阅读说明：本技术 一种负载型催化剂及其制备方法与应用 (Supported catalyst and preparation method and application thereof ) 是由 于磊 方文娟 张戈 董菁 张永振 王文 于 2019-11-13 设计创作，主要内容包括：本发明公开了一种负载型催化剂及其制备方法与应用。本发明公开的催化剂包含以下组分：a)多孔载体；b)负载在所述多孔载体的外表面的孔道外活性组分和负载在所述多孔载体的孔道内表面的孔道内活性组分；和c)沉积在所述多孔载体的外表面上的惰性组分硅。由本发明制备的催化剂适用于两步串联反应的催化,尤其适用于柠檬醛制备过程中由缩醛生成柠檬醛的反应催化,使得反应可以在一个反应器中高效进行,极大地降低生产成本以及操作难度。(The invention discloses a supported catalyst and a preparation method and application thereof. The catalyst disclosed by the invention comprises the following components: a) a porous support; b) an outer-cell active component supported on an outer surface of the porous carrier and an inner-cell active component supported on an inner surface of a cell of the porous carrier; and c) an inert component silicon deposited on the outer surface of the porous support. The catalyst prepared by the method is suitable for catalysis of two-step series reaction, and is particularly suitable for catalysis of reaction for generating citral from acetal in the citral preparation process, so that the reaction can be efficiently carried out in one reactor, and the production cost and the operation difficulty are greatly reduced.)

1. A catalyst comprising the following components:

a) a porous support;

b) an outer-cell active component supported on an outer surface of the porous carrier and an inner-cell active component supported on an inner surface of a cell of the porous carrier; and

c) an inert component silicon deposited on the outer surface of the porous support.

2. The catalyst of claim 1, wherein: the content of the active component in the pore channel is 1-10 wt%, preferably 3-8 wt% calculated by the mass of the porous carrier as 100 wt%;

the active components in the pore channels are preferably one or two of tin and magnesium, and when the active components in the pore channels are tin and magnesium, the mass ratio of tin to magnesium is 1:9-9: 1;

the active component tin in the pore channels is derived from a compound containing tin, preferably one or more of potassium stannate trihydrate, anhydrous stannous chloride, sodium stannate trihydrate, stannic iodide, anhydrous stannic chloride, stannic difluoride, stannous sulfate and stannous chloride dihydrate, and more preferably the potassium stannate trihydrate;

the active component magnesium in the pore channel is derived from a magnesium-containing compound, preferably one or more of magnesium carbonate, methyl magnesium bromide, magnesium sulfate monohydrate, ethyl magnesium bromide, magnesium acetate and anhydrous magnesium sulfate, and more preferably anhydrous magnesium sulfate.

3. The catalyst of claim 1, wherein: the content of the active component outside the pore channel is 1-10 wt%, preferably 3-8 wt% calculated by the mass of the porous carrier as 100 wt%;

the active components outside the pore channels are one or two of aluminum and phosphorus, and when the active components outside the pore channels are aluminum and phosphorus, the mass ratio of the aluminum to the phosphorus is 1:9-9: 1;

the aluminum serving as the active component outside the pore channel is derived from an aluminum-containing compound, preferably one or more of aluminum phosphate, aluminum isopropoxide, trioctyl aluminum, aluminum sec-butoxide, aluminum tert-butoxide, aluminum acetylacetonate, 8-hydroxyquinoline aluminum, sodium aluminate, aluminum sulfate, trimethyl aluminum, dichloroethyl aluminum and aluminum ammonium sulfate, and more preferably sodium aluminate;

the active component phosphorus outside the pore canal is derived from a phosphorus-containing compound, is preferably one or more of anhydrous trisodium phosphate, ethyldiphenylphosphine, triphenylphosphine, diphenylphosphine oxide, (methoxymethyl) triphenylphosphine chloride, (tert-butoxycarbonylmethylene) triphenylphosphine, and is more preferably anhydrous trisodium phosphate.

