JP2008127405A - Core-shell type spherical silica-based mesoporous body and catalyst and adsorbent using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a core-shell type spherical silica-based mesoporous body having mesopores modified with an organic group different in a hierarchical state and exhibiting different properties depending on pore sites in the same particle. <P>SOLUTION: The core-shell type spherical silica-based mesoporous body comprises a core particle composed of a first silica into which a first organic group having at least one kind of a function group selected from the group consisting of a sulfonic acid group, a carboxylic acid group and an amino group is introduced and a shell layer which is composed of a second silica into which at least one kind of a second organic group selected from the group consisting of an aliphatic compound-based organic group and a cyclic compound-based organic group is introduced and is laminated to the outsides of the core particle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a core-shell type spherical silica-based mesoporous material, a catalyst using the same, and an adsorbent.

  In recent years, silica-based mesoporous materials having meso-sized pores (mesopores) with a pore diameter of about 1 to 50 nm have attracted attention as materials and catalysts for adsorbing and storing various substances, and research on functional development. Has been actively conducted. As such a silica-based mesoporous material, a silica-based mesoporous material into which a sulfonic acid group or an amino group is introduced has been reported.

  Examples of such a silica-based mesoporous material into which a sulfonic acid group has been introduced include those in which a sulfonic acid is introduced into a silica-based mesoporous material such as MCM or HMS (WMV Rhijn, et al. Chem. Commun., 1998, pp. 317 to 318 (Non-patent Document 1)), and a silica-based mesoporous material as described above, in which a fluorine-based sulfonic acid that is a strong acid is introduced (D J. Macquarrie, et al., Chem. Commun., 2005, page 2363-2365 (Non-patent Document 2)) is known.

  In addition, as a silica-based mesoporous material into which an amino group has been introduced, for example, JP-A-2003-112051 (Patent Document 1) discloses a silica-based mesoporous material in which an amino group is directly bonded to a silicon atom, A silica-based mesoporous material in which an amino group is introduced into FSM-16 is disclosed.

  Further, as a silica-based mesoporous material, for example, a silica-based mesoporous material obtained by radially arranging pores using tetraethoxysilane and cetyltrimethylammonium salt is known (G. Van Tendero, O. I. Lebedev, O. Collart, P. Cooland EF Vansant, “J. Phys. Condens. Matter”, Vol. 15, 2003, p3037-p3046 (Non-patent Document 3)). Furthermore, in JP-A-2005-89218 (Patent Document 2), a silica raw material and a specific surfactant are mixed in a specific solvent, and the surfactant is introduced into the silica raw material. It is obtained by a production method comprising a first step of obtaining porous precursor particles and a second step of obtaining a spherical silica-based mesoporous material by removing the surfactant contained in the porous precursor particles. A spherical silica-based mesoporous material is disclosed.

However, in such spherical silica-based mesoporous materials described in Non-Patent Documents 1 to 3 and Patent Documents 1 and 2, basically only one type of organic group could be introduced. For example, when two or more organic groups are introduced into the spherical silica-based mesoporous material described in Non-Patent Documents 1 to 3 and Patent Documents 1 to 2, the organic in the resulting spherical silica-based mesoporous material The groups were not site-specific but were introduced randomly. Thus, in the spherical silica type mesoporous material described in Non-Patent Documents 1 to 3 and Patent Documents 1 and 2, a structure in which different organic groups are modified in a hierarchical manner has not been obtained. Therefore, in the conventional spherical silica-based mesoporous material, for example, when this is used as a catalyst, it is not possible to separate the adsorption region and the active site region to advance the oxidation catalyst reaction or the reduction catalyst reaction. It was.
JP 2003-112051 A JP 2005-89218 A W. M.M. V. Rhijn, et al. , Chem. Commun. , 1998, pages 317-318 D. J. et al. Macquarrie, et al. , Chem. Commun. , 2005, 2363-2365. G. Van Tendeloo, O.D. I. Lebedev, O.M. Collart, P.M. Cooland E.M. F. Vansant, “J. Phys. Condens. Matter”, Vol. 15, 2003, p3037-p3046

  The present invention has been made in view of the above-described problems of the prior art, has mesopores modified with different organic groups in a hierarchical manner, and exhibits different properties depending on the location of the pores in the same particle. It is an object of the present invention to provide a core-shell type spherical silica-based mesoporous material that can be used, and a catalyst and an adsorbent that can exhibit sufficiently high performance using the same.

  As a result of intensive studies to achieve the above object, the present inventors have found that the core particles composed of the first silica into which the first organic group having a specific functional group is introduced, and the specific second organic The core-shell type spherical silica-based mesoporous material comprising a shell layer made of a second silica having a group introduced therein and laminated on the outside of the core particle has found that the above object is achieved, and the present invention It came to be completed.

That is, the core-shell type spherical silica mesoporous material of the present invention is the first organic group having at least one functional group selected from the group consisting of a sulfonic acid group, a carboxylic acid group and an amino group. Core particles composed of a single silica,
It consists of second silica into which at least one second organic group selected from the group consisting of aliphatic compound-based organic groups and cyclic compound-based organic groups is introduced, and is laminated on the outside of the core particles. Shell layer,
It is characterized by providing.

  The first organic group according to the present invention is a chain hydrocarbon group which may have a linear or branched hetero atom having 18 or less carbon atoms, or a hetero atom having 18 or less carbon atoms. It is preferable that the functional group is bonded to a cyclic hydrocarbon group which may have, and the first organic group is a methyl group, an ethyl group, a linear or branched chain Propyl group, linear or branched butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched chain Octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched chain Tetradecyl group, linear or branched hexadecyl group, linear or branched octet Selected from the group consisting of decyl, allyl, vinyl, phenyl, alkylphenyl, biphenyl, naphthyl, cyclohexyl, pyridyl, pyrimidyl, quinolyl, isoquinolyl, imidazole, indole and purine groups It is more preferable that the functional group is bonded to at least one kind of group.

In addition, as the second organic group according to the present invention, an aliphatic compound-based organic group which may have a linear or branched hetero atom having 18 or less carbon atoms, and 18 or less carbon atoms. It is preferably at least one selected from the group consisting of cyclic compound-based organic groups optionally having heteroatoms, and further, a methyl group, an ethyl group, a linear or branched propyl group, Linear or branched butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, Linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tetradecyl group, Linear or branched hexadecyl group, linear or branched Octadecyl group, an allyl group, a vinyl group, a phenyl group, alkylphenyl group, a biphenyl group, a naphthyl group, a cyclohexyl group, a pyridyl group, pyrimidyl group, quinolyl group, isoquinolyl group, imidazole group, indole group, a purine group, and,
These groups include at least selected from the group consisting of hydroxyl group, carbonyl group, aldehyde group, imino group, cyano group, azo group, azide group, nitro group, thiol group, amide group, ureido group, ester group and ether group. A group to which an organic group having a functional group containing one kind of heteroatom is bonded;
More preferably, it is at least one selected from the group consisting of:

  The catalyst of the present invention comprises the core-shell type spherical silica mesoporous material of the present invention.

  Furthermore, the adsorbent of the present invention is characterized by comprising the core-shell type spherical silica mesoporous material of the present invention.

  The reason why the above object is achieved by the core-shell type spherical silica-based mesoporous material of the present invention is not necessarily clear, but the present inventors speculate as follows. That is, in the core-shell type spherical silica-based mesoporous material of the present invention, different organic groups are introduced hierarchically into the mesopores, so that different properties can be exhibited depending on the position of the pores in the same particle. It becomes possible. For example, when such a core-shell type spherical silica-based mesoporous material is used as a catalyst, an organic group having a high affinity with the substrate is introduced into the silica of the shell layer, and the catalytic reaction between the substrate and the silica is efficiently performed on the silica of the core particles. By introducing an organic group that can be generated automatically, the shell layer can function as an adsorption region of the substrate, and the core particle can function as an active site region. Therefore, in such a catalyst comprising a core-shell type spherical silica-based mesoporous material, first, a substrate having a high affinity with the organic group of the shell layer is selectively and efficiently incorporated into the shell layer, and then incorporated. The resulting substrate moves inside and reacts rapidly with the organic groups of the core particles. Therefore, when the core-shell type spherical silica-based mesoporous material of the present invention is used as, for example, a catalyst, a specific substrate can be incorporated with high selectivity, and more efficiently by the functional group introduced into the core particle. Therefore, it is possible to exhibit a higher catalytic reaction performance. In addition, when a core-shell type spherical silica-based mesoporous material is used as an adsorbent, an organic group having a high affinity with the adsorbent is introduced into the silica of the shell layer, and the adsorbent is chemically bonded to the silica of the core particle. The present inventors speculate that by introducing an organic group that can be used, the shell layer can function as an adsorption region selection region, and the core particles can function as an adsorption region.

  According to the present invention, a core-shell type spherical silica-based mesoporous material having mesopores modified with different organic groups in a hierarchical manner and capable of exhibiting different properties depending on the location of the pores in the same particle, In addition, it is possible to provide a catalyst and an adsorbent capable of exhibiting sufficiently high performance using the same.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

First, the core-shell type spherical silica mesoporous material of the present invention will be described. That is, the core-shell type spherical silica mesoporous material of the present invention is the first organic group having at least one functional group selected from the group consisting of a sulfonic acid group, a carboxylic acid group and an amino group. Core particles composed of a single silica,
It consists of second silica into which at least one second organic group selected from the group consisting of aliphatic compound-based organic groups and cyclic compound-based organic groups is introduced, and is laminated on the outside of the core particles. Shell layer,
It is characterized by providing.

  Since the core-shell type spherical silica-based mesoporous material of the present invention has different organic groups introduced into the core particles and the silica constituting the shell layer, the core-shell type is modified with organic layers hierarchically different from each other. It is a spherical silica-based mesoporous material. Therefore, when the core-shell type spherical silica-based mesoporous material of the present invention is used as a catalyst, the shell layer functions as an adsorption region (substrate selection site), and the core particle functions as an active site region (substrate reaction). It is possible to function as a site), and thereby sufficiently high catalytic activity can be exhibited.

  The core particle concerning this invention consists of a 1st silica in which said 1st organic group was introduce | transduced. Such a first organic group is not particularly limited as long as it has at least one functional group selected from the group consisting of a sulfonic acid group, a carboxylic acid group, and an amino group. The organic group which has can be used suitably.

