CN103394353A - Catalyst for preparing benzenediol through phenol hydroxylation and preparation method of catalyst - Google Patents
Catalyst for preparing benzenediol through phenol hydroxylation and preparation method of catalyst Download PDFInfo
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- CN103394353A CN103394353A CN2013103507920A CN201310350792A CN103394353A CN 103394353 A CN103394353 A CN 103394353A CN 2013103507920 A CN2013103507920 A CN 2013103507920A CN 201310350792 A CN201310350792 A CN 201310350792A CN 103394353 A CN103394353 A CN 103394353A
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Abstract
The invention provides a catalyst for preparing benzenediol through phenol hydroxylation and a preparation method of the catalyst. The preparation method comprises the following steps: treating the diatomite serving as a carrier of the catalyst by using an alkaline solution or an acidic solution, loading copper or iron to the diatomite by using an impregnation method, and washing and baking to obtain the copper/diatomite, iron/diatomite or iron and copper composite oxide/diatomite catalyst. Through liquid-phase chromatographic detection, the conversion rate of phenol, the selectivity of the phenol and the ratio of the catechol to the phenol are calculated. The catalyst has the characteristics of simple preparation method, low cost and environmental-friendliness and is suitable for industrial production.
Description
Technical field
The present invention relates to a kind of Catalysts and its preparation method, the preparation method of the tripolite loading metal oxide catalyst used of a kind of phenol hydroxylation with hydrogen peroxide catechol processed and hydroquinones specifically, the Catalysts and its preparation method of the phenol hydroxylation preparing benzenediol of abbreviation.
Background technology
The problems such as catechol and hydroquinones are important industrial chemicals, and there is the production process complexity in traditional production technology, and accessory substance is many, and environmental pollution is serious.
The technique of hydrogen peroxide phenol hydroxylation coproduction catechol and hydroquinones, because its step is few, the reaction condition gentleness, accessory substance is few, and environmental pollution is little, is subject to increasing attention.The main distinction of industrialized production process is the catalyst that uses difference.There is certain weak point in the catalyst that these processes are used, as: Rhone-Poulene method and Ube method are used the liquid acid as catalyst, and catalyst and product are not easily separated, reclaim difficulty, and equipment corrosion is serious; The Brichima method utilizes molysite and cobalt salt to be catalyst, and to need to use volume fraction be that 60% hydrogen peroxide is oxidant, the dangerous increase of production process, and the phenol conversion per pass is low; Enichem method TS-1 catalyst, the catalyst preparation process complexity, preparation cost is high, and is expensive, need to often regenerate.
For the technique of improved hydrogen oxide phenol hydroxylation preparing benzenediol, one of focus of research is the development of new catalyst at present.It is simple that metal oxide catalyst has the preparation method, and cheap advantage can be used for phenol hydroxylation with hydrogen peroxide and prepares phenol, but exist catalytic activity to hang down and short two large problems of life-span.
Diatomite is comprised of diatom and other biological remains, and Main Ingredients and Appearance is SiO
2, having unique microcellular structure, specific area and pore volume are larger, can be used to adsorbing metal ions, organic matter etc., are suitable for metal oxide-loaded.It is abundant, cheap that diatomite has reserves simultaneously, lighter weight, the advantages such as stable chemical nature.Through retrieval, not yet have take diatomite as carrier, prepare the report of support type phenol hydroxylation preparing benzenediol catalyst.
Summary of the invention
The present invention seeks to the many deficiencies for prior art, and metal oxide catalyst prepares phenol for phenol hydroxylation with hydrogen peroxide, there is the two large problems that catalytic activity is low, the life-span is short, one is to provide a kind of catalyst of easy to operate, phenol hydroxylation preparing benzenediol that environmental pollution is little, and two are to provide that a kind of process is simple, the preparation method of the catalyst of the phenol hydroxylation preparing benzenediol that is suitable for suitability for industrialized production.
Realize that above-mentioned purpose is by the following technical solutions:
A kind of phenol hydroxylation with hydrogen peroxide catechol processed and hydroquinones catalyst, described catalyst is take diatomite as carrier, mass ratio according to 1:1～1:100, with infusion process, metallics is loaded on diatomite support, through the tripolite loading metallic catalyst that washs, roasting obtains.
Further, described metallics is iron or copper.
Further, with infusion process, copper or iron are loaded on diatomite, through washing, roasting, obtain copper diatomite, iron diatomite or iron, copper composite oxides diatomite catalyst.
Further, described molysite is ferric nitrate, ferric acetate, copper chloride, and described copper is copper nitrate, Schweinfurt green, copper chloride.