4. A catalyst according to any one of claims 1 to 3, characterized in that: the inert component silicon is derived from one or more of methyl orthosilicate, ethyl orthosilicate, silicon tetrachloride and polysiloxane;

the porous carrier is an all-silicon molecular sieve, activated carbon or ceramic beads, and preferably is an all-silicon molecular sieve.

5. A process for preparing a catalyst as claimed in any one of claims 1 to 4, comprising the steps of:

(1) loading the active component in the pore channels on the inner surface of the pore channels of the porous carrier;

(2) depositing the inert component silicon on the outer surface of the porous support;

(3) and loading the active component outside the pore channels on the outer surface of the porous carrier.

6. The method of claim 5, wherein: soaking the porous carrier in a solution containing active components in pore channels by adopting an isometric soaking method, standing, drying and roasting to load the active components in the pore channels on the inner surfaces of the pore channels of the porous carrier;

the standing condition is preferably 10-20 ℃ for 10-20 h;

the drying condition is preferably vacuum drying at 80-120 ℃ for 3-5 h;

the roasting condition is preferably 100-300 ℃ for 3-5 h.

7. The method of claim 5, wherein: step (2) adopting a gas phase or liquid phase silicon deposition method, dipping the product of step (1) into a silicon-containing solution, drying and roasting to deposit the inert component silicon on the outer surface of the porous carrier;

the impregnation condition is preferably vacuum impregnation for 10-20 h;

the drying condition is preferably drying for 10-20h at the temperature of 20-30 ℃;

the roasting condition is preferably that the temperature is slowly increased to 500-550 ℃ at the temperature increase rate of 2-4 ℃/min, and the roasting is carried out for 1-2h at constant temperature;

the number of depositions is 2-5, preferably 3-4.

8. The method according to any one of claims 5-7, wherein: step (3) adopting an isometric impregnation method, impregnating the product obtained in the step (2) in a solution containing the active component outside the pore channel, standing, drying and roasting to load the active component outside the pore channel on the outer surface of the porous carrier;

the standing condition is preferably that the mixture is kept for 10 to 20 hours at the temperature of between 10 and 20 ℃;

the drying condition is preferably vacuum drying at 80-120 ℃ for 3-5 h;

the roasting condition is preferably roasting at 100-300 ℃ for 3-5 h.

9. Use of a catalyst according to any one of claims 1 to 4 for catalysing a two-step series reaction.

10. A process for the preparation of citral from acetals comprising the step of catalyzing, in a reactor, the reaction of a substrate acetal to citral with a catalyst as claimed in any of claims 1 to 4.

Technical Field

The invention belongs to the field of catalysts, and relates to a supported catalyst, and a preparation method and application thereof.

Background

Citral is a perfume compound with citrus fruit fragrance, is commonly used in food and cosmetics as a flavoring agent, a preservative and an aromatic, is also a main raw material for synthesizing products such as vitamin A, vitamin E, menthol, ionone and the like, and has very wide application in the fields of perfume synthesis and health care products.

The citral can be obtained by separating and extracting from vegetable essential oil, or by chemical synthesis. The natural citral mainly exists in plant essential oil such as lemongrass oil, litsea cubeba oil, grass oil, wormwood oil, verbena oil and the like, and the method for separating and extracting the natural citral from the plant essential oil has the defects of high dependence on limited resources and low product yield, so that the method is high in production cost and is not suitable for large-scale production. At present, the industrial production of citral is mainly a chemical synthesis method.

The chemical giant BASF adopts an aldol condensation rearrangement method to prepare citral, and the process route is as follows:

in the process route, after the acetal is prepared, the final product citral can be obtained only by one-step cracking and two-step rearrangement, wherein the cracking reaction is carried out on an acidic catalyst (such as sodium dihydrogen phosphate, phosphoric acid, sulfuric acid and the like), the catalyst is not recyclable and has high requirements on equipment, the two-step rearrangement reaction has longer reaction time and lower yield of the final product because no catalyst participates, and in addition, the three-step reaction is carried out in a plurality of reactors connected in series, so that the equipment investment and the generation of leftovers are increased.

