JP2009249242A - POROUS SILICA (MeKIT-5) INTO WHICH METAL IS ADDED AND METHOD FOR PRODUCING THE SAME - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide porous silica (MeKIT-5) in which a metal is added, and a method for producing the same and further to provide porous silica (MeKIT-5) into which highly concentrated metal is added and a method for producing the same. <P>SOLUTION: The porous silica has a porous structure comprising a prescribed space groups into which a metallic element selected from a group comprising Al, Fe, Ti, Co and Ga is added. The method of producing the porous silica comprises a step of: mixing a surfactant F127, an acid, water, a silicon source and the metallic element selected from a group comprising Al, Fe, Ti, Co and Ga; a step of: heating the raw material mixture obtained in the mixing step and silicifying it; and a step of: firing the silicide obtained by the silicifying step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a porous silica (MeKIT-5) to which a metal is added and a method for producing the same, and more specifically, to a porous silica (MeKIT-5) to which a highly concentrated and highly oriented metal is added and the production thereof. Regarding the method.

  Oriented porous silica materials are attracting attention because they are expected to be applied to the fields of catalyst, adsorption, separation and fuel cells. Recently, highly oriented cage-type porous silica (KIT-5) has been developed as one of such porous silica materials (see, for example, Non-Patent Document 1).

  According to Non-Patent Document 1, KIT-5 is synthesized without adding a salt or an organic additive in an acidic medium with tetraethylorthosilicate (TEOS) as a silica source and surfactant F127 as a structure indicator. Such KIT-5 has a high specific surface area, a large pore diameter, and a high specific pore capacity in addition to a high orientation and a cage type. Further, according to Non-Patent Document 1, the hole diameter and cage diameter of KIT-5 can be controlled by hydrothermal treatment in a temperature range of 45 ° C to 150 ° C.

  However, KIT-5 has drawbacks such as poor stability, weakness to acids, and low ion exchange capacity, and has limited applications. Therefore, it is desirable that KIT-5 having excellent stability, acid resistance, and high ion exchange ability can be obtained.

F. Kleitz et al. Phys. Chem. B 107 (2003) 14296

  Accordingly, an object of the present invention is to provide a porous silica (KIT-5) to which a metal is added and a method for producing the same. A further object of the present invention is to provide porous silica (KIT-5) to which a high concentration of metal is added and a method for producing the same.

(1) Porous silica to which a metal is added, wherein the metal is a metal element selected from the group consisting of Al, Fe, Ti, Co, and Ga, and the space group of the porous silica is a surface It is a centered cubic Fm3m.
(2) In the porous silica according to (1) above, the molar ratio (n _Si / n _Me ) between silicon and the metal in the porous silica is in the range of 1 × 10 ^{1 to} 7 × 10 ¹ . It is characterized by being.
(3) In the porous silica according to the above (1), the specific surface area of the mesoporous carbon is in the range of 6.3 × 10 ^{2 to} 1.0 × 10 ³ m ² / g, and the ratio of the mesoporous carbon The pore volume is in the range of 4 × 10 ^{−1 to} 7 × 10 ⁻¹ cm ³ / g, and the pore diameter of the mesoporous carbon is in the range of 5 to 6 nm.
(4) In the method for producing porous silica to which a metal is added, a step of mixing a surfactant F127, an acid, water, a silicon source, and a metal source, wherein the metal source is Al A process including a metal element selected from the group consisting of Fe, Ti, Co, and Ga, a process of heating and siliciding the raw material mixture obtained by the mixing process, and a process of silicidation And a step of firing the obtained silicide.
(5) In the method according to the above (4), the silicifying step is performed in a temperature range of 3.5 × 10 ¹ ° C. to 6 × 10 ¹ ° C. 1 × 10 ¹ hour to 2.4 × 10 ¹ hour. The mixture is heated with stirring for ⁵ hours and then hydrothermally treated in the temperature range of 8 × 10 ¹ ° C. to 1.5 × 10 ² ° C. for 6 hours to 4.8 × 10 ¹ hours.
(6) In the method according to the above (4), in the step of baking, the silicide is 1 × 10 ¹ hour to 2.4 × in a temperature range of 5 × 10 ² ° C. to 5.5 × 10 ² ° C. 10 It is characterized by firing for ¹ hour.
(7) In the method according to (4), the mixing step includes silicon source: metal source: F127: acid: H ₂ O = 1.0: 0.033 to 0.071: 0.0035: 0. .25 to 0.4166: 116.6 to 119, which is mixed.
(8) In the method according to (4), the metal source is selected from the group consisting of metal nitrates, metal chlorides, metal sulfides, and metal isopropoxides of the selected metal. It is characterized by.
(9) In the method according to (4), the acid is selected from the group consisting of hydrochloric acid, sulfuric acid, and nitric acid.
(10) In the method according to (4), the silicon source is selected from the group consisting of tetraethylorthosilicate (TEOS), tetramethylorthosilicate (TMOS), sodium aluminate, and colloidal silica. how to.
(11) The method according to (4) above, wherein in the mixing step, the raw material mixture is mixed so that the pH is higher than 1.

The porous silica (MeKIT-5) to which the metal according to the present invention is added is a metal element selected from the group consisting of Al, Fe, Ti, Co and Ga, and the space group is cubic Fm3m. It is characterized by being. Since the metal is introduced into the silica frame structure, the porous silica according to the present invention (MeKIT-5) has stability, acid resistance and ion exchange capacity in addition to the highly oriented three-dimensional cage structure. Prepare. In particular, porous silica in which the molar ratio of silicon to metal (n _Si / n _Me ) in the porous silica is in the range of 1 × 10 ^{1 to} 7 × 10 ¹ is added to the highly oriented three-dimensional cage structure. In addition, it has excellent stability, acid resistance, and ion exchange capacity, and thus is preferable for practical use.

  The method of the present invention includes a step of mixing a surfactant F127, an acid, water, a silicon source, and a metal source, a step of heating and siliciding the raw material mixture obtained by the mixing step, And the step of firing the silicide obtained by the silicidation step. The metal source includes a metal element selected from the group consisting of Al, Fe, Ti, Co, and Ga. Thereby, a metal atom can be easily introduced into the frame structure of porous silica (KIT-5). Further, in the mixing step, it is finally obtained by adjusting the molar ratio of acid and water, adjusting the molar ratio of the silicon source and the metal source, adjusting the pH of the raw material mixture, and / or selecting the metal source. The metal content in the porous silica (MeKIT-5) to which the metal to be added is added can be adjusted. This is preferable because porous silica (MeKIT-5) to which a metal having a metal content corresponding to the application is added can be obtained.