A kind of phenol hydroxylation with hydrogen peroxide catechol processed and hydroquinones, with the preparation method of catalyst, comprise the steps:
A. according to metering, get diatomite, diatomite was soaked 2～72 hours with alkaline solution or acid solution, after filtration, washing is to neutral, drying, obtain diatomite support;
B. according to metering, get metallics, add diatomite support after adding the water stirring and dissolving, under the environment of low temperature, stir, filter, drying, 300～900
oUnder C air atmosphere environment, calcined 2～8 hours, obtain the tripolite loading oxide catalyst;
C. according to metering, get phenol, deionized water, tripolite loading oxide catalyst, be blended in 50
oUnder under the environment of C, stirring, obtain the aqueous solution, the hydrogen peroxide that is 30% by mass fraction is added drop-wise in the aqueous solution, then drips 1 ~ 2 of acetic acid, after reacting 2 h, remove by filter the tripolite loading oxide catalyst, the tripolite loading oxide catalyst is with after ethanol washing drying, reusing;
D. use liquid chromatographic detection, calculate the ratio of selective, the catechol hydroquinones of phenol conversion, benzenediol.
Further, described alkaline solution is that molar concentration is a kind of of the NaOH of 0.01～5 mol/L or potassium hydroxide.
Further, described acid solution is that molar concentration is hydrochloric acid, acetic acid or nitric acid a kind of of 0.01～5 mol/L.
Further, described low temperature environment is 35 ℃.
Compared with prior art, the present invention, take diatomite as carrier, utilizes alkalescence or acid solution to soak diatomite to technical scheme of the present invention, and washing, drying obtain diatomite support.The tripolite loading metal oxide catalyst carries out the technique of phenol hydroxylation with hydrogen peroxide coproduction catechol and hydroquinones, have that catalyst can be recycled, catalyst is cheap, catalyst and separation of products is easy, building-up process is simple, phenol conversion is high, be suitable for the advantage of suitability for industrialized production.
The specific embodiment
The present invention will be further described below in conjunction with specific embodiment.
Disclosed by the invention is phenol hydroxylation with hydrogen peroxide catechol processed and hydroquinones Catalysts and its preparation method.Invention thought of the present invention is: take diatomite as carrier, with infusion process, metallics is loaded on diatomite support, through the tripolite loading metallic catalyst that washs, roasting obtains.Phenol, deionized water, tripolite loading metallic catalyst are carried out to hydroxylation reaction, the hydroxylation reaction process is as follows: in the batch reactor that thermostat, reflux condensate device and magnetic stirring apparatus are arranged, be sequentially added into respectively solvent, catalyst, phenol, after temperature rises to certain value, drip acetic acid, continuously or intermittently add hydrogen peroxide, adjust the amount of hydrogen peroxide, guarantee that reaction temperature fluctuates in very little scope.Hydrogen peroxide added afterreaction 0.5～72 hour, removed by filter catalyst, obtained catechol and hydroquinones.Catalyst recycles after washing, drying, calcining.
Specific embodiment is as follows:
Embodiment 1
Get 5 g diatomite, with the hydrochloric acid solution of 1 mol/L, soak 2 h, filter, washing is extremely neutral, and drying is standby.Get 24 g copper nitrates, add water 100 mL, after stirring and dissolving, add diatomite 4 g, 25
oC stirs 12 h.Filter drying, 500
oThe C air atmosphere, calcining 2 h, obtain the tripolite loading copper oxide catalyst.
Get 2 g phenol, 20 mL deionized waters, 0.2 g tripolite loading copper oxide catalyst, 50
oUnder C stirred, the hydrogen peroxide that is 30% by 10 mL mass fractions was added drop-wise in above-mentioned solution, after being added dropwise to complete, drips 1～2 of acetic acid again, after reaction 2 h, removed by filter catalyst, and catalyst is with after ethanol washing drying, reusing.Use liquid chromatographic detection, calculating phenol conversion is 50%, benzenediol be selectively 82%.Catechol/hydroquinones is 1.54.
Embodiment 2
Get 5 g diatomite, with the sodium hydroxide solution of 1 mol/L, soak 24 h, filter, washing is extremely neutral, and drying is standby.Get 24 g copper nitrates, add water 100 mL, after stirring and dissolving, add the diatomite after processing, 35
oC stirs 2 h.Filter drying, 500
oThe C air atmosphere, calcining 2h, obtain the tripolite loading copper oxide catalyst.
Get 2 g phenol, 20 mL deionized waters, 0.1 g tripolite loading copper oxide catalyst, 50
oUnder C stirred, the hydrogen peroxide that is 30% by 10 mL mass fractions was added drop-wise in above-mentioned solution, after reaction 2 h, removed by filter catalyst, and catalyst is with after ethanol washing drying, reusing.Use liquid chromatographic detection, calculating phenol conversion is 40%, benzenediol be selectively 78%.Catechol/hydroquinones is 1.50.