Disclosure of Invention

The invention aims to solve the problems of complex equipment and complex operation in the process of preparing citral from acetal in a citral synthesis process by preparing a novel catalyst.

In order to solve the technical problems, the invention provides a catalyst, which comprises the following components:

a) a porous support;

b) an outer-cell active component supported on an outer surface of the porous carrier and an inner-cell active component supported on an inner surface of a cell of the porous carrier; and

c) an inert component silicon deposited on the outer surface of the porous support.

In one embodiment, in the above catalyst, the content of the active component in the pore channels is 1 to 10 wt%, preferably 3 to 8 wt%, based on 100 wt% of the mass of the porous support.

In one embodiment, in the above catalyst, the active component in the pore channel is one or two of tin and magnesium, the active component in the pore channel can be loaded alone or in a mixed manner, and when the active component in the pore channel is tin and magnesium (i.e. mixed loading), the mass ratio of tin to magnesium is 1:9-9: 1;

the active component tin in the pore channels is derived from a compound containing tin, preferably one or more of potassium stannate trihydrate, anhydrous stannous chloride, sodium stannate trihydrate, stannic iodide, anhydrous stannic chloride, stannic difluoride, stannous sulfate and stannous chloride dihydrate, and more preferably the potassium stannate trihydrate;

the active component magnesium in the pore channel is derived from a magnesium-containing compound, preferably one or more of magnesium carbonate, methyl magnesium bromide, magnesium sulfate monohydrate, ethyl magnesium bromide, magnesium acetate and anhydrous magnesium sulfate, and more preferably anhydrous magnesium sulfate;

the size of the tin-containing compound and the magnesium-containing compound should be as small as possible, and it is particularly important that the spatial size of these compounds is not larger than the pore size of the porous support employed in the present invention.

In one embodiment, in the catalyst described in any of the above, the content of the active component outside the pore channels is 1 to 10 wt%, preferably 3 to 8 wt%, based on 100 wt% of the mass of the porous carrier.

In one embodiment, in any of the catalysts described above, the active component outside the channels is one or two of aluminum and phosphorus, the active component outside the channels can be loaded alone or in a mixture, and when the active component outside the channels is aluminum and phosphorus, the mass ratio of aluminum to phosphorus is 1:9-9: 1;

the aluminum serving as the active component outside the pore channel is derived from an aluminum-containing compound, preferably one or more of aluminum phosphate, aluminum isopropoxide, trioctyl aluminum, aluminum sec-butoxide, aluminum tert-butoxide, aluminum acetylacetonate, 8-hydroxyquinoline aluminum, sodium aluminate, aluminum sulfate, trimethyl aluminum, dichloroethyl aluminum and aluminum ammonium sulfate, and more preferably sodium aluminate;

the active component phosphorus outside the pore canal is derived from a phosphorus-containing compound, is preferably one or more of anhydrous trisodium phosphate, ethyldiphenylphosphine, triphenylphosphine, diphenylphosphine oxide, (methoxymethyl) triphenylphosphine chloride, (tert-butoxycarbonylmethylene) triphenylphosphine, and is more preferably anhydrous trisodium phosphate.

In one embodiment, the catalyst of any of the above, wherein the inert component silicon is derived from one or more of methyl orthosilicate, ethyl orthosilicate, silicon tetrachloride, and polysiloxane.

In one embodiment, in any of the catalysts described above, the porous support is an all-silica molecular sieve, activated carbon, or ceramic beads, preferably an all-silica molecular sieve.

In order to solve the above technical problem, the present invention further provides a preparation method of any one of the above catalysts, comprising the following steps:

(1) loading the active component in the pore channels on the inner surface of the pore channels of the porous carrier;

(2) depositing the inert component silicon on the outer surface of the porous support;

(3) and loading the active component outside the pore channels on the outer surface of the porous carrier.

