material (C) obtained as described above was mixed with a structure directing agent shown in Tables 1 to 16 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 the pH and time shown in Tables 1 to 16. Thereafter, the resulting precipitate was filtered off, washed with water, dried at 100° C. for 12 hours or more, and further calcined in air at 600° C. for 24 hours to obtain a functional structure having a framework shown in Tables 1 to 16 and metal oxide fine particles as a functional substance (Examples 1 to 576).

(Comparative Example 1)
In Comparative Example 1, cobalt oxide powder (II, III) (Sigma-Aldrich Japan LLC) having an average particle size of 50 nm or less was mixed with MFI-type silicalite to obtain a functional structure in which cobalt oxide 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 76 to 81, except for the step of adding the metal.

(Comparative Example 2)
In Comparative Example 2, MFI-type silicalite was synthesized in the same manner as in Comparative Example 1, except that the step of adhering cobalt oxide 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-Section Observation For the functional structures of the above-mentioned Examples and the silicalite with cobalt oxide microparticles attached thereto of the Comparative Example, observation samples were prepared by a pulverization method, and cross-sections were observed using a transmission electron microscope (TEM) (TITAN G2, manufactured by FEI).
As a result, it was confirmed that the functional material was present and held inside the framework made of silicalite or zeolite in the functional structures of the above examples, whereas in the silicalite of Comparative Example 1, the functional material was only attached to the outer surface of the framework and was not present inside the framework.
In addition, for the functional structures in the above examples in which the metal oxide was iron oxide fine particles (FeOx), a cross section was cut out by FIB (focused ion beam) processing, and the cross section was examined with a SEM (SU8020
Cross-sectional elemental analysis was performed using an EDX (X-Max, manufactured by Horiba, Ltd.) and an EDX (Hitachi High-Technologies Corporation). As a result, Fe element was detected from inside the skeleton.
From the results of the above-mentioned cross-sectional observations using TEM and SEM/EDX, it was confirmed that fine iron oxide particles were present inside the framework.

[B] Average inner diameter of the pathways of the skeleton and average particle size of the functional substance From the TEM image taken by the cross-sectional observation performed in the above evaluation [A], 500 pathways of the skeleton were randomly selected, the major axis and minor axis of each were measured, and the inner diameter of each was calculated from the average value (N=500). The average value of the inner diameters was then calculated, and this was taken as the average inner diameter D _F of the pathways of the skeleton. Similarly, for the functional substances, 500 functional substances were randomly selected from the above TEM image, the particle size of each was measured (N=500), and the average value was calculated, and this was taken as the average particle size D _C of the functional substances. The results are shown in Tables 1 to 16.
Furthermore, in order to confirm the average particle size and dispersion state of the functional material, analysis was performed using SAXS (small angle X-ray scattering). 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 particle size. The particle size was measured for a functional structure in which the metal oxide was iron oxide fine particles. For comparison, commercially available iron oxide fine particles (manufactured by Wako) were observed and measured using a SEM.
As a result, while the commercially available product contains randomly-distributed iron oxide fine particles of various sizes in the particle size range of about 50 nm to 400 nm, the functional structures of the examples, which had an average particle size of 1.2 nm to 2.0 nm as determined from TEM images, also showed scattering peaks of particle sizes of 10 nm or less in the SAXS measurement results. From the SAXS measurement results and the cross-sectional measurement results by SEM/EDX, it was found that functional substances of particle sizes of 10 nm or less were present within the framework with uniform particle sizes and in a highly dispersed state.