Embodiment 3
Get 5 g diatomite, with the hydrochloric acid solution of 2 mol/L, soak 10 h, filter, washing is extremely neutral, and drying is standby.Get 24 g copper nitrates, 40 g ferric nitrates, add water 100 mL, after stirring and dissolving, adds the diatomite after processing, 30
oC stirs 10 h.Filter drying, 400
oThe C air atmosphere, calcining 2 h, obtain tripolite loading copper-ferriferous oxide catalyst.
Get 2 g phenol, 20 mL deionized waters, 0.1 g tripolite loading copper-ferriferous oxide catalyst, 50
oUnder C stirred, the hydrogen peroxide that is 30% by 10 mL mass fractions was added drop-wise in above-mentioned solution, after reaction 2 h, removed by filter catalyst, and catalyst is with after ethanol washing drying, reusing.Use liquid chromatographic detection, calculating phenol conversion is 80%, benzenediol be selectively 65%.Catechol/hydroquinones is 1.45.
Embodiment 4
Get 5 g diatomite, with the hydrochloric acid solution of 1.5 mol/L, soak 72 h, filter, washing is extremely neutral, and drying is standby.Get 40.4 g ferric nitrates, add water 100 mL, after stirring and dissolving, add the diatomite after processing, 35
oC stirs 24 h.Filter drying, 700
oThe C air atmosphere, calcining 2 h, obtain the tripolite loading ferric oxide catalyst.
Get 20g phenol, 100 mL deionized waters, 5 g tripolite loading ferric oxide catalysts, 60
oC stirs, and the hydrogen peroxide that is 30% by 20 mL mass fractions is added drop-wise in above-mentioned solution, after reaction 2 h, removes by filter catalyst, and catalyst is with after ethanol washing drying, reusing.Use liquid chromatographic detection, calculating phenol conversion is 64.5%, benzenediol be selectively 70%.Catechol/hydroquinones is 1.54.
Embodiment 5
Get 4 g diatomite, with the hydrochloric acid solution of 0.5 mol/L, soak 72 h, filter, washing is extremely neutral, and drying is standby.Get 400 g ferric nitrates, add water 1000 mL, after stirring and dissolving, add the diatomite after processing, 35
oC stirs 72 h.Filter drying, 700
oThe C air atmosphere, calcining 6 h, obtain the tripolite loading ferric oxide catalyst.
Get 60 g phenol, 200 mL deionized waters, 6 g tripolite loading ferric oxide catalysts, 60
oC stirs, and the hydrogen peroxide that is 30% by 50 mL mass fractions is added drop-wise in above-mentioned solution, after reaction 6 h, removes by filter catalyst, and catalyst is with after ethanol washing drying, reusing.Use liquid chromatographic detection, calculating phenol conversion is 80%, benzenediol be selectively 80%.Catechol/hydroquinones is 1.54.
Embodiment 6
Get 4 g diatomite, with the hydrochloric acid solution of 1 mol/L, soak 2 h, filter, washing is extremely neutral, and drying is standby.Get 4 g ferric nitrates, add water 50 mL, after stirring and dissolving, add the diatomite of processing, 35
oC stirs 12 h.Filter drying, 700
oThe C air atmosphere, calcining 2 h, obtain the tripolite loading ferric oxide catalyst.
Get 5g phenol, 20 mL deionized waters, 2 g tripolite loading ferric oxide catalysts, 60
oC stirs, and the hydrogen peroxide that is 30% by 20 mL mass fractions is added drop-wise in above-mentioned solution, after reaction 2 h, removes by filter catalyst, and catalyst is with after ethanol washing drying, reusing.Use liquid chromatographic detection, calculating phenol conversion is 80%, benzenediol be selectively 75%.Catechol/hydroquinones is 1.5.
Above-described embodiment has only been expressed one embodiment of the present invention, but can not therefore be interpreted as limitation of the scope of the invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.
Claims (8)
1. the catalyst of a phenol hydroxylation preparing benzenediol, it is characterized in that, described catalyst is take diatomite as carrier, according to the mass ratio of 1:1～1:100, with infusion process, metallics is loaded on diatomite support, through the tripolite loading metallic catalyst that washs, roasting obtains.
2. the catalyst of phenol hydroxylation preparing benzenediol according to claim 1, is characterized in that, described metallics is iron or copper.
3. the catalyst of phenol hydroxylation preparing benzenediol according to claim 1, is characterized in that, with infusion process, copper or iron loaded on diatomite, through washing, roasting, obtains copper diatomite, iron diatomite or iron, copper composite oxides diatomite catalyst.
4. the catalyst of phenol hydroxylation preparing benzenediol according to claim 2, is characterized in that, described molysite is ferric nitrate, ferric acetate, iron chloride, and described copper is copper nitrate, Schweinfurt green, copper chloride.