The present inventor has found that the above problem can be overcome by introducing a heteroatom into KIT-5. Porous silica to which a metal according to the present invention is added (hereinafter referred to as MeKIT-5 for the sake of simplicity. Here, Me represents the added metal) MeKIT-5 has the following characteristics. In the case where a specific metal element is used as Me, for example, when Al is selected as the metal element, a specific metal element may be displayed instead of Me as in AlKIT-5.
Space group: Face-centered cubic Fm3m
Metal Me: a metal element selected from the group consisting of Al, Fe, Ti, Co and Ga

  Each of these metals Me is a highly oriented three-dimensional cage structure of porous silica having a space group of face-centered cubic Fm3m (hereinafter, porous silica not containing metal Me is simply referred to as KIT-5). While being introduced into the frame structure. In addition, MeKIT-5 to which these metals Me are added is chemically stable, and the acid resistance and ion exchange ability are improved by the metal Me. Among these, Al is preferable because it can be easily introduced into KIT-5.

In particular, in MeKIT-5, when the molar ratio of silicon to metal Me (n _Si / n _Me ) is in the range of 1 × 10 ^{1 to} 7 × 10 ¹ , a highly oriented three-dimensional cage structure is formed. Since it is possible to obtain MeKIT-5 which is further excellent in chemical stability, acid resistance, and ion exchange capacity while maintaining it, it is practically advantageous.

Further, when MeKIT-5 further has the following characteristics, it is extremely effective for a catalyst utilizing the characteristics of the three-dimensional cage structure, and for use in adsorption and separation.
The specific surface ^{area: 6.3 × 10 2 m 2 /g~1.0×10} 3 m 2 / g
Hiana ^{Capacity: 4 × 10 -1 cm 3 /} g~7 × 10 -1 cm 3 / g
Pore diameter: 5 nm to 6 nm

The above-mentioned n _Si / n _Me ratio, specific surface area, specific pore volume, and pore diameter are adjusted for the molar ratio of acid to water during production, and adjusted for the molar ratio of silicon source to metal source, as will be described later. Controlled by adjusting the pH of the raw material mixture and / or selecting the metal source.

  The present inventors have found MeKIT-5 having the above-described crystal structure and the above-mentioned characteristics through ingenuity.

  Next, a manufacturing method of the above-described MeKIT-5 will be described. In general, it is difficult to introduce heteroatoms into the KIT-5 silica framework in highly acidic media where the solubility of the metal source of the heteroatoms is required. More particularly, in highly acidic media, heteroatoms are present as cations rather than the corresponding oxo species. This suppresses contact between the heteroatom and the silica species, so that the heteroatom cannot be introduced into the silica frame structure of KIT-5. The present inventors have found a method for introducing a heteroatom into KIT-5 by ingenuity.

  FIG. 1 is a flowchart showing a manufacturing process of mesoporous silica (MeKIT-5) to which a metal according to the present invention is added.

Step S110: Surfactant F127, acid, water, silicon source, and metal source are mixed. The surfactant F127 is a block copolymer composed of ethylene oxide (EO) and propylene oxide (PO) and having a structure of EO ₁₀₀ -PO ₆₅ -EO ₁₀₀ , and can function as a template.

  As the acid, any acid capable of dissolving the metal source is applied, but it is preferably selected from the group consisting of hydrochloric acid, sulfuric acid and nitric acid. These acids can easily dissolve the metal source. The silicon source is selected from the group consisting of tetraethylorthosilicate (TEOS), tetramethylorthosilicate (TMOS), sodium aluminate and colloidal silica. These silicon sources are readily available.

  The metal source includes a metal element selected from the group consisting of Al, Fe, Ti, Co, and Ga. As described above, these metals are introduced into the frame structure while maintaining the highly oriented three-dimensional cage structure of KIT-5, so that MeKIT-5 is chemically stabilized and its acid resistance is improved. Improve ion exchange capacity. Among these, Al is preferable because it can be easily introduced into KIT-5. The metal source is selected from the group consisting of nitrate metal, metal chloride, metal sulfide, and metal isopropoxide of the selected metal element. Since these metal sources are easily dissolved in the above-mentioned acid, the reaction is accelerated.

  In particular, it is desirable to adjust the acid so that the pH of the raw material mixture is greater than 1. Thereby, the addition amount of a metal can be increased. Specifically, when the pH of the raw material mixture is 1 or less, the silica species (silicon source) is positively charged because it is lower than the equipotential of silica. In addition, since the metal source has a large solid capacity, the metal atom is present not as an oxo species but as a cation. As a result, electrostatic repulsion occurs between the metal cation and the positively charged silica species, so that the interaction between the metal cation and the positively charged silica species is suppressed, and the amount of added metal is suppressed. .

  On the other hand, when the pH of the raw material mixture is larger than 1, it becomes higher than the equipotential of silica, so that the silica species is negatively charged. Further, in the metal source, the metal atom exists as an oxo species (metal oxo species) rather than the metal cation, and is stabilized. As a result, the interaction between the metal oxo species and the negatively charged silica species is promoted, increasing the amount of metal added.

In particular, the preferable mixing molar ratio of the raw material mixture is silicon source: metal source: F127: acid: water (H ₂ O) = 1.0: 0.033 to 0.071: 0.0035: 0.25 to 0 .4166: 116.6-119. Within this range, the molar ratio of silicon and metal _{Me (n} Si _/ n Me) is, is MeKIT-5 in the range of ¹ × ¹⁰ 1 ~7 × ¹⁰ 1 is obtained. Such MeKIT-5 is practically advantageous because MeKIT-5, which maintains a highly oriented three-dimensional cage structure and is further excellent in chemical stability, acid resistance and catalytic activity, can be obtained.

For example, when Al is selected as the metal of the metal source and the amount of Al in the raw material mixture is fixed, adjusting the raw material mixture to have a high pH results in a high Al content, a high unit cell constant, a high specific surface area, a high AlKIT-5 having a specific pore volume and a high cage diameter is obtained. For example, when Al is selected as the metal of the metal source, and the amount of Al in the raw material mixture and the pH of the raw material mixture are fixed, if a metal source having a low Hoffmeister series binding force is selected, a high Al content, a high unit AlKIT-5 having a lattice constant, a high specific surface area, a high specific pore volume and a high cage diameter is obtained. For example, when Al is selected as the metal of the metal source and the pH in the raw material mixture is fixed, if the n _Si / n _Al ratio in the raw material mixture is 15 or less, the n _Si / n _Al ratio is 10 to 70. AlKIT-5 having a high Al content, a high unit cell constant, a high specific surface area, a high specific pore volume and a high cage diameter, especially when the n _Si / n _Al ratio in the raw material mixture is 7 5 is obtained. Again, with reference to FIG. 1, a manufacturing process is explained in full detail.

Step S120: The raw material mixture obtained in Step S110 is heated to polymerize and then silicide. Specifically, the heating is performed while stirring at a temperature range of 3.5 × 10 ¹ ° C. to 6 × 10 ¹ ° C. for 1 × 10 ¹ hour to 2.4 × 10 ¹ hour, and then 8 × 10 10 Hydrothermal treatment is performed in the temperature range of ¹ ° C. to 1.5 × 10 ² ° C. for 6 hours to 4.8 × 10 ¹ hour. The silica source in the raw material mixture is polymerized by heating in the temperature range of 3.5 × 10 ¹ ° C. to 6 × 10 ¹ ° C. Subsequently, the raw material mixture is silicified by heating in a temperature range of 8 × 10 ¹ ° C. to 1.5 × 10 ² ° C.