As such a first organic group,
(I) a linear hydrocarbon group which may have a linear or branched hetero atom having 18 or less carbon atoms, or
(Ii) a cyclic hydrocarbon group optionally having a hetero atom having 18 or less carbon atoms,
What the said functional group couple | bonded is preferable.

  When the carbon number of such a chain hydrocarbon group (i) or cyclic hydrocarbon group (ii) exceeds the upper limit, the pore volume decreases, and mass transfer, catalytic reaction and adsorption in the pores are reduced. It tends to be less likely to occur. Such a chain hydrocarbon group (i) or cyclic hydrocarbon group (ii) is appropriately selected according to the use of the obtained core-shell type spherical silica-based mesoporous material, and is particularly limited. Is not to be done.

  Examples of such a chain hydrocarbon group (i) include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group. Group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl Group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tetradecyl group, linear or branched hexadecyl group, linear or branched octadecyl group Group, allyl group or vinyl group is preferred.

  The cyclic hydrocarbon group (ii) includes a phenyl group, an alkylphenyl group, a biphenyl group, a naphthyl group, a cyclohexyl group, a pyridyl group, a pyrimidyl group, a quinolyl group, an isoquinolyl group, an imidazole group, an indole group, or a purine group. preferable.

  In such a first organic group, the chain hydrocarbon group (i) or the cyclic hydrocarbon group (ii) has another organic group having a hetero atom (for example, a hydroxyl group, a carbonyl group, an aldehyde group, An organic group having another functional group containing a hetero atom such as an imino group, a cyano group, an azo group, an azido group, a nitro group, a thiol group, an amide group, a ureido group, an ester group, an ether group, etc. May be.

  Furthermore, the first organic group in the case of having an amino group as the functional group according to the present invention may be any of primary, secondary and tertiary. In addition, when the functional group according to the present invention has an amino group, the first organic group is a cyclic group such as the aforementioned pyridyl group, pyrimidyl group, quinolyl group, isoquinolyl group, imidazole group, indole group or purine group. The hydrocarbon group (ii) may contain an amino group. In addition, the first organic group having such an amino group may be one having two or more amines in the molecule, for example, N 2 having two amines. -(2-Aminoethyl) 3-aminopropyl group and the like are mentioned, and those having three amines include 3- [2- (2-aminoethylamino) ethylamino] propyl group and the like. In addition, in the core particle concerning this invention, the above-mentioned 1st organic group should just be introduce | transduced, and the 2nd organic group mentioned later may further be introduce | transduced into the silica frame | skeleton.

  The shell layer according to the present invention is made of the second silica into which the second organic group is introduced, and is laminated on the outside of the core particle. Such a second organic group is not particularly limited as long as it is at least one selected from the group consisting of an aliphatic compound-based organic group and a cyclic compound-based organic group.

  As such an aliphatic compound-based organic group, an aliphatic compound-based organic group which may have a linear or branched hetero atom having 18 or less carbon atoms is preferable. When the number of carbon atoms of such an aliphatic compound-based organic group exceeds the upper limit, the pores become small, and the substrate and the adsorbing material tend not to enter the pores.

  Moreover, as said cyclic compound type organic group, the cyclic compound type organic group which may have a C18 or less hetero atom is preferable. When the carbon number of such a cyclic compound-based organic group exceeds the above upper limit, the pores become small, and the substrate and the adsorbing material tend to be difficult to enter the pores.

  Further, such an aliphatic compound-based organic group or cyclic compound-based organic group is appropriately selected according to the use of the obtained core-shell type spherical silica-based mesoporous material, and is particularly limited. However, as the aliphatic compound-based organic group, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, Linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, Linear or branched undecyl group, linear or branched dodecyl group, linear or branched tetradecyl group, linear or branched hexadecyl group, linear or branched octadecyl group, Allyl group, vinyl group, or these Select from the group consisting of hydroxyl group, organic group, hydroxyl group, carbonyl group, aldehyde group, imino group, cyano group, azo group, azi group, nitro group, thiol group, amide group, ureido group, ester group and ether group A group to which an organic group having a functional group containing at least one hetero atom is bonded is more preferable. Examples of the cyclic compound-based organic group include a phenyl group, an alkylphenyl group, a biphenyl group, a naphthyl group, a cyclohexyl group, a pyridyl group, a pyrimidyl group, a quinolyl group, an isoquinolyl group, an imidazole group, an indole group, a purine group, or These cyclic compound-based organic groups consist of a hydroxyl group, a carbonyl group, an aldehyde group, an imino group, a cyano group, an azo group, an azide group, a nitro group, a thiol group, an amide group, a ureido group, an ester group, and an ether group. A group to which an organic group having a functional group containing at least one hetero atom selected from the group is bonded is more preferable. For example, when the substrate or the adsorbing substance has hydrophobicity, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched chain Pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched chain Decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tetradecyl group, linear or branched hexadecyl group, linear or branched chain In the case where an octadecyl group, a phenyl group, an alkylphenyl group, a biphenyl group, a naphthyl group, a cyclohexyl group, or the like is suitably used and the substrate or the adsorbing substance has hydrophilicity, the aliphatic compound-based organic group or Cyclic organic group , A hydroxyl group, a carbonyl group, an aldehyde group, an imino group, a cyano group, an azo group, an azido group, a nitro group, a thiol group, an amide group, a ureido group, an ester group, and an ether group. A group to which an organic group having a functional group containing an atom is bonded is preferably used.

  Further, such a shell layer may be composed of a single-layer silica layer composed of the second silica, or may be composed of a plurality of silica layers, including the silica layer composed of the second silica. Good.

  The term “spherical” as used in the present invention is not limited to a true sphere, but includes a substantially sphere having a minimum diameter of 80% or more (preferably 90% or more) of the maximum diameter. In the case of a substantially spherical body, the particle size is an average value of the minimum diameter and the maximum diameter in principle.

  The core-shell type spherical silica-based mesoporous material of the present invention has a highly crosslinked network structure based on a skeleton —Si—O— in which silicon atoms are bonded via oxygen atoms. Such a core-shell type spherical silica-based mesoporous material only needs to have silicon atoms and oxygen atoms as main components, and at least part of the silicon atoms form carbon-silicon bonds at two or more organic groups. It may be what you have.

  In addition, the core-shell type spherical silica-based mesoporous material of the present invention preferably includes 60% or more of the total pore volume in the range of ± 40% of the central pore diameter in the pore size distribution curve. The core-shell type spherical silica-based mesoporous material satisfying such conditions means that the pore diameter is very uniform. Here, the center pore diameter is a curve (pore diameter distribution curve) in which a value (dV / dD) obtained by differentiating the pore volume (V) with respect to the pore diameter (D) is plotted against the pore diameter (D). ) At the maximum peak. The pore size distribution curve can be obtained by the method described below. That is, silica-based mesoporous particles are cooled to a liquid nitrogen temperature (-196 ° C.), nitrogen gas is introduced, the adsorption amount is determined by a constant volume method or a gravimetric method, and then the pressure of the introduced nitrogen gas is gradually increased. And the adsorption amount of nitrogen gas for each equilibrium pressure is plotted to obtain an adsorption isotherm. Using this adsorption isotherm, a pore size distribution curve can be obtained by a calculation method such as Cranston-Inklay method, Dollimore-Heal method, BJH method or the like.

The specific surface area of the core-shell type spherical silica-based mesoporous material of the present invention is not particularly limited, but is preferably 700 m ² / g or more. Such a specific surface area can be calculated as a BET specific surface area from the adsorption isotherm using the BET isotherm adsorption equation.

  Furthermore, the core-shell type spherical silica-based mesoporous material of the present invention preferably has one or more peaks at a diffraction angle corresponding to a d value of 1 nm or more in the X-ray diffraction pattern. The X-ray diffraction peak means that a periodic structure having a d value corresponding to the peak angle is present in the sample. Therefore, having one or more peaks at a diffraction angle corresponding to a d value of 1 nm or more means that the pores are regularly arranged at intervals of 1 nm or more.

  In addition, the pores of the core-shell type spherical silica mesoporous material of the present invention are formed not only on the surface of the porous material but also inside. The arrangement state (pore arrangement structure or structure) of the pores in such a porous body is not particularly limited, but is preferably a 2d-hexagonal structure, a 3d-hexagonal structure, or a cubic structure. Such a pore arrangement structure may have a disordered pore arrangement structure.

  Here, that the porous body has a hexagonal pore arrangement structure means that the arrangement of the pores is a hexagonal structure (S. Inagaki, et al., J. Chem. Soc., Chem. Commun. 680, 1993; S. Inagaki, et al., Bull. Chem. Soc. Jpn., 69, 1449, 1996, Q. Huo, et al., Science, 268, 1234, 1995). Moreover, the porous body having a cubic pore arrangement structure means that the arrangement of the pores is a cubic structure (JC Vartuli, et al., Chem. Mater., 6, 2317, 1994). Q. Huo, et al., Nature, 368, 317, 1994). Further, that the porous body has a disordered pore arrangement structure means that the arrangement of the pores is irregular (PT Tanev, et al., Science, 267, 865, 1995; S; A. Bagshaw, et al., Science, 269, 1242, 1995; R. Ryoo, et al., J. Phys. Chem., 100, 17718, 1996). The cubic structure is preferably Pm-3n, Im-3m or Fm-3m symmetric. The symmetry is determined based on a space group notation.

  Further, the core-shell type spherical silica mesoporous material of the present invention is preferably one in which mesopores are arranged from the center of the particle toward the outside of the spherical particle while maintaining regularity. For example, when such a core-shell type spherical silica-based mesoporous material is used as a catalyst, mass transfer of a substrate or a product can be efficiently performed, and thus the catalytic activity tends to be higher. is there.

  In addition, since the core-shell type spherical silica-based mesoporous material of the present invention has different organic groups introduced into the pores of the core particle and the shell layer, the core particle is a reaction site of the substrate, and the shell layer The material used for the catalyst that distinguishes the reaction region from the adsorption region where is a selective substrate adsorption site, the core particle is the adsorption site for adsorbents such as dyes, and the shell layer is the selection site for adsorbents It is suitable as a material used for a certain adsorbent. Moreover, although the core-shell type spherical silica-based mesoporous material of the present invention may be used as a powder, it may be molded and used as necessary. Any molding means may be used, but extrusion molding, tablet molding, rolling granulation, compression molding, CIP and the like are preferable. The shape can be determined according to the place of use and method, and examples thereof include a columnar shape, a crushed shape, a spherical shape, a honeycomb shape, an uneven shape, and a corrugated plate shape.