In one embodiment, in the above method, in the step (1), the porous carrier is immersed in a solution containing the active component in the pore channel by an isometric immersion method, and the active component in the pore channel is loaded on the inner surface of the pore channel of the porous carrier through standing, drying and roasting;

the standing condition is preferably 10-20 ℃ for 10-20 h;

the drying condition is preferably vacuum drying at 80-120 ℃ for 3-5 h;

the roasting condition is preferably 100-300 ℃ for 3-5 h.

In one embodiment, in the above method, the solution of the active component in the pore channels is an aqueous solution of the active component in the pore channels;

the active components in the pore channels are one or two of tin and magnesium, and are independently loaded when only one of the tin and the magnesium is loaded, and are mixed loaded when the two components are loaded;

the active component tin in the pore channels is derived from a compound containing tin, preferably one or more of potassium stannate trihydrate, anhydrous stannous chloride, sodium stannate trihydrate, stannic iodide, anhydrous stannic chloride, stannic difluoride, stannous sulfate and stannous chloride dihydrate, and more preferably the potassium stannate trihydrate;

the active component magnesium in the pore channel is derived from a magnesium-containing compound, preferably one or more of magnesium carbonate, methyl magnesium bromide, magnesium sulfate monohydrate, ethyl magnesium bromide, magnesium acetate and anhydrous magnesium sulfate, and more preferably anhydrous magnesium sulfate;

the size of the tin-containing compound and the magnesium-containing compound should be as small as possible, and it is particularly important that the spatial size of these compounds is not larger than the pore size of the porous support.

In one embodiment, in any of the above methods, the porous support is preferably an all-silica molecular sieve, activated carbon, or ceramic beads, more preferably an all-silica molecular sieve.

In one embodiment, in any of the above methods, the step (2) is carried out by immersing the product of the step (1) in a solution containing silicon by a vapor phase or liquid phase silicon deposition method, drying and calcining to deposit the inert component silicon on the outer surface of the porous carrier;

the impregnation condition is preferably vacuum impregnation for 10-20 h;

the drying condition is preferably drying for 10-20h at the temperature of 20-30 ℃;

the roasting condition is preferably that the temperature is slowly increased to 500-550 ℃ at the temperature increase rate of 2-4 ℃/min, and the roasting is carried out for 1-2h at constant temperature;

the number of said depositions is 2-5, preferably 3-4;

the silicon is loaded on the outer surface of the carrier, so that the purposes of modulating the size of the pore channel of the carrier and covering the original active center on the outer surface of the carrier can be achieved, and when the silicon deposition times are determined to be 3-4 times according to experiments, the modulating effect on the carrier is best, for example, in the process of preparing citral from acetal, the cleavage product of substrate acetal is allowed to enter the pore channel, and the acetal is not allowed to enter the pore channel, so that the final product citral can be ensured not to generate side reaction on the outer surface any more.

In one embodiment, in the above method, the silicon-containing solution has a silicon content of 1 to 10 wt%, preferably 2 to 8 wt%, preferably a petroleum ether solution of silicon;

the inert component silicon is derived from one or more of methyl orthosilicate, ethyl orthosilicate, silicon tetrachloride and polysiloxane.

In one embodiment, in any one of the above methods, in the step (3), the product obtained in the step (2) is immersed in a solution containing the active component outside the pore channels by an isometric immersion method, and the solution is subjected to standing, drying and roasting, so that the active component outside the pore channels is loaded on the outer surface of the porous carrier;

the standing condition is preferably that the mixture is kept for 10 to 20 hours at the temperature of between 10 and 20 ℃;

the drying condition is preferably vacuum drying at 80-120 ℃ for 3-5 h;

the roasting condition is preferably roasting at 100-300 ℃ for 3-5 h.