Step S130: The silicide obtained in Step S120 is baked to remove the surfactant F127. Specifically, the calcination is performed in the temperature range of 5 × 10 ² ° C. to 5.5 × 10 ² ° C. for 1 × 10 ¹ hour to 2.4 × 10 ¹ hour. Under this condition, F127 is completely removed.

  As described above, porous silica (MeKIT-5) to which a metal is added can be obtained.

  Next, the method of the present invention will be described using specific examples, but it should be understood that the present invention is not limited to the examples.

  In Example 1, the metal content in MeKIT-5 obtained by adopting the method according to the present invention and changing the molar ratio of water to acid in the raw material mixture (ie, pH in the raw material mixture), It shows that the specific surface area, specific pore volume, pore diameter and wall thickness can be controlled.

Surfactant F127 (EO ₉₇ PO ₆₉ EO ₉₇ , molecular weight 12500, 5.0 g), hydrochloric acid HCl (35 wt%) as an acid, distilled water (240 g), tetraethylorthosilicate TEOS (24 g) as a silicon source, Aluminum isopropoxide AiPr was mixed as a metal source (step S110 in FIG. 1). F127 is Sigma Co. AiPr and TEOS were obtained from Aldrich. The molar ratio of Si and Al in the raw material mixture to _(n Si _{/ n Al)} is fixed to 12, water _(H 2 O) and the molar ratio of HCl to _{(n H2O / n HCl),} 132,198,278 And 463. Note that the molar ratio of the raw material mixture SiO ₂ : Al ₂ O ₃ : F127: HCl: H ₂ O = 1.0: 0.025 to 0.071: 0.0035: 0.25 to 0.88: 116.6 ~ 119.

The raw material mixture having each n _H2O / n _HCl ratio was heated with stirring at 60 ° C. for 24 hours, and then hydrothermally treated at 100 ° C. for 24 hours (step S120 in FIG. 1). Each silicide obtained was filtered and dried at 100 ° C. without washing. Next, each silicide was baked at 540 ° C. for 10 hours to remove the remaining F127 (step S130 in FIG. 1).

The samples thus obtained are referred to as Sample 1, Sample 2, Sample 3, and Sample 4, respectively. Sample 1 has an n _H2O / n _HCl ratio of 132 in the raw material mixture, Sample 2 has an n _H2O / n _HCl ratio of 198 in the raw material mixture, and Sample 3 has an n _H2O / n _HCl ratio in the raw material mixture. 278 and Sample 4 has a n _H2O / n _HCl ratio of 463 in the raw material mixture. The pH in the raw material mixture increases in the order of Sample 1, Sample 2, Sample 3, and Sample 4.

  Samples 1 to 4 were subjected to structural analysis by powder X-ray diffraction before and after firing (steps S120 and S130 in FIG. 1). Powder X-ray diffraction was performed with a Rigaku diffractometer using CuKα (λ = 0.15406 nm) rays. Measurement conditions were 40 kV and 40 mA, a range of 2θ = 0.7 ° to 10 ° with a step of 0.01 ° and a step time of 6 seconds. The results are shown in FIGS. 2 and 3 and will be described later.

  Samples 1 to 4 were subjected to elemental analysis and element mapping using inductively coupled plasma (ICP) and HRSEM-EDS (Hitachi S-4800 HR-FESEM). The acceleration voltage was 30 kV. The results are shown in FIGS. 4 to 6 and Table 1, and will be described later.

  Samples 1 to 4 were measured for nitrogen adsorption / desorption isotherm at -196 ° C using a Quantachrome Autosorb 1 adsorption amount measuring device. The results are shown in FIG. From FIG. 7, the BET specific surface area, specific pore volume and pore diameter of Samples 1 to 4 and KIT-5 were calculated. The results are shown in Table 1. Here, the maximum value of the pore size distribution was taken as the pore size and calculated from the adsorption branch of the nitrogen adsorption / desorption isotherm using the Barett-Joyner-Halenda (BJH) method.

Further, for samples 1 to 4, the cage diameter was determined from the formula D _me = a × (6ε _me / πν) ^1/3 according to Ravikovitch et al. Here, D _me is the pore diameter of the porous body having the unit cell constant a, ε _me is the volume fraction of the holes, and ν is the number of holes existing in the unit cell (ν = in the case of the Fm3m space group). 4). Moreover, the wall thickness was calculated _| required from the formula h = ( _Dme / 3) (1- (epsilon) _me ) / (epsilon) _me about the samples 1-4 using the obtained cage diameter. The results are shown in Table 1 and will be described later.

  FIG. 2 is a diagram showing an XRD diffraction pattern of Samples 1 to 4 before firing.

  FIG. 3 is a diagram showing XRD diffraction patterns after firing of samples 1 to 4.

  2 and 3, in addition to Samples 1 to 4, KIT-5 to which no metal (Al in Example 1) was added (KIT-5 was synthesized except that no Al source was added). The XRD diffraction pattern (similar to the synthesis procedure) is also shown. As shown in FIGS. 2 and 3, the diffraction patterns before and after firing Samples 1 to 4 both show the same diffraction pattern as KIT-5, suggesting that they are regularly oriented. Each diffraction pattern also shows three diffraction peaks corresponding to (111), (200) and (220) reflections, and samples 1-4 have a space group of face-centered cubic Fm3m as in KIT-5. It was confirmed. This suggests that the orientation and crystal structure are maintained well before and after firing.

  From FIG. 2 and FIG. 3, the diffraction intensity was improved and the diffraction peak was shifted to the high angle side after firing. This is presumably because atomic rearrangement occurred in the Al—O—Si frame structure of the porous body wall of AlKIT-5 during firing. In particular, in FIG. 3, it was found that the diffraction pattern of sample 4 had a narrower half-value width than that of KIT-5.

Using the formula a ₀ = d ₁₁₁ √3 from the diffraction peak due to (111) reflection in FIG. 3, the unit cell constants a ₀ of samples 1 to 4 and KIT-5 were determined. The results are shown in Table 1. It was confirmed that the interplanar spacing d ₁₁₁ obtained from the diffraction peak was comparable to the face-centered cubic Fm3m space group.

As shown in FIG. 3, as the n _{H2O 2} / n _HCl ratio in the raw material mixture increased (that is, the pH of the raw material mixture increased), the diffraction peak shifted to the lower angle side. From this, as shown in Table 1, it was found that the unit cell constant a ₀ also increased from 16.39 nm to 16.97 nm as the n _{H 2 O 2} / n _HCl ratio in the raw material mixture increased. This suggests that the lattice constant of the resulting AlKIT-5 can be controlled by adjusting the n _{H 2 O} / n _HCl ratio in the raw material mixture.