  Next, a preferred embodiment of a method capable of producing such a core-shell type spherical silica-based mesoporous material of the present invention will be described.

As a method capable of producing such a core-shell type spherical silica-based mesoporous material, basically,
A first step of mixing a surfactant and a first silica raw material in a solvent and precipitating the core particles into which the surfactant is introduced in silica;
After the core particles are precipitated, a second silica raw material is mixed in the solvent, and a shell layer in which the surfactant is introduced into silica is laminated outside the core particles, and the core particles and A second step of obtaining porous precursor particles in which the surfactant is introduced into the shell layer;
A third step of removing the surfactant contained in the porous precursor particles;
It is a method including. In such a method for producing a core-shell type spherical silica-based mesoporous material, when the core particle contains a precursor of a first organic group, the precursor is converted into a first organic group. It further includes a fourth step of performing the processing. Hereinafter, it demonstrates for every process.

(First step)
The first step is a step of mixing the surfactant and the first silica raw material in a solvent to precipitate the core particles into which the surfactant has been introduced.

  Here, the term “precipitation” refers to the time when the diffraction peak on the 100 plane of hexagonal pores begins to appear by X-ray diffraction measurement of the reaction solution, and the diffraction peak gradually increases. The time when it reaches a certain value is defined as the end time of deposition.

  As long as such first silica raw material is capable of forming a silicon oxide (including a silicon composite oxide) into which a first organic group or a precursor of the first organic group is introduced. Well, not particularly limited. The precursor of the first organic group may be an organic group having a functional group that can be converted into a sulfonic acid group, a carboxylic acid group, or an amino group, and includes, for example, a mercapto group and a cyano group. Examples thereof include organic groups in which a functional group selected from the group is bonded to a chain hydrocarbon group (i) or a cyclic hydrocarbon group (ii).

  Moreover, as such a 1st silica raw material, the 1st alkoxysilane which has a 1st organic group or the precursor of a 1st organic group, and the other silica raw material which does not have a 1st organic group It is preferable to use a mixture thereof.

  Examples of such first alkoxysilane include trialkoxysilane having three alkoxy groups in addition to the first organic group or the precursor of the first organic group, the first organic group, or the first organic group. In addition to the precursor, dialkoxysilane having two alkoxy groups can be used as appropriate. The type of such an alkoxy group is not particularly limited, but those having a relatively small number of carbon atoms in the alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group (about 1 to 4 carbon atoms) From the viewpoint of reactivity.

  Examples of such first alkoxysilane include 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, and 3-cyanopropyl. Trimethoxysilane, 3-cyanoethyltrimethoxysilane, N- [3- (trimethoxysilyl) propyl] aniline, (N, N-dimethylaminopropyl) trimethoxysilane, 3- (methylamino) propyltrimethoxysilane, 3 -Diethylaminopropyltrimethoxysilane, 2- (4-chlorosulfonylphenyl) -ethyltrimethoxysilane, N- (trimethoxysilylpropyl) -4,5-dihydroimidazole, 2- (trimethoxysilylethyl) pyridine, 2- Trimethoxysilylpi Gin, 3- (trimethoxysilylethyl) pyridine, 3-trimethoxysilylpyridine, 4-aminobutyltrimethoxysilane, (aminoethylaminoethyl) phenethyltrimethoxysilane, N- (6-aminohexyl) aminomethyltrimethoxy Silane, N- (6-aminohexyl) aminopropyltrimethoxysilane, N- (2-aminoethyl) -11-aminoundecyltrimethoxysilane, 3- (aminophenoxy) propyltrimethoxysilane, aminophenyltrimethoxysilane N-3- [amino (polypropyleneoxy)] aminopropyltrimethoxysilane, bis (trimethylsilyl) cytosine, 3-mercaptopropyltriethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) 3- Minopropyltriethoxysilane, 3-cyanopropyltriethoxysilane, 3-cyanoethyltriethoxysilane, N- [3- (triethoxysilyl) propyl] aniline, (N, N-dimethylaminopropyl) triethoxysilane, 3- (Methylamino) propyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, 2- (4-chlorosulfonylphenyl) -ethyltriethoxysilane, N- (triethoxysilylpropyl) -4,5-dihydroimidazole, 2- (Triethoxysilylethyl) pyridine, 2-triethoxysilylpyridine, 3- (triethoxysilylethyl) pyridine, 3-triethoxysilylpyridine, 4-aminobutyltriethoxysilane, (aminoethylaminoethyl) phenethyl rie Toxisilane, N- (6-Aminohexyl) aminomethyltriethoxysilane, N- (6-Aminohexyl) aminopropyltriethoxysilane, N- (2-aminoethyl) -11-aminoundecyltriethoxysilane, 3- (Aminophenoxy) propyltriethoxysilane, aminophenyltriethoxysilane, N-3- [amino (polypropyleneoxy)] aminopropyltriethoxysilane, bis (triethylsilyl) cytosine and the like.

  Moreover, as another silica raw material which does not have said 1st organic group, the alkoxysilane which does not have a 1st organic group can be used suitably. As such an alkoxysilane as another silica raw material, tetraalkoxysilane having 4 alkoxy groups, trialkoxysilane having 3 alkoxy groups, and dialkoxysilane having 2 alkoxy groups can be used. Such alkoxy groups are the same as those described for the first alkoxysilane. When the alkoxysilane has 3 or 2 alkoxy groups, an organic group other than the first organic group, a hydroxyl group, or the like may be bonded to the silicon atom in the alkoxysilane. Although it does not restrict | limit especially as another silica raw material which does not have such a 1st organic group, For example, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane etc. are mentioned. It is done. In addition, such other silica raw material may contain a second alkoxysilane having a second organic group described later at least partially.

  Such other silica raw materials not having the first organic group can be used alone or in combination of two or more. Moreover, in the other silica raw material which does not have such a first organic group, a monoalkoxysilane having one alkoxy group is combined with an alkoxysilane having 2 to 4 alkoxy groups as described above. It is also possible to use it.

  In the case where a mixture of the first alkoxysilane and the other silica raw material not having the first organic group is used as the first silica raw material, the first silica raw material in the first silica raw material is used. The content ratio of the alkoxysilane is preferably 0.1 to 30 mol% with respect to the total amount of the first silica raw material. When the content ratio of the first alkoxysilane is less than the lower limit, the catalyst and the adsorption performance tend to be lowered. On the other hand, when the upper limit is exceeded, the pores are blocked and the substrate or the adsorbent is difficult to enter the pores. Thus, the catalyst and the adsorption performance tend to decrease. The method for producing such a mixture of the first alkoxysilane and the other silica raw material is not particularly limited. For example, the first alkoxysilane and the other silica raw material are mixed in a dry nitrogen stream. The method can be adopted.

  Further, the first alkoxysilane and the other silica raw material generate silanol groups by hydrolysis, and the generated silanol groups are condensed to form a silicon oxide. In this case, an alkoxysilane having a large number of alkoxy groups in the molecule has many bonds generated by hydrolysis and condensation. Therefore, in the present invention, it is preferable to use tetraalkoxysilane having many alkoxy groups as the other silica raw material not having the first organic group. As such a tetraalkoxysilane, it is particularly preferable to use tetramethoxysilane or tetraethoxysilane from the viewpoint of reaction rate.

  The surfactant used in the first step is not particularly limited, and a known surfactant that can be used when producing a spherical silica mesoporous material can be appropriately used. Moreover, as such surfactant, the following general formula (1):

[Wherein R ¹ , R ² and R ³ may be the same or different and each represents an alkyl group having 1 to 3 carbon atoms, X represents a halogen atom, and n represents an integer of 7 to 25, respectively. ]
The alkyl ammonium halide represented by these is preferable.

R ¹ , R ² and R ³ in the general formula (1) may be the same or different and each represents an alkyl group having 1 to 3 carbon atoms. Examples of such an alkyl group include a methyl group, an ethyl group, and a propyl group, and these may be mixed in one molecule. From the viewpoint of symmetry of the surfactant molecule, R ¹ , R ² , R ³ Are preferably the same. When the symmetry of the surfactant molecule is excellent, aggregation of the surfactants (formation of micelles, etc.) tends to be facilitated. ^Furthermore, R ^1, it is preferable that at least one of R 2, ^{R 3} is a methyl ^group, and more preferably all of R ^1, R 2, ^{R 3} is a methyl group.

  Moreover, n in the said General formula (1) shows the integer of 7-25, and it is more preferable that it is an integer of 11-17. In the case of the alkyl ammonium halide having n of 6 or less, although spherical core particles can be obtained, the formation of pores tends to be difficult because the aggregating action of the surfactant is insufficient. On the other hand, in the case of the alkyl ammonium halide having n of 26 or more, the hydrophobic interaction of the surfactant is too strong, so that a layered compound is generated and it becomes difficult to obtain spherical core particles.

  Furthermore, X in the general formula (1) represents a halogen atom. The type of such a halogen atom is not particularly limited, but X is preferably a chlorine atom or a bromine atom from the viewpoint of easy availability.

Therefore, as the surfactant represented by the general formula (1), all of R ¹ , R ² and R ³ are methyl groups and alkyltrimethylammonium halides having a long-chain alkyl group having 8 to 26 carbon atoms. Among them, octyltrimethylammonium halide, decyltrimethylammonium halide, dodecyltrimethylammonium halide, tetradecyltrimethylammonium halide, hexadecyltrimethylammonium halide, octadecyltrimethylammonium halide, eicosyltrimethylammonium halide, docosyltrimethylammonium halide are more preferable. preferable.

  Such a surfactant forms a complex in the solvent together with the first silica raw material. The silica raw material in the composite is changed to silicon oxide by the reaction, but silicon oxide is not generated in the part where the surfactant is present, so pores are formed in the part where the surfactant is present. Will be. That is, the surfactant is introduced into the silica raw material and functions as a template for pore formation. Such surfactants can be used alone or in combination of two or more. As described above, the surfactant is used as a template for forming pores in the reaction product of the silica raw material. Since the type and the effect greatly affect the pore shape of the porous body, in order to obtain a more uniform spherical porous body, it is preferable to use only one type of surfactant.

  In addition, the content ratio of the surfactant to the silicon atoms in the first silica raw material (surfactant / silicon atoms in the first silica raw material) is 0.1 to 20 (more preferably 0). .2 to 10) is preferable. When the content ratio of such a surfactant is less than 0.1, the amount of the surfactant to be a template is insufficient, so that good core particles tend not to be obtained. Thus, since the surfactant functions as a template (template) for pores, the content ratio of the surfactant to the silicon atoms contained in the first silica raw material is at least The ratio is more than necessary to form the pores. Moreover, when the content ratio of the surfactant exceeds 20, the formation of particles is inhibited, and it tends to be difficult to obtain uniform particles.