In one embodiment, in the above method, the solution of the extra-porous active component is an aqueous solution of the extra-porous active component;

the active components outside the pore channels are one or two of aluminum and phosphorus, and when only one of the aluminum and the phosphorus is loaded, the active components are independently loaded, and when the two are loaded, the active components are mixed loaded;

the aluminum serving as the active component outside the pore channel is derived from an aluminum-containing compound, preferably one or more of aluminum phosphate, aluminum isopropoxide, trioctyl aluminum, aluminum sec-butoxide, aluminum tert-butoxide, aluminum acetylacetonate, 8-hydroxyquinoline aluminum, sodium aluminate, aluminum sulfate, trimethyl aluminum, dichloroethyl aluminum and aluminum ammonium sulfate, and more preferably sodium aluminate;

the active component phosphorus outside the pore canal is derived from a phosphorus-containing compound, is preferably one or more of anhydrous trisodium phosphate, ethyldiphenylphosphine, triphenylphosphine, diphenylphosphine oxide, (methoxymethyl) triphenylphosphine chloride, (tert-butoxycarbonylmethylene) triphenylphosphine, and is more preferably anhydrous trisodium phosphate;

the spatial dimensions of the aluminum-containing compound and the phosphorus-containing compound are larger than the pore channel dimensions of the porous support after silicon deposition.

In order to solve the above technical problem, the present invention also provides the use of any one of the above catalysts in the catalysis of a two-step series reaction, preferably in the preparation of citral from an acetal.

In order to solve the technical problem, the invention also provides a method for preparing citral from acetal, which comprises the step of catalyzing the reaction of substrate acetal to prepare citral by using any one of the catalysts in a reactor, wherein the amount of the catalyst is 1-3 wt% of the substrate acetal;

the reaction temperature is preferably 80-150 ℃, more preferably 100-120 ℃, and the absolute pressure of the reactor is preferably 3-6kPa, more preferably 4-5 kPa;

the reactor is preferably a batch reactor;

advantageously, during the reaction process, the product isopentenol produced by decomposing acetal is distilled off at the same time, so as to ensure the efficient operation of the experiment.

The invention can selectively load different catalytic active components on the outer surface of the porous carrier and the inner surface of the pore channel according to requirements, thereby achieving the purposes of catalyzing specific reaction on the outer surface of the porous carrier and the inner surface of the pore channel and improving the reaction selectivity. The catalyst prepared by the invention is suitable for the catalysis of two-step series reaction (firstly the reaction on the outer surface of the porous carrier, and then the reaction on the inner surface of the pore channel of the porous carrier), and is particularly suitable for the catalysis of the reaction for generating citral from acetal in the preparation process of citral (the cleavage reaction of the acetal is carried out on the outer surface of the catalyst, and then the rearrangement of an ether intermediate is carried out in the pore channel), so that the reaction can be efficiently carried out in one reactor, and the production cost and the operation difficulty are greatly reduced. Compared with the prior art, the catalyst can prepare citral by an acetal one-step method, and can achieve the purposes of reducing equipment investment and improving yield.

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The present invention will be further described with reference to the following examples. It should be understood that the following examples are illustrative only and are not intended to limit the scope of the present invention.

An analytical instrument:

gas chromatograph: agilent 7890, column DB-5; sample inlet temperature: 300 ℃; the split ratio is 50: 1; carrier gas flow: 50 ml/min; temperature rising procedure: maintaining at 120 deg.C for 15min, increasing to 250 deg.C at a rate of 10 deg.C/min, and maintaining for 10 min; detector temperature: 280 ℃.

Raw materials and reagents:

potassium stannate trihydrate is a product of Aladdin reagent (Shanghai) Co., Ltd., and has a purity of 99.5 wt%.

Anhydrous magnesium sulfate is a product of Aladdin reagent (Shanghai) Co., Ltd., and the purity is 99.99 wt%.

Tetraethoxysilane is a product of Aladdin reagent (Shanghai) Co., Ltd., and the purity is 99.99 wt%.

The all-silicon molecular sieve S-1 is a product of chemical technology Limited company of big-connected engineering, Qiwangda.

Sodium aluminate is a product of Aladdin reagent (Shanghai) Co., Ltd., and has a purity of 85 wt%.

The anhydrous trisodium phosphate is a product of Aladdin reagent (Shanghai) Co., Ltd., and has a purity of 96 wt%.