FIG. 4 is a graph showing the dependence of the Al content and unit cell constant on the n _{H 2 O 2} / n _HCl ratio in the raw material mixture.

  FIG. 5 is a diagram illustrating the HRSEM-EDS patterns of Samples 1 to 4.

  FIG. 6 is a diagram showing element mapping of samples 1 to 4.

From FIG. 4 and Table 1, as the n _{H 2 O 2} / n _HCl ratio in the raw material mixture increases (that is, the pH of the raw material mixture increases), the lattice constants of the obtained samples 1 to 4 increase and are obtained. It was also found that the n _Si / n _Al ratio in Samples 1 to 4 decreased (that is, the Al content increased). This suggests that the Al content in AlKIT-5 can be controlled by changing the pH of the raw material mixture. More specifically, when the n _{H 2 O} / n _HCl ratio in the raw material mixture was increased from 132 to 463, the n _Si / n _Al ratio in AlKIT-5 was reduced from 435 to 44. In particular, if the n _H2O / n _HCl ratio in the raw material mixture is 440 or more, the n _Si / n _Al ratio in AlKIT-5 is 10 to 70, and the added metal further improves acid resistance and ion exchange capacity. This is preferable.

From FIG. 5, only the peaks of Al, Si and O were detected in all of samples 1 to 4. This indicates that in Samples 1 to 4, residual F127 and acid (HCl in Example 1) are not present as impurities. Further, the Al peak in FIG. 5 increased with an increase in the ratio of n _{H 2 O} / n _HCl in the raw material mixture. This result agrees with the result of ICP elemental analysis in FIG.

  As can be seen from FIG. 6, in any of the samples 1 to 4, the elements are uniformly present throughout the sample. Samples 1-4 were confirmed to be homogeneous AlKIT-5 throughout the sample.

4 to 6, the Al content can be controlled by adjusting the n _{H 2 O} / n _HCl ratio in the raw material mixture when the n _Si / n _Al ratio in the raw material mixture is fixed. It has been shown. Specifically, the n _{H 2 O} / n _HCl ratio 132 (sample 1) in the raw material mixture is preferable for obtaining AlKIT-5 having a low Al content. When the n _H2O / n _HCl ratio in the raw material mixture is 132, the pH of the raw material mixture is much lower than 1, which is the equipotential of the silica species, and the silica species is positively charged. Further, the Al source is easily dissolved in the acid, and Al exists as a cation. As described above, since the silica species are positively charged, the Al cation and the positively-charged silica species are electrostatically repelled, thereby suppressing mutual interaction. As a result, AlKIT-5 with a low Al content is obtained.

An n _{H 2 O} / n _HCl ratio of 463 (sample 4) in the raw material mixture is preferred for obtaining AlKIT-5 with a high Al content. When the _nH2O / _nHCl ratio in the raw material mixture is 463, the pH of the raw material mixture is much higher than 1 which is the equipotential of silica and is 2 or more, and the silica species is negatively charged. At pH 2 or higher, the Al source is more stable when present as an Al oxo species (Al (OH) ₂ ⁺ ) than when present as a cation. As a result, the Al oxo species promotes the interaction with the negatively charged silica species, so that AlKIT-5 having a high Al content can be obtained.

Also, from the results of FIGS. 2 to 6, the Al content and the unit cell constant increase as the n _{H 2 O} / n _HCl ratio in the raw material mixture increases (that is, as the pH in the raw material mixture increases). It is considered that this is because Al—O—Si bond is formed by substitution of Si with Al in the frame structure of AlKIT-5. Considering the atomic size of Al and Si and assuming that Al and Si are both tetracoordinate, the atomic radius of Al ³⁺ (0.53Å) is larger than the atomic radius of Si ⁴⁺ (0.40Å). . As a result, the distance of Al—O is increased, that is, the distance between the two closest holes is increased. In addition, when the n _{H 2 O} / n _HCl ratio in the raw material mixture is larger, the interaction between the Al oxo species and the silica species becomes larger, so that the Al content increases and the lattice constant becomes larger.

  FIG. 7 is a diagram showing nitrogen adsorption / desorption isotherms of Samples 1 to 4.

For reference, FIG. 7 also shows the nitrogen adsorption / desorption isotherm of KIT-5. The nitrogen adsorption and desorption isotherms of any sample showed type IV with sharp capillary action (step) and H2 type hysteresis loop. From this, it was found that all of the obtained samples had large uniform cage-type holes as in KIT-5. The sharp capillary phenomenon seen in the nitrogen adsorption / desorption isotherms of Samples 1 to 4 increases as the n _{H 2 O} / n _HCl ratio in the raw material mixture increases (that is, as the pH in the raw material mixture increases). Shifted to. This indicates that in all samples, nitrogen condensation occurs in the cage-type three-dimensional mesopores and maintains good mesopore orientation and high uniformity even after addition of Al. Suggest.

As shown in Table 1, as the n _{H2O 2} / n _HCl ratio in the raw material mixture increases (ie, as the pH in the raw material mixture increases), the specific surface area and specific pore volume may also increase relatively. I understood. More specifically, the specific surface area and the specific pore volume are respectively determined from the specific surface area 614 m ² / g and the specific pore volume 0.39 cm ³ / g of the n _{H 2 O} / n _HCl ratio 132 (sample 1) in the raw material mixture, The n _{H 2 O} / n _HCl ratio 463 (sample 4) in the raw material mixture increased to a specific surface area of 713 m ² / g and 0.45 cm ³ / g.

Furthermore, it was found that as the n _{H 2 O} / n _HCl ratio in the raw material mixture increased, the pore diameter increased with the cage diameter of AlKIT-5. More specifically, the cage diameter and the pore diameter are determined from the cage diameter 9.6 nm and the pore diameter 5.0 nm of the n _H2O / n _HCl ratio 132 (sample 1) in the raw material mixture, respectively, from the n _{H2O 2} / n in the raw material mixture. _{The HCl} ratio of 463 (sample 4) increased to a cage diameter of 10.3 nm and a pore diameter of 5.2 nm. This result was in good agreement with the result of XRD diffraction in FIG. In particular, it was found that the specific surface area, specific pore volume and pore diameter of Sample 4 were larger than those of KIT-5, and were improved by the addition of metal.

From the above, in addition to the Al content and unit cell constant of AlKIT-5, the specific surface area of AlKIT-5 by changing the n _H2O / n _HCl ratio in the raw material mixture (that is, the pH in the raw material mixture), It has been shown that the specific pore volume and pore size can be controlled.