[C] Relationship between the amount of metal-containing solution added and the amount of metal encapsulated in the framework A functional structure was prepared in which metal oxide fine particles were encapsulated in the framework with the amount of atomic ratio Si/M = 50, 100, 200, 1000 (M = Co, Ni, Fe, Cu), and then the amount of metal (mass%) encapsulated in the framework of the functional structure prepared with the above amount of addition was measured. In this measurement, the functional structures with atomic ratio Si/M = 100, 200, 1000 were prepared by adjusting the amount of metal-containing solution added in the same manner as the functional structures with atomic ratio Si/M = 100, 200, 1000 in Examples 1 to 576, respectively, and the functional structures with atomic ratio Si/M = 50 were prepared in the same manner as the functional structures with atomic ratio Si/M = 100, 200, 1000, except that the amount of metal-containing solution added was different.
The amount of metal was determined by ICP (inductively coupled plasma) alone or by a combination of ICP and XRF (X-ray fluorescence analysis). XRF (energy dispersive X-ray fluorescence analyzer "SEA1200VX", manufactured by SSI NanoTechnology Co., Ltd.) was performed under the conditions of a vacuum atmosphere and an acceleration voltage of 15 kV (using a Cr filter) or 50 kV (using a Pb filter).
XRF is a method for calculating the amount of metal present by fluorescence intensity, and quantitative values (mass % conversion) cannot be calculated by XRF alone. Therefore, the amount of metal in the functional structure to which metal was added at Si/M=100 was quantified by ICP analysis, and the amount of metal in the functional structure to which metal was added at Si/M=50 and less than 100 was calculated based on the results of XRF measurement and ICP measurement.
As a result, it was confirmed that, at least within the range of the atomic ratio Si/M of 50 to 1000, the amount of metal encapsulated in the functional structure increases with an increase in the amount of metal-containing solution added.

[C] Performance Evaluation The catalytic ability (performance) of the functional material (catalyst material) was evaluated for the functional structures of the above-mentioned Examples and the silicalite of the Comparative Example.

(1) Measurement of average particle size and confirmation of dispersibility The average particle size and dispersibility of the catalyst were measured by small angle X-ray scattering (SAXS) (manufactured by Rigaku Corporation, product name "Nano-viewer IP"). As an index of dispersibility, when the particle size of the catalyst was less than 2.0 nm, the dispersibility was evaluated as particularly good "◎", when it was 2.0 nm or more and less than 5.0 nm, the dispersibility was evaluated as good "○", and when it was 5.0 nm or more, the dispersibility was evaluated as normal "△".

(2) Catalytic Activity Catalytic activity was evaluated under the following conditions.
First, 0.2 g of the functional structure was packed into an atmospheric pressure flow type 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 (N ₂ ) as a carrier gas (5 ml/min).
After the reaction was completed, the recovered product gas and product liquid were analyzed for components by gas chromatography mass spectrometry (GC/MS).
A 10GC (manufactured by Thermo Fisher Scientific Inc., detector: thermal conductivity detector) was used, and 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)) was used as the analyzer for the product liquid.
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 the substances of compounds having a molecular weight smaller than that of butylbenzene contained in the product liquid relative to the amount (mol) of butylbenzene before the start of the reaction.
In this example, when the yield of compounds having smaller molecular weights than butylbenzene contained in the product liquid was 40 mol% or more, the catalytic activity (resolution) was judged to be excellent and marked with "◎", when it was 25 mol% or more and less than 40 mol%, the catalytic activity was judged to be good and marked with "◯", when it was 10 mol% or more and less than 25 mol%, the catalytic activity was judged to be not good but to be at an acceptable level (passable) and marked with "△", and when it was less than 10 mol%, the catalytic activity was judged to be poor (unacceptable) and marked with "X".

Comparative examples 1 and 2 were also subjected to the same performance evaluation as in the above evaluations (1) and (2). Note that comparative example 2 is the framework itself and does not contain any functional substances. Therefore, in the above performance evaluation, only the framework of comparative example 2 was filled in place of the functional structure. The results are shown in Tables 1 to 16.

As is clear from Tables 1 to 16, the functional structures (Examples 1 to 576) in which it was confirmed by cross-sectional observation that functional substances were retained inside the framework showed superior catalytic activity in the decomposition reaction of butylbenzene compared to a functional structure in which functional substances were simply attached to the outer surface of the framework (Comparative Example 1) or the framework itself without any functional substances (Comparative Example 2).