  Here, excess surfactant more than the amount of surfactant necessary to form pores prevents aggregation between the precipitated core particles, and additionally adds a second silica raw material to be described later. The porous precursor particles obtained in this way are used for pore formation. That is, by controlling the content ratio (molar ratio) of the surfactant to the silicon atoms in the first silica raw material as described above, uniform core particles (spherical bodies) are generated and grown. In addition, after the core particles are precipitated, the amount of surfactant necessary to form the pores of the shell layer is present when the second silica raw material is mixed. Generation and growth of body precursor particles can be realized. In addition, by controlling the content ratio (molar ratio) as described above, in combination with the use of a mixed solvent described later, the particle diameter of the obtained porous precursor particles is made more highly uniform. It is also possible to control.

  Moreover, in such a 1st process, said 1st silica raw material and said surfactant are mixed in a solvent. In general, the silica raw material reacts under basic and acidic conditions and changes to silicon oxide, but the surfactant content is controlled as described above using the surfactant. In some cases, since the reaction hardly proceeds under acidic conditions, it is preferable to react the silica raw material in a basic solvent. In addition, when the silica raw material is reacted under basic conditions, the reaction point of silicon atoms is increased when the reaction is performed under basic conditions, and a silicon oxide having excellent physical properties such as moisture resistance and heat resistance is obtained. Therefore, mixing under basic conditions is also preferable in this respect.

  The pH value of such a basic solvent is preferably 7.5 to 13, and more preferably 8 to 12. When such a pH value is less than the lower limit, pore formation of the core particles tends to be difficult, and on the other hand, when the upper limit is exceeded, the precipitation amount of the core particles tends to decrease. In addition, the method for adjusting the pH value of such a basic solvent is not particularly limited, but a method of appropriately adjusting the pH value by adding a basic substance such as an aqueous sodium hydroxide solution to the solvent described later can be mentioned. .

  As such a solvent, it is preferable to use a mixed solvent of water and alcohol. Examples of such an alcohol include methanol, ethanol, isopropanol, n-propanol, ethylene glycol, and glycerin, and methanol or ethanol is preferable from the viewpoint of solubility of the first silica raw material.

  Moreover, as such a mixed solvent, it is more preferable to use a water / alcohol mixed solvent having an alcohol content of 85% by volume or less. Furthermore, among such a mixed solvent of water and alcohol, it is possible to realize generation and growth of uniform spheres, and the core particles in which the surfactant is introduced into the obtained first silica raw material From the viewpoint that the diameter can be controlled highly uniformly, it is more preferable to use a mixed solvent having an alcohol content of 45 to 80% by volume, and a mixture having an alcohol content of 50 to 70% by volume. It is particularly preferable to use a solvent. When the alcohol content is less than 45% by volume, it is difficult to control the particle size and particle size distribution, and the uniformity of the particle size of the obtained core particles tends to be low, while the alcohol content is low. When it exceeds 80% by volume, it is difficult to control the particle size and particle size distribution, and the uniformity of the particle size of the obtained core particles tends to be low.

  Further, in the mixed solvent of water and alcohol, by changing the ratio of water and alcohol, the particle size of the core particle can be easily increased while maintaining the uniformity of the particle size of the core particle at a high level. It becomes possible to control. For example, when the ratio of water is high, the core particles are likely to precipitate, so that core particles with a small particle diameter can be obtained. Conversely, when the ratio of alcohol is high, core particles with a large particle diameter can be obtained.

  The reaction conditions (reaction temperature, reaction time, etc.) in the first step are not particularly limited, and the reaction temperature is, for example, -20 ° C to 100 ° C (more preferably 0 ° C to 80 ° C, more preferably 10 ° C). ~ 40 ° C). In addition, the reaction is preferably allowed to proceed with stirring. Specific reaction conditions are preferably determined based on the type of silica raw material used.

  For example, when a mixture of the first alkoxysilane and the second alkoxysilane is used as the first silica raw material, core particles can be obtained as follows. First, a basic solution containing a surfactant is prepared by adding a surfactant and a basic substance to the mixed solvent of water and alcohol described above, and the mixture is added to the solution. The mixture added in this manner is hydrolyzed (or hydrolyzed and condensed) in the solution, and core particles (white powder) are deposited within a few seconds to several tens of minutes after the addition. In this case, the reaction temperature is preferably 0 ° C to 80 ° C, more preferably 10 ° C to 40 ° C. The solution is preferably stirred. In addition, the core particle obtained in this way has the silica modified with the first organic group or the precursor of the first organic group.

(Second step)
Next, the second step will be described. In the second step, after the core particles are precipitated, a second silica raw material is mixed in the solvent, and a shell layer in which the surfactant is introduced into the silica is laminated on the outside of the core particles. And obtaining porous precursor particles in which the surfactant is introduced into the core particles and the shell layer.

  Such a second silica raw material is not particularly limited as long as it can form a silicon oxide (including a silicon composite oxide) into which the second organic group is introduced. As such a second silica raw material, a mixture of a second alkoxysilane having a second organic group and another silica raw material not having the first organic group and the second organic group is used. It is more preferable.

  Such a second alkoxysilane is not particularly limited as long as it is an alkoxysilane having a second organic group. For example, a trialkoxysilane having three alkoxy groups in addition to the second organic group, A dialkoxysilane having two alkoxy groups in addition to the two organic groups can be used. Examples of such second alkoxysilane include methyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, octadecyltrimethoxysilane, phenyltrimethoxysilane, allyltrimethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, and the like. Ethoxysilane, propyltriethoxysilane, hexyltriethoxysilane, octadecyltriethoxysilane, phenyltriethoxysilane, allyltriethoxysilane, (1-naphthyl) triethoxysilane, [2- (cyclohexenyl) ethyl] triethoxysilane, Dimethoxydimethylsilane, diethoxydimethylsilane, diethoxy-3-glycidoxypropylmethylsilane, dimethoxydiphenylsilane, dimethoxydimethylphenylsilane, Rutrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, isopropyltrimethoxysilane, pentyltrimethoxysilane, heptyltrimethoxysilane, octyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetra Decyltrimethoxysilane, hexadecyltrimethoxysilane, phenylethyltrimethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, isopropyltriethoxysilane, pentyltriethoxysilane, heptyltriethoxysilane, octyltriethoxy Silane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, tetradecylto Silane, hexadecyl triethoxysilane, phenyl triethoxysilane, trimethyl methoxy silane, trimethyl ethoxy silane, 3-chloropropyl dimethylmethoxysilane, and the like.

  Further, other silica raw materials not having the first organic group and the second organic group are not particularly limited, and alkoxysilanes having no first organic group and second organic group (for example, tetrasilane) Methoxysilane, tetraethoxysilane, etc.) can be preferably used.

  In the case of using a mixture of the second alkoxysilane and other silica raw materials not having the first organic group and the second organic group as such a second silica raw material, It is preferable that the mixing ratio of silane is 0.1 to 50 mol% in terms of molar ratio with respect to the total amount of the second silica raw material. If the mixing ratio of the second alkoxysilane is less than the lower limit, the selectivity to the substrate and the adsorbent tends to be reduced. On the other hand, if the upper limit is exceeded, the pores are blocked, and the substrate or adsorbent is contained in the pores. Tends to be difficult to enter. In addition, the manufacturing method of such a mixture is not particularly limited. For example, in a dry nitrogen stream, the second alkoxysilane, and other silica raw materials not having the first organic group and the second organic group It is possible to adopt a method of mixing.

  Further, by using such a second silica raw material, a core-shell type spherical silica-based mesoporous body in which a shell layer made of a second silica having a second organic group introduced is laminated on the outside of the core particle. Can be obtained.

  The particle diameter of the core-shell type spherical silica-based mesoporous material thus obtained is not particularly limited and can be adjusted according to the intended use. For example, the particle diameter is about 0.1 to 5 μm. It is also possible. Such adjustment of the particle diameter can be performed by appropriately adjusting the conditions of the solvent, the mixing amount of the second silica raw material, and the like.

  Further, the method for mixing the second silica raw material is not particularly limited, and after the core particles have been precipitated, the addition of the second silica raw material in addition to the method of adding the second silica raw material all at once. And the like, and a method of repeatedly adding the second silica raw material continuously. By mixing the second silica raw material in this way, the second silica raw material is added to the solvent in a state in which condensation does not proceed at all. A shell layer made of the second silica in which the surfactant is introduced and the surfactant is introduced outside the core particles can be laminated.

  In addition, the mixing amount of the second silica raw material includes silicon atoms contained in the second silica raw material with respect to silicon atoms already contained in the first silica raw material already contained in the solvent. More preferably, the molar ratio is in the range of 0.01 to 2000 (more preferably 0.05 to 500). If the mixing amount of the second silica raw material is less than the lower limit, the proportion of the shell layer is too small, so that particles having only the characteristics of the core particles tend to be generated. The proportion of particles tends to be reduced, and particles having only the characteristics of a shell layer tend to be produced.

  Further, when the shell layer into which the surfactant is introduced is laminated outside the core particles by mixing the second silica raw material, the pH value of the solvent is set for the same reason as in the first step. It is preferably 7.5 to 13, and more preferably 8 to 12. From such a viewpoint, a basic substance can be added as necessary in the second step.

  The reaction conditions (reaction temperature, reaction time, etc.) in the second step are not particularly limited, and the reaction temperature is, for example, -20 ° C to 100 ° C (preferably 0 ° C to 80 ° C, more preferably 10 ° C to 40 ° C.). In addition, the reaction is preferably allowed to proceed with stirring. The specific reaction conditions are preferably determined based on the type of the second silica raw material used.

  For example, after the core particles are precipitated, the second silica raw material is mixed, and the solution is stirred at 0 ° C. to 80 ° C. (preferably 10 ° C. to 40 ° C.) for 1 hour to 10 days, whereby the core particles The layer which consists of a 2nd silica raw material can be laminated | stacked on the outer side. Then, after the stirring is completed, the porous precursor particles can be obtained by filtering and washing the precipitate obtained by stabilizing the system by allowing it to stand overnight at room temperature as necessary. it can.