As shown in Table 1, the wall thickness of AlKIT-5 after the addition of Al decreased from 4.3 nm to 4 nm as the n _{H 2 O} / n _HCl ratio in the raw material mixture increased from 132 to 463. This means that if there is a high concentration of H ⁺ ions in the raw material mixture (for example, if the n _{H 2 O} / n _HCl ratio in the raw material mixture is 132), the interaction between the silanol group and the Al oxo species is It is suppressed, the condensation rate of silanol groups is increased, and the number of silicate layers around the surfactant micelle is increased. As a result, the wall thickness of AlKIT-5 becomes thicker when the n _{H 2 O} / n _HCl ratio in the raw material mixture is lower (that is, the pH in the raw material mixture is lower).

As described above, in Example 1, the method according to the present invention was adopted, Al was selected as the metal, aluminum isopropoxide was used as the metal source, hydrochloric acid was used as the acid, and the molar ratio of Si and Al in the raw material mixture ( When n _Si / n _Al ) is fixed at 12, the metal content in MeKIT-5 obtained by changing the molar ratio of water to acid in the raw material mixture (that is, pH in the raw material mixture) It was shown that the specific surface area, specific pore volume, pore diameter and wall thickness can be controlled.

  Example 2 shows that the metal content, specific surface area, specific pore volume, pore diameter and wall thickness in the resulting AlKIT-5 can be controlled by adopting the method according to the present invention and changing the type of metal source. .

The molar ratio of Si and Al in the raw material mixture to _(n Si _{/ n Al)} to 12, water _(H 2 O) and the molar ratio of HCl to _(n H2O _/ n _HCl) was fixed to 463, as the metal source Aluminum isopropoxide (AiPr), aluminum sulfide (AS), aluminum chloride (AC), and aluminum nitrate (AN) were used. The synthesis procedure was the same as in Example 1.

  The samples thus obtained are referred to as Sample 4, Sample 5, Sample 6, and Sample 7, respectively. Sample 4 is the same as Sample 4 of Example 1, the metal source is AiPr, Sample 5 is the metal source AS, Sample 6 is the metal source AC, and Sample 7 is the metal source AN. is there.

In the same manner as in Example 1, elemental analysis by EDS by powder X-ray diffraction, XRD pattern, nitrogen adsorption isotherm, and various structural parameters obtained from these are shown in FIGS. This will be described later with reference to FIG. 10 and Table 2.

As shown in Table 2, when the n _{H 2 O} / n _HCl ratio and the n _Si / n _Al ratio in the raw material mixture are fixed, the metal content n _Si / n _Al ratio in the sample obtained according to the type of metal source used It can be seen that (that is, the Al content) can be controlled. Specifically, the Al content in the obtained sample is as follows: Sample 4 (n _Si / n _Al = 44)> Sample 5 (n _Si / n _Al = 91)> Sample 6 (n _Si / n _Al = 115) )> Sample 7 (n _Si / n _Al = 137). When obtaining AlKIT-5 having the highest Al content, AiPr is preferred as the metal source. In order to obtain AlKIT-5 having the lowest Al content, AN is preferable as the metal source.

Thus, it can be considered that the Al content in AlKIT-5 obtained by the type of the metal source can be controlled due to the binding force between the silica species and the metal source. It is known that the order of the binding strength of the anion Hoffmeister series to the cation molecule is NO ₃ ⁻ > Cl ⁻ > SO ₄ ²⁻ > iPr ⁻ . Also, counter ions with high binding energy (eg, NO ₃ ⁻ or Cl ⁻ ) increase the interaction between the positively charged surfactant and the cationic silica species and promote silica condensation. Or catalyze the silica concentration. As a result, the silica monomer species in the raw material mixture is reduced. When the number of silica monomer species is small, a strong interaction with the Al source cannot be obtained, so that formation of Al—O—Si bonds in the resulting AlKIT-5 is suppressed. As a result, the Al content in AlKIT-5 is reduced. From this, when obtaining MeKIT-5 having a high metal content, a metal source having a small Hofmeister series binding force is adopted, and when obtaining MeKIT-5 having a low metal content, Hofmeister is used. It is suggested that it is desirable to employ a metal source having a large cohesive strength.

Moreover, the Al content of Samples 6 and 7 is smaller than that of Samples 4 and 5. This releases Cl ⁻ and NO ₃ ⁻ anions from the metal sources of Samples 6 and 7, respectively, lowering the pH of the raw material mixture to 1 or less, resulting in positively charged silica species. As described above, when a positively charged silica species is formed, the interaction of the cation with the Al species is suppressed, and the amount of Al introduced into the silica frame structure is reduced.

  FIG. 8 is a diagram showing the HRSEM-EDS patterns of Samples 4-7.

  The Al peaks in the patterns of Samples 6 and 7 were very weak compared to those of Samples 4 and 5, and were consistent with the above results.

  FIG. 9 is a diagram showing XRD diffraction patterns after firing Samples 4-7.

The XRD patterns of Samples 4, 6 and 7 showed three distinct diffraction peaks indexed to the (111), (200) and (220) reflections that are symmetrical with the face centered cubic Fm3m. Moreover, it turned out that peak intensity changes with kinds of metal source. This is due to generation of counter ions (in Example 2, Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ , C ₃ H ₇ O ³⁻ ) that affect the interaction between the surfactant and the silica species. .

Specifically, the intensity of the (111) peak in the XRD pattern of samples 6 and 7 was stronger than that of samples 4 and 5. This is due to the relationship between counter ions and surfactants and silica species. As mentioned above, the relationship between Cl ⁻ , NO ₃ ⁻ and cation molecules is much better when compared to that of SO ₄ ²⁻ and C ₃ H ₇ O ³⁻ . For this reason, the relationship between the counter ion, the surfactant and the silica species becomes stronger through the S ⁰ H ⁺ X ⁻ I ⁺ assembly that neutralizes the charge of the surfactant micelle. The neutrality of the charge results in the formation of stable and rigid surfactant micelles, resulting in high structural orientation as shown in the XRD patterns of Samples 6 and 7.

Still referring to FIG. The (111) peak seen on the low-angle side of the XRD pattern of sample 5 is shifted to the high-angle side as compared with that of samples 4, 6 and 7. Specifically, the unit cell constant and interplanar spacing d of sample 5 are reduced, and their peak intensity is much smaller than that of the other samples 4, 6 and 7. Further, in Sample 5, no high angle side peak was observed. This is because, in a highly acidic medium, sulfate ions are formed from Al ₂ (SO ₄ ) ₃ and HSO ₄ ⁻ species are generated in the raw material mixture. Since the binding force between the HSO ₄ ⁻ species and the cationic surfactant and silica species is extremely low, the formation of S ⁰ H ⁺ X ⁻ I ⁺ assembly is suppressed. As a result, the structural orientation is lowered and the unit cell constant is also reduced.

  From the above, it was shown that the structural orientation of the obtained MeKIT-5 can be controlled by the type of metal source used.

  FIG. 10 is a diagram showing nitrogen adsorption / desorption isotherms of Samples 4-7.