In addition, when the dispersibility of the functional substance inside the framework was excellent, excellent catalytic activity was obtained in the decomposition reaction of butylbenzene. In particular, in the example in which the ratio (atomic ratio: Si/O-15) of silicon (Si) constituting the precursor material (A) to the amount of additive (O-15) added to the precursor material (A) was 5, the dispersibility judged based on particle size was further improved and even more excellent catalytic activity was obtained, compared to the example in which the ratio was 25 and the example in which the additive (O-15) was not added.

In addition, the relationship between the amount of metal (mass%) encapsulated in the framework of the functional structure measured in the above evaluation [C] and the yield (mol%) of compounds having a smaller molecular weight than butylbenzene contained in the product solution 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, converted into the atomic ratio Si/M (M = Fe) (the content of the metal element (M) of the metal oxide microparticles relative to the functional structure was 0.5 to 2.5 mass%), the yield of compounds having a smaller molecular weight than butylbenzene contained in the product liquid was 32 mol% or more, and the catalytic activity in the decomposition reaction of butylbenzene was at or above the acceptable level.

On the other hand, the functional structures of Comparative Examples 1 to 4, in which the functional substance was attached only to the outer surface of the framework, were inferior in catalytic activity in the decomposition reaction of butylbenzene to the functional structures of Examples 1 to 576, just like the framework of Reference Example 1 itself, which had no functional substance.

On the other hand, the framework of Comparative Example 2, which did not have any functional material, showed almost no catalytic activity in the decomposition reaction of butylbenzene, and had inferior catalytic activity compared to the functional structures of Examples 1 to 576.

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

Claims (13)

A porous framework composed of a zeolite compound;
At least one functional substance present within the scaffold;
Equipped with
the functional substance is a substance that exerts a catalytic function alone or in cooperation with the framework,
the functional material is an oxide of one metal selected from the group consisting of Co, Ni, and Fe;
The framework has passages communicating with each other,
the passage has 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;
The functional material is present in at least the passages of the framework, and the average particle size of the functional material is 5.00 nm or more and less than 30 nm;
A functional structure, wherein a ratio of an average particle size of the functional material to an average inner diameter of the passages is 6.76 to 35.71, and the average inner diameter of the passages is calculated from an average value of a minor axis and a major axis of a pore constituting any one of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores. The functional structure according to claim 1, wherein the ratio of the average particle size of the functional material to the average inner diameter of the passage is 8.93 to 35.71. The functional structure according to claim 1 or 2, excluding those in which the average major axis of the skeleton is 50 to 1000 nm. The functional structure according to any one of claims 1 to 3, excluding those in which the framework structure of the zeolite-type compound is an MFI type . 5. The functional structure according to claim 1 , wherein the functional substance is present by being included in at least the enlarged diameter portion. The functional structure according to any one of claims 1 to 5 , wherein the enlarged diameter portion connects a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole to each other. The functional structure according to any one of claims 1 to 6 , wherein the framework is a carrier that supports the functional substance. 8. The functional structure according to claim 1 , wherein an average particle size of the functional substance is equal to or smaller than an inner diameter of the expanded diameter portion. The functional structure according to any one of claims 1 to 8 , wherein 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. the average inner diameter of the passageways is between 0.1 nm and 1.5 nm;
The functional structure according to any one of claims 1 to 9 , wherein the inner diameter of the expanded portion is 0.5 nm to 50 nm. The functional structure according to any one of claims 1 to 10 , further comprising at least one functional material carried on the outer surface of the framework, the functional material being a catalytic material. 12. The functional structure according to claim 11 , wherein the content of the at least one functional substance present inside the framework is greater than the content of the at least one functional substance held on the outer surface of the framework. The functional structure according to any one of claims 1 to 12 , wherein the zeolite type compound is a silicate compound.

Images