  The shell layer formed in this way may be composed of a plurality of silica layers. As a method for forming such a shell layer composed of a plurality of silica layers, first, a silica raw material (a) selected from the second silica raw materials is mixed, and silica (a) is formed on the surface of the core particles. A method of further laminating a silica raw material (b) other than the silica raw material (a) selected from the second silica raw materials after laminating the silica layer composed of the above can be mentioned. After laminating the silica layer made of silica (a) on the surface of the core particles in this way, other silica raw materials (b) other than the silica raw material (a) selected from the second silica raw materials are mixed. Thus, a shell layer including a silica layer made of silica (a) and a silica layer made of silica (b) can be laminated on the outside of the core particles. In addition, it is also possible to repeat such a process two or more times.

(Third step)
Next, the third step will be described. The third step is a step of removing the surfactant contained in the porous precursor particles.

  Examples of the method for removing such a surfactant include a method for treating with an organic solvent and an ion exchange method. In the case of employing such a method of treating with an organic solvent, the surfactant is extracted by immersing the porous precursor particles in a good solvent having high solubility in the used surfactant. When the ion exchange method is employed, the porous precursor particles are immersed in an acidic solution (such as ethanol containing a small amount of hydrochloric acid) and stirred while heating at, for example, 50 to 70 ° C. Thereby, the surfactant existing in the pores of the porous precursor particles is ion-exchanged with hydrogen ions. In addition, although hydrogen ions remain in the hole by ion exchange, the problem of blockage of the hole does not occur because the ion radius of the hydrogen ion is sufficiently small.

  The core-shell type spherical silica-based mesoporous material thus obtained includes core particles made of silica having a first organic group and / or a precursor of the first organic group, and a shell layer made of the second silica. And a core-shell type spherical silica-based mesoporous material whose pores are modified by hierarchically different organic groups. When the core particles in such a core-shell type spherical silica-based mesoporous material are core particles made of silica having a first organic group, the core shell of the present invention is obtained by such a third step. A spherical silica-based mesoporous material is obtained. On the other hand, when the core particle is made of silica having a precursor of the first organic group, the core-shell type spherical silica-based mesoporous material of the present invention is obtained by performing the fourth step described below. can get.

(Fourth process)
The fourth step is a step of performing a process of converting the precursor of the first organic group introduced into the silica forming the core particles in the core-shell type spherical silica-based mesoporous material into the first organic group. .

  The method for converting the precursor of the first organic group into the first organic group is not particularly limited as long as it is a method capable of converting the precursor into the first organic group. Various methods can be adopted depending on the type of the first organic group precursor and the type of the first organic group to be converted, etc., and the functional group of the precursor includes sulfonic acid, carboxylic acid group and You may employ | adopt suitably the well-known method which can be converted into the at least 1 sort (s) of functional group selected from the group which consists of an amino group.

  As the treatment for converting into such a first organic group, for example, when the functional group of the precursor of the first organic group is a mercapto group, and this is converted into a sulfonic acid group, an oxidizing agent is used. It is possible to employ a method of oxidizing. The method of oxidizing using such an oxidizing agent is not particularly limited as long as it is a method capable of oxidizing a mercapto group and converting it into a sulfonic acid group using an oxidizing agent. The oxidizing agent is not particularly limited as long as it can oxidize a mercapto group and convert it into a sulfonic acid group, and examples thereof include hydrogen peroxide, nitric acid, sulfuric acid, and crown ether. It is done. Among these oxidizing agents, hydrogen peroxide is preferable from the viewpoints of high reactivity and pore retention. In addition, conditions such as reaction temperature and reaction time in the method of oxidizing using such an oxidizing agent are not particularly limited, but the reaction temperature is 100 ° C. or less (more preferably 10 to 80 ° C.). The reaction time is preferably within 30 minutes to 6 hours. When the reaction temperature and reaction time are less than the lower limit, the mercapto group is hardly oxidized, and it tends to be difficult to oxidize the mercapto group and convert it to a sulfonic acid group. In addition, the pores of the spherical silica-based mesoporous material are partly collapsed, and when used as an acid catalyst, the acid catalyst performance tends to decrease.

  In addition, as a treatment for converting into such a first organic group, the functional group of the precursor of the first organic group is a cyano group, and when this is converted into a carboxylic acid group, an oxidizing agent is used. It is possible to employ a method of oxidizing. Such an oxidizing agent is not particularly limited as long as it can oxidize a cyano group to be converted into a carboxylic acid group. For example, an acid such as sulfuric acid, hydrochloric acid, acetic acid, formic acid, or a peroxidic acid can be used. Examples thereof include hydrogen and crown ether. Among such oxidizing agents, sulfuric acid is preferable from the viewpoints of high reactivity and pore retention. In addition, conditions such as reaction temperature and reaction time in the method of oxidizing using such an oxidizing agent are not particularly limited. However, when sulfuric acid having a concentration of 1 mol / L or more is used, it is 25 to 150 ° C. ( More preferably, the mixture is refluxed for about 1 to 24 hours under a temperature condition of 50 to 130 ° C.

  In addition, when the functional group of the precursor of the first organic group is a chlorosulfonylphenyl group and this is converted into a sulfonic acid group, the surfactant is extracted using an acidic solution in the third step described above. At this time, a method of exchanging the sulfonic acid group with the acidic solution may be adopted.

  In the core-shell type spherical silica mesoporous material of the present invention obtained as described above, the core-shell type spherical silica meso has extremely high particle size uniformity by adjusting the alcohol concentration or the like in the solvent used. A porous body can be obtained. For example, a core-shell type spherical silica meso having extremely high particle size uniformity in which 90% by weight or more (preferably 95% by weight or more) of the total particles obtained has a particle size in the range of ± 10% of the average particle size. It is possible to obtain a porous body.

  The core-shell type spherical silica-based mesoporous material of the present invention has been described above. Hereinafter, the catalyst of the present invention will be described.

  The catalyst of the present invention comprises the core-shell type spherical silica mesoporous material of the present invention. In the catalyst of the present invention, since the core-shell type spherical silica-based mesoporous material of the present invention is used, the types of the first organic group and the second organic group are determined according to the type of substrate for the catalytic reaction, respectively. By selecting, a catalyst having a desired design can be obtained in which the shell layer functions as an adsorption region of the substrate and the core particle functions as an active site region. Therefore, according to such a catalyst of the present invention, a specific substrate can be adsorbed with high selectivity, and a catalytic reaction can be efficiently performed.

  In the catalyst of the present invention, it is preferable to use a second organic group having a high affinity with the substrate and a low interaction with the substrate. By using a second organic group that has a high affinity with the substrate and a low interaction with the substrate, it becomes possible to incorporate the substrate with a higher selectivity and to bring the substrate into the interior more efficiently. It tends to be possible to move. In addition, when an organic group having a low affinity with the substrate is selected as the second organic group, it tends to be difficult to incorporate the substrate into the pores, and as the second organic group, When an organic group having a strong interaction with the substrate is selected, it tends to be difficult to move the substrate to the inner core particles.

  Furthermore, the catalyst of the present invention can be suitably used as an acidic catalyst when the first organic group has a sulfonic acid group or a carboxylic acid group. On the other hand, when the first organic group has an amino group, it can be suitably used as a basic catalyst.

  The adsorbent of the present invention comprises the core-shell type spherical silica mesoporous material of the present invention. Since the adsorbent of the present invention uses the core-shell type spherical silica mesoporous material of the present invention, the type of the first organic group and the second organic group are selected according to the type of the adsorbent. Thus, an adsorbent having a desired design can be obtained in which the shell layer functions as an adsorption material selection region and the core particle functions as an adsorption region. Therefore, according to the adsorbent of the present invention, it is possible to adsorb a specific adsorbent with high selectivity and efficiently adsorb it.

  In the adsorbent of the present invention, it is preferable to use a material having a high affinity with the adsorbing substance and a low interaction as the second organic group. By using a second organic group that has a high affinity with the adsorbent and a low interaction, it is possible to incorporate the adsorbent with higher selectivity, and more efficiently incorporate the adsorbent into the interior. It tends to be possible to move. When an organic group having a low affinity with the adsorbing material is selected as the second organic group, it tends to be difficult to incorporate the adsorbing material into the pores.

  Furthermore, when the first organic group has a sulfonic acid group or a carboxylic acid group, the adsorbent of the present invention is suitable for basic substances, biological substances, metal compounds and the like that are chemically bonded to these functional groups. It can be suitably used as an adsorbent. On the other hand, when the first organic group has an amino group, it can be suitably used as an adsorbent for acidic substances, biological substances, metal compounds and the like that are chemically bonded to these functional groups.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

(Example 1: first organic group <core particle>; 3-propylsulfonic acid group, second organic group <shell layer>; phenyl group)
The core-shell type spherical silica mesoporous material of the present invention in which the first organic group was a propylsulfonic acid group and the second organic group was a phenyl group was produced. That is, first, 7.04 g of hexadecyltrimethylammonium chloride (surfactant) was dissolved in 1600 g of a mixed solution of water and methanol (water / methanol: 50/50 = w / w), and the temperature was adjusted to 25 ° C. in a constant temperature water bath. The solution was obtained while stirring. Next, 6.84 g of 1 mol / L sodium hydroxide solution was added to the resulting solution to obtain a basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) prepared in advance by mixing in a dry nitrogen stream (molar ratio: (TMOS) / (MPTMS) = 9/1) 3 .47 × 10 ⁻² mol was added to the basic solution as the first silica raw material. Thus, when the 1st silica raw material was added, precipitation of particle | grains was seen in several minutes, the said basic solution became cloudy, and the core particle | grains by which the said surfactant was introduce | transduced in the silica were obtained.

Next, 30 minutes after the addition of the first silica raw material, 3.42 g of a 1 mol / L sodium hydroxide solution was added to the basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and phenyltrimethoxysilane (PhTMS) prepared by mixing in a dry nitrogen stream in advance (molar ratio: (TMOS) / (PhTMS) = 9/1) 1.73 × 10 ⁻² mol was added to the basic solution as a second silica raw material. And after stirring the said basic solution to which the 2nd silica raw material was added for about 8 hours, it was left still overnight and the shell layer was laminated | stacked on the outer side of a core particle. Thereafter, the operation of filtering the obtained product and redispersing in water was repeated twice, followed by drying overnight at a temperature of 45 ° C., and the surfactant was introduced into the core particles and the shell layer. Porous precursor particles were obtained.