  The nitrogen adsorption and desorption isotherms of any sample showed type IV with sharp capillary action (step) and H2 type hysteresis loop. From this, it was found that all of the obtained samples had uniform cage-type holes. Table 2 shows the structural parameters obtained from the nitrogen adsorption / desorption isotherm.

From Table 2, it was found that all the samples had a high specific surface area of 680 m ² / g or more. The pore size of sample 5 was smaller than that of other samples 4, 6 and 7. This result agrees well with the result of the XRD diffraction described with reference to FIG. The specific pore capacity and pore diameter of Sample 4 were 0.45 cm ³ / g and 5.2 nm, which were found to be larger than those of Samples 5-7.

  From the above, it was found that Al isopropoxide is preferable as the metal source when obtaining AlKIT-5 having a high metal content concentration and good structural parameters.

In Example 3, by adopting the method according to the present invention and changing the molar ratio (n _Si / n _Al ) between Si and Al in the raw material mixture, the metal content and specific surface area in the resulting AlKIT-5 It shows that the specific pore volume, pore diameter and wall thickness can be controlled.
Aluminum isopropoxide (AiPr) used as metal source, the molar ratio of water _(H 2 O) and HCl in the raw material mixture to _(n H2O _/ n _HCl) was fixed to 463, Si and Al in the raw material mixture The molar ratio (n _Si / n _Al ) was 7, 10, 12, 15 and 20. The synthesis procedure was the same as in Example 1.

The samples thus obtained are referred to as Sample 8, Sample 9, Sample 4, Sample 10, and Sample 11, respectively. Sample 8, Sample 9, Sample 4, the molar ratio of Si and Al in the sample 10 and sample 11 _(n Si _/ n _Al), respectively, were 7,10,12,15 and 20. Sample 4 is the same as Sample 4 in Example 1 and Example 2.

Similarly to Example 1, ICP elemental analysis, element mapping by EDS, XRD pattern, and nitrogen adsorption / desorption isotherm of samples 8 to 11 after firing were measured, and various structural parameters were obtained therefrom. Samples 4, 8, 9 and 11 after firing were subjected to morphology observation by HRSEM (acceleration voltage 10 kV), and sample 4 was subjected to topology observation (acceleration voltage 300 kV) by high-resolution transmission electron microscope HRTEM (JEOL JEM-2100F). It was. About the sample 4 and 8-10 after baking, the NMR spectrum measurement was performed using the Bruker MSL-500 spectrometer, and the coordination state of Al was investigated. The NMR spectrum measurement was performed using a zirconia rotor having a diameter of 4 mm at a resonance frequency of 130.319 MHz and a rotation frequency of 12 kHz. Further, the acid resistance and catalytic activity of the calcined samples 4 and 8 to 10 were examined by temperature programmed adsorption. Temperature programmed adsorption was performed on a Micromeritics Autochem 2910. The above results are shown in FIGS. 11 to 19 and Table 3, and will be described later.

From Table 3, both, Al content of the finally obtained sample _n Si _{/ n Al} ratio, it can be seen that is larger than _n Si _{/ n Al} ratio in the raw material mixture. That is, the Al content in the finally obtained sample (AlKIT-5) is smaller than the Al content present in the raw material mixture. Specifically, when the n _Si / n _Al ratio in the raw material mixture was reduced from 20 to 7, the metal content n _Si / n _Al ratio in the sample was reduced from 193 to 10. In particular, in Samples 10 and 11, it was found that the difference between the Al content in the raw material mixture and the Al content in the finally obtained sample was large. This is because if the Al content in the raw material mixture is low (that is, the value of the n _Si / n _Al ratio is large), the interaction between the Al oxo species and the anionic silica species is inhibited. .

  FIG. 11 is a diagram showing the HRSEM-EDS patterns of Sample 4 and Samples 8-11.

The EDS spectrum clearly shows the peaks of the elements Al, Si and O, and the higher the Al content in the raw material mixture (that is, the smaller the value of the n _Si / n _Al ratio in the raw material mixture), the higher the peak intensity of Al Increased. Specifically, the Al peak intensity decreased in the order of samples 8, 9, 4, 10 and 11. This result was in good agreement with the result of ICP elemental analysis shown in Table 3.

  FIG. 12 is a diagram showing element mapping of Sample 4 and Samples 8 to 10.

  According to FIG. 12, the dots indicating Al increased as the Al content in the sample increased. That is, the amount of dots indicating Al increased in the order of samples 10, 4, 9 and 8. This agrees well with the results of ICP elemental analysis. Moreover, it can be seen from the dispersion state of Al and Si atoms that Al atoms are uniformly dispersed throughout the sample.

As described above, AlKIT-5 having a maximum n _Si / n _Al ratio of 10 can be reliably obtained by controlling the n _Si / n _Al ratio and the n _{H 2 O} / n _HCl ratio in the raw material mixture. Indicated.

  FIG. 13 is a diagram showing XRD diffraction patterns of Sample 4 and Samples 8-11.

  The XRD diffraction pattern of any sample showed three diffraction peaks corresponding to (111), (200) and (220) reflections, and was the same diffraction pattern as KIT-5 shown in FIG. From this, it was confirmed that Sample 4 and Samples 8 to 11 have a space group of face-centered cubic Fm3m and have a highly oriented three-dimensional cage type hole structure.

  Further, it was found that the intensity of the diffraction peak of (111) reflection of Sample 4 and Samples 8 to 11 was higher than that of KIT-5. Specifically, as the Al content in the sample increased, the intensity of the (111) reflection diffraction peak also increased. This indicates that the structural orientation of AlKIT-5 was dramatically improved by adding Al into the silica frame structure while maintaining the three-dimensional structure of the porous material.

Furthermore, the diffraction peak shifted to the lower angle side as the Al content increased. This indicates that the unit cell constant in the sample increases as the Al content increases. As shown in Table 3, as the n _Si / n _Al ratio in the final sample decreases from 193 to 10 (ie, the Al content in the sample increases), the unit cell constant is , Increased from 16.65 nm to 18.44 nm. In particular, in the sample 8 with the highest Al content, the increase in the unit cell constant was remarkable. As described above, since the Al—O bond length is longer than the Si—O bond length, the number of Al—O bonds increases as the Al content increases. As a result, the unit cell constant increases.

  FIG. 14 is a diagram showing nitrogen adsorption / desorption isotherms for Sample 4 and Samples 8-11.

  FIG. 15 is a diagram showing the pore size distribution of Sample 4 and Samples 8-11.

  The nitrogen adsorption and desorption isotherms of any sample showed type IV with sharp capillary action (step) and H2 type hysteresis loop. From this, it was found that all of the obtained samples had uniform cage-type holes. In particular, it is advantageous to maintain a structure having a uniform cage-type hole even in a sample having a high Al content. Specifically, as the Al content increased, the amount of nitrogen adsorption increased. This indicates that the sample having a large Al content has a high specific surface area and a specific pore volume, and the pore structure is improved. Furthermore, as the Al content increased, the size of the hysteresis loop also increased. This suggests that the cage diameter increased with increasing Al content.

