A kind of preparation method of organic and inorganic conjugated solid acid
Technical field
The invention belongs to a kind of preparation method of organic and inorganic conjugated solid acid, specifically the synthetic a kind of method that has Lewis acid (L acid) and Bronsted acid (B acid) the mesoporous organic and inorganic conjugated solid acid that the center is adjustable, total acid content is adjustable simultaneously of one-step method.
Background technology
Acid catalyzed reaction is one of important course of reaction in the chemical industry, traditional handicraft mostly is the acid catalyzed intermittent reaction of homogeneous phase, compare with heterogeneous reaction, there are many shortcomings aborning, as exist equipment corrosion seriously, not easily separated, be difficult to realize shortcoming such as continuously production, the researcher constantly researchs and develops the multiphase solid acid catalyst and substitutes the homogeneous liquid acid catalyst for this reason, to solve above-mentioned problems.Solid acid catalyst research has obtained important achievement through the development of last 100 years.Wherein the SOLID ORGANIC acid catalyst is because the organic acid of modification partly has very big adjustable sex change, can synthesize solid acid catalyst with definite acid site number and acid strength, thereby caused the great interest of scientific research personnel [Chem.Commun.1998 such as Elings, 2707].At present, research focuses mostly at mesoporous SiO
2Carrier upper surface organic acid is functionalized, the organic group of modification has now expanded to benzene sulfonic acid, propane sulfonic acid, Perpropionic Acid, phenylpropyl alcohol sulfonic acid etc., solid acid catalyst as modified with organic acids, but owing to adopt the organic-inorganic hybrid material of the synthetic modified with organic acids of one-step method, organic group supports and reaches as high as 40% under the situation that does not change material structure, and this has just had certain restriction to the solid acid catalyst that requires synthetic peracid amount.
Summary of the invention
The preparation method who the purpose of this invention is to provide a kind of L acid and B acid site organic and inorganic conjugated solid acid adjustable, that total acid content is big.
The present invention adopts one-step method that Al and sulfonic acid group are implanted to SiO simultaneously
2On the matrix, to strengthen its acid activated centre, synthetic AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Concrete preparation method of the present invention is as follows:
(1) polyethylene glycol-glycerine-polyethylene glycol triblock polymer (P123) is made into the aqueous solution of 2-4wt%, stirred 2-4 hour under the room temperature;
(2) further hydrochloric acid is dissolved in the above-mentioned solution under stirring condition, is warming up to 40-60 ℃, stirred 30-60 minute;
(3) ethyl orthosilicate (TEOS) and aluminium salt are added in the above-mentioned solution, 40-60 ℃ was stirred 2-4 hour down;
(4) with after 3-mercaptopropyl trimethoxysilane (MPTMS) and the hydrogen peroxide mixing, add in the above-mentioned solution, stirred 24-36 hour;
(5) solution is transferred to have in the teflon-lined autoclave 100-150 ℃ following crystallization 24-36 hour;
(6) then after filtration, washing, drying, former powder organic and inorganic conjugated solid acid;
(7) former powder organic and inorganic conjugated solid acid is used ethanolic solution extracting 48-72 hour, remove template agent P123, get AlSBA-15-SO
3The H organic and inorganic conjugated solid acid;
The mol ratio of each raw material components is:
P123: TEOS: aluminium salt: MPTMS: HCl: H
2O
2=(0.7-1.4): (32.9-39): (12.3-4.1): (4.1-8.2): (20-30): (73.8-82).
Aforesaid aluminium salt is aluminium isopropoxide, aluminum nitrate or aluminum sulfate.
The present invention compared with prior art has following advantage:
1 simple to operate, easy to make, reaction condition is gentle.
2 regulate and control in mesoporous scope solid acid B acid, L acid acid amount and total acid content by regulating material proportion or technological parameter.
The total acid content of 3 gained solid acids is 2.5-3.7mmol/g, and L acid acid amount is 0.7-2.1mmol/g, and B acid acid amount is 1.3-2.4mmol/g.
The specific embodiment
Embodiment 1
The P123 of 4g is dissolved in the 97.58g deionized water, at room temperature stirs 2h; Add 1.97g concentrated hydrochloric acid (37%), be warming up to 40 ℃, stir 60min; The TEOS and the 2.54g aluminium isopropoxide that add 7.68g stir 240min and add 0.80g MPTMS and 8.37g H again
2O
2(30%), H
2O
2Sulfhydryl oxidase can be become sulfonic group, the 150mL that packs into behind 40 ℃ of following 24h of stirring is with in the teflon-lined stainless steel autoclave static crystallization 36h under 100 ℃, suction filtration is carried out in taking-up, to synthetic former powder molecular sieve extracting 48h, remove template agent P123 with absolute ethyl alcohol, promptly get AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Embodiment 2
The P123 of 3g is dissolved in the 97.58g deionized water, at room temperature stirs 4h; Add 3.0g concentrated hydrochloric acid (37%), be warming up to 60 ℃, stir 30min; The TEOS and the 0.90g aluminum sulfate that add 3.84g stir 180min and add 0.60g MPTMS and 4.65g H again
2O
2(30%), H
2O
2Sulfhydryl oxidase can be become sulfonic group, the 150mL that packs into behind 60 ℃ of following 36h of stirring is with in the teflon-lined stainless steel autoclave static crystallization 24h under 100 ℃, suction filtration is carried out in taking-up, to synthetic former powder molecular sieve extracting 48h, remove template agent P123 with absolute ethyl alcohol, promptly get AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Embodiment 3
The P123 of 2g is dissolved in the 97.58g deionized water, at room temperature stirs 3h; Add 1.97g concentrated hydrochloric acid (37%), be warming up to 50 ℃, stir 30min; The TEOS and the 0.77g aluminum nitrate that add 6.84g stir 120min and add 1.2g MPTMS and 8.37g H again
2O
2(30%), H
2O
2Sulfhydryl oxidase can be become sulfonic group, the 150mL that packs into behind 50 ℃ of following 24h of stirring is with in the teflon-lined stainless steel autoclave static crystallization 24h under 150 ℃, suction filtration is carried out in taking-up, to synthetic former powder molecular sieve extracting 72h, remove template agent P123 with absolute ethyl alcohol, promptly get AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Embodiment 4
Adopt the preparation process of above-mentioned example 1, under the same conditions, the amount of TEOS and aluminium isopropoxide can be 7.26g and 1.02g, promptly gets AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Embodiment 5
Adopt the preparation process of above-mentioned example 2, under the same conditions, the amount of TEOS and aluminum sulfate can be 4.06g and 2.22g, promptly gets AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Embodiment 6
Adopt the preparation process of above-mentioned example 3, under the same conditions, the amount of TEOS and aluminum nitrate can be 7.68g and 1.48g, promptly gets AlSBA-15-SO
3The H organic and inorganic conjugated solid acid.
Adopt NH respectively
3-TPD and pyridine-FTIR method is measured the AlSBA-15-SO that obtains among the embodiment
3H organic-inorganic solid acid acid amount the results are shown in following table.
Embodiment |
Total acid content (mmol/g SiO
2)
|
L acid acid amount (mmol/g SiO
2)
|
B acid acid amount (mmol/gSiO
2)
|
Embodiment 1 |
3.7 |
1.3 |
2.4 |
Embodiment 2 |
2.4 |
0.7 |
1.7 |
Embodiment 3 |
2.7 |
1.3 |
1.4 |
Embodiment 4 |
3.3 |
2.1 |
1.2 |
Embodiment 5 |
2.3 |
1.0 |
1.3 |
Embodiment 6 |
2.7 |
1.2 |
1.5 |