  Next, after dispersing 1 g of the obtained porous precursor particles in 100 mL of ethanol, 1 mL of hydrochloric acid is added, and the surfactant is extracted from the porous precursor particles by stirring at 60 ° C. for 3 hours in an oil bath. did. After the surfactant was extracted in this manner, the obtained particles were sufficiently washed with ethanol and dried at a temperature of 45 ° C. to obtain a core-shell type silica-based mesoporous material. The core-shell type silica-based mesoporous material obtained in this way has a core particle modified with a 3-mercaptopropyl group and a shell layer modified with a phenyl group.

  Next, 0.5 g of the obtained core-shell type silica-based mesoporous material is added to 10 ml of 30% by mass hydrogen peroxide (oxidant) and stirred at a temperature of 50 ° C. for 6 hours. The introduced mercapto group was converted to a sulfonic acid group. Then, the obtained particles are filtered and dried under a temperature condition of 45 ° C., whereby the first organic group is a 3-propylsulfonic acid group and the second organic group is a phenyl group. A type spherical silica-based mesoporous material was obtained.

(Example 2: first organic group <core particle>; 3-propylsulfonic acid group, second organic group <shell layer>; propyl group)
A mixture of tetramethoxysilane (TMOS) and propyltrimethoxysilane (PTMS) (molar ratio: (TMOS) / (PTMS) = 9/1) 1.73 × 10 ⁻² mol was used as the second silica raw material. Except for the above, a core-shell type spherical silica-based mesoporous material of the present invention in which the first organic group was a 3-propylsulfonic acid group and the second organic group was a propyl group was produced in the same manner as in Example 1.

(Example 3: first organic group <core particle>; 3-propylsulfonic acid group, second organic group <shell layer>; isobutyl group)
A mixture of tetramethoxysilane (TMOS) and isobutyltrimethoxysilane (IBTMS) (molar ratio: (TMOS) / (IBTMS) = 9/1) 1.73 × 10 ⁻² mol was used as the second silica raw material. Except for the above, a core-shell type spherical silica-based mesoporous material of the present invention in which the first organic group was a propylsulfonic acid group and the second organic group was an isobutyl group was produced in the same manner as in Example 1.

(Example 4: first organic group <core particle>; 3-propylsulfonic acid group, second organic group <shell layer>; hexyl group)
A mixture of tetramethoxysilane (TMOS) and hexyltrimethoxysilane (HTMS) (molar ratio: (TMOS) / (HTMS) = 9/1) 1.73 × 10 ⁻² mol was used as the second silica raw material. Except for the above, a core-shell type spherical silica mesoporous material of the present invention in which the first organic group was a 3-propylsulfonic acid group and the second organic group was a hexyl group was produced in the same manner as in Example 1.
(Example 5: first organic group <core particle>; 3-propylsulfonic acid group, second organic group <shell layer>; dodecyl group)
6.72 g of octadecyltrimethylammonium chloride is used as the surfactant, and a mixture of tetramethoxysilane (TMOS) and dodecyltriethoxysilane (DDTES) as the second silica raw material (molar ratio: (TMOS) / (DDTMS) = 9). / 1) A book in which the first organic group is a 3-propylsulfonic acid group and the second organic group is a dodecyl group in the same manner as in Example 1 except that 1.73 × 10 ⁻² mol is used. The core-shell type spherical silica-based mesoporous material of the invention was produced.

(Example 6: first organic group <core particle>; N- (2-aminoethyl) -3-aminopropyl group, second organic group <shell layer>; phenyl group)
A core-shell type spherical silica-based mesoporous material of the present invention in which the first organic group was N- (2-aminoethyl) -3-aminopropyl group and the second organic group was phenyl group was produced. That is, 7.04 g of hexadecyltrimethylammonium chloride (surfactant) was dissolved in 1600 g of a mixed solution of water and methanol (water / methanol: 50/50 = w / w) and stirred at 25 ° C. in a constant temperature water bath. To obtain a solution. Next, 6.84 g of 1 mol / L sodium hydroxide solution was added to the resulting solution to obtain a basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (AEAPTMS) prepared by mixing in a dry nitrogen stream (molar ratio: (TMOS) / (AEAPTMS) = 19/1) 3.47 × 10 ⁻² mol was added to the basic solution as a first silica raw material. Thus, when the 1st silica raw material was added, precipitation of particle | grains was seen in several minutes, the solution became cloudy, and the core particle | grains in which the said surfactant was introduce | transduced in the silica were obtained.

Next, 30 minutes after the addition of the first silica raw material, 3.42 g of a 1 mol / L sodium hydroxide solution was added to the basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and phenyltrimethoxysilane (PhTMS) prepared by mixing in a dry nitrogen stream in advance (molar ratio: (TMOS) / (PhTMS) = 9/1) 1.73 × 10 ⁻² mol was added to the basic solution as a second silica raw material. And after stirring the said basic solution to which the 2nd silica raw material was added for about 8 hours, it was left still overnight and the shell layer was laminated | stacked on the outer side of a core particle. Thereafter, the operation of filtering the obtained product and redispersing in water was repeated twice, followed by drying overnight at a temperature of 45 ° C., and the surfactant was introduced into the core particles and the shell layer. Porous precursor particles were obtained.

  Next, 1 g of the obtained porous precursor particles are dispersed in 100 mL of ethanol, and then 1 mL of hydrochloric acid is added and the surfactant is extracted from the porous precursor particles by stirring in an oil bath at 60 ° C. for 3 hours. did. After the surfactant was extracted in this manner, the obtained particles were thoroughly washed with ethanol and then dried overnight at a temperature of 45 ° C. so that the first organic group was N- (2-aminoethyl). The core-shell type spherical silica-based mesoporous material of the present invention which was a -3-aminopropyl group and the second organic group was a phenyl group was obtained.

(Example 7: First organic group <core particle>; N- (2-aminoethyl) -3-aminopropyl group, second organic group <shell layer>; propyl group)
A mixture of tetramethoxysilane (TMOS) and propyltrimethoxysilane (PTMS) (molar ratio: (TMOS) / (PTMS) = 9/1) 1.73 × 10 ⁻² mol was used as the second silica raw material. In the same manner as in Example 4, the core-shell type spherical silica meso of the present invention in which the first organic group is N- (2-aminoethyl) -3-aminopropyl group and the second organic group is propyl group. A porous body was obtained.

(Example 8: first organic group <core particle>; N- (2-aminoethyl) -3-aminopropyl group, second organic group <shell layer>; ureidopropyl group)
A mixture of tetramethoxysilane (TMOS) and ureidopropyltrimethoxysilane (UPTMS) (molar ratio: (TMOS) / (UPTMS) = 9/1) 1.73 × 10 ⁻² mol is used as the second silica raw material. The core-shell type of the present invention wherein the first organic group is N- (2-aminoethyl) -3-aminopropyl group and the second organic group is ureidopropyl group in the same manner as in Example 4 except that A spherical silica-based mesoporous material was obtained.

(Example 9: first organic group <core particle>; 3-aminopropyl group, second organic group <shell layer>; phenyl group)
A mixture of tetramethoxysilane (TMOS) and 3-aminopropyltrimethoxysilane (APTMS) as the first silica raw material (molar ratio: (TMOS) / (APTMS) = 19/1) 3.47 × 10 ⁻² mol The core-shell type spherical silica mesoporous material of the present invention in which the first organic group is a 3-aminopropyl group and the second organic group is a phenyl group is obtained in the same manner as in Example 4 except that is used. It was.

(Example 10: first organic group <core particle>; 3-aminopropyl group, second organic group <shell layer>; ureidopropyl group)
A mixture of tetramethoxysilane (TMOS) and 3-aminopropyltrimethoxysilane (APTMS) as the first silica raw material (molar ratio: (TMOS) / (APTMS) = 19/1) 3.47 × 10 ⁻² mol And a mixture of tetramethoxysilane (TMOS) and ureidopropyltrimethoxysilane (UPTMS) as the second silica raw material (molar ratio: (TMOS) / (UPTMS) = 9/1) 1.73 × 10 ⁻² The core-shell type spherical silica mesoporous material of the present invention in which the first organic group is a 3-aminopropyl group and the second organic group is a ureidopropyl group in the same manner as in Example 4 except that mol is used Got.

(Example 11: first organic group <core particle>; 3-propyl carboxyl group, second organic group <shell layer>; phenyl group)
7.04 g of hexadecyltrimethylammonium chloride (surfactant) was dissolved in 1600 g of a mixed solution of water and methanol (water / methanol: 50/50 = w / w), stirred at 25 ° C. in a constant temperature water bath, A solution was obtained. Next, 6.84 g of 1 mol / L sodium hydroxide solution was added to the resulting solution to obtain a basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and 3-cyanopropyltrimethoxysilane (CPTMS) prepared by mixing in a dry nitrogen stream (molar ratio: (TMOS) / (CPTMS) = 9/1) 3.47 × 10 ⁻² mol was added to the basic solution as the first silica raw material. When the silica raw material was added in this way, precipitation of particles was observed in a few minutes, the solution became cloudy, and core particles in which the surfactant was introduced into silica were obtained.

Next, 30 minutes after the addition of the first silica raw material, 3.42 g of a 1 mol / L sodium hydroxide solution was added to the basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and phenyltrimethoxysilane (PhTMS) prepared by mixing in a dry nitrogen stream in advance (molar ratio: (TMOS) / (PhTMS) = 9/1) 1.73 × 10 ⁻² mol was added to the basic solution as a second silica raw material. The basic solution to which the second silica raw material was added was stirred for about 8 hours, and then allowed to stand overnight. Thereafter, the operation of filtering the obtained product and redispersing in water was repeated twice, followed by drying overnight at a temperature of 45 ° C., and the surfactant was introduced into the core particles and the shell layer. Porous precursor particles were obtained.

  Next, 1 g of the obtained porous precursor particles are dispersed in 100 mL of ethanol, and then 1 mL of hydrochloric acid is added and the surfactant is extracted from the porous precursor particles by stirring in an oil bath at 60 ° C. for 3 hours. did. After the surfactant was extracted in this manner, the obtained particles were sufficiently washed with ethanol and dried at a temperature of 45 ° C. to obtain a core-shell type silica-based mesoporous material. In addition, the core-shell type silica mesoporous material thus obtained has a core particle modified with a 3-cyanopropyl group and a shell layer modified with a phenyl group.