Referring to Table 3, the specific surface area obtained from FIG. 14, Hiana capacity and cage diameter, respectively, from 630m ² / g to 989m ² / g, from 0.40 cm ³ / g to 0.68 cm ³ / g, And it changed from 9.8 nm to 12.0 nm.

Reference is again made to FIG. As the n _Si / n _Al ratio in the raw material mixture decreased from 20 to 7, the capillary phenomenon shifted to the high relative pressure P / P ₀ side. This correlates with the diameter of the mesopore, and shows that the pore diameter of AlKIT-5 increases with the increase of Al introduction into the silica frame structure. Specifically, the pore size increased from 5.1 nm to 6.0 nm.

  According to FIG. 15, it was found that the higher the Al content, the greater the spread of the pore size distribution of AlKIT-5. This is because, when a large amount of Al isopropoxide (AiPr) is used as the Al source, the excessively generated isopropanol group functions as an organic swelling agent. Specifically, three isopropanol molecules are produced from one AiPr. Therefore, when a high concentration of AiPr is used, a large number of isopropanol molecules are generated. These isopropanol molecules are accumulated at the interface between the surfactant micelle and water, have a higher hydrophobicity than water, increase the capacity of the surfactant micelle, and become a longer-chain surfactant micelle. When the amount of AiPr in the raw material mixture increases, a large amount of long-chain surfactant micelles are generated in the raw material mixture. These long-chain surfactant micelles promote the increase in the pore size of AlKIT-5 with a high Al content.

  The broadening of the pore size distribution of AlKIT-5 with increasing Al content is also due to incomplete condensation of Al oxo species and silanol groups caused by the presence of excess isopropanol molecules in the raw material mixture. This is because the isopropanol molecule easily forms a hydrogen bond with the alkene oxide and increases the hydrophilicity of the head group of the surfactant. These macromolecules bind to silanol groups or Al oxo species and penetrate into the porous silica wall, thereby increasing the unit cell constant of AlKIT-5. Furthermore, such penetration processes affect the condensation of Al oxo species and silanol groups, further increasing the unit cell constant.

  When the condensation of the wall proceeds during the heating and baking in step S120 (FIG. 1), the unit cell constant shrinks and the pore diameter of AlKIT-5 increases. This suggests that the pore size of AlKIT-5 can be controlled without the need for additional expansion agents and high temperature expansion treatment while maintaining a well-ordered three-dimensional pore structure of KIT-5.

Further, as shown in the inset of FIG. 15, the pore diameter, unit cell constant, specific surface area and specific pore capacity of AlKIT-5 are such that the n _Si / n _Al ratio is 10 to 70, preferably 10 to 50. It has been found that it varies linearly in range. Specifically, the smaller the n _Si / n _Al ratio (that is, the higher the Al content), the larger the pore diameter, unit cell constant, specific surface area, and specific pore volume, and the higher the n _Si / n _Al ratio. The smaller the Al content (ie, the smaller the Al content), the smaller the pore diameter, unit cell constant, specific surface area and specific pore volume. When the n _Si / n _Al ratio exceeds 70, the effect of adding Al becomes small.

From the above results, it was shown that the specific surface area, specific pore volume and unit cell constant of AlKIT-5 can be easily controlled by changing the Al content in the sample. In particular, it is extremely advantageous to obtain AlKIT-5 (sample 8) having a high Al content with an n _Si / n _Al ratio of 10 while maintaining a three-dimensional cage structure.

  FIG. 16 is a diagram showing HRSEM images of Samples 4, 8, 9 and 11.

  According to FIG. 16, it can be seen that there are differences in the particle size and shape of the AlKIT-5 particles depending on the difference in the Al content. The particle size of the KIT-5 particles was in the range of 3.2 μm to 3.5 μm, and the shape thereof was a uniform sphere (not shown). However, as the Al content increased, the particle-shaped spheres deformed. In the order of sample 11, sample 4, sample 9, and sample 8, the shape of AlKIT-5 particles became non-uniform.

Specifically, the shape of the sample 11 with low Al content (n _Si / n _Al = 193) is a uniform sphere, but its size is 1.6 μm to 2.6 μm, and KIT-5 It was smaller than that. On the other hand, as for the shape of sample 8 (n _Si / n _Al = 10) with a large Al content, the sphere was partly deformed or particles were aggregated. The particle size of sample 8 was 1 μm to 2.3 μm, which was smaller than that of KIT-5 and further smaller than that of sample 11.

  From the above, it was found that the particle size of AlKIT-5 decreases as the Al content increases. This is due to the difference in curvature of the surfactant micelle before and after the addition of Al. This is because the polymeric micelles adsorb, aggregate or form around the surfactant micelles to change the surfactant micelle length, and as a result, the curvature of the surfactant micelles decreases. In particular, as described above, when AiPr is added to the raw material mixture as an Al source, a large amount of isopropanol molecules and Al atoms generated from the Al source are adsorbed on the surfactant micelles, and between the silica species. Can inhibit the condensation reaction. This process suppresses the neutrality of the charge and greatly reduces the electrostatic repulsion between the surfactant head groups to obtain longer chain surfactant micelles. As a result, the particle size of the resulting AlKIT-5 is reduced. When AiPr is added excessively, this effect becomes more prominent and irregularly shaped spherical particles are generated (for example, sample 8).

  FIG. 17 is a diagram showing an HRTEM image of the sample 4.

  From FIG. 17, sample 4 clearly shows a highly oriented pore structure in which mesopores and walls are linearly arranged. Such a pore structure is a characteristic of KIT-5, and it was confirmed that AlKIT-5 also maintained the characteristics of KIT-5. The inset in the figure shows a fast Fourier transform (FFT) pattern and an inverse fast Fourier transform (IFFT). Both showed cubic (specifically face-centered cubic) three-dimensional mesopore networks, which were in good agreement with the results obtained from XRD diffraction. From these, it was shown that well-aligned mesopores having a three-dimensional cubic pore structure exist in AlKIT-5.

  FIG. 18 is a diagram showing NMR spectra of Sample 4 and Samples 8-10.

Both samples show two peaks centered at 53 ppm and 0 ppm regardless of the Al content. The peak at 53 ppm is attributed to Al tetrahedrally coordinated with silicon, and the peak at 0 ppm is attributed to Al octahedrally coordinated with silicon. As the Al content increases, the peak intensity at 53 ppm increases, while the relative peak intensity between the octahedral coordination peak and the tetrahedral coordination peak decreases as the Al content increases. These results suggest that the amount of tetrahedrally coordinated Al in the silica framework can be controlled simply by adjusting the n _Si / n _Al ratio in the raw material mixture.

FIG. 19 is a diagram showing NH ₃ -TPD spectra of Sample 4 and Samples 8 to 10.