5. the preparation method of the catalyst of phenol hydroxylation preparing benzenediol as claimed in claim 1, is characterized in that, comprises the steps:
A. according to metering, get diatomite, diatomite was soaked 2～72 hours with alkaline solution or acid solution, after filtration, washing is to neutral, drying, obtain diatomite support;
B. according to metering, get metallics, add diatomite support after adding the water stirring and dissolving, under the environment of low temperature, stir, filter, drying, 300～900
oUnder C air atmosphere environment, calcining 2-8 hour, obtain the tripolite loading oxide catalyst;
C. according to metering, get phenol, deionized water, tripolite loading oxide catalyst, be blended in 50
oUnder the environment of C, stir, obtain the aqueous solution, the hydrogen peroxide that is 30% by mass fraction is added drop-wise in the aqueous solution, then drips 1～2 of acetic acid, after reacting 2 h, remove by filter the tripolite loading oxide catalyst, the tripolite loading oxide catalyst is with after ethanol washing drying, reusing;
D. use liquid chromatographic detection, calculate the ratio of selective, the catechol hydroquinones of phenol conversion, benzenediol.
6. the preparation method of the catalyst of phenol hydroxylation preparing benzenediol according to claim 5, is characterized in that, described alkaline solution is that molar concentration is a kind of of 0.001～5% NaOH or potassium hydroxide.
7. the preparation method of the catalyst of phenol hydroxylation preparing benzenediol according to claim 5, is characterized in that, described acid solution is that molar concentration is hydrochloric acid, acetic acid or nitric acid a kind of of 0.01～5 mol/L.
8. the preparation method of the catalyst of phenol hydroxylation preparing benzenediol according to claim 5, is characterized in that, described low temperature environment is 25 ℃.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105622351A (en) * | 2016-03-31 | 2016-06-01 | 唐山师范学院 | Method for preparing benzenediol |
| CN107670665A (en) * | 2017-11-02 | 2018-02-09 | 肇庆高新区国专科技有限公司 | A kind of diatomite catalyst for phenol hydroxylation |
| CN107999131A (en) * | 2017-11-06 | 2018-05-08 | 天津大学 | The metal Organic composite catalyst that a kind of catalytic hydroxylation prepares the method for benzenediol and its uses |
| CN109908896A (en) * | 2019-03-13 | 2019-06-21 | 济南大学 | A kind of Cu/ activated clays catalyst of efficient catalytic furfural furfuryl alcohol and preparation method thereof |
| CN110898836A (en) * | 2019-12-06 | 2020-03-24 | 怀化学院 | Copper-doped MOF-based derivative catalyst and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3662006A (en) * | 1969-05-12 | 1972-05-09 | Universal Oil Prod Co | Hydroxylation of aromatic compounds |
| CN1228355A (en) * | 1998-03-10 | 1999-09-15 | 北京燕山石油化工公司研究院 | Compound oxide catalyst for phenol hydroxylation and its preparing method |
| CN101612594A (en) * | 2008-06-27 | 2009-12-30 | 北京化工大学 | A kind of method of preparing supported iron-based composite catalyst by dipping method |
-
2013
- 2013-08-13 CN CN2013103507920A patent/CN103394353A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3662006A (en) * | 1969-05-12 | 1972-05-09 | Universal Oil Prod Co | Hydroxylation of aromatic compounds |
| CN1228355A (en) * | 1998-03-10 | 1999-09-15 | 北京燕山石油化工公司研究院 | Compound oxide catalyst for phenol hydroxylation and its preparing method |
| CN101612594A (en) * | 2008-06-27 | 2009-12-30 | 北京化工大学 | A kind of method of preparing supported iron-based composite catalyst by dipping method |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105622351A (en) * | 2016-03-31 | 2016-06-01 | 唐山师范学院 | Method for preparing benzenediol |
| CN107670665A (en) * | 2017-11-02 | 2018-02-09 | 肇庆高新区国专科技有限公司 | A kind of diatomite catalyst for phenol hydroxylation |
| CN107999131A (en) * | 2017-11-06 | 2018-05-08 | 天津大学 | The metal Organic composite catalyst that a kind of catalytic hydroxylation prepares the method for benzenediol and its uses |
| CN109908896A (en) * | 2019-03-13 | 2019-06-21 | 济南大学 | A kind of Cu/ activated clays catalyst of efficient catalytic furfural furfuryl alcohol and preparation method thereof |
| CN110898836A (en) * | 2019-12-06 | 2020-03-24 | 怀化学院 | Copper-doped MOF-based derivative catalyst and preparation method and application thereof |
| CN110898836B (en) * | 2019-12-06 | 2023-05-12 | 怀化学院 | Copper-doped MOF-based derivative catalyst and preparation method and application thereof |
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Application publication date: 20131120 |