  Subsequently, the treatment which converts the cyano group introduced into the core particle in the obtained core-shell type silica-based mesoporous material into a carboxylic acid group was performed. In such treatment, first, 6.3 ml of 18 mol / L concentrated sulfuric acid (oxidant) and 3.7 ml of water were mixed and allowed to stand, and cooled to about 50 ° C. to prepare a solution. Next, 0.5 g of the core-shell type silica-based mesoporous material is added to the obtained solution, and the mixture is heated and refluxed at 100 ° C. for 6 hours to convert the cyano group introduced into the core particles into a carboxylic acid group. Converted to. Then, the obtained particles are filtered and dried under a temperature condition of 45 ° C., and the core-shell type sphere of the present invention in which the first organic group is a 3-propylcarboxyl group and the second organic group is a phenyl group. A silica-based mesoporous material was obtained.

(Example 12: first organic group <core particle>; 3-propyl carboxyl group, second organic group <shell layer>; propyl group)
A mixture of tetramethoxysilane (TMOS) and propyltrimethoxysilane (PTMS) (molar ratio: (TMOS) / (PTMS) = 9/1) 1.73 × 10 ⁻² mol was used as the second silica raw material. Except for the above, a core-shell type spherical silica-based mesoporous material of the present invention in which the first organic group was a 3-propylcarboxyl group and the second organic group was a propyl group was obtained in the same manner as in Example 11.

(Comparative Example 1)
7.04 g of hexadecyltrimethylammonium chloride (surfactant) was dissolved in 1600 g of a mixed solution of water and methanol (water / methanol: 50/50 = w / w), stirred at 25 ° C. in a constant temperature water bath, A solution was obtained. Next, 6.84 g of 1 mol / L sodium hydroxide solution was added to the resulting solution to obtain a basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) prepared in advance by mixing in a dry nitrogen stream (molar ratio: (TMOS) / (MPTMS) = 9/1) 3 .47 × 10 ⁻² mol was added to the basic solution as a silica raw material. Thus, when the silica raw material was added, precipitation of particle | grains was seen in several minutes, and the solution became cloudy. And the basic solution which added the silica raw material was stirred for about 8 hours, and left still overnight. Thereafter, the operation of filtering the obtained product and redispersing in water was repeated twice, followed by drying overnight at a temperature of 45 ° C. to obtain porous particles into which the surfactant was introduced.

  Next, after dispersing 1 g of the obtained porous particles in 100 mL of ethanol, 1 mL of hydrochloric acid was added, and the surfactant was extracted from the porous particles by stirring at 60 ° C. for 3 hours in an oil bath. After the surfactant was extracted in this manner, the obtained particles were thoroughly washed with ethanol and dried at 45 ° C. to obtain a spherical silica-based mesoporous material modified with a 3-mercaptopropyl group.

  Next, 0.5 g of the obtained spherical silica-based mesoporous material is added to 10 ml of 30% by mass hydrogen peroxide (oxidant) and stirred at a temperature of 50 ° C. for 6 hours, thereby converting mercapto groups into sulfonic acid groups. Converted to. Thereafter, the obtained particles were filtered and dried under a temperature condition of 45 ° C. to obtain a comparative spherical silica-based mesoporous material modified with a 3-propylsulfonic acid group.

(Comparative Example 2)
2. Mixture of tetramethoxysilane (TMOS) and N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (AEAPTMS) as a silica raw material (molar ratio: (TMOS) / (AEAPTMS) = 19/1) A spherical silica-based mesoporous material as a comparison modified with an N- (2-aminoethyl) -3-aminopropyl group was obtained in the same manner as in Comparative Example 1 except that 47 × 10 ⁻² mol was used.

(Comparative Example 3)
A mixture of tetramethoxysilane (TMOS) and 3-aminopropyltrimethoxysilane (APTMS) (molar ratio: (TMOS) / (APTMS) = 19/1) 3.47 × 10 ⁻² mol was used as a silica raw material. Except for the above, a spherical silica mesoporous material as a comparison modified with a 3-aminopropyl group was obtained in the same manner as in Comparative Example 1.

(Comparative Example 4)
7.04 g of hexadecyltrimethylammonium chloride (surfactant) was dissolved in 1600 g of a mixed solution of water and methanol (water / methanol: 50/50 = w / w), stirred at 25 ° C. in a constant temperature water bath, A solution was obtained. Next, 6.84 g of 1 mol / L sodium hydroxide solution was added to the resulting solution to obtain a basic solution. Thereafter, a mixture of tetramethoxysilane (TMOS) and 3-cyanopropyltrimethoxysilane (CPTMS) prepared in advance by mixing in a dry nitrogen stream (molar ratio: (TMOS) / (CPTMS) = 9/1) 3 .47 × 10 ⁻² mol was added to the basic solution as a silica raw material. Thus, when the silica raw material was added, precipitation of particle | grains was seen in several minutes, and the solution became cloudy. And the basic solution which added the silica raw material was stirred for about 8 hours, and left still overnight. Thereafter, the operation of filtering the obtained product and redispersing in water was repeated twice, followed by drying overnight at a temperature of 45 ° C. to obtain porous particles into which the surfactant was introduced.

  Next, after dispersing 1 g of the obtained porous particles in 100 mL of ethanol, 1 mL of hydrochloric acid was added, and the surfactant was extracted from the porous particles by stirring at 60 ° C. for 3 hours in an oil bath. After the surfactant was extracted in this manner, the obtained particles were sufficiently washed with ethanol and dried at 45 ° C. to obtain a spherical silica mesoporous material modified with a 3-cyanopropyl group.

  Next, 6.3 ml of 18 mol / L concentrated sulfuric acid (oxidant) and 3.7 ml of water were mixed and allowed to stand, and cooled to about 50 ° C. to prepare an oxidant-containing solution. Then, 0.5 g of the spherical silica-based mesoporous material obtained as described above is added to the obtained oxidant-containing solution, and the mixture is heated and refluxed at a temperature of 100 ° C. for 6 hours. The modified cyano group was converted to a carboxyl group. Thereafter, the obtained particles were filtered and dried under a temperature condition of 45 ° C. to obtain a spherical silica-based mesoporous material modified with a 3-propylcarboxyl group.

[Evaluation of characteristics of core-shell type spherical silica mesoporous materials obtained in Examples 1-12 and spherical silica-based mesoporous materials obtained in Comparative Examples 1-4]
<Confirmation of organic group structure>
The structure of the organic group introduced into the porous body was confirmed by Raman spectrum measurement and FT-IR measurement.

<Measurement of pore structure by X-ray diffraction>
The regularity of the mesopore structure was measured with a Rigaku powder XRD apparatus RINT-2200. The X-ray diffraction patterns of the core-shell type spherical silica mesoporous material obtained in Examples 1 and 2 and the spherical silica mesoporous material obtained in Comparative Example 1 are shown in FIG. Further, the peak of d ₁₀₀ value of the obtained core-shell type spherical mesoporous silica material in Examples 1 to 12 shown in Table 1, Table peaks obtained spherical mesoporous silica material in Comparative Examples 1 to 4 It is shown in 2.

As is clear from the results shown in FIG. 1, peaks of (100), (110), (200) corresponding to the hexagonal arrangement of the pores are observed in all particles, and the regularity of the pores is high. confirmed. Moreover, as is clear from the results of the peak of d ₁₀₀ value shown in Tables 1 and 2, the core-shell type spherical silica-based mesoporous material obtained in Examples 1 to 12 and Comparative Examples 1 to 4 were obtained. It was confirmed that the obtained spherical silica-based mesoporous material has high pore regularity.

<Measurement of average particle size and standard deviation>
The particle morphology was measured at an acceleration voltage of 19 eV using a scanning electron microscope (SEM) SIGMA-V manufactured by Akashi Seisakusho. And using the SEM photograph of each particle of the core-shell type spherical silica-based mesoporous material obtained in Examples 1-12 and the spherical silica-based mesoporous material obtained in Comparative Examples 1-4, 50 particles Were measured, and the average particle size and standard deviation were calculated. The obtained results are shown in Tables 1 and 2. Further, a scanning electron microscope (SEM) photograph of the core-shell type spherical silica mesoporous material obtained in Example 1 is shown in FIG. 2, and a scanning electron microscope (SEM) photograph of the spherical silica mesoporous material obtained in Comparative Example 1 is shown. Is shown in FIG.

  As is apparent from the average particle diameter and standard deviation values shown in Tables 1 and 2, the core-shell type spherical silica-based mesoporous material obtained in Examples 1 to 12 and Comparative Examples 1 to 4 were obtained. It was confirmed that each particle of the spherical silica-based mesoporous material was monodispersed spherical.

  Moreover, since the thing which laminated | stacked the shell layer on the spherical silica mesoporous material obtained in Comparative Example 1 corresponds to the core-shell type spherical silica mesoporous material obtained in Example 1, the core shell obtained in Example 1 was used. The type spherical silica mesoporous material and the spherical silica mesoporous material obtained in Comparative Example 1 were compared. As is clear from the photographs shown in FIGS. 2 and 3, the core-shell type spherical silica-based mesoporous material obtained in Example 1 has an average particle size of 0.60 μm (standard deviation 5.0%), Since the spherical silica mesoporous material obtained in Comparative Example 1 has an average particle size of 0.51 μm (standard deviation 4.4%), Example 1 was compared with the spherical silica mesoporous material obtained in Comparative Example 1. It was confirmed that the core-shell type spherical silica mesoporous material obtained in Example 1 had a large particle size, and the core-shell type spherical silica mesoporous material obtained in Example 1 had a shell layer outside the core particle. It was confirmed that they were laminated.

<Measurement of specific surface area, central pore diameter and pore volume>
The _{N 2} adsorption isotherm of the obtained spherical mesoporous silica material in the core-shell type spherical mesoporous silica material as well as Comparative Examples 1 to 4 obtained in Examples 1 to 12 using manufactured by BEL Japan BELSORP-mini, It was measured by the constant volume method under the condition of liquid N ₂ temperature (77K). Then, to calculate the pore volume from N ₂ adsorption isotherm obtained, to calculate the specific surface area by using further the BET adsorption isotherm equation. Furthermore, the central pore diameter was calculated from the obtained N ₂ adsorption isotherm by the BJH method. The obtained results are shown in Tables 1 and 2.