  All samples showed two broad peaks centered between 100 ° C. and 200 ° C. and between 500 ° C. and 550 ° C. These suggest that there are two types of acid sites in AlKIT-5. The desorption peak on the low temperature side is caused by Al (tetrahedrally coordinated Al) in the silica frame structure of KIT-5, while the desorption peak on the high temperature side is Al (octahedrally coordinated) outside the silica frame structure. Due to Al).

  As the Al content increases, a rapid increase in the desorption temperature for desorbing ammonia molecules adsorbed on tetrahedrally coordinated Al sites is observed. Specifically, in the order of sample 10, sample 4, sample 9, and sample 8, the peak observed at 100 ° C. to 200 ° C. shifted to the high temperature side. This is because tetrahedrally coordinated Al in AlKIT-5 increases rapidly as the Al content increases.

  On the other hand, the intensity of the desorption peak on the high temperature side of the sample 10 (this peak is generated by adsorption of ammonia molecules on octahedrally coordinated Al) is higher than that of the other samples. This is because the amount of Al in octahedral coordination of the sample 10 is much larger than that of the other samples. These results were in good agreement with the NMR spectrum results of FIG.

Table 4 shows the acidity and catalytic activity of Sample 4 and Samples 8-10.

  Table 4 shows the results of examining the catalytic activity for acetylation of veratrol using acetic anhydride. Table 4 also shows the results of various zeolite catalysts in addition to AlKIT-5. According to Table 4, it can be seen that the acidity of AlKIT-5 was significantly improved as the Al content increased. Sample 8 showed excellent conversion efficiency and was found to be superior to other AlKIT-5, H-mordenite, zeolite H-Y, zeolite H-β and HSM-5. This is because the high catalytic activity of the sample 8 exhibits a three-dimensional cage type pore structure having a high specific surface area and high acidity. This is to promote the diffusion of the reactive molecules and allow easy access to all active sites. The results of these catalysts are consistent with Sample 8 having a high Al content that is tetrahedrally coordinated.

  As described above, according to the present invention, by adjusting various conditions (for example, selection of metal Me and metal source, pH, metal amount, etc.) in the raw material mixture, It has been shown that the metal content, specific surface area, specific pore volume, pore diameter, wall thickness, catalytic activity, acid resistance, etc. can be controlled. In the embodiments, the metal Me has been described as being limited to Al, but the present invention is not limited to this. Of course, similar effects can be obtained with metals other than Al (for example, Fe, Ti, Co, and Ga).

  The porous silica (MeKIT-5) to which the metal according to the present invention is added has a high catalytic activity and a strong acid site due to the added metal, while having the same three-dimensional pore structure as KIT-5. Such MeKIT-5 can be used for acid-catalyzed organic conversion, biomolecule support, molecular recognition, separation, nanocatalyst reactor, and the like.

The flowchart which shows the manufacturing process of the mesoporous silica (MeKIT-5) by which the metal by this invention was added. The figure which shows the XRD diffraction pattern before baking of samples 1-4 The figure which shows the XRD diffraction pattern after baking of samples 1-4 The figure which shows the _nH2O / _nHCl ratio dependence in the raw material mixture of Al content and a unit cell constant The figure which shows the HRSEM-EDS pattern of samples 1-4 The figure which shows elemental mapping of samples 1-4 The figure which shows the nitrogen adsorption-desorption isotherm of samples 1-4 The figure which shows the HRSEM-EDS pattern of the samples 4-7 The figure which shows the XRD diffraction pattern after baking of samples 4-7 The figure which shows the nitrogen adsorption-and-desorption isotherm of samples 4-7 The figure which shows the HRSEM-EDS pattern of the sample 4 and the samples 8-11 The figure which shows the element mapping of the sample 4 and the samples 8-10 The figure which shows the XRD diffraction pattern of the sample 4 and the samples 8-11 The figure which shows the nitrogen adsorption-and-desorption isotherm of sample 4 and samples 8-11 The figure which shows the hole diameter distribution of the sample 4 and the samples 8-11 The figure which shows the HRSEM image of sample 4, 8, 9 and 11 The figure which shows the HRTEM image of the sample 4 The figure which shows the NMR spectrum of the sample 4 and the samples 8-10 Shows the _NH 3 -TPD spectra of Sample 4 and Sample 8-10

Claims (11)

Porous silica to which a metal is added,
The metal is a metal element selected from the group consisting of Al, Fe, Ti, Co and Ga;
The porous silica is characterized in that a space group of the porous silica is face centered cubic Fm3m. 2. The porous silica according to claim 1, wherein a molar ratio (n _Si / n _Me ) between silicon and the metal in the porous silica is in a range of 1 × 10 ^{1 to} 7 × 10 ^1. And porous silica. In the porous silica according to claim 1,
The mesoporous carbon has a specific surface area of 6.3 × 10 ^{2 to} 1.0 × 10 ³ m ² / g,
The specific pore capacity of the mesoporous carbon is in the range of 4 × 10 ^{−1 to} 7 × 10 ⁻¹ cm ³ / g,
Porous silica, wherein the mesoporous carbon has a pore diameter in the range of 5 to 6 nm. In the method for producing porous silica to which a metal is added,
A step of mixing a surfactant F127, an acid, water, a silicon source, and a metal source, wherein the metal source is a metal element selected from the group consisting of Al, Fe, Ti, Co, and Ga Including a process,
Heating and silicifying the raw material mixture obtained by the mixing step;
And firing the silicide obtained by the silicidation step. 5. The method according to claim 4, wherein the silicifying step is performed in a temperature range of 3.5 × 10 ^{1 to} 6 × 10 ¹ ° C for 1 × 10 ¹ hour to 2.4 × 10 ¹ hour. And then hydrothermally treating in the temperature range of 8 × 10 ¹ ° C. to 1.5 × 10 ² ° C. for 6 hours to 4.8 × 10 ¹ hour. 5. The method according to claim 4, wherein the step of baking is performed at a temperature range of 5 × 10 ² ° C. to 5.5 × 10 ² ° C. for 1 × 10 ¹ hour to 2.4 × 10 ¹ hour. A method characterized in that it is calcined. 5. The method according to claim 4, wherein the mixing step includes silicon source: metal source: F127: acid: H ₂ O = 1.0: 0.033 to 0.071: 0.0035: 0.25 to 0. 4166: 116.6 to 119, and mixing.   5. The method of claim 4, wherein the metal source is selected from the group consisting of metal nitrates, metal chlorides, metal sulfides, and metal isopropoxides of the selected metal. ,Method.   5. A method according to claim 4, characterized in that the acid is selected from the group consisting of hydrochloric acid, sulfuric acid and nitric acid.   5. A method according to claim 4, characterized in that the silicon source is selected from the group consisting of tetraethylorthosilicate (TEOS), tetramethylorthosilicate (TMOS), sodium aluminate and colloidal silica.   5. The method according to claim 4, wherein, in the mixing step, mixing is performed so that the pH of the raw material mixture is greater than 1.