<Measurement of acid catalyst performance (functional group: sulfonic acid group)>
The core-shell type spherical silica-based mesoporous material obtained in Examples 1 to 5 and the spherical silica-based mesoporous material obtained in Comparative Example 1 were used as catalysts for Friedel-Crafts alkylation reaction, respectively, and performance as an acidic catalyst Was measured. That is, 60 mg of a catalyst was added to 0.6 g of 2-methylfuran and 1.39 ml of acetone, and the reaction was performed at a temperature of 50 ° C., and the product turnover after 1 hour, 2 hours, and 4 hours. Number was measured. A graph showing the relationship between the reaction time and the turnover number is shown in FIG. The turnover number was calculated by filtering the reaction mixture, removing the catalyst and washing with acetone, then performing GC-measurement of the resulting solution, quantifying the product.

  As is clear from the results shown in FIG. 4, the core-shell type spherical silica-based mesoporous material obtained in Examples 1 to 5 is a comparative example 1 formed only from particles corresponding to the core particles of each of the above examples. It was confirmed that the turnover number was high compared to the spherical silica-based mesoporous material obtained in the above, and thus the core-shell type spherical silica-based mesoporous material (Examples 1 to 5) of the present invention was sufficiently advanced. It was confirmed that the catalyst activity can be exhibited. As is clear from the results shown in FIG. 4, the core-shell type spherical silica mesoporous material (Example 2 or 3) in which a propyl group or an isobutyl group is introduced into the silica of the shell layer is turned after 4 hours. The over number was about 1.7 times the turn over number of the spherical silica-based mesoporous material for comparison (Comparative Example 1), and it was confirmed that the catalyst performance was particularly high. . As a result, in the core-shell type spherical silica mesoporous material obtained in Example 2 or 3, the hydrophobic propyl group or isobutyl group introduced into the silica of the shell layer is a hydrophobic 2-methylfuran. The present inventors infer that this is because the substrate is easily taken into the pores and the catalytic reaction is likely to occur in the core particles.

<Measurement of basic catalyst performance (A) (functional group: N- (2-aminoethyl) -3-aminopropyl group)>
The core-shell type spherical silica-based mesoporous material obtained in Examples 6 to 8 and the spherical silica-based mesoporous material obtained in Comparative Example 2 were used as catalysts for the ester hydrolysis reaction, respectively. It was measured. That is, 20 mg of the catalyst was added to a mixed solution of 300 μL of 0.1 M nitrophenol acetate solution (dissolved in DMSO) and 1200 μL of 10 mM Tris / HCl solution (pH 7.5), and shaken at room temperature, and the decomposition product p -The relationship between the amount of nitrophenol produced and the reaction time was measured. The graph which shows the relationship between reaction time and the production amount of p-nitrophenol is shown in FIG. The amount of p-nitrophenol produced was quantified by separating the catalyst from the reaction mixture by centrifugation and measuring the absorbance at 405 nm of the resulting supernatant.

  As is clear from the results shown in FIG. 5, the core-shell type spherical silica-based mesoporous material obtained in Examples 6 to 8 is a comparative example 2 formed only from particles corresponding to the core particles of each of the above examples. It was confirmed that the catalyst performance was sufficiently high compared to the spherical silica mesoporous material obtained in 1. Further, as is clear from the results shown in FIG. 5, in the core-shell type spherical silica mesoporous material obtained in Examples 6 to 8, depending on the type of the second organic group introduced into the silica of the shell layer. The core-shell type spherical silica-based mesoporous material (Example 6) in which a phenyl group was introduced as the second organic group had the highest catalyst performance from the beginning, and the catalyst performance was 15 minutes later. The amount of p-nitrophenol produced was about 1.4 times that of the spherical silica-based mesoporous material obtained in Comparative Example 2. Further, the core-shell type spherical silica mesoporous material (Example 8) in which the ureidopropyl group having a hydrophilic functional group was introduced as the second organic group also had a relatively high catalytic performance. Such a result shows that since the substrate nitrophenol acetate has both a hydrophobic functional group and a hydrophilic functional group, a core-shell type spherical silica mesoporous material having a phenyl group or a ureidopropyl group introduced ( The present inventors speculate that this is because the substrate is easily taken into the pores of Example 6 or 8) and the catalytic reaction easily occurs in the core particles.

<Measurement of basic catalyst performance (B) (functional group: 3-aminopropyl group)>
Measurement of basic catalyst performance (A) described above, except that the core-shell type spherical silica mesoporous material obtained in Examples 9 to 10 and the spherical silica mesoporous material obtained in Comparative Example 3 were used as catalysts. A similar method was adopted to evaluate the performance as a basic catalyst. A graph showing the relationship between the reaction time and the amount of p-nitrophenol produced is shown in FIG.

  As is clear from the results shown in FIG. 6, the core-shell type spherical silica-based mesoporous material obtained in Examples 9 to 10 is formed of only particles corresponding to the core particles of the above Examples. The amount of p-nitrophenol produced in the initial stage of the reaction was higher than that of the spherical silica-based mesoporous material obtained in Step 1, and the amount of p-nitrophenol produced after 15 minutes was obtained in Comparative Example 3. It was confirmed that the ratio was about 1.8 times that when the mesoporous material was used, thereby confirming that the catalyst performance was sufficiently high.

<Dye adsorption test (functional group: carboxylic acid group)>
The core-shell type spherical silica-based mesoporous material obtained in Examples 11 to 12 and the spherical silica-based mesoporous material obtained in Comparative Example 4 were used as samples, and the adsorption amount of the dye was measured. That is, 100 mL (1000 mg / L) of methylene blue was added to 0.1 g of each sample, shaken at 22 ° C. for 1 hour, filtered, and the absorbance of the resulting solution was measured at 291 nm. The adsorption amount of methylene blue was measured. The obtained results are shown in Table 3.

  As is apparent from the results shown in Table 3, the spherical silica-based mesoporous material for comparison (Comparative Example 4) also adsorbs methylene blue (basic dye). It was confirmed that the core-shell type spherical silica-based mesoporous material of the present invention (Examples 11 to 12) into which a hydrophobic organic group was introduced can adsorb a sufficient amount of the dye. As a result, in the core-shell type spherical silica-based mesoporous material (Examples 11 to 12) of the present invention, the second organic group (phenyl group) in which a highly hydrophobic dye was introduced into the silica of the shell layer Or the propyl group), the present inventors speculate that it is derived from the fact that it is selectively incorporated into the second organic group.

  As described above, according to the present invention, the core-shell type spherical shape has mesopores modified with different organic groups in a hierarchical manner, and can exhibit different properties depending on the position of the pores in the same particle. It is possible to provide a silica-based mesoporous material, and a catalyst and an adsorbent capable of exhibiting sufficiently high performance using the same.

  Therefore, since the core-shell type spherical silica-based mesoporous material of the present invention can exhibit different performance between the core particle and the shell layer, different compounds can be adsorbed in the same particle and the oxidation reaction and the reduction reaction can be performed simultaneously or the same. It is useful as a material or the like that can adsorb a dye in the particles and move electrons from the inside to the outside of the particles.

It is a graph which shows the X-ray-diffraction pattern of the core-shell type spherical silica mesoporous material obtained in Examples 1-2 and the spherical silica mesoporous material obtained in Comparative Example 1. 2 is a scanning electron microscope (SEM) photograph of the core-shell type spherical silica-based mesoporous material obtained in Example 1. 2 is a scanning electron microscope (SEM) photograph of a spherical silica mesoporous material obtained in Comparative Example 1. The relationship between reaction time and turnover number when the core-shell type spherical silica-based mesoporous material obtained in Examples 1 to 5 and the spherical silica-based mesoporous material obtained in Comparative Example 1 are used as an acidic catalyst is shown. It is a graph. Reaction time and decomposition product p- when the core-shell type spherical silica mesoporous material obtained in Examples 6 to 8 and the spherical silica mesoporous material obtained in Comparative Example 2 were used as basic catalysts It is a graph which shows the relationship with the production amount of nitrophenol. Reaction time and decomposition product p- when the core-shell type spherical silica mesoporous material obtained in Examples 9 to 10 and the spherical silica mesoporous material obtained in Comparative Example 3 were used as basic catalysts It is a graph which shows the relationship with the production amount of nitrophenol.

Claims (7)

Core particles made of first silica into which a first organic group having at least one functional group selected from the group consisting of a sulfonic acid group, a carboxylic acid group and an amino group is introduced;
It consists of second silica into which at least one second organic group selected from the group consisting of aliphatic compound-based organic groups and cyclic compound-based organic groups is introduced, and is laminated on the outside of the core particles. Shell layer,
A core-shell type spherical silica-based mesoporous material comprising:   The first organic group has a linear or branched hetero atom having 18 or less carbon atoms, or a hetero atom having 18 or less carbon atoms. The core-shell type spherical silica-based mesoporous material according to claim 1, wherein the functional group is bonded to a good cyclic hydrocarbon group.   The first organic group is a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, a linear or branched chain Hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched chain Undecyl group, linear or branched dodecyl group, linear or branched tetradecyl group, linear or branched hexadecyl group, linear or branched octadecyl group, allyl group, vinyl group, At least one selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, naphthyl group, cyclohexyl group, pyridyl group, pyrimidyl group, quinolyl group, isoquinolyl group, imidazole group, indole group and purine group Based, core-shell spherical mesoporous silica material according to claim 1 or 2, wherein the functional group is obtained by coupling.   The second organic group has an aliphatic compound-based organic group which may have a linear or branched heteroatom having 18 or less carbon atoms, and a heteroatom having 18 or less carbon atoms. The core-shell type spherical silica-based mesoporous material according to any one of claims 1 to 3, wherein the core-shell type spherical silica-based mesoporous material is at least one selected from the group consisting of cyclic compound-based organic groups. The second organic group is a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, a linear or branched chain Hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched chain Undecyl group, linear or branched dodecyl group, linear or branched tetradecyl group, linear or branched hexadecyl group, linear or branched octadecyl group, allyl group, vinyl group, Phenyl, alkylphenyl, biphenyl, naphthyl, cyclohexyl, pyridyl, pyrimidyl, quinolyl, isoquinolyl, imidazole, indole, purine, and
These groups include at least selected from the group consisting of hydroxyl group, carbonyl group, aldehyde group, imino group, cyano group, azo group, azide group, nitro group, thiol group, amide group, ureido group, ester group and ether group. A group to which an organic group having a functional group containing one kind of heteroatom is bonded;
The core-shell type spherical silica-based mesoporous material according to any one of claims 1 to 4, wherein the core-shell type spherical silica-based mesoporous material is at least one selected from the group consisting of:   A catalyst comprising the core-shell type spherical silica-based mesoporous material according to any one of claims 1 to 5.   An adsorbent comprising the core-shell type spherical silica-based mesoporous material according to any one of claims 1